LIBRARY OF THE UNIVERSITY OF CALIFORNIA. Class T HE POCKET BOOK OF REFRIGERATION AND ICE-MAKING EDITED BY A. J. WALLIS-TAYLER, C.E. ASSOC. MEMB. INST. C.E. AUTHOR OF "REFRIGERATING AND ICE-MAKING MACHINERY," "REFRIGER ATJOH COLD STORAGE AND ICE-MAKING," ETC. ETC. JFiftfj dHittton, ILLUSTRATED BY THIRTY-ONE DIAGRAMS NEW YORK THE NORMAN W. HENLEY PUBLISHING COMPANY 132 NASSAU STREET 1909 /\ PUBLISHERS' PREFACE. THE rapid extension of the use of Refrige- rating and Ice-making Machinery, in recent years, with the establishment in important centres of Cold Stores and Ice Factories, has led to the demand for a handy POCKET-BOOK which should contain in an accessible form such formulae, data, tables, and memoranda as are constantly re- quired by persons engaged or interested in the industries connected with Refrigeration and Cold Storage. The present little volume (which, since its first issue, has been revised and enlarged by the addition of fresh matter and diagrams) is designed to meet this demand. The contents of the POCKET-BOOK may be briefly described as comprising amongst other matter the subjects of Refrigeration (in outline); Cold Storage; Ice-making and the Storing of Ice ; Insulation ; 201355 iv PUBLISHERS' PREFACE. the Testing and Management of Refrigerating Machinery ; General Tables and Memoranda, etc., etc. There is also a carefully prepared Index, whereby reference may readily be made to the information furnished upon any particular subject TABLE OF PRINCIPAL CONTENTS. SECTION I. REFRIGERATION IN GENERAL : The Mechanical Theory of Heat Refrigerating Apparatus The Chemical or Liquefaction Process Cold-air Machines Vacuum Machines Absorption Machines The Compression Machine The Application of the Entropy, or Theta-phi, Diagram to Refrigerating Machines The Comparative Efficiency of various Refrigerating Machines The Pro- duction of very Low Temperatures Capacity of Re- frigerating Machines Approximate Allowance per Ton Capacity to be made when selecting a Machine for Refrigerating Purposes Condensers The Forecooler The Analyser The Liquid Receiver Ether Machines Tables, etc. 1-67 SECTION II. COLD STORAGE: Amount of Refrigeration required Amount of Refrigerating Pipes necessary for Chilling, Storage, and Freezing-chambers Number of cubic feet covered by i -ton Refrigerating Capacity for Twenty-four Hours Estimate of Refrigeration in Breweries Refrigerating Capacity in B.T.U. required per cubic foot of Storage Room in Twenty-four Hours Refrigerating Capacities Variation in Capacity of a Refrigerating Machine, etc., and Economy of Direct Expansion Cubic feet of Ammonia Gas per Minute to produce one ton of Refrigeration per Day Determination of Moisture in Air Psychrometers Hygrometers Correct Relative Humidity for a Given Temperature in Egg Rooms Specific Heat and Composition of Victuals Tempera- tures adapted for the Cold Storage of Various Articles Mean Temperature of Principal Cities of the World Cold Storage Charges (England) Conditions of Deposit and Regulations Cold Storage Charges (United States) Terms of Payment of Cold Storage and Freezing Rates Cold Storage Charges (France) Tables, etc. 68-99 SECTION III. ICE-MAKING AND STORING ICE: Ice-making Pure Water Simple Rules for ascertaining the Quality of VI CONTENTS. So-called Mineral Water Testing by Reagents Freezing Tank or Box Brine for Use in Refrigerating and Ice-making Plants Solutions of Chloride of Calcium Comparison of Various Hydrometer Scales Freezing Times for Different Temperatures and Thicknesses of Can Ice Storing Ice Tables, etc. 100-114 SECTION IV. INSULATION : Results of Tests to determine the Non- conductive Values of Different Materials Heat in Units transmitted per Square Foot per Hour through Various Substances Walls for Cold Stores Divisional Partitions for Cold Stores Flooring for Cold Stores Flooring for Ice Houses Ceilings for Cold Stores and Ice Houses Door Insulation Window Insulation Tank Insulation Tables, etc 115-135 SECTION V. TESTING AND MANAGEMENT OF REFRIGERATING MA- CHINERY : Testing Interpretation of Compressor Diagram Management of Ammonia Compression Machines Leaks in Ammonia Apparatus Leaks in Carbonic Acid Machines Lubrication of Refrigerating Machinery Form- for Engineer's Daily Report Light- ing Cold Stores ... ... ... ... ... 136-150 SECTION VI. GENERAL TABLES AND MEMORANDA : Experiments in Wort Cooling Tension of Aqueous Vapour Physical Constant of Gases Properties of Saturated Steam Heat of Combustion of Various Fuels Specific Heat of Water at Various Temperatures Specific Heat of Metals Specific Heat of Liquids Specific Heat of Gases Thermal Units Loss of Pressure by Friction of Compressed Air Friction of Air in Tubes Coefficients for Efflux of Air from Orifices Centrifugal Fans Hydraulics Useful Information 151-175 INDEX 177-184 ILLUSTRATIONS. FIG. *AGE 1. Diagram illustrating Cold-air Cycle 6 2. Diagram illustrating Operation of Absorption Machine 8 3. Diagram illustrating Cycle wherein a Volatile Liquid and Compression are employed 9 4. Diagram illustrating Theoretically Perfect Reversible Cycle, with Pressure Volume Ordinates 13 5. Diagram illustrating Theoretically Perfect Reversible Cycle, with Temperature Entropy Ordinates 13 6, 7. Diagrams illustrating Operations in Air Refrigerators with Open Cycle 14 8. Entropy Diagram, showing application to the Cold-air Cycle 15 9. Entropy Diagram for i Ib. of Saturated Ammonia Vapour 16 10. Entropy Diagram for i Ib. of Saturated Carbonic Acid Vapour 16 11. Entropy Diagram, showing Working Cycle for i Ib. of Saturated Ammonia Vapour 18 12. Entropy Diagram, showing Working Cycle for i Ib. of Saturated Carbonic Acid Vapour 19 13. Diagram showing Loss of Efficiency with Ammonia and Carbonic Acid owing to use of Expansion Valve ... 21 14. Diagram showing Percentage of Efficiency of Working Cycle of Carbonic Acid as compared with Ammonia 21 15. Diagram showing Loss of Efficiency with Brine Circula- tion compared with Direct Expansion of Ammonia ... 23 16. Diagram showing Relative Compressor Capacity with Ammonia at Various Expansion Pressures and Tempe- ratures 23 Vlll ILLUSTRATIONS. FIG. PAGE 17. Diagram showing Hampson's Apparatus for the pro- duction of very Low Temperatures 25 1 8. Diagram showing Linde's Apparatus for the production of very Low Temperatures 25 19. 20. Diagrams showing Curves of Latent Heat of Vapori- sation, and Curves of Absolute Pressure for Saturated Vapours of Ammonia, Sulphurous Acid, and Carbonic Acid 48 21. Diagram giving Efficiency Curves of a Perfect Refrige- rating Machine at Various Limits of Temperature ... 64 22. Diagram showing Variation in Capacity, Cost of Fuel, and Work Required, of a Refrigerating Machine ... 74 23. Diagram from Compressor with Parts in Good Order ... 139 24. Diagram from Compressor with an Excessive Amount of Clearance 139 25. Diagram from Compressor indicating the Binding of the Pressure Valve 139 26. Diagram from Compressor indicating too great a Resist- ance in the Pressure and Suction Valves 139 27. Diagram from Compressor indicating the Binding of the Suction Valve 140 28. Diagram from Compressor indicating Leaking of Com- pressor Valves 140 29. Diagram from Compressor indicating Defective Packing of Piston 140 30. Diagram illustrating Arrangement of Electric Lighting on the Series Circuit System 150 31. Diagram illustrating Arrangement of Electric Lighting on the Parallel Circuit System 150 THE POCKET-BOOK OF REFRIGERATION AND ICE-MAKING. SECTION I. REFRIGERATION IN GENERAL. THE MECHANICAL THEORY OF HEAT. HEAT pervades every substance known. Lord Armstrong said, "According to the new theory, heat is an internal motion of molecules, capable of being communicated from the molecules of one body to those of another; the result of this imparted motion being either an increase of tempera- ture or the performance of work." The result of Joule's experiments was to demonstrate that under all circum- stances the quantity of heat generated by the same amount of force is fixed and invariable. Professor Clerk Maxwell was of the opinion that heat, considered with respect to its power of warming things and changing their state, is a quantity strictly capable of measurement, and not subject to any variation of quality or kind. The deductions to be arrived at on accepting this theory are, that if heat is a motion it must be an eternal one ; the generation of heat in any substance must be additional to the heat that has been already generated in it or transferred thereto; heat can be lost or done away with to a degree only, as it is always of uniform quality, and it follows therefore that its annihilation must in every case be a definite part of the entire amount, and cannot be a reduction in quality. B 2 REFRIGERATION AND ICE-MAKING. The rational conclusion to be come to from the above is that the reduction of temperature or cooling of any substance is simply the withdrawal or annihilation of a greater or lesser part of its own heat. Refrigeration may be defined as the art of reducing the temperature of any body, or of maintaining the said temperature below that of the atmosphere. REFRIGERATING APPARATUS. Widely, refrigerating apparatus may be classed under two main heads, viz. chemical and mechanical. In the first, or apparatus working on the chemical system, the more or less rapid dissolution of a solid is utilised to abstract heat, and it is generally designated the liquefaction process. The second, or mechanical process, comprises apparatus operating on four different systems, viz. : cold-air machines, in which the air is first compressed, then cooled, and afterwards permitted to expand whilst doing work, that is to say, practically, by first applying heat to ultimately produce cold; vacuum machines, wherein the evaporation of a portion of the liquid to be cooled, assisted by the action of an air-pump, and of sulphuric acid, effects the abstraction of heat ; absorption machines, in which the abstraction of heat is effected by the evaporation of a separate refrigerating agent of a more or less volatile nature, under the direct action of heat, which agent again enters into solution with a liquid; and lastly, compression machines, wherein the abstraction of heat is effected by the evaporation of a separate refrigerating agent of a more or less volatile nature, which agent is subsequently restored to its original physical condition by mechanical compression and cooling. THE CHEMICAL OR LIQUEFACTION PROCESS. During the change of the physical condition of a sub- stance, for instance, whilst it is passing from a solid to a liquid form, the cohesive force is overcome by energy in the REFRIGERATION IN GENERAL. 3 form of heat, and this may be brought about without change in sensible temperature, provided the heat be absorbed as fast as it is supplied from the exterior, as in the case of melting ice, the temperature of which remains constant at 32 Fahr., any increase or decrease in the heat supplied simply hastening or retarding the rate of melting, but in no way affecting the temperature. Mixtures composed of some salts with water or acids, and of certain salts with ice, however, forming liquids having freezing points lower than the original temperatures of the mixtures, act in a different manner, the tendency to pass into the liquid form being in this case so strong that a more rapid absorption of heat takes place than is capable of being supplied from without, and consequently a consumption takes place of the store of heat of the melting substances themselves. The natural result of this action is that the temperature of the latter falls, until such time as the rate of melting and the rate at which heat is supplied from the exterior become equalised. The degree to which the temperature can be lowered depends to a certain extent on the state of hydration of the salt and the percentage of it present in the mixture. The salts used in ordinary freezing mixtures are generally those of certain alkalies which almost ex- clusively possess the necessary degree of solubility at low temperatures, and the following table gives the mixtures usually employed : REFRIGERATION AND ICE-MAKING. TABLE OF PRINCIPAL FREEZING MIXTURES. COMPOSITION OF FREEZING MIXTURES. Reduction of temperature in degrees Fahr. lountof 1 in de- es Fahr. From To <<*& Snow or pounded ice 2 parts ; muriate of soda I + 32 + 32 + 32 + 32 + 32 + 32 + 32 + 32 + 32 -10 -18 -40 -68 + 50 + 50 + 50 + 50 + 50 -r 5 + 50 + 50 + 50 + 50 - 5 12 -18 -25 -40 o -50 -23 -27 -30 -40 -50 -51 - 5 12 -18 -25 -56 -25 -73 -91 + 4 + 4 + 4 + 3 o - 3 7 TO 12 -14 72 32 82 55 59 62 L 2 83 46 7 33 23 46 46 46 47 50 53 57 60 62 64 Snow 5 ; muriate of sodium 2 ; munate of am- monia I . . . . . . Snow 24 ; muriate of sodium 10 ; muriate of am- monia 5 ; nitrate of potash 5 Snow 12 ; muriate of sodium 5; nitrate of am- Snow 4 ; muriate of lime 5 Snow I ; chloride of sodium or common salt I . Snow 2 ; muriate of lime crystallized 3 . . Snow 3 ; dilute sulphuric acid 2 . . Snow 3 ; hydrochloric acid 5 Snow 7 ; dilute nitric acid 4 . . . . Snow 8 ; chloride of calcium 5 Snow 2 ; chloride of calcium crystallized 3 Snow 2 ; chloride of sodium I Snow 5 ; chloride of sodium 2 ; chloride of am- monia i Snow 14; chloride of sodium 10; chloride of am- monia 5 ; nitrate of potassium 5 Snow 12 ; chloride of sodium 5 ; nitrate of am- monia 5 Snow 2 ; dilute sulphuric acid I ; dilute nitric acid i Snow 12 ; common salt 5 ; nitrate of ammonia 5 Snow i ; muriate of lime 3 , Snow 8 ; dilute sulphuric acid 10 . . Chloride of ammonia 5 ; nitrate of potassium 5 ; water 16 Nitrate of ammonia I ; water I Chloride of ammonia 5 ; nitrate of potassium 5 ; sulphate of sodium 8 ; water 16 Sulphate of spdium 5 ; dilute sulphuric acid 4 . . Sulphate of sodium 8 ; hydrochloric acid 9 Nitrate of sodium 3 ; dilute nitric acid 2 Nitrate of ammonia I ; carbonate of sodium I ; water i . . Sulphate of sodium 6 ; chloride of ammonia 4 ; nitrate of potassium 2 ; dilute nitric acid 4 . . Phosphate of sodium 9 ; dilute nitric acid 4 Sulphate of sodium 6 ; nitrate of ammonia 5 ; - dilute nitric acid 4 REFRIGERATION IN GENERAL. TABLE OF PRINCIPAL FREEZING MIXTURES Continued. r COMPOSITION OF FREEZING MIXTURES. (Materials previously cooled.) Reduction of temperature in degrees Fahr. Amount of fall in de- grees Fahr. From To Phosphate of sodium 5 ; nitrate of ammonia 3 -34 + 20 -IS IO o 20 -40 -68 -34 -So -48 -66 -68 -56 -46 -60 -73 -91 34 16 68 66 53 46 46 40 33 .23 Phosphate of sodium 3 ; nitrate of ammonia 2 Snow 3 ; muriate of lime 4 Snow i ; muriate of lime crystallized 2 . . Snow 2 ; muriate of lime 3 bnow 8 ; dilute sulphuric acid 3 ; dilute nitri Snow 3 ; dilute nitric acid 2 . . . . , Snow i ; dilute sulphuric acid I . . Snow 2 ; muriate of lime crystallized 3 . . Snow 8 ; dilute sulphuric acid 10 . COLD-AIR MACHINES. This class of machine is based upon one of the simplest principles of physics, that is to say, that the compression of air or other gas generates heat, and the subsequent expansion of this air or gas, cold. Mechanical work and heat being respectively convertible, it naturally follows that if air or other gas be caused to perform certain work on a piston during expansion, the performance of this work will cause its store of caloric to become exhausted to a degree equal to the thermal equivalent of the work done, the air or other gas after expansion being at a lower temperature than that at which it was before expansion ; that is, of course, provided always that no heat be supplied from any source to restore that so lost. Cold-air machines all operate on the same general principle (see diagram, Fig. i). The air is first com- pressed in a compressor, and the heat which is generated by this compression is removed by means of water, the cold air produced by expansion being employed for refrigeration. But there have been several notable 6 REFRIGERATION AND ICE-MAKING. improvements during the past few years, practically removing most of the old defects, which make them compare favour- ably, with machines using more or less volatile agents, Cole's " Arctic " Machine being one that embodies im- portant improvements. The cycle of operations may be a perfect or closed one when the same air is in constant circulation, or where it is desirable to have pure air in the storage chambers, the air is rejected after once passing through the cycle, and fresh air is admitted at each stroke of the compressor. Air machines, working at a comparatively low pressure, necessitate the compression and expansion cylinders being of a larger size than in compression machines using higher WASTE: FIG. i. Diagram illustrating cold-air cycle. pressures, but the total actual space occupied is no more, as cold-air machines are generally self-contained, there being no additional apparatus required in the form of ex- pansion pipes, condensers, circulating pumps, etc., obviously, therefore, a simple, cold-air system, in which the defects of the old machines have been eliminated, has much to recommend it. In the early days of cold air it was considered a disad- vantage and uneconomical to reduce air to a very low temperature ; but these objections are now entirely overcome by the improved methods of making the cold-air ducts or trunking, by which the loss is reduced to a minimum, and is almost inappreciable. REFRIGERATION IN GENERAL. VACUUM MACHINES. Vacuum machines, together with absorption machines, compression machines, and binary, or dual, or mixed, absorption and compression machines, all come under the category of vaporisation machines, that is to say, of machines which practically utilise the heat of vaporisation for purposes of refrigeration. In a vacuum machine the refrigerating agent or medium is, as has been already stated, water, its volatilisation at a temperature sufficiently low being effected by the means of a vacuum pump, assisted by sulphuric acid, by which the vapours are absorbed as soon as they are formed, and in this manner rendering the action of the vacuum very effective. The sulphuric acid can be again concentrated for use, and so on ad infinitum. ABSORPTION MACHINES. In its action the absorption machine resembles the vacuum machine, with this difference, however, that in- stead of water, some such liquid as anhydrous ammonia (NH 3 ), capable of evaporating at a low temperature with- out the assistance of a vacuum, is employed as a refrigerat- ing agent or medium. Instead of sulphuric acid being employed to absorb the vapour, water is employed for that purpose, and from this water the vapour is again separated by distillation and is liquefied by the pressure which takes place in the still, and by the action of the condensing water. (See diagram, Fig. 2.) In this manner absorption machines can be operated continuously, the ammonia solution or aqua ammonia being passed into a still or generator, usually heated by a steam coil or worm, and the ammonia vapour being conducted thence to a condenser in which it is cooled and becomes liquefied into anhydrous ammonia owing to the pressure due to its own accumulation. The anhydrous ammonia is kept in a liquid ammonia receiver, from which it passes to the coils of the refrigerator wherein it expands or evaporates, effecting an amount of refrigeration corre- sponding to its heat of vaporisation. After performing 8 REFRIGERATION AND ICE-MAKING. this duty the vapour enters the absorber and is there brought into contact with the weak solution of ammonia coming from the bottom of the still, and is reabsorbed by it with generation of heat, which latter is removed by the cooling water. Both the rich and cold solution of ammonia coming from the absorber and going to the still, as well as the poor and hot solution coming from the still FIG. 2. Diagram illustrating operation of absorption machine. and going to the absorber, are passed through a device called an interchanger, by which their temperatures are equalised. The rich ammonia solution is pumped from the absorber into the still or generator. THE COMPRESSION MACHINE. Machines operating on the compression principle (see diagram, Fig. 3) utilise the latent heat of vaporisation of the substances having a low boiling point, and, whatever the refrigerating agent or medium that may be employed, they all practically act in the same manner; that is to say, the vapour or gas due to the expansion or vaporisation of the refrigerating agent or medium, in the refrigerating or expansion coils, passes into a compressor operated by any suitable power by which the gas or vapour is forced into the REFRIGERATION IN GENERAL. 9 coils of the condenser, and is there liquefied by the aid of the cooling water; the liquid thus formed then enters a liquid receiver, from which it is allowed to pass to the refrigerating coils through an expansion or flash valve or cock, by which the desired regulation can be effected. It will be seen that the process is a continuous one, represent- ing a complete cycle of operations, inasmuch as the ope- rating agent or medium periodically returns to its primary condition in a way that will more or less approach reversi- bility in accordance with the method of working peculiar to each machine. EXPANSION VALVE. FIG. 3. Diagram illustrating cycle wherein a volatile liquid and compression are employed. A perfect reversible compression system comprises the following changes, viz. : An isothermal change due to the vaporisation or gasification of the refrigerating agent or medium at the constant temperature of the refrigerator; an adiabatic change, caused by the compression of the vapour or gas without the addition of heat; a second isothermal change, due to the condensation of the com- pressed gas or vapour at the constant temperature of the condenser; and, finally, a second adiabatic change, owing to the temperature of the liquid being reduced from that of the condenser to that of the refrigerator by a portion of the liquid being vaporised or gasified, and performing work by moving a piston, thus once more returning the refrigerating 10 REFRIGERATION AND ICE-MAKING. medium or agent to its primary state, and thereby com- pleting the cycle. It is presumed that the above changes take place in such a manner that the transfers of heat follow infinitesimal variations in temperature only, and the changes in volume occur in connection with infinitesimal variations of pressure. The changes can be likewise carried out in the obverse direction, the cycle being therefore a reversible one, and a refrigerating machine, which, it may here be observed, is the exact obverse to a heat engine, operated on this plan, will give as economical results as it is possible to obtain in practice. For this reason it has been observed by Professor J. E. Siebel that the heat H, removed by a refrigerating appara- tus operated strictly on the above-mentioned bases, has a certain and well-defined relation to the work or mechanical power, W, required to lift the same in the cycle of opera- tion. If, in a refrigerating machine so operated, ^ is the temperature of the condenser and / the temperature of the refrigerator (T! and T designating the corresponding abso- lute temperatures), thermodynamics teach us that the follow- ing relations exist : H _ ; + 460 _ T! w = *-* "Ti-To Thermodynamically speaking, says the same authority, there should be no difference in economy on account of the nature of the circulating fluid if a perfect cycle of operation was carried out ; but practically, this is not done. In all compression machines, the fourth operation, the reduction of the temperature of the liquid while doing work, is not carried out, but the liquid is cooled at the expense of the refrigeration of the system. No work is attempted, as the amount obtainable would not be in proportion to the expense involved in procuring the same. The value of a circulating medium, it will be seen, is dependent upon its latent heat of vaporisation per pound, inasmuch as this quality governs its refrigerating effect. Regarding the choice of the circulating medium or agent, therefore, the above point must be taken into considera- tion, as well as the fact that the size of the compressor depends on the number of cubic feet of vapour that must REFRIGERATION IN GENERAL. II be taken in to produce a certain amount of refrigeration, and that the strength of its parts will depend on the pressure of the circulating medium. Also that the loss of refrigera- tion, on account of cooling the liquid circulating medium, depends on the specific heat of the liquid as compared with the heat of volatilisation. From the following table it will be seen that with ammonia the loss due to the cooling of the liquid, as shown in percent- ages for every degree difference in temperature of condenser and refrigerator, is less than in the case of other liquids, and total refrigerating effect per pound of liquid is largest, thus readily accounting for the preference generally given to ammonia as the circulating medium or agent. The only advantage possessed by sulphurous acid is the lower pressure of its vapour, and that of carbonic acid the smaller size of compressor necessary ; the loss due to heating of liquid is very large in the latter case. TABLE OF QUALITIES OF PRINCIPAL LIQUIDS EMPLOYED IN REFRIGERATION. (Siebel.) & c .2 fc c .0 * g, II I .0 rt fa "S rt * a^ c -o ressure in Ibs luare inch, at sat of Vapori per Ib., at o [ume cubic fe Ib., at o F Specific Hea Liquid. sat of Vapori per cubic fo< .elative Volui mpressor for Refrigeratic ass due to Co Liquid. H > w W o ^ Sulphurous Acid . . 10 I7I-2 7'35 0- 4 I 23-3 6170 Per cot. 0-24 Carbonic Acid . . 3IO 123-2 0-277 i-oo 447- 3' 2 4 0-81 Ammonia . . . . 30 555-5 Q-IO 1-02 61-7 0-18 THE APPLICATION OF THE ENTROPY, OR THETA-PHI, DIAGRAM TO REFRIGERATING MACHINES. Entropy is the co-ordinate with the temperature of energy, that is to say, length on a diagram, the area of which is energy in heat-units, and the height of which is 12 REFRIGERATION AND ICE-MAKING. absolute temperature ; the abscissae being the quotients found by the division of the heat quantity by the absolute temperature. Absolute temperature is denoted by the Greek letter theta, and entropy by the Greek letter phi, hence the temperature-entropy diagram is generally called the theta-phi (0, <) diagram. In the case of an indicator diagram the co-ordinates are pressure and volume, the work done per stroke in foot- pounds being represented by the area. The theta-phi diagram represents the heat units as converted into work per pound of the working fluid, the area representing a quantity of heat in heat units, the vertical ordinates absolute temperatures, and the horizontal ordinates the quantity known as entropy. The special applicability of entropy diagrams to refrigeration was pointed out in 1892 by an American engineer, Mr. George Richmond, and they have also been used by Professor Linde for a considerable time past. The following application of the entropy diagram to refrigerators is abstracted from a useful little work (to which the reader is referred for fuller information on the subject) by Henry A. Golding, A.M.I.M.E., on "The Theta-phi Diagram," published by the Technical Publishing Co., Ltd., Manchester : " The cycle of operations in refrigerators is exactly the reverse of that in the Carnot hot-air engine. Instead of taking in heat at a high temperature r lt and transforming part of it into work, and rejecting the re- mainder at a lower temperature r 2 , as in the heat-engine, the working substance in the refrigerator receives its heat at the lower temperature r 2 , and discharges it at a higher temperature T X , the extra energy required being obtained from external work done on the gas. The theoretically perfect cycle that is reversible is shown in Fig. 4 with pressure-volume ordinates, and in Fig. 5 with temperature- entropy ordinates. The first stage of the cycle, A to B, consists of the adiabatic expansion of a certain quantity of air, the temperature falling from r x to r 2 . From B to C the expansion is continued isothermally at constant temperature r 2 , the air receiving heat from the body which it is desired to cool, the amount of heat abstracted being equal to the area EBCF (Fig. 5). Compression commences REFRIGERATION IN GENERAL. 13 at C, and is at first carried on adiabatically at constant entropy (or isentropically) from C to D, the temperature rising from r 2 to r ly and is finally completed by isothermal compression from D to A, at constant temperature T 15 a quantity of heat being rejected to the water-jacket equal VOLUME FIG. 4. Diagram showing Theoreti- cally Perfect Reversible Cycle, with Pressure Volume Ordinates. ENTROPY FIG. 5. Diagram showing; Theoreti- cally Perfect Reversible Cycle, with Temperature-Entropy Ordi- nates. to FDAE. The heat expended in the process is the equivalent of the work done on the gas, and is equal to the area ABCD in both diagrams. The heat absorbed from the substance to be cooled is equal to the rectangle EBCF (Fig. 5), and the efficiency, therefore (in its thermodynamic sense), is equal to the ratio EBCF r, ABCD T. 2 It is thus seen clearly how the efficiency is increased by reducing the difference of temperature between TJ and r 2 , and as the ratio TI -t 2 may sometimes be greater than unity, it is better known as " the coefficient of performance " (see Howard Lectures, by Professor Ewing, on " The Mechanical Production of Cold," Society of Arts, 1897). The series of operations in air refrigerators with an open cycle is somewhat different, and is shown in Figs. 6 and 7. REFRIGERATION AND ICE-MAKING. In this cass the air is taken from the cold room, and com- pressed adiabatically from A to B. It is then cooled at constant pressure, the temperature falling from B to C (Fig. 7), and contracting in volume from B to C (Fig. 6), after which it is passed into the expansion cylinder, where it expands adiabatically from C to D, and is discharged to the cold room again. The work done on the air in the compression cylinder is equal to the area EBAF (Fig. 6), or GCBH (Fig. 7), and that done by the air in the expansion cylinder is equal to ECDF (Fig. 6), or GDAH (Fig. 7) ; so that the net external work required is the difference of these VOLUME FIG. 6. Diagram showing Operations in Air Refrigerators with Open Cycle. ENT ROPY FIG. 7. Diagram showing Operations in Air Refrigerators with Open Cycle. two quantities, represented by the area enclosed by ABCD in both diagrams. The efficiency of the process will be represented by the ratio of the two areas ECDF ECAF (Fig. 6) but, as AB and CD are similar adiabatic curves, this will be equal to the ratio EC FD EB Or FA The following brief extracts from a paper on " The Theory and Practice of Mechanical Refrigeration," by Mr. T. R. Murray, Wh.Sc., read before the Institution of Engineers and Shipbuilders, Scotland, in December, 1897, will be cf interest : The entropy diagram (Fig. 8) shows an REFRIGERATION IN GENERAL. 1 5 example of an application to the cold-air cycle, the air being taken in at a temperature /i of 18 Fahr., the temperature of the refrigeration chamber, and rejected at a temperature t. 2 of 70 Fahr., which is the temperature of the air after being cooled by the cooling water ; the tempera- ture at which the cold air is discharged into the chamber to be taken as 85 Fahr., and the highest temperature to which it is heated in compression to be taken as 250 Fahr. Considering the machine to be theoretically perfect, then FIG. 8. Entropy Diagram, showing Application to the Cold-air Cycle. the diagram ABCD is obtained, in which D to C is the rise of temperature of the air during compression from 18 Fahr. to 70 Fahr. ; CB represents the removal of heat in the cooler j B to A represents the cooling in expansion cylinder ; and A to D, the collection of heat in the refrigerated chamber. The proportions of the areas ABCD and ADEF represent the proportion of work done to the refrigeration produced. The rectangle AE will be found to 'be 9' 19 times the rectangle BD. In the working cycle, where the air is raised to 250 Fahr. in the compressor, this will be represented on the diagram by point H, and the fall in REFRIGERATION AND ICE-MAKING. temperature during cooling by HB. The temperature being again lowered in expansion cylinder to 85 Fahr., is represented by the vertical line BG, and the collection of heat in the chamber by GD. The diagram of work is now BHDG, which is about 375 times the theoretical amount, and when compared with the refrigeration done, now repre- sented by area GDEF, gives an efficiency of only a little over 2. Losses by friction, moisture, etc., reduce this in practice to a little over f . Fig. 9 is an entropy diagram for i Ib. of saturated r>>u - 1500 460- tOO 300 150 ftoo :Jo 2 ^r 77/7 V7Y7 777; ^77x \" A n :$*/- $ m m m m K /A ^JG 3 /^v 1 i DC z | 1 Ifc I s 1 3 ]b'0 300 V) Q- 1 3 2 1 5 oJ | F j ^ \X\N s\\- \NX b F -I '1 -6 -7 E N T ROPY 560 5'to 5*0 $c ^60 T ioo B :S ^ :r ^ IfM fiO -2.0 -HW r ^^ 35o i 1 \ 3oo- or X ! ^ 9 So < u_ | ^ U.0(y i i | llCQ. If) Q. k i y ON( y CL 21 h Z ! w 100- 2 r r $J a *>o- u ( s ^ o F ] J O-l -1 -3-* FIG. 9. Entropy Diagram for i Ib. of Saturated Ammonia Vapour from 40 to +100 Fahr. FIG. 10. Entropy Diagram for i Ib. of Saturated Carbonic Acid Vapour from 40 to +100 Fahr. ammonia vapour, from the temperature of 40 Fahr. to +ioo Fahr. FE is the basis line, the temperature at this point being absolute zero, - 460 Fahr.; A, the absolute temperature at -40 Fahr. = 420 Fahr. = T 2 .; B, the absolute temperature at, +100 Fahr. = 560 Fahr. = T 2 ; AD = the entropy at T l ; and considering that a unit weight of ammonia, say i Ib. is being dealt with, the length AD can be determined by taking ;= = 3 45 = 1*436. In J. 420 REFRIGERATION IN GENERAL. I/ the same way, BC = =? _ 0-922. The point G has still to la be determined in order to find the position of point B. Considering, however, that DC represents the compression in compressor, CB the giving out of heat to the condenser, BA the expansion through the orifice of expansion valve, and AD the taking in of heat in the refrigerator, it will be understood that AG really represents the entropy of the liquid heat carried into the refrigerator ; and its length may T be found by the expression AG = clog,, -?, where c = mean AI specific heat of liquid between Tj and T 2 . A simpler formula is AG = ,7: rr?r , where h = liquid heat T 2 liquid heat Tj. By calculating these values for various temperatures between T 1 and T 2 , the points through which to draw the line BA are found. For ammonia it will be found to be practically a straight line, so that it is quite near enough to find the point B only and draw a straight line between A and B. By plotting as abscissae the values of the entropy of the latent heat at same temperatures, the curve CD will be formed. Fig. 10 is an entropy diagram for i Ib. of saturated carbonic acid vapour from the temperature of 40 Fahr. to +100 Fahr., the same construction also applying in this case, but the formation being a continuous curve with a rounded top. To find the efficiency, by means of these diagrams, of a machine working with the same temperatures T a and T 2 as taken with the cold-air cycle, and considering, in the first place, the cycle as being the Carnot or perfect one, compression and expansion will both be adiabatic, therefore they will be represented by vertical lines, and the giving up of heat to the condenser, as well as the collection of same in the refrigerator, being isothermal, then will be shown as horizontal lines. Draw horizontals ad and be, and verticals ^^/and che. Then the area bh will represent the work of the compressor, and the area ge the refrigeration done. C i8 REFRIGERATION AND ICE-MAKING. These equal respectively b e x T 2 - T x , and be X T x . The efficiency will therefore = _ T ) = 9'*9 as before. In considering how nearly the actual working cycle approaches the above in practice, it must first be remembered REFRIGERATION IN GENERAL. Ip that the cooling agent simply circulates in pipes through the chambers being cooled, and must of necessity be colder in order to secure a transference of heat. The difference in temperature depends on the cooling surface, or length of piping, as compared with the cubic capacity of the chamber, and may be in practice from 10 to 25 Fahr. Suppose that allowance be made for a difference of 18 Fahr., then the lower temperature T! will correspond to o Fahr. Again, the working cycle falls away from the Carnot cycle in not being 2O REFRIGERATION AND ICE-MAKING. reversible, owing to expansion taking place through a small orifice instead of by means of an expansion cylinder. Thus the liquid carries a certain amount of heat into the re- frigerator, which goes to heat up the expanded gas, render ing part of it unavailable for refrigeration. The amount of this liquid heat varies for each agent, and the entropy diagrams, Figs, n and 12, to a larger scale, show the working cycle in each case. In these, the areas agb represent the additional work that the use of an expansion cycle would have obviated The heat which ought to have been spent in producing this work is carried by the liquid into the refrigerator, and this therefore falls to be deducted from the refrigeration done, so that the latter is now represented by the area g h ef lt being less than before by the rectangle gf ly which is equal to area agb. COMPARATIVE EFFICIENCY OF REFRIGERATING MACHINES. Professor Ewing estimates the efficiency of the absorp- tion machine at from two and a half to three times that of the cold-air machine, and the efficiency of the vapour- compression machine at from five to six times that of the cold-air machine, and from two and a half to three times that of the absorption machine. In comparing one system with another, the theoretical values obtained at the machines are not sufficient, as the combined losses in piping, brine cooling, circulating pumps, fans, and any other auxiliary apparatus, must be con- sidered, and only the actual net useful duty performed taken into account. And further, an amount must be added to the capital interest in a plant for recharging with gas (except air machines), including incidentals such as calcium chloride and other items necessary to the system. Refrigerating machines, to be efficient, must be efficient when working in hot weather or tropical climates. Some systems fall off considerably when the cooling water is about 60 Fahr., and the atmosphere above 70 Fahr., and in some the cost of working is so high under tropical con- ditions as to render their use almost prohibitive. The cold- air system does not fall off in the same ratio, and for many purposes is the most economical. All the losses under this system are in the machine, as the air after leaving the REFRIGERATION IN GENERAL. 21 machine does not pass through any secondary process, but is conducted direct to the storage or cooling chamber without the use of brine, circulation pumps, fans, etc. RATIO OF PRESSURE OF SO 2 , NH 3 , and CO. 2 . (From Landolt &* Bornsteiii's Physico-Chemical Tables, Lister & Co., Ltd., Catalogue.} Temperature in Degrees Fahr. Pressure expressed in pounds per square inch. Sulphurous Acid. S0 2 . Ammonia. NH 3 . Carbonic Acid. C0 2 . -4 12 2 7 6 + 5 18 325 H 27 374 23 4 35 435 3 2 8 46 502 4i ii 59 566 50 18 73 660 59 2 5 90 750 68 32 108 840 77 4 1 129 95 86 51 J52 i, 060 95 62 1 80 1,280 104 75 208 1,320 \\ FIG. 13. Diagram showing Loss of Efficiency with NHa and C02 owing to use of Expan- sion Valve. (Murray, hist. Engrs. and Shipbuilders, Scotland, 1897.) ."0-. 8 " a . \ > fe \ \ ^ S \ 8 . \ \ S" \\ \ FIG. 14. Diagram showing Per- centage of Efficiency of Work- ing Cycle of CO2 as compared with NHs. (Murray, Inst. Engrs. and Shipbuilders, Scotland, :897.) 22 REFRIGERATION AND ICE-MAKING. RESULTS OF TEST EXPERIMENTS WITH COLD-AIR MACHINES. Haslam.* Bell- Coleman.+ ColeV'Arctic"* No. 4 Size. No. i Size. Diameter of comp. cy. in ins. 25^2 cy.) 28 II 63 Diameter of exp. cy. in ins I9| 21 9 5? Stroke of each 36 2 4 12 8 Revs, per minute 72 63-2 9 6 1 60 Air pres. in receiver (abs.) in Ibs. per sq. in. . . 64 61 65 75 Temp, of air entering comp. cy. (cont. vapour up to 88 per cent. of sat.) in deg. Fahr 65-5 4 8 46 Temp, of comp. air admitted to exp. cy., Fahr. 35 Temp, of air after expansion, Fahr. -85 -52 -81 -98 Init. temp, of cooling water, Fahr. 62 4 1 I. H.P. in comp. cy. . . 346-4 124-5 14-5 3-28 I. H.P. in exp. cy 176-2 SB'S 7-8 1-68 Per cent, of I. H.P. of comp. retained in expander Si 47 54 5i EFFECTIVE COOLING POWER OBTAINABLE FROM THE EX- PENDITURE OF ONE POUND OF STEAM IN THEORETI- j CALLY PERFECT MACHINES. (Tuxen & HammericW s Cat.} Ammonia by the absorption system. Thermal Units 294 Carbonic Anhydride ... 652 Ammonia by the compres- sion system 978 equal to 24 Ibs. of ice per Ib. of coal consumed, equal to 26 Ibs. of ice per Ib. of coal consumed. equal to 40 Ibs. of ice per Ib. of coal consumed. * " Proceedings, Manchester Society of Engineers," 1894. t Prof. Schroeter, " Untersuchungen an Kaeltemaschieren schiedener Systeme," 1881. J A. J. Wallis-Tayler, A.M.I.C.E., 1902. Ver. REFRIGERATION IN GENERAL. TESTS OF AMMONIA AND CARBONIC ACID MACHINES. (Schroder, Experimental Refrigerating Station^ Munich, Germany.} NO. OF TEST AMMONIA MACHINE. CARBONIC ACID MACHINE.* i 2 3 4 5 6 , 7 8 Temperature in brine tank, de- ' grees Celsius -6-1 -6-4 -6-4 -4-8 -4-0 -4-8 -4-8 -6-7 Temperature in condenser, de- grees Celsius 21-4 21-4 21-4 34'9 20-9 21'2 22-2 30 Temperature before expan- sion valve, de- grees Celsius -6-7 n-6 18-4 28-3 -7'9 IO'O 16-8 28-8 Refrigeration per hour, per horse power of steam - engine in calories ... 3897 3636 3508 2237 3832 3178 2867 1477 BOVE ATMOSPHERE CONDENSER TEMPS. \, fe UJ 4 UJ JIFFEI ENCE ^f^* 0"F ^- 1 . a a ^, ^^ a- 66- 70' BO' POT l t>.QO ON O Tt- N O t^.O O >o rj- rj u-> t-. O lor^i-ooooo cot^ooo i-i rt- op O ^ O o ^ ; t->. -. w ON O N ONC lO -J-OO t- O^ i-i ' at->. 1-^. H-l O *- ^ " ^ I^,X saqoui ui COO"- 1 ON rooo PO *-- rj-bob ONN io-ivO coOOO woo O fOOt^- ON i-i 1-1 M fO CO MOOvO ^'J-LoO ON COO t^-O rj-o O co r^O * O ON O ^ "- ~ ^00 NN^O^^^,^.^ ONOO O oo 1-1 LOO ")*- t^OO O >0 ? iob b ^o 10 ON rt- M r~-oo ^J- M o ON co M N COLOOO M 1-1 M ooooo cocooo t-- cooo M cocor^.Tt-O >-ON O LOLONOO -< i-i N LOONV I^OOO -i ^ > M Tf C< vO >O t^OO ONO 28 REFRIGERATION AND ICE-MAKING. saqsui ut jgjatuBiQ jbpii;i^3 M CM PO rt- LOO t^OO ON O CM rJ-O OO O CM -KO LENGTH OF STROKE IN INCHES. C M U POONCM PO '-' O OO O CMO POONPO LOO rj- CM O . O r^ONi^b ON rh LO 1-1 >- PO ON t>OO CM ON t~ O CM CM POO i-iO "3- PO Th O CM O LOO <*< LO >-i PO LO r>. O CM LOCO *- co LO PO -< O O O O OS *"* t-^H- tt-. LOO ONOO ON O Tj- ON iO CM CM r~- 1^. rt-O c O t- LO 00 en C U O CM OO ^O ^J-CO O^CMO'-i'^-OOOON POO . M HI POOO LO LOCO PO 1-1 ON t--O Vh PO POO - c u CO PO HH to ON rhOO CMO 1-1 ONt->.LOCM OO rj-LO . " r^.O ^>.db rt-ONOOO bob ONLOON LOi-i ONt~>.POOOOCOOO ONO O !- ^t- CM LO i-i vO CNCM O CM Ttf-LOi^ONi-ivO t-i t^ co ONO PO "-" VO 1 u ON d-CO OO CM COCO -^ "-> O>OO POLOLO*- Tt-LOrJ- C OO O POO OO CM OOOCO i-i OO ON^t-CM ^-O t^J^-ONCM O CM POLO 1-^.CO CM l^-^-O PJOO ri-i-i c U vO iniot_oi-r>row f^oooo ONO t^- to CJ O ^t* r ^^ "PV^Lo^CMi^OQi-i r)-CO Th ON LO toLOPOONPOO r^.r^"-i t^OO LOI^POCM POOO i^-O OOoo O O CM ^-LOONCMO O LOO LOO Tj- s u coo CM CM TJ- ^1- ONOO OO toi-Ot--O ^J- ONO CO -. COO-.t-OO CM ^.^^.^ os^^,^^ ob CM O LOO ^-PO 1 -" POLOCM O CMO CM i-i POO oo LO eo * O Q '** O * n LOCO "-i rt-oo CM o O CO ^J- LOO r-OO w-ii-ii--iCMCMC)POPO'^ ,0 j c u ON t--. ON ON POOO d-00 OOO ^J- i-i r^CM tot->.t^N OO PO ONO POOOOO LO^-t-i PO LOCO ** -4- t~~ O M PO PO ^t- LOO O t-^CO ONwM-ii-iCMCMtMPO M a U OOOOO Cl CMO CM rJ-CMOOOOO LOt-~ ^"OO OO to t^ PO CM POCO I--.OO O -^-O PO >- O !-" PO ONCMOOLOOLOOOCMOOOCM >^-O CO O H c U POONPOPO" i-iOOO NO COONPO LOO rt- CM OO coO r^ONt^O ON-^LO-H i-i PO OM^OO CM ON ? PO CM POO O ^t-PO^hO CM b LOO ^t- r^ i-i LO i-i PO LO t^ O CM LOCO 'rOLOPO'-'OOOO OM_.-II-II- < CMCMCMCMPOCO^- LOO t^oo ON saqout m laiauiBiQ japuji^Q H N CO ^- LOO t^CO ON O CM ^-O OO O CM ^J-O REFRIGERATION IN GENERAL. 2 9 z , o u g > H I u o w _) ^ saqoui n ' saipui ui co ** LOO t^-00 ON O >- N co vj M ON >-i "->OO Tf- r->. t-i cooo ON t-^ co LO P .r^r^ONw I* OQ co O woooo "OO OO N CO *-i O Ol^t^W N LOGO M r^ -> HH <* 1^ M M ff) Tf O ON >-> IH 1-1 M N CO HH HH 1-1 N OOCON'^-t^MOOOOO > T^-k-iiOCO M 1-4 fo LOGO M ^QQ -OO rt w COOO "- 1 ^I^.O f> -! M w N I-H M LO t-N. )-( N i^. i_r^ ^ ( %JTI 1 ." t ^T ls PvOOO ^- i- \O t--.fOOOO ON ' OO LOO tt N ON I-H fOir>rt-rON LOON--< <-< 1-1 -+ O fO 1-1 eo N \O LOO ON *3- N O <+ N LO f^OO rj- LO ro POO O O rh - ro LO N fO LOOO -" N co <3-O i^ ON >-> i-> -> ^-CO OO ONrJ-cOf^.co>-i <-> M LO O\O O M CO LO t~>. >- CM CO Tj- LOO OO i- M M -. N CM co ^ LOO t^OO ON O -" M REFRIGERATION AND ICE-MAKING. saqom ui J9}9nnjiQ japing TJ- LOO t^OO ON O M *^-O OO O N <3-O HIHIHIHIHIHINMMMMPOPOPOPO LENGTH OF STROKE IN INCHES. Th A u LOHI Tj-LOW t^OO H3- M "j-O O PO M LOT}- l^O O O^ >-< VO MOO rJ-i-iOO LO OO r^l^ONrOl^-^t- co ^t- ^t- LO^O *O t- ON O N ^i-O ^ >-> '* N 3 u \O *^ fO LO fOO LOONLOOOOOOO VO t- fO POOO t^.MMNO'O OfOrJ-PO oooo M a\CNcoi-"vo LOOO ^ LO a\ r-oo rOOO ^ <^> LO M OS fO OVvO LO LOO O fO rO CO ^ -1- LOO OOO ONH- fOLOt^ONN N 8 m c U t^fONVOfOLONOOOOOOOOO OO ^f'-' CNOsO fON f^OO LO ^ LOOO t~- t-^ ro N fOOO *^OO O Tf M t-i fOOO LO <* OLOOLoOO^OOOfO | - | O>-'< v O CO CO ^ ^ LO LOO 1^. C\ O N ^O OO O 1-1 M M IM HI N oo M a i i O 00 00 1-1 <0 * LOOO fOOi^OOOOO O O ONLOO fO^-N fOO fOfOO M "-" r^OO >-i OO OO O LO ^ rj- LOOO N t->. Tj- 1-1 l~^i-i\O O LOi-OOO >-> LOO t~ LOO PO N CO PO ^ ** LO LOO 00 OS M * POOO VO i u O rhONO Lort-LO-iNOOOOOOO rO t->.O >-* OO MOO rJ-M ONOO O LO VO M >-" ro^^PO^^oo roONLoOO M t^. ri-OO M O O LO O O M -^-OO COOO LO M M M PO CO -^ rj- LOO t^OO OS M -*-O >o H c U O * s *> O ON ^ ONOO Os PO O O O O osO LO^I-M M M LO POO M POOO oo OLO>~'O'-'LO>-(OOOOPOOO | -*LO PO O O rt-CO M t--t->.I~>.OSMO OO M M M PO PO PO <3- ^ LOO t^ OS O M rO LO * Q M U p-iOOOi^-Lo^J-MOOTj-OLoOO OO LO TJ- rj- ->. M ONOO >-< popooo oso o LO t~- -H r~>.vo o OSM POPOM OSLO>-I <* >-, _oo - LOOSPOPOPO ^-O CO M r^ M M M M PO PO PO <* LOO 1^00 ON "-> M ^*- ro 1 !J i-iMOOt^OooO^OOt^.'-'OOO ** r>.POOOO LO^J-i-i 1-1 M T^-ONLOM N OS 1-1 LO O OO OO ^1-OO O O OO LO O PO MOO POO O OSOO ON O i- 1 "^-OO M MMMMPOPO^-Tl- LOO OO OS O PO N N d O M LOt^t^O POOS LOO O PO OS O O t^bMPOPOMOSi-'ob'-.OSMOLO^J- rj-M >-i M LOOOO M r^-OO OO LO OS HI OO ^ *J-f^O ti-t^LOrhPOrO rt-O OO M wMMMPOPO OS rj- HI OS O^ HI LOOO *~- <* t~. r^ rj-oo OO O O*M -^J^HI Tt- osoo r^f^oo ON HI HI HIM M M COPO^*^ LOO t^-OO Os " saqoai m ja^iuBiQ a'apui^O ri- LOO t^OO OS O M ^-O OO O M rt-O REFRIGERATION IN GENERAL. II a 2 r^ C '-a 8 s REFRIGERATION AND ICE-MAKING. REFRIGERATION IN GENERAL. 33 APPROXIMATE ALLOWANCES PER TON CAPACITY TO BE MADE WHEN SELECTING A MACHINE FOR REFRIGER- ATING PURPOSES. (Triumph Ice Machine Company.) Beer wort: 15 barrels per ton on Baudelot cooler. One thousand gallons of sweet water per ton from 70 to 40. Six beeves, 600 to 700 Ibs. each, per ton. Ten to twenty hogs, per ton. One thousand cubic feet of space per ton for small machines up to 2 tons. Four thousand cubic feet of space per ton for machine from 10 to 15 tons. Ten thousand cubic feet of space per ton for larger machines used for general purposes. The above will serve as a guide, but it must be borne in mind that the climate, construction, and exposure of buildings that are to be refrigerated, character of the insulation, management and method of handling work, all have to be taken into consideration. (See also Section on Cold Storage.) CONDENSERS. On the efficiency of the condenser largely depends the economical working of the machine. Condensers are of two kinds or classes, viz. the submerged and the open air, or atmospheric, the latter being the more economical in the matter of cooling water, but occupying the larger amount of space. According to Professor Siebel, under average conditions (incoming condenser water 70, and outgoing condenser water 80, more or less), for each ton of refrigerating capacity (or for one half-ton of ice-making capacity) 40 square feet of condenser surface, corresponding to 64 running feet of 2-inch pipe, and to 90 running feet of i^-inch pipe, will be re- quired in a submerged condenser. The amount of cooling water used varies from 3 to 7 gallons per minute per ton ice-making capacity in twenty-four hours. The pipe required in an open air condenser is 40 square feet per ton of refrigerating capacity (or for one half-ton of ice-making capacity), equivalent to 64 running feet of 2 -inch pipe, or 90 running feet of iinch pipe. The amount of cooling water used is about 50 per cent, less than with condensers of the submerged type. u 34 REFRIGERATION AND ICE-MAKING. Double pipe condensers are made which are claimed to possess the best qualities of both submerged and open air condensers. This condenser consists of a coil made up with one pipe inside another of larger diameter, the cooling water circulating through the internal pipe, and the com- pressed gas in the annular space or clearance between the two pipes. The gas is thus exposed to the action of both cooling water and the atmosphere. EVAPORATION OF LIQUIDS. (Lightfoot.) Liquid or gas. Water. Anhydrous Ammonia. Sul- phuric ether. Mythylic ether. Sulphur diox- ide. Pictet's liquid. Specific gravity of\ vapour, compared > 0-622 o'S9 2-24 1-61 2-24 with air =1-000. ) Fahr. Fahr. Fahr. Fahr. Fahr. Fahr. Boiling point at \ atmospheric pres- [ 212 -37'3 96 10-5 14 -2-2 sure . . . ) Latent heat ofvapor- j isation at atmos- J 966 900 165 473 182 pheric pressure . ) Fahr. Ibs. Ibs. Ibs. Ibs. Ibs. Ibs. in A - 40 __ 20 19-4 12-0 5'7 11-6 g 30-0 !'5 18-7 9-8 I5'4 c e + 20 477 2-6 28-1 16-9 22-O 2 JjJ + 32 0-089 61-5 3-6 36-0 22-7 27-0 s + 40 0-122 73'0 4'5 42'S 27-3 3^3 _OJ T3 w + 60 + 80 0-254 0-503 108-0 i5 2 -4 7-2 10-9 61-0 86-1 41-4 60-2 44-0 60'0 N 100 0-942 210-6 16-2 118-0 84-5 79-1 >* 120 1-685 283-7 23-5 "7'5 99-7 2 140 2-879 33'5 ||s 1 60 4*731 45'6 t/J Q< rj 180 7'S 11 62-0 ,Q M 4j 4B ! { 200 11-526 81-8 fc t^ | -i ,.<.r p i> in in co ^- co w rj-vp p^ 50 'c\ "OMDO i> ^t co "M "w b oo t* i> >o >n M c\ OM COCOCONN >n co p M oo co>p p RSv*'**'*'*'*'? ** *"*"< 'i'*:*^ 1 CM O ^p O O O p p w M p M co p co p p CM "co b w CM co V in ini) t^cJo CM CM CM CM CM CM CM COCOCOCOCOCOCOCOCOCO > > a\ >- O p p l> p ."">oo p p 00 p p\ p pppp trrrrTTT TTTTTTTT T M o c?iO t^-o o r*M oino crit^o cot^ & ? 5? 8 * p r> J> r 5 w .^ * y p Vi- Vo "CM M b b b w CM CM "co Vj-vb >b c^-oo o\ 1 1 1 1 1 ++ O w CM CO ^- Tj- in^O in M op vo opp o jo o o u~> o in 1 co co"oo" oo cc? inoo c< ^* TJ- r^ o\ in o\ t^ M cj co co QQH wojcjc^coco ^" in in in in X) CO M invb t->oo vo vo vo vo vo O vp co co Tj- o\ b>oo oo Kvb vb in In in Vj- Vo co "M cococo corofocococo cococococo in m in in in O i> O co in MD i> oo oo o b 'N c* co co in in r^ (NNN NNCOCOCOCO COCOCOCOCO CO CO CO CO CO l> CO OO CO CO CO N CO CO c\ b M N co Vj- in vb t> oo b> '>-> N <* co-'t'^- ^^-^^^^' ^^ininin 8OO OOMQOO OOCOOO p p p O TT- p in p p p p> p p V invb Koo qj b w N co Vh in K 'o\ in in in m in invo vo vo vo vo vo vo vo 'too Nino^coi>Min vpTfTj-pic* *M b o b>oo r^ t~vb vb in Vf "co N M M LOVO inmnminvninin inmminm in in in m in ej o p O O O O O O O O O ^ in O e O ^ u !l!a b^oo t^vb inTt-coNMbS' M ' co ' f> ' fl * > 1 I I I I I I I I +^+ vo w oo rf r^ en T}- t^vo r^ o o vo o o V invb vb t^oo 60 'o\ o\ b M N "ro invb CJNWWNMNNINCO COCOCOCOCO jnioj S REFRIGERATION AND ICE-MAKING. SOLUBILITY OF AMMONIA IN WATER AT DIFFERENT TEMPERATURES. (Sims.) Degrees Fahr. Sb.ofNH 3 to i Ib. of Water. Volume of NH S in i Volume of Water. Degrees Fahr. Sb.ofNH 3 to i Ib. of Water. Volume of NH 3 in i Volume of Water. 32-0 0-899 1,180 125-6 0-274 359 35-6 0-853 1,120 129-2 0-265 348 39'2 0-809 I,O62 132-8 0-256 336 42-8 0-765 1,005 136-4 0-247 324 46-4 0-724 951 140-0 0-238 3 I2 50-0 0-684 898 143-6 0-229 301 53-6 0-646 848 I47-2 0-220 389 57-2 0-611 802 I50-8 0-2II 277 60-8 0-578 759 I54-4 0-202 265 64-4 0-546 717 158-0 0-194 254 68-0 0-518 683 161-6 0-186 2 44 71-6 0-490 643 165-2 0-178 234 75'2 0-467 613 168-8 0-170 223 78-8 0-446 585 172-4 0-162 212 82-4 0-426 559 176-0 0-154 2O2 86-0 0-408 536 179-6 0-146 192 89-2 0-393 Si6 183-2 0-138 181 93'2 0-378 496 186-8 0-130 170 96-8 0-363 478 190-4 0-122 160 100-4 0-350 459 194-0 O-II4 149 104-0 0-338 444 197-6 OT06 *39 107-6 0-326 428 201-2 0-098 128 111*2 0-315 414 204-8 0-090 118 114-8 0-303 399 208-4 0-082 107 118-4 0-294 386 2I2'O 0-074 97 I22'O 0-284 373 THE FORECOOLER. This is a supplementary condenser through which the compressed ammonia passes before reaching the main con- denser, and cooled by the overflow water from the latter. If composed of one coil, it should be the same size as dis- charge pipe from compressor ; if of a number of coils, the manifold pipe, and the aggregate area openings of small pipes, should be equal to that of the discharge pipe. REFRIGERATION IN GENERAL. 39 SOLUBILITY OF AMMONIA IN WATER AT DIFFERENT TEMPERATURES AND PRESSURES. (Sims.) i Ib. of water (also unit volume) absorbs the following quantities of ammonia : Absolute Pressure in Ibs. persq. in. 32 F. 68 F. 104 F. 212 F. Ibs. vols. Ibs. vols. Ibs. vols. grms. vols. 14-67 0-899 180 0-518 0-683 0-338 0-443 0-074 0-97 J 5'44 Q'937 231 o-535 0-703 0-349 0-458 0-078 0-102 16-41 0-980 287 o-556 0-730 0-363 0-476 0-083 O-IO9 17-37 029 '35 1 o-574 0-754 0-3/8 0-496 0-088 0-II5 18-34 077 414 o*594 0-781 0-391 0-513 0-092 0-120 19-30 126 478 0-613 0-805 0-404 0-531 0-096 O-I26 20-27 177 546 0-632 0-830 0-414 0-543 o-ioi 0-I32 21-23 236 -615 0-651 0-855 0-425 0-558 0-106 0-139 22-19 283 685 0-669 0-878 0*434 0-570 o-iio 0-I40 23-16 336 754 0-685 0-894 0*445 0-584 0-115 0-I5I 24-13 388 823 0-704 0-924 0-454 0-596 0-120 0-157 25-09 442 894 0-722 0-948 0-463 0-609 0-I25 0-164 26-06 496 965 0-741 o-973 0-472 0-619 OT30 0-I70 27-02 '549 2-034 0-761 0-999 0-479 0-629 0-135 0-177 27-99 603 2-105 0-780 023 0-486 0-638 28-95 656 2-175 o-?oi 052 o-493 0-647 . , . . 30-88 758 2-309 0-842 106 0-511 0-671 . . 32-81 1-861 2-444 0-881 157 0-530 0-696 3474 1-966 2-582 0-919 207 o-547 0-718 . . 36-67 2-070 2-718 o-955 254 0-565 0-742 . . , , 38-60 . . . . 0-992 302 o-579 0-764 . . 40'53 o-594 0-780 SOLUBILITY OF AMMONIA IN WATER AT DIFFERENT TEMPERATURES. (Roscoe.) Ibs. of Ibs. of Degrees Celsius. Degrees Fahrenheit. NH 3 to I Ib. Of Degrees Celsius. Degrees Fahrenheit. NH 3 to i Ib. of Water, Water. 32-0 0-875 8 46-4 0-713 2 35-6 0-833 10 50-0 0-679 4 39-2 0-792 12 53-6 0-645 6 42-8 0-751 H 57-2 0-612 REFRIGERATION AND ICE-MAKING. SOLUBILITY OF AMMONIA IN WATER AT DIFFERENT TEMPERATURES. (Roscoe.) ( Continued.) Ibs.of Ibs. of Degrees Celsius. Degrees Fahrenheit. NH 3 to i Ib. of Degrees Celsius. Degrees Fahrenheit. NH 3 to i Ib. of Water. Water. 16 60-8 0-582 36 96-8 0*343 18 Jf4 0'S54 38 IOO-4 0-324 20 68-0 0-526 40 104-0 0-307 22 71-6 0-499 42 107-6 0-290 2 4 75-2 0-474 44 III-2 0-275 26 78-8 0-449 46 114-8 0-259 28 82-4 0-426 48 Il8'4 0-244 30 86-0 0-403 50 122-0 0-229 3 2 89-6 0-382 52 125-6 0-214 34 93' 2 0-362 54 I29-2 0-200 56 I32-8 0-186 STRENGTH OF LIQUOR AMMONIA. Percentage of Ammonia by Weight. Specific Gravity. Degrees Beaume, Water, 10. O I -000 IO'O 2 0-986 12-0 4 0-979 I 3 -0 6 0-972 I4-0 8 0-966 I5-0 10 0-960 16-0 12 o'953 17-1 H o'945 18-3 16 0-938 I9-5 18 0-931 20-7 20 0-925 21-7 22 0-919 22-8 2 4 0-913 23-9 26 0-907 24-8 28 30 0-902 0-897 257 26-6 3 2 0-892 27'5 34 0-888 28-4 36 0-884 29-3 38 0-880 3 0-2 REFRIGERATION IN GENERAL. YIELD, ETC., OF ANHYDROUS AMMONIA FROM AMMONIA SOLUTIONS. (Redwood.) SOLUTION. ANHYDROUS AMMONIA. Weight of Ice. ill "c 2-841 54-9 39-6 31-0 7'25 50 419 2'6lO 5'7 36-0 29-0 7'34 62 382 2-379 46-0 32-5 27-2 26-O 7-42 7H8 74 83 346 320 2-156 1-993 41-7 38-5 29-1 26-6 2 5 -6 7-50 86 3" 1-937 37*5 25-8 23-7 7'59 98 277 1-726 33'4 22-8 22-2 7-67 110 244 1-520 29-4 197 TEMPERATURES TO WHICH AMMONIA GAS is RAISED BY COMPRESSION. Absolute ABSOLUTE SUCTION PRESSURE. Temperature of Suction. Con- densing Pressure. 20 25 30 35 40 45 Fahr. 9 199 165 138 116 9 8 83 100 216 181 153 131 "3 97 1 10 232 196 166 145 126 109 I2O 245 211 181 158 138 121 130 26l 222 193 169 150 I 3 2 140 273 235 205 181 161 143 IIS 285 2 9 6 246 257 216 226 191 202 171 181 163 REFRIGERATION AND ICE-MAKING. TEMPERATURES TO WHICH AMMONIA GAS is RAISED BY COMPRESSION. (Continued.) Temperature of Suction. Absolute Con- densing 1 Pressure ABSOLUTE SUCTION PRESSURE. 20 25 30 35 40 45 5 Fahr. 90 266 172 145 123 104 89 IOO 223 1 86 1 60 138 119 103 1 10 239 203 174 151 *3 2 "5 1 20 254 218 188 163 145 127 130 268 230 200 176 156 139 140 281 242 212 188 167 150 150 293 254 22 3 198 178 160 1 60 305 234 209 188 170 10 Fahr. 90 213 178 151 129 IIO 96 IOO 231 195 167 144 I2 5 109 IIO 247 210 181 158 139 122 120 261 226 195 171 134 130 275 237 207 183 163 145 140 289 250 219 195 174 156 ISO 301 262 231 205 185 I6 7 1 60 313 273 241 216 195 I 7 6 15 Fahr. 90 221 185 158 '35 117 101 IOO 238 202 173 151 115 IIO 254 217 188 164 145 128 120 26 9 233 202 178 158 140 130 283 245 214 191 170 152 140 297 257 226 202 181 I5O 309 269 238 213 192 173 1 60 321 28l 249 223 202 183 20 Fahr. 9 228 I 9 2 164 123 1 06 IOO 245 2O9 1 80 157 137 121 IIO 262 224 195 171 150 134 120 277 240 209 185 164 146 I 3 291 252 222 197 176 158 140 305 265 234 209 188 169 15 277 245 220 198 180 1 60 329 288 ?-? 2 3 209 190 25 Fahr. 90 235 199 I 4 8 129 in IOO 252 216 I is 7 163 144 127 IIO 269 230 200 I 7 8 155 140 120 284 247 216 191 171 153 I 3 299 259 229 204 183 l6 5 140 271 2 4 I 216 194 176 15 3 2 5 284 2 53 227 205 187 1 60 338 296 264 237 216 197 REFRIGERATION IN GENERAL. 43 TEMPERATURES TO WHICH AMMONIA GAS is RAISED BY COMPRESSION. (Continued.) Temperature of Suction. Absolute Con- densing Pressure. ABSOLUTE SUCTION PRESSURE. 20 25 30 35 40 45 30 Fahr. 90 242 206 177 154 134 u8 100 260 223 193 170 150 133 no 277 239 208 184 164 J 47 I2O 292 255 223 198 177 159 I 3 307 267 236 211 190 171 I4O 3 2t 280 248 22 3 201 183 ISO 334 292 260 234 212 '93 1 6O 34& 304 271 245 223 203 32 Fahr. 90 245 209 179 157 137 121 IOO 263 225 196 173 153 135 110 280 241 211 I8 7 167 149 1 20 295 256 226 201 1 80 162 130 310 270 239 213 192 174 140 324 283 251 226 204 185 337 350 295 307 26 3 274 237 2 4 8 215 226 I 9 6 2O6 35 Fahr. 90 249 213 182 1 60 141 124 IOO 268 229 200 1 7 6 156 139 no 286 246 215 I 9 I 170 '53 120 300 260 230 205 I8 4 1 66 I 3 3i5 274 243 217 I 9 6 178 140 3 2 9 288 2.S5 230 208 189 ISO 34i 300 268 2 4 I 219 200 1 60 354 312 279 252 230 2IO THE ANALYSER. The analyser is placed in upper part of still or generator of absorption machine, and serves as a dehydrator, also increasing temperature of rich liquor from 150 to 170, at which it arrives, to about 200. The device consists essentially of superimposed shelves down which the rich ammonia liquor is delivered and over which it trickles, whilst the heated vapour from generator passes over them in an upward direction. In this manner 44 REFRIGERATION AND ICE-MAKING. the hot vapour is caused to come in contact with a large surface of the rich ammonia liquor, and becomes both enriched in ammonia and deprived of a large percentage of water by the time it reaches the top of the analyser. PROPERTIES OF SATURATED AMMONIA GAS. (Yaryan.) Tempera- ture .b'ahr. Pressure from vacuum in Ibs. per sq. in. Heat of vaporization. Volume of vapour per Ib. cubic ft. Volume of liquid per Ib. cubic ft. Gauge pressure per sq. in. -40 I0'69 579-67 24-38 0-0234 o- -35 12-31 576-69 21-21 0-0236 o- -3 14* I 3 573- 6 9 18-67 0-0237 o- -25 16-17 570-68 16-42 0-0238 1-47 20 18-45 567-67 L 14-48 o -0240 3-75 -15 20-99 5 6 4-64 12-81 0-0242 6-29 IO 2377 561-61 11-36 o -0243 9-07 - 5 27-57 558-56 9-89 o -0244 12-87 30-37 555-5 Q-I4 o -0246 15-67 + 5 34-17 552-43 8-04 o -0247 19-47 + 10 38-55 549-35 7-20 0-0249 23-85 + 15 4 2 -93 546-26 6-46 o -0250 28-23 + 20 47-95 543-15 5-82 0-0252 33-25 + 25 53-43 540*03 5-24 0-0253 38-73 + 30 59'4 l 536-92 4'73 0-0254 44-71 + 35 65-93 533-78 4-28 0-0256 5 r *23 + 40 73-00 530-63 3-88 0-0257 58-30 + 45 80-66 527-47 3-53 0-0260 65-96 + 50 88-96 524-30 3'2i 0-02601 74-26 + 55 97-63 521-12 2-93 0-02603 82-93 + 60 107-60 5I7-93 2-67 0-0265 92-90 + 65 118-03 5I5-33 2-45 0-0266 103-33 + 70 129-21 511-52 2-24 0-0268 114-51 + 75 141-25 508-29 2-05 0-0270 126-55 + 80 154-11 504-66 1-89 0-0272 I39H 1 + 85 167-86 501-81 1-74 0-0273 + 90 182-8 498-11 1-61 0-274 168-10 + 95 I98-37 495-29 1-48 0-277 183-67 + 100 215-14 491-5 1-36 0-279 200-44 REFRIGERATION IN GENERAL. 45 .- C O N ON tooo PO ON PO rJ-vQ i-ivo <-> N w ri- PO PO t^t^w O N TO vQ TO NOO POO i* 6 6 ONOO TO t^ t^ O O w O N TO vQ TO NOO t^t^O ^O l^vQ O t^ O O TO W t^ W TO PO ON to N TO to w o to N O OOON.'-ON>-i>-iO^N > - | OON POO M PO *"> rj- N 1-1 OOON.'- iO\>O *- >-< M ot-iv WOO O "O POrt- C^N O O O O ONTO TO t^ O 5 O OO ONO to rJ-OO CM O O^ POTO POTO PO ~ M O O M t^ to 10 vo PO to ON ON POTO M ON N O 1 M r-vo ON*O -ooo N O ON TO ** ^ MVO O OM to OO *O t- t-^TO CX) ON O 1 . 8S*SS REFRIGERATION AND ICE-MAKING. O MOO PO LO PO rj- ON O CO M M t^t^M M t^OCO W> OO *d" O OO O sO *-O LO ^>-OO * ' ^t~ r^ H* *O ""* O M OO LO MMMi-HN-i-ii-ibbbbbboNONONONbN O ONOO ^-ONM MOO M M r^ONLOt-^^-LOM M O CO O rj- -3- rh rj-vO OO O PO t->. 1-1 O >* POi-iOpvO ^t-M OOOO ^ PO ** ONOO VO MOO^LOPOM_M M PO ^o ONMO M LO^O PO ^ ^S!~!!~!"!~!P.PPP. 9. pcTNONdNdNON ONOO cb '5 o I ,0 o 2 O r-h I/"* O r4- lf\ lS-\ i i ^^ t^f*\ /^svrt (V^ *^\.<~* (S| (s| QQ y^ |s^ 7 ^ ^5 ob o o o' f^.oo co o ^ M PO ^ M CO M MONPOi-"VO *>M M t^.O O CO CO PO O O POPOM ^O ONrf-PO"-" POO MOO H-tbbbbboNONbNONONON ONOO ob cb do cb l-!n r-in iH|M r-l|M 1-lfM LOO O t^ r-^OO OOOCT> N M M M M M M M M REFRIGERATION IN GENERAL. N'-oooNO'NOO'-'N PO n-o oo " ^* >J-ON ONOO REFRIGERATION AND ICE-MAKING. VOLUME OF AMMONIA GAS AT HIGH TEMPERATURES. (Redwood^) GAUGE PRESSURE TEMPERATURE OF GAS. 60 74 80 84 90 95 VOLUME OF i LB. OF GAS IN CUBIC FEET. 80 85 90 95 IOO 105 no "5 120 125 130 135 140 145 ISO 155 3'470 3-292 3-I3I 3-035 2-900 2785 2-695 2-590 2-490 2-4I8 2-333 2-252 2-204 2-134 2-088 2-037 6iO 500 ill * III H iffto Z Uo 3 til m 2 aso y HSo CO " 00 NHj 1050 Qg 1000 Ul 150 a. qoo . 950 [ \. \ \y \ -i tt $ itf 2 300 1 Z. vxo L. K-00 ' 180 160 31 IIS 2 100 91 Ki = = ; SO 33 150 - ^ 5 S 5oo CO H5J = ^E 5 \ ^ If -> JL50 CO 100 lO 150 \ - tf ^ , J S \ COi * # tO o . - ^ C* 50 . COt o_ n *^, r jj 5= -. * ^ ^. ^- NH 3 *SOv O-30-U-IO 10 lx> 50 . fo 60 70 solo 100 , a c TEMPS. F AH. T E MPS, FAH. FIGS. 19 and 20. Diagrams showing Curves of Latent Heat of Vaporisation (i Ib. each Saturated Vapour), and Curves of Absolute Pressure for Saturated Vapours of NH 3 , SO 2 , and CO 2 , from -40 to +100 Fahr. i Ib. each Saturated Vapour. (Murray, Inst. Engrs. and Shipbuilders, Scotland, 1897.) REFRIGERATION IN GENERAL. 49 aanjBJaduiaj, ;ooj m iad jo O O^sOO ^i 1 OO POOO N OS N N Cl . . _ POM PO O O 1-1 t^ N " PO PO M M >-H M O u-> O Tt- Os }.r^.ppo>o Ot-^POOt^. PO9vpPOOs y->>-.nvp9 Tj-popopop* ^Nww6 bbbb Mill Mill 1I+++ Si* 3 3 / qom bs jad 'sq'i ON Q sO O Th -^- rj- if) if) O ON rrjPO'-i *- PO O ti-O t^LO bs aad sq'j d r^ P< t-^% P4 oo PO Os ^ o vo r>. t~-.oc ooosos OO'-'NM w _<_, NC4MMC4 * O O^OO t^V COPOPOPOPO PONNNM I I REFRIGERATION AND ICE-MAKING. a*a >-O ^ N M i-l ONOO C-.VO LOThPON hi ajn;*jadiuaj. 1 1 1 joqj oiqnD jad -sqj ^o O *-o O ^t* to co M o >-o HI VO I-l I-H N l->- M l^ COOO ut pitibji jo ;q3ja^ ^^^-^-^ ^^^^^ ****? CO, jooj Diqno jad *sqj 00 -5*- O VO N O M ^ LO t~>. c^^^^-S ONOO OO OO OO t^. ON * i PO i-O ut jitodfeA. jo ;qSia_/vi O O ^ O O O o" o"^ *o < Q O O O O O 00000 ooooo ON M inoo I-" CO ON ON ONO 0^8 g^ 2" f gffjf'g jad ptnbi'j jo auin[o^ N N M c* N O O O O ooooo ooooo 00000 00000 ooooo rt *}aaj oiqno 'qj ^- O O M CO r^ PO i^ to o O *-o O t^- ^o LO M OO -sh hi rt-l^ O ON ON OO >-o C< CNvO vo vo UOLO ^h Th ri-po POPO Cl N N M hi OO OO 00 CO t>. vo O ^-oo 01 ^vo ^^^> #S"3<33 'uoiVESUodu^ jo I'eajj RRvg;^^ to LO >-O >-O uo ^H^ vO vo vo VO vo i-^ >-i LO ^^ 'O *^- PO rj-vO ON POOO TJ- N M OO CO ON iO 'ainssajjj a3ivE) """ CO ^t- Tj-u^uo VO vO t-^ t^OO / -qout r^ w too r^ i t vo O *-O ON to ^j- PO ^vo ON COOO ^-N ON 10 O O N bs jad -sqi O O f- *> 00 OO ON ON O N N N C? || 5 coo"c?^r^ M n vo VO hi CO O ^t" *-O Cl '.OO ON * i v ^^^N M O ONOO t'^VO U^Tj-CON hi 1 1 1 REFRIGERATION IN GENERAL. JBSfe O ONOO t^O M 1 LO ^" fO CN| M O w C^ CO ^* 1 + ;ooj oiqriD jad -sqt LO Tf- rt- O O rooo ro O LO >- O O O ON O^^^O u-jQLoO^o ONOO fr* t^ ^> VO *O *O *-O ^~ m pmb;i jo ?q3ta^\. ^-^^^-^- ooooo ooooo m }Ooi Diqno jad 'sqj OO s * w CO ^O t^> CJ\ c^i r^-\O 'o'o o'o'o" ?>- ro LOOO O roLOCO M OOOO I-I (_| >- 1-1 NJ ui anode A jo }qSia^\. b b b b b b b b b bbbbb T-i rOO ON N ooooo ooooo bbobb obobb a, '?aaj oiqnD -qj ro M OO O ro LO ^f~ ON ON ^t* OO LO O O O h-iOO^O^-<^ OOOO^"^ jad anod^A jo amn[OA - O O O O O\ ON O^ ON ONOO 00 OO OO i-i ON 0*00 t^ vO ON ro r^ ** VO ^t" f O ^O ""^ O OO t^ LO ^J" "-" O O ON ON |_O LO LO LO LO OOt^r^OO Lo^-^-roro LO LO LO LO LO *-O LO LO LO LO LO LO *O LO LO >-O LO LO LO LO O O *tf-^- M r^ ro ON LO S"S,LO ^O^-O^O ON ON O O n N N ro * ^ LOO r^i^oo 8 jn S saJ d a*uB + + -* ^ *qoui O O - rj-t^ N ONO LOLO t^. O * O OO ON LO c^ ONO ro "" OO O ro bs jad -sqi U ro ^ LO LONO O t^OO oo ON O >- M ro NMNMN rororororo II LO t^ f-^ LO f-- f^ ON ON ^ ro LONOOOO ONO^oO oo O rft^ON n roo ON rj- . l^>. o o o o ON ooooo ooooo M O >-< LO N PO ON LO M ON ^1-PO N O LOCO NH ONOO ONOO OO ^ T- -3- LO LO LO LO LO VO POw ON -^ c^ vo O PO t^ VO LOLO i*-PO LOLOLOLOLO CN O PO N hH O ON 00 ONO " NOO Op ON PO ^f- LOVO O i ON ro u-> j^ O N LO U-) UO M ONOO O -* N 1-1 POt-- N-^l^i-i-Th OOCJVOO LOVO r-^. ON O I-H PO "^-vo LO LO LO LOO VO VO vO vO ' LTjVO t>-00 ON LOVO t^OO ON ( F fRIGERATION IN GENERAL. 53 j saajSsfi ajrejBjaduiaj, 8M N ro TJ- N N N N + tovo r^oo ON N N W w N + O M N PO Th POPOPOCOPO + 102 ;ooj oiqna jgd -sqi n; pmbji jo ^qSp^ M IO M I-H C\ OO PO I^>. Tj- *->. \O ^O LO 10 rj- N \O ONN -> O rt-0 r< M M ^ ^ ON ON ON fO CO ro CO CO ON ON ON ON ON PO PO PO PO ro ON ON ON ON ON PO PO PO PO PO 02 ;ooj oiqno jad -sqi m anodT> A jo ;qSpAl IH 00 Tt-N O M rd-OO W VO t^t^ t^OO CO t^. t-^ r^vo ON ON PO t->. i-i to OO ON ONO O ON M to ON PO ON td-OO M t^ O -! -i CM M N M M C^ M 00000 00000 OOOOO T/2 'j93j oiqn3 'qj J9d pmbii jb QuinioA O fOt^. ON fO N W M N fO 10 to *-o >-o LO SN N w N O O O VO ON M tOQO PO r^> *$ Th^t- to to to *-O to sssss l-< Tj- 1~^ >-i ^J- to to too O U-) 10 to to to sssss O O O O O ooooo OOOOO /z *;aaj oiqno -qj J9d anod^A jo goin^o^ CO CM LTjOO OO *f-o* O oo t^ 00 l^sO ^-fO O POOO O oo t~-o too to W w O ONOO POCO t^O O O o r~oo o l^O to "3- "!j- ur> tr> u-> i o >-O uo to to ^t- ^d- ^^^^"^ y 'sjitm ^emjaqj 'UOlJBSUodUA JO JB9II ILOCOO OO VO I-H LO ON N O PO w 00 VO PO O rj-t^ i-< to M oo o PO o ON N O O ^** CO N M >-. O ^ThrJ-^rf to >-o ^o LO >-o O ONOO 00 J^ rhfO PO POPO to to to to to vo O to to T*- PO PO PO PO PO to to to to to qom *bs J9d *q{ 'gjnSSgjjJ 9Sni2) tow ONOO O N ro ro <3-O PO ONVO O t^ t~OO O N "* N t^lOtOOO 1^ ON w tooo m^-ioo ~^ f . ro ro fO CO + OO ON - N PO + ri- to t^oo ON + / -qoui DS J9d -sqi 2 VO *-" ONOO O ON O O IH co POONO ^O t^ r}-tot^ ON M N t^. to toOO ^O ON M to t^ ON O <-< N 3- T*-LOU->LO PO-3- to>O OO to to to to to ON O >- PO ^t- toO vO VO O 11 ^^ V -looj bs J9d sq'j OO to fO t^.^O vO M ro M ON N ONO CO VO toco H PO to r}-00 1-1 N t--. ON c>< t^ PO Tj- t^. M O O O LOW t^ ro ON O N rO>-0 sO t^* t^* l^ t^* .00 ON OO ^*- 5S o-nco^ 'i- & J S89J39Q O H- (^ ro -rf- t4 N M M N + too r^oo ON N N N N N + O 1-1 N PO rj- fOPO POOPO + 54 REFRIGERATION AND ICE-MAKING. j saaaSaQ aanjBjadraaj, u-AO i^OO O fO COPO fO ro + O -i N CO rj- + LOO t^OO ON + I/M jooj oiqtiD J3d -sq[ m pmbii jo ;qSi9 A Y o -3-0 o\a\ "^- OM-OOO N CTsOO CO X^. t^. rj- o^ LO O ON CO co ON LO ON O \O LOLO Tt- M r-~ coco * VD HI l^ N CO rl- rj- co co P* CO OO CO CO OO fO fOfO fO rO 00 OO OO 00 OO CO CO CO CO CO OO CO CO CO CO CO co co co CO v }ooj otqno jad 'sqi ui jnodBA jo }qSpAY CO N fOOO 1^ i-t \d 1-1 10 o <-O ro rj- rf >J-> M N M C^ N rj- LO LOVO l^. LOO LOO LO LOO vo r-- x^ N M 0< M M ON co !-- ^J- 1- O O 1-1 ^ M OO 00 ON ONO W N C4 C4 CO O O O O O O o o o o o t/z -jaaj oiqno *qi jad pmbii jo 8uin[o A OO HH rhOO M V) t^, t^l^OO l-O UO LT) LO LO W M M M M O O O O LOCO H-. rht^ OO OO O. ON ON LO LO LO LO\O N M N N M O O O O O JcoO ON M O O O -> O O O O ca M rj M cj O O O O O o o o o o o o o o o o o o o o a '}aaj oiqno -qt jad jnodBA jo aomjoA <3- -rr-r^oo O\ ^4 rOLOvO OO ro N HH o ON LO ONvO LO t^ coo ON ca ONOO t^O O ON COOO M CO LOON M O O LO ^ Tf coco ^^-^-^-co fO coco coco CO coco COCO y -S4iun jBinjaq} 'noi^BsuodB^jo j^ajj OO PO N CNVO t^ HH LOCXD N COONO co O vO ON co r--. HH t^ co O r^- co rt-oo N LO ON ro row >- M ro ro fO fO fO LO IT) VT) ^5 >-O O ON ONOO CO CO N M M N LO LO LO LO LO r-O o LO ^f- N M M M N LO LO LO LO LO qDui -bs aad -qi '9jnssaj. P< OO CO O t^- O O LO ON LO M oo LO M M COIiOVO LO -O >-O LO -O + oo a\ - N TJ- LOLOO O O + LO t~ ON O N VO VO VO t- t-* + Pressure Absolute. / -qont bs aad -sqi N OvOO O\ CO ON N ^O O LO ONOO ON N co C> Tj-ON LO O O t-^ O O LO O Cl ON LO C4 Lor^-oo O "-< N rh LO t^ ON O N CO LO t-~. OO OO OO OO 00 -j -;ooj bs jad sqi t-^ rf LOt-( CO O O i-- ONOO o LOCO co M i-i ONW ON W M rh O - VO t-i O CO *">. CO ON O^ ON ON O rj-vo 00 O co ON ON ON O O -i M ^t-O OO Z'oSZ? LOO 1-1 o co -H ttOO CM O O OO O CO LO i-t >-< CM ^5^O t^OO ON $ o o 8' HH N CO^t- LO 18 LOO t^CO ON a ^ saajSaQ iOO i-^OO ON CO CO co CO CO + O >- N CO ^t- + LOO t~>.00 ON + REFRIGERATION IN GENERAL. 55 J Saa-lSaQ; aanjuiadmaj, O M N fO r}- 1^LOIT)U-)LO + iovO t^oo ON UO LO VO >-O LO + Q M f$ CO rl- \O vo vo vo *O + fm ;ooj oiqno jad -sqj ui pmbji jo ;qSi9j\! vo t^ rj- O I"- <^l VO C4 CO f^) d _ _, o O Tj-VO CO LOCO ON co ON co ON ON ONOO OO t^ \O OO M ON CO cor-- n r^ M j>vo vo LO LO CXD 00 OO OO CXD fO fOcrjfO fO CO CO CO COCO co^Joc^c^ nz ;ooj oiqriD jad -sqj in jnodB A jo qqSia^V Tj-fO M 00 O OO -<*-O LO M O 1-1 M N CO CO fO ro CO CO O N LOOO w OO ^- O VO CO CO ^ LO <-O\O CO co co CO co r^ M -t oo co ONVO co O^vO \O t-CO OO ON CO co co CO fO 00000 00000 O O 1/z -jaaj oiqtiD qj Jad pinbii jb aum[o A vO O PO^O ON i M M W W VO ^O ^O *O *O sssss M VO O~> COO w <^-OO -i LO vO O VO VO O N W M M (M O O O O VO vO O vO vO N N N cq M o o o o o 00000 00000 00000 tt *}aaj oiqno -qj iad JnodBA jo amnio A N N -^t- ON N ^-OO N VO t-i C4 M hH O O CO LO CO N CO LO O LO O LO ON ONOO OO l~>. uooo O LOO O LO ** VO M t~-VO O LO LO fO coco rorO c< ci 01 cs M O O M O N if 'S^jun ^Brajaq; 'aoi;Bsu6d-B^jo ^ajj O O co OvO co^O O coi->. M OO Tj- O ^ M ^OO M LO co ON LO HH r^ ON N -O O co rj- coco N M - O ON ONOO 1^ ^-O VO LO 10 LO if) LO IO LOLOLOLOLO O LO LO LO LO qoui 'bs jad 'qj 'aanssajjj] ^Sme^) vO O ^O 10 t^ M O f~~- ^ CO N O O rt-0 ca t-i o ON ON OM-I VC LOvO OO ON ONO -" ^-O r- O\ M t~- t^ t^. 1^00 + COLO t^OO O CO 00 00 OO ON + N rt-sO ON 1-1 ON ON ON ON O + f 'qotn bs jad -sq^ B4 vo O v> ir^r-, ONt^ ^l-W O N O O r}- O ONOO t>.O O ON *4 VO LOO LOO ^0 t-.oo 00 ON ON ON ON t->. ON >-> CO'LO ONONO O O t -. ON >-> co LO o o M HH _ P *< W ^ooj bs aad sq'j l-i M CO N 1 ^- ON N ^->^O r^- M OO 00 OO t^. ON ON c^ ON co t~- IH LO O W O LO J^- ON O -3- N rt- O OO i- r^ CO CO O CO W)OO O CO co co ^O 8O LO covO 1"~. Tj- N O H- co O ON N Tf Tf *f rt- LO CO 'tf-ON ON CO ONOO t~- t^OO ef 1^ O COO LO LOO o o 'J. -9;niosqv 3 "rt ? O M N fO^- VO 9 LOVO t^OO ON LO $ o M N ro rt- M LO & s .j saaaSaQ O "-1 N CO '* u-> 10 vo ^O LO + lOvO t^OO ON UOLOLOLOLO + O HH N CO "^ O O O vO O + REFRIGERATION AND ICE-MAKING. ;ooj otqno aad -sqj a; pmb;i jo jqSp 00 COOO cococococo fOcocococo - OM ON ;ooj Diqtn ja ui anodBA jo -sqj OOOOO OOOOO i/z *j8aj otqno 'qj aad pmb;i jb suinio co M LOOO w O ON co i^ O O *^ 1^* t^OO OO OO ON ON O OOOOO OOOO*^- ssssp 88888 bbbbb bbbbb 00000 ft ";o9j oiqno 'qi aad ro s . t-i O lONLON OOLOHlCNLO MHIHI pOOONON C4 M M M Q\ ""> M < O -3-OO O\ TJ-ON. ^- O\ W vo O> coo co >.o o t-n O O O O - qom 'bs wd -qj -mm sq'j COOO COCOON ONrJ-O'- 1 '*' NNO^LO O HI COO OO HiLOQ\cot^ Mt^-.NOO'^- bs aad OQLOO-Hi COOi-HNN OOLONIO LO *^> 7*"5 ) p v^Pr'r^r* HIOOOOOOO h HI M CO Ol LOO HI M OO Tt-OO W t--. CO ONO CO O ON N O O\ COO O ^-OO OOONONO\ OOHIHIHI O\ O M Tj-t> ON rO\O ON W VO t~>- t^> *^OO cB ir,^O t^OO ON LOO t^*00 ON O ^* W CO *^" LOO fr^OO ON REFRIGERATION IN GENERAL. 57 J S99J^3(J aanjuaaduiaj, oo oo oo oo oo CO OO 00 00 00 O i-i M ro rh ON ON ON ON ON ?ooj oiqno jad -sqj MVO t^fO ON vo ON vo O rh t~vO vO vo vo SS,= CO ONVO rj-vo VOM VO , ui pmbji J ?^! 8 A\. vO vO vo vO vO to ro rO ro CO vo vo vO vO vO VO vO vO vO O m ;ooj oiqtn aad -sq\ vo ^t- N cooo O ONOO *> vo W N corhio vo vo vo vovO O ON t^CO OO CSJ H-l I-I I-I t-l i-i Cl CO ^ vo vo VO vo vo vo ut anodB A jo ^Bp^ O O O O O 00000 00000 HI voco N vo CO ^ ^ vO vo CO i-i vo ON N vovO VO vO 1^. iad pmbi'j jb 8uin[o^ M M C4 C4 O O O O O SN CJ C4 N o o o c o o o o o o o o o o 00000 00000 a 'jaaj DtqtiD 'qj jad JtiodiJA. jo 9tun[OA. M OO vo ^ ON ONOO OO OO r^ t^* ^f i 1 OO ^O CO O OO VO CO VO VO vo vo vo voO0 >-> voO vo O 00 i-i >-000 N vo ON Tf ON ** VOOO M vo ON .4wurs H o o o o o vo vo VO vo VO O O O O^ O^ tO u-> LO ^- ^J- ON ON ON ON ON O OO O vO v* Tj- O OO VOCO ^O^^oVi? N ON ON ^t 1 CO CN ON O N ^J- qout 'bs jad *q| 'ojnssajj aSnBQ ON C4 rf- t^ O COO OO i-i ^J- vo vo vo'O VO ^"R^I^O? + M M + + OOO O VO LO CO vovO i-i ON OO t*vO vO ""> N ON ON rf-co vo vo t^ ON-I bs jad 'sq^i VO vO vovO VO ". CO OO 00 ON ON 11 bs jad 'sqi lOi-i OO 00 " HH VOCJO COCO b vb ob vo i^. ON t"vO vO O 1 t vo ON CO t^ I-I N O VO Tt- vp ONCO M ~ iocb f- N N (-1 vo O ^OO Tj -* vo vo 'O CO CO VO COVO OO OO vo ^j- N t^ ONVO ONOO ON cooo CO ON a t-~ I-H vo O vo o *^* t^oo C4 M M N N | ,,n^ V O VO Q_M N fO^- VO vo vo vO Q I-I CO ^*- vo vo | . salasa OO 00 OO 00 OO voO t^OO ON oooooooo oo O " M CO rj- ON ON ON 0^ ON REFRIGERATION AND ICE-MAKING. x'-v 1 T < s o 1 < 1 h I ^C/3 b I j saaaSgQ sjmjuiaduiaj, ON ON ON ON ON M T/ }ooj oiqna Jad 'sqi u; pmb'ji jo }q3ja.Al rr> M ONM ON Sl^ 1-1 OO M ONONOO oo 00 ro ^O *-O to lO to CO fO ro CO CO ;ooj cnqno jad -sqj uj anode^ jo ^qSia^vV ^sO r^OO ON O b b b b b b la, -jaaj oiqno 'q^ jad pmbt'j jo 9uin[O^Y oo999 b b o o o p a, ';9aj oiqno -q^ jad jnodB^ jo auinfo^ O "O ro N ON I-H OO vO rt- w ^N ro y *s^iun iBnijaq? O\ ror^ N O M vO ON coo lO Vh CO CO N O ON s ON ON P ON <3- ;s IO N * O\OO vO ON M to ON i" C4 00 OO CN ON ON + -i bs aad sq'j 10 M rfCNOO M->\O O\ M *O M OO 1-1 'J-OO i-* ^SS^ M O o en bsaad-sqi S^JoS> 00 1 roro O fON \O fO M ONOO vo O >-O ON ^*- 00 ON ON ON O Temperature. *4U *O 1 V vrjvO t^OO ON O ON ON ON ON ON REFRIGERATION IN GENERAL. 59 CO < ~ ll M W I ^> 8 S % H 5 W o v* HH $H w g S 0> OO O ^OO 00 PO T*- to ~ t^ POOO 1^ -^t- 2 M LO O POOO ^- O VO PO ONOO i-- I--O C^ PO PO CO vj~ LO LOO O l^CO ON O 8 8 POrOW NOO CTNi-HOO LOi-OO t^O 2 I ^ LO *"* Tt" ON ^~ O *^ PO O ONOO OO t~^ .5 '5 ^ rt oo ON ^~oo *^ *^- w to ON ON c-j i^> to ON LOO LOO PO LO t~* ^ P^ O ONOO t^ B 3 sr b w PO PO PO ^- to too rtoo oo ON O E & P. J3 00 ^-> VO t^ ONO O POOO I~>. ONO OO N i- rf- OO ONO^H-iOO O POM OOO l^ONON & d - H bo a W PO PO ^J~ ^t" LO LOO i^^OO ON O O .H 1 3 3 o *> O *^~ ^f" ^^ PO ^h O oo w POOO i^ ON -i PO PO LO POO O OO OO t*-* O ON O 8 j M PO PO -^ ^J- LO LOO r^OO ON O "- 1 1 5 b J 55 rt- o Mt^n o woo ONONPOPOrt- ^ t-. t^ ONOO WO LOLOLOO O N B I* B o u O M LO O O PO ONO PO N W PO N M PO PO ^ ^ to LOO t^OO ON O *-" H . K c 'd c > t^ O ^H r^- PO t^ w c^ P**. ^ LO O PO Hi O POO *** t^^ PO O i^* *=d- PO PO ^" PO M PO PO ^ Tj- LOO O t~00 ON O N o U in 1-1 Ooo -h*-i Mi--.t^N O ^t-torj- O ^- ^oo oo POOO ON HH PO to >-i LO " N PO PO sh ^ LOO O r^oo ON O - 50 *5 o rf-o oo-icoo < oootoO'- r^ r->. r^ ON *. ON NO O >-O M M ON t> II O ^i" ^ ^*^O M ONO OO T|-ON O O M ON M ON N t^ -t- rOOO rocb >-> 1-1 l^ 6 00 co H4 N 1-1 t- ONVO i- 1 N vQ O C^IQO t^ O 1-- ON " M O M3 l^- 'sJ'vO ooi-| MM coi-iH3 10 M M m ^3- toco *^* O *o c* 1 rj-oo O op >ot-. -" OO N P O fO ONOO N C* ONO ^-VO co O N rt- ON t-^ M vo HH MI coco vb r>. CO r}- -3-00 OO ON N rh VO OO M O HH CO COOO r^. LOCO oo LO I-H o ri- ro O O T*- ^f vO 1-1 CO co*^ co N M I-H W pcj H o ?i - P4 PM^tH Temperature of refrigerated brine j Q^^ Specific heat of brine (per unit of volume) guantity of brine circulated per hour, cubic old produced, B.T.U. per hour . . Temperature of cooling water in condenser Quantity of cooling water per hour in cubi Heat eliminated by condenser B.T.U. per I.H.P. in compressor cylinder I.H.P. in steam engine cylinder . . Consumption of steam per hour in Ibs. ( Per I.H. Cold produced per hour B.T.U. { Per I.H. ( Per Ib. c 62 REFRIGERATION AND ICE-MAKING. in o o c/2 fc O a 1 2 " l * H MS ei H o oo ONWU-JN t-vot^O ro *-^ M ^ ro LO O PO ^* M i^.vO O r~^ ON ^t- w^^raror^Tj-p-iOM^Loroi-i ^-rOC-ii-i>-ippOpp b b b b b b boob bob O ^- O O 00 00 vO O N O N \O vO '-oo ^oo c^ op p t^bob r^ob b O ON N N O t^ 10 0^0 CO NO tv. LO Q\ O ' ^- ON o N (7\oo I I REFRIGERATION IN GENERAL. o a I i l4i -bg * .N O LOON^-fOLOt^tO^t^CNM H.Mi-iUOMWLO^'^-Ot^'^-NOaN 2 o a ill "jjH o 3 p O COOOOVOUO^i-COMNNWMI-lt-l O c ri^ 's.2 1 * .Mvo Q\w N M LOOO O N -^-VO OO O HI CO Tt- uo 1^00 C^i ^Cd^ ^ H rO ro ^d" ^" T ^" ^" ^i" *-O *J^ 1 O ^-O w^ to f) *-O S'S W PQ 11 |3 O 'OC^N POfO>-*OO rOI^^O OvvO N C>i OOO OO ^*O toro^ Ooo r^.Tt-ci O I" 8 ! 1 " H vb Tj-M Ocbvb rf-N OCXO ioroh-i Qsf^ r^. t-~. r^ t-~.vo O vO vo vo LO 10 to LO rh TJ- 3 1 fQ 3 S 3 ^; u J-rJ-S ID O O u-> oo LOfOOt^LOMOM LOOO >-> POO O\ M gl&r* ^ 00 gua W2 H K C\O rO ON^O fO O fO^O O"^ POO ON M O M HH 1-4 1 I 1 1-1 HI M M M III' lid w+S b h-j_.-2 |D ^ rt- Tt- PO O O i-< ^000 O ON OM^ rt- O Tj-O CO O M PO i-OVO t~>. ON C\ O *-" N PO llj^ H r^OO CN *H N CO ^h >-OO t-^OO O M N ro 1O LO IOO OOOO OOOt-^t^t^t^. *! P J.. l^- s . $ O PO t^O ** - POOO 10 PO >-< OO ^J- M LON N i^.f^.PO l O-^-N O\O PO POO PO ^ 5 " CL ?H LO t^. ON >H -^-00 N r^ PO O\ t^\O O t^ O i-ii-itHNC^roPOTf io\o t^ a\ u ri llr l w d gv* 1 i N fO^LO^PON 1-1 O ONOO t-^vo vo rf. r <- i M M PO "4- LO too r>.oo LorOOvO NVOOOO rO^ CXD rO^.- o O LO 1 ?^P9 828*? B pinbi'j 800 O O N v N OO 10 Tf t- O i- w rt-O ob >-> ro^C Q r*. N TJ-O OO 00 ro LO ^ O N H4 (s| N N N qom aJBnbs jad sqi'ui eunss.u j ro LOCO N ^ ri- ro 'd-OO Tf LO ONTO N OOOO ri-N OOOO TfN OOC CO LOO OO O N ^-LOt^.Ol'-' ro Tj- 66 REFRIGERATION AND ICE-MAKING. The following particulars regarding an ether machine are given * by Mr. Lightfoot as being the result of actual experiments made in this country, and serving to show what may be expected under ordinary conditions : Production of ice per twenty-four hours ' . . 15 tens. ,, ,, per hour . . . . . . 1,400 Ibs. Heat abstracted in ice-making, per hour . . 245,000 units ** Indicated horse-power in steam cylinder, excluding that required for circulating the cooling water and for working cranes, etc. 83 I . H . P. Indicated horse-power in ether pump .. 46^ I.H.P. Thermal equivalent of work in ether pump, per hour 119,261 units** Ratio of work in pump to work in ice-making I to 2-05 Temperature of water entering condenser 52 Fahr. Mr. Frederick Colyer, C.E., M.I.C.E., states t that he obtained the following results with a first-class apparatus when testing the working of some of the leading ether machines, viz. : " In an ether machine made by Messrs. Siebe, Gorman and Co., capable of cooling 3,200 gallons of water from 60 down to 50, or abstracting 320,000 heat units** per hour, the average experiments gave 4,250 gal- lons per hour cooled to 10 Fahr. The temperature of the water at the inlet was 54, and that of the water used for condensing purposes was the same. The maximum cooling effected was 449,437 heat units** abstracted per hour, being from 35 to 40 per cent, above the nominal power of the machine. The condensing water used per hour was 1,262 gallons, or about 3-ioths of a gallon for every gallon of water cooled. The coal consumed was 3-5 cwts. per hour; it was of indifferent quality, or the consumption would have been smaller. The steam cylinder was 2 1 in. diameter and 27 in. stroke; the air-pump 24 in. diameter and 27 in. stroke. The speed of the engine was 58 revo- lutions per minute, with 48 Ibs. of steam cut off at one- third of the stroke. The indicated power of the engine was 53 horse-power, and of the air-pump 29*2 horse-power. The boiler was 7 ft. diameter and 24 ft. long, and gave an ample supply of steam." * " Proceedings, Institution of Mechanical Engineers," 1886, p. 214. ** A thermal unit is that amount of heat required to raise the tem- perature of I Ib. of water i by the Fahr. scale when at 39*4. t " Proceedings, Institution of Mechanical Engineers," 1886, p. 248. REFRIGERATION IN GENERAL. EFFICIENCY OF ETHER MACHINES. Output of 15 tons of ice in twenty-four hours. Ab- straction of heat per hour, 245,000 B.T.U. Indicated horse-power of engine, 83 ; of which 46 I.H.P. was used for the ether compressor, balance in pumping water, work- ing cranes, friction, etc. Temperature of cooling water, 52. Ice production, about 8-3 tons of ice per ton of coal consumed. PICTET'S LIQUID. Temperature Degrees Fahr. Pressure (Absolute) in Atmospheres. Temperature Degrees Fahr. Pressure (Absolute) in Atmospheres. 22 0-77 50 2'55 !3 0-89 2-98 -4 0-98 68 3-40 2'2 5 I -00 ri8 11 3-92 4'45 14 !'34 95 5-05 23 i -60 104 572 3 2 1-83 "3 6-30 4* 2 -2O 122 6-86 FORMULA FOR CALCULATING THE AMOUNT OF AIR DE- LIVERED PER HOUR BY COLD-AIR MACHINES, WHEN THE REVOLUTIONS AND THE SIZE OF THE COMPRES- SORS ARE KNOWN. (Haslanfs Catalogue of " Ice-mating and Refrigerating Machinery.") A X N X 2R X S X 60 1728 xc Air discharged per hour = Where A = area of each compressor, in inches. N = number of compressors. 2R = strokes per minute (or twice the revolutions). 60 = minutes per hour. S = stroke in inches. 1728 = cubic inches in one foot. C = factor of efficiency which is taken as o'8 for short strokes, and 0*85 for long strokes. SECTION II. COLD STORAGE. COLD storage may be defined as the preservation of perish- able articles by keeping them in rooms or chambers maintained constantly at a low temperature by refrigeration ; and refrigeration may be denned as the maintenance of any place at a lower temperature than that of the atmosphere. A most important point in the construction of a cold store is the insulation, and it is almost superfluous to observe that the aim is to render this latter as perfect as possible, so as to afford as great a protection as is practicable against the escape of the cold air from the interior and the transmission of heat from the exterior. The refrigeration of cold stores may be carried out on the brine circulation system, the direct expansion system, and the air-blast system. In the first, refrigerated or cooled brine is circulated through cooling pipes, or their equivalent, arranged in the cold store ; and in the second the ammonia or refrigerating medium is allowed to expand direct in the above pipes. In the third, or air-blast system, air reduced to a low temperature by passing it over cooled pipes or surfaces, or by means of a cold-air machine, is admitted to the store. The dimensions of cold stores vary, from that of a few cubic feet space, such as those in private houses, hotels, butchers' shops, etc., up to those of several millions of cubic feet. In the case of a large store it is found most advantageous to arrange for the delivery of goods to or from the store to take place from the highest part of the building, as by this means greater obstacles are offered to the transmission of heat from the exterior to the interior COLD STORAGE. 69 of the store, and also to the escape of the cold air there- from, which latter, owing to its being heavier than the sur- rounding atmosphere, and to its consequent tendency to sink to the lowest level, will not escape from above, whilst it does so readily from any open aperture at a lower level. AMOUNT OF REFRIGERATION REQUIRED. The refrigeration required will be governed by the size of the store, the amount of and frequency with which the goods are brought into the store and removed from it, the temperature of the goods, and their specific heat, the mean external temperature, the greater or lesser perfection of the insulation, and various other matters, which render it totally impossible to lay down any hard-and-fast rules. A very usual practice is to provide i foot run of 2-inch pipe for every 7 cubic feet of space contained in the store, but sometimes the proportion used is as much as one to five, whilst again it is occasionally reduced to one to twelve. For refrigerating meat, in which case it is not desirable to cool the exterior too rapidly before the interior has had time to cool to a certain extent, the best proportion to employ is one to ten. AMOUNT OF REFRIGERATING PIPES NECESSARY FOR CHILLING, STORAGE, AND FREEZING CHAMBERS. Chilling-rooms or Chambers, refrigerated on the direct expansion system, i ft. run of 2 -in. piping for each 14 c. ft. of space ; on the brine-circulation system, i ft. run of 2-in. piping for each 8 c. ft. of space. Freezing-rooms or Chambers, refrigerated on the direct expansion system, i ft. run of 2-in. piping for each 8 c. ft. of space; on the brine-circulation system, i ft. run for each 3 c. ft. of space. Storage-rooms or Chambers, refrigerated on the direct expansion system, i ft. run of 2-in. piping for each 45 c. ft. of space ; on the brine-circulation system, i ft. run of 2-in. piping for each 1 5 c. ft. of space. REFRIGERATION AND ICE-MAKING. THE FOLLOWING TABLE GIVES THE EXTREME LIMITS OF CUBIC FEET OF SPACE PER RUNNING FOOT OF 2-iNCH PIPING. American Practice. Breweries Medium insulation. Chip and Stock Rooms Fermenting and Settling Rooms . . Packing Rooms Hop Rooms Packing House. Chill Rooms for Beef Hogs Freezing Rooms , Cold Storage. Cold Storage Rooms. . Cold Storage House and Freezing Rooms . For Eggs, brine preferred Cold Storage Ice Storage Fish Freezing (Direct Expansion) to 22 20 18 25 12 10 6 or or 30 12 25 2O 2 The following five tables are given by Prof. Siebel in the " Compend of Mechanical Refrigeration" LINEAL FEET OF I-INCH PIPING REQUIRED PER CUBIC FOOT OF COLD STORAGE SPACE. vpl 1 08 TEMPERATURE, DEGREES FAHR. K lll 3 p Hi o , IO. 20. 30. 40. 50. TOO Excellent. 3-o 1-78 0^8 0-36 O-24 0-15 Poor. b-o 1-50 O-9O 0-66 0-48 0-30 1,000 Excellent. ro 0-26 0-16 O-I2 0'08 0-05 Poor. 2-O 0-50 0-30 0-22 0-16 o-io 10,000 Excellent. 0-61 0-16 O'lO 0-075 0-055 0-035 30,000 Poor. Excellent. 1-2 0-13 0-20 0-08 "I 0-06 o-ii 0-040 0-07 0-025 100,000 Poor. Excellent. i-o 0-38 0-25 o-io 0-15 O'O6 O'H 0-045 0-03 0-03 0-05 0-009 Poor. 0-75 O'2O 0-12 O-O9 0-06 0-018 NOTE. The above quantities of pipe refer to direct expansion, and should be made one and one-half times to twice the length for brine circulation. To find the corresponding lengths of i^-inch pipe, divide by 1*25 or multiply by 0-8 ; of 2-inch pipe divide by 1-08, or multiply by 0-55. COLD STORAGE. 71 NUMBER OF CUBIC FEET COVERED BY ONE FOOT OF I-INCH IRON PIPE. JTf jj "8 *>- 2.s*g .2 15 TEMPERATURE, DEGREES FAHR. .22;s w-s^S mOg i 3 1 0. 10. 20. 30. 40. 50. 100 Excellent. 0-3 i'3 2'I 2-8 4'2 7-0 Poor. 0-15 07 I'l **5 2'I 3'5 1,000 Excellent. 1-0 4-0 6-0 8-4 I2'4 20-0 Poor. *5 2'O 3'2 4*5 6-2 IO'O 10,000 Excellent. 17 6-0 IO'O 13-0 18-0 28-0 Poor. 0-85 3-0 5'0 6-5 9-0 I4*O 30,000 Excellent. 2'0 8-0 14-0 18-0 25-0 40-0 Poor. I'O 4-0 7-0 9-0 13-0 20-0 100,000 Excellent. 2'6 IO'O 17-0 22-0 33'0 IIO'O Poor. i'3 S'O 8'S I I'O 17-0 55-o NOTE. The above figures refer to direct expansion, from one-half to two-thirds of the spaces only would be covered by the same amount of pipe in case of brine circulation. To find the corresponding amounts of cubic feet of space which would be covered by one lineal foot of i^-in. pipe, multiply by 1-25 or divide by 0*8; of 2-in. pipe, multiply by 1-08 or divide by 0-55. NUMBER OF CUBIC FEET COVERED BY I-TON REFRIGERAT- ING CAPACITY FOR 24 HOURS. sfll c TEMPERATURE, DEGREES FAHR. .32-- *3 WO H s 0. 10. 20. 30. 40. SO - 100 Excellent. 15 600 800 1000 1600 3000 Poor. 70 300 400 600 900 2OOO 1,000 Excellent. 500 2500 3000 4000 6000 12000 Poor. 250 1500 1800 2500 5OOO IOOOO 10,000 Excellent. 7OO 3000 4000 6000 9000 18000 Poor. 300 1800 2500 3500 7OOO I4OOO 30,000 Excellent. 1OOO 5000 6000 8000 13000 25000 Poor. 500 3000 3500 5000 IIOOO 20000 100,000 Excellent. 1500 7500 9000 14000 20000 40000 Poor. 800 4500 5000 8000 I600O 35000 REFRIGERATION AND ICE-MAKING. 000000 t'tOTf-fOONV IO ^ fO N t^ - G-ao M" PO *r o 00000000 Tt-loOOtoOOiO ^ t^ ^-\Q OO OO O M M to 6" fo t^oo" N~ T? to oooo l^OOO-tf- O- f^VO ^- oooooooo ^t-vO t^ HI t*v Q^ w ovO O fOOO ^Ow\O^-Ot^ oooooooooooooooooooo OO-rOOioOOOOOOOtoOOiOOOtO to O CN O M vo tooo ^-OOOfOt^OOt^-Otow M" ro fOvo'od' O o" O" M" cT M" rood" M" r? tC rC O~ M" oT H cf ef^tCoo cRdJdJo- o M toco o o M toco o cpjfvo O ^- O; 0; r. O to\o" oooooooooooooooooo ^OvOr^OOO*3-OOOroioOOtoOOiO O<,JX> \O ro TJ-OO^ C^NM^OO'J-N^OO^^fO M" co rf lOvcT \O~vo" t^ tCoo" w" ^ r?vO~vo"od I oo' O^ o . - 4J ^ OJ u. -" ^ai *5 *** 8S ig 3 ro^J-O O^OO c^vo'O ^ O O N oo r rONNWMWMh,MH OOOO M b b b b b b b b b b b b b b b b b b b i-T o" o" o" o o' o o o o o o o" o" o" o" o" o" MN^to^OOOOO 8800000 am 5 ^sssssssssss 8,s-g,v8 <2 as xxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx ">28 5-^^8888888888 COLD STORAGE. 73 ROUGH ESTIMATE OF REFRIGERATION IN BREWERIES. A ready method of obtaining a rough estimate in tons of the amount of refrigeration required in a brewery is to divide the capacity of the brewery in barrels by 4. REFRIGERATING CAPACITY IN B.T.U. REQUIRED PER CUBIC FOOT OF STORAGE ROOM IN TWENTY-FOUR HOURS. iP! I ' TEMPERATURE, DEGREES FAHR. .S2'5 o 3 Icj I 1 0. 10. 20. 30. 4 o. 50. 100 Excellent. Poor. 1, 800 4,000 4 80 9 60 480 284 470 1 80 330 95 140 1,000 Excellent. Poor. 550 I,IOO no 190 95 165 70 1 10 47 55 3 ro,ooo Excellent. Poor. 400 900 95 1 60 70 no 47 81 30 40 16 20 30,000 Excellent. Poor. 280 550 55 95 47 81 35 55 22 26 II 100,000 Excellent. Poor. 190 350 11 30 55 20 35 18 7 4 VARIATION IN CAPACITY, ETC., OF A REFRIGERATING MACHINE. The following diagram (Fig. 22) and table (on page 75), showing the variation in capacity, etc., of a refrigerating machine, and the economy of direct expansion, is drawn up by the De La Vergne Company : 74 REFRIGERATION AND ICE-MAKING. 40 35 30 25 2O M IS SS SI 4S 39 33 10 24- 25 45 -5 -10 -13* 16 13 9 ff FIG. 22. Diagram showing Variation in Ca Required of a Refrigerating Machine. ity, Cost of Fuel, and Work La Vergne Company.} In the above diagram the line marked "capacity of machine " shows the diminished capacity as the back pres- sure is reduced. If the machine has a capacity of ten tons at a return pressure of 28 pounds, as shown by vertical height of the curve, it has a capacity of five tons only with a return pressure of six pounds. Under the same circum- stances the cost of fuel per ton is increased in the ratio of the vertical heights to the curve marked " cost of fuel," namely, from 14-5 to 25. In other words, the cost per ton is nearly doubled while the capacity is halved. The work, as seen by the curve marked "work required," diminishes very slowly. COLD STORAGE. 75 This shows very plainly the economy of direct expansion. The ammonia in the coils of the brine tank must be cooled below the brine or the directly expanded ammonia. If the difference be 10, say 5 instead of 15, then the capacity of the machine is reduced in the ratio of 10 to 8, or 20 per cent., and the cost for fuel increased in the ratio of from i4'5 to 17*5, or 20 per cent. These are physical facts which cannot be explained away, and the economy of direct expansion in practice over both brine and air circulation is usually greater than the diagram and table illustrates. CUBIC FEET OF AMMONIA GAS PER MINUTE TO PRODUCE ONE TON OF REFRIGERATION PER DAY. CONDENSER. P 103 US 127 139 153 1 68 185 200 218 P t 65 70 75 80 8 5 90 95 100 105 . 4 -20 5-84 5'9 5-96 6-03 6-09 6-16 6-23 6-30 6-43 o 6 ~~ I 5 5'35 5*4 5'46 5-52 5^8 5^4 570 577 5-83 H 9 -10 4-66 473 476 4'8l 4'86 4-91 4'97 5-05 5-08 13 -5 4-09 4-12 4-17 4'2I 4^5 4.30 4*35 4-40 4*44 16 o 3'59 3*63 3;66 370 374 378 3;83 3-87 3-9I 20 5 3-20 3' 2 4 3-30 3'34 3-38 3'45 3'49 w 24 10 2-87 2-9 2'93 2*96 2'99 3-02 3-06 3-09 3-12 28 15 2-61 2-65 2-68 271 273 276 2-80 2-82 33 20 2-31 2'34 2-36 2-38 2-41 2'44 2-46 2'49 2-51 39 25 2-06 2-08 2'IO 2'12 2-15 2-17 2'20 2'22 2-24 45 30 1-85 1-87 1-89 1-9! 1-97 2-00 2-01 35 170 172 174 176 177 179 1-81 I-8 3 1-85 DETERMINATION OF MOISTURE IN AIR. (Siebel.) The moisture in the atmosphere may be determined by a wet-bulb thermometer, which is an ordinary thermometer, the bulb of which is covered with muslin kept wet, and ?6 REFRIGERATION AND ICE-MAKING. which is exposed to the air, the moisture of which is to be ascertained. Owing to the evaporation of the water on the [ muslin, the thermometer will shortly acquire a stationary temperature, which is always lower than that of the surrounding air (except when the latter is actually saturated with moisture). If / is the temperature of the atmosphere, and / x the temperature of the wet-bulb ther- mometer in degrees Celsius, the tension e, of the aqueous vapour in the atmosphere, is found by the formula e = -OO ^OO^O^OO t-^.r-^t~>. 1-1 N co * r*- LO uoo r^OO ON <^ O ! t^ r^. t^ r^.oo oo oo oo oo oo oo oo oo N co <*- -^- ^h LOVO vo vO t-~ i^oo oo oooooooooooooooooooooooooo REFRIGERATION AND ICE-MAKING. The hygrometer of Professor Marvin is a sling psychro- meter of improved construction. HYGROMETERS. While the term " hygrometer " applies to all instruments calculated to ascertain the amount of moisture in the air, it is specifically used to designate instruments on which the degree of humidity can be read off directly on a scale without calculation and table. Their operation is based on the change of the length of a hair, or similar hygroscopic substance under different conditions of humidity. Table giving weights of aqueous vapour held in sus- pension by 100 Ibs. of pure dry air when saturated, at different temperatures, and under the ordinary atmospheric pressure of 29^9 in. of mercury. (Box and Light/oof.) Temper- ature. Weight of vapour. Temper- ature. Weight of vapour. Fahr. Fahr. degs. Ibs. degs. Ibs. 20 0-0350 102 4-547 10 0-0574 112 6-253 0-0918 122 8-584 + 10 0-1418 132 II-77I 20 0-2265 I 4 2 16-170 3 2 G'379 IS 2 22-465 4 2 0-561 162 31*713 52 0-819 172 46*338 62 I-I79 182 7I-300 72 1-680 192 122-643 8 9 2-361 202 280-230 92 3-289 212 Infinite N.B. The weight in Ibs. of the vapour mixed with 100 Ibs. of pure air at any given temperature and pressure is given by the formula 62- 3 E _ 29-9 29'9-E / Where E = elastic force of the vapour at the given tem- perature, in inches of mercury (to be taken from Tables). / = absolute pressure in inches of mercury. = 2 9' 9 for ordinary atmospheric pressure. COLD STORAGE. 79 CORRECT RELATIVE HUMIDITY FOR A GIVEN TEMPERA- TURE IN EGG ROOMS. (Madison Cooper.) TEMPERATURE IN DEGREES FAHR. RELATIVE HUMIDITY PER CENT. 28 80 2 9 78 30 76 31 74 32 71 33 69 34 67 65 36 62 37 60 38 5? 39 56 40 53 SPECIFIC HEAT AND COMPOSITION OF VICTUALS. Water. Solids. Specific rleat above Freezing Calc. Specific Heat below Freezing Calc. Latent Heat of Freezing Calc. Lean beef . . 72-00 28-00 0-77 0-41 102 Fat beef . . 51-00 49-00 0-60 0'34 72 Veal 63-00 37-00 0-70 0-39 90 Fat pork . . 39-00 61-00 0- 5 I 0-30 55 Eggs 70-00 30-00 0-76 0-40 IOO Potatoes . . 74-00 26-00 0-80 0-42 105 Cabbages . . 9I-00 9-00 0-93 0-48 129 Carrots 83-00 17-00 0-87 o-45 118 Cream 59^5 3075 0-68 0-38 84 Milk 87-50 12-50 0-90 0-47 124 Oysters White fish .. 80-38 78-00 19-62 22-00 0-84 0-82 0-44 o-43 114 in Eels 62-07 37-93 0-69 0-38 88 Lobsters 76-62 23-38 0-81 0-42 108 Pigeons 72-40 27-60 0-78 0-41 Poultry 7370 26-30 0-80 0-42 80 REFRIGERATION AND ICE-MAKING. I s 5 *' 6 3 ^ a I a S I s ii i! 1 S> | | 3-co^ 3- co 1133- 3-2" | S COJ-co So N LO o> c M i i TTi $\ \ i i i i i 1 1 1 1 1 1 1 CO co "a-dS VO ^0_ 8, O Ui 1 i 1 i 1 31 i I I I 31 O 1 *-O 1 -O O ^o W cfl fO O M co vO CO "tf- co co co c^ ^ g V> >-0 N CO u'cf.S 1 1 1 1 Ul 1 1 I 1 31 N O CO MINN ^J CO Th co co . ONLO to "w O i Toi i ^.^^TTTi i x N t^.O CO CO CO i To i <*> i rj - 1 1 N 1 CO 1 CO N CO .J VO "> >-O IO CO co CO N JB Ml 1 ||*l 1 1^1 U CO CO CO CO . M VO N 10 1 T^i i i$Ti i i T3i co d- CO i Ti i i i i co co co co 3, 33- 3- i- B 1 1 1 1 1 311 1131 N ON CO VD CO "3- CO co CO 5J- 1 CO CO ^ co c^ ; o 1 1 | 1 ||| , ||j. i.iijl. COLD STORAGE. 8l a M 1 II NOO|NN NiOCO|OONiOOOO|OOt^r*-|O'-O| |OO 5? S M 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 OO Y 1 d 3 fO O O to O O 3 o S2!? Scjo -i M u-> CO | 1 tO 1 to j 1 | I to 1 1 1 1 1 to 1 1 1 | 10 CO rollco 1 O I 1 ) I U> 1 Illrolllico C^ IO ^^" f*O *-O *JO r ! 3 T3 2 Tj-CO O >0 O < $ 9&d .2 ^~ T^l 1 Tl 1 1 1 1 1 1 1 1 Tl 1 J 1 1 31 5-1 1 1 o "S5 CO rJ-|CO||>-O I 1 O||I||| LOLOll tOVD I O I OO IO colfOlIrO Ifollllll fON||fOrol^-|fOCO fa O fO O ^J if) *4- io co \O O W O < 1 i TTiiTin MiiiTimiiTiTiii 3 COM ro co co co M 3 "s I c^ io co O O co O CO CO Ti~ LO CO CO i Mil i i i i i i i im 1 1813*1 LI COM O 10 M uo CO co rO ^- co N 8 U ( . ^- co O ^ to O to O s H f< II CO CO ^" ro CO ro to ^" iroOltO Itoitol |tol 1 1 |0| I I i to |ro^-lco |ro|rol|to| to Illcol llco MCJO V COO VOO ^ < ^"rt^aj^rt PH S : : r 2 : :^?s 12 : : : : :^ ^ S^Sj :-S f>4> S'r^'C C ''' t/3- '-'5.2i 1 *^^ 'S^ H llllsllJJlllJIIIlllllIlllll REFRIGERATION AND ICE-MAKING. Madiso Cooper 1 1 8J 81 1 1 1 1 1 itl 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 805 oo oo oo o o N M fO ^J- rj- l I l 1 ^! 1 IOD^O) 1 1 1 1 | i^U^ 1 1 i*lj 1 1 1 1 M H ro CO CO II 1 '"' |:i!l 1*1 1 1 M lL OfO LOLOLO cotO^fOrO ^t" rh TJ- rj- *d 1 ST| I 1 1 1 J5JI I I I 3,1 1 1 LOON OO 1-^Tt-uoO L vooo >o o vr> in o ro M fO ^t- fO N ^ 1 1 1 1 1 1 1 1 1 1 1 311 1 1 1 ( 1 1 1 OO LO rj- N fO OO LO M M CO fO ro I-H ro 1 1 Cl OO O VO O LO fO M rf fO rj- rt- \ \ 11^1 1 1 1 1 1 1 1 I 31 uo u"> M ro "O O MM CO ro rO ro 1 81 1 1 Wal Tayl M OO OO OO sTTT i T$i i UOLOLO vO M M *-" CO O 1 1 i i i VO rO i i x a - COLD STORAGE. Si 1O M O LO M ^t" co LO co 1 M vo co LO M 1 | *3*oo | O O ^- T ^ N ^ co co co co "^ 1 co co co *3- co 1 1 co C^l | ** ^- O oo oo O O MM I M M i9 CO co CO co co -d < O O LO LO O O M Hi rj- LO co v 1 LOO LOLO 1 1 -OO|LO| 1 corfcoco II M CO 1 co 1 \.T) 1JO CO L/" > rh CO M LO O 1 1 1 1 1 I 1 LO CO^- 1 1 1 1 1 1 1 CO > >o oo oo M CO co^hco Tt ..'; CO M M 1|| O O *-OvO O O i si i i TTi i i i i TTi i i i TTi i i ^f- LO LO ^h VO CO J CO Tf ^ -co CO N oo vo i/ > O CO co rl II I I LO N 1 1 LOO N Th 1 coco co^-coco oo o 1 1 1 LO o\7 1 ! co ^*- COM 10 LO L<- LT> CO co f > 1 O ^ vo vo oo i Ti i i^Ti i i i i T7i i i i M i i i CO CO co co co w 1 CO CO CO LOVO C-J VO O CO CO rh co TJ- coco 1 1 1 1 1 1^1 1 1 1 1 1 1 1 II 1 1 1 1 1 1 LO M LOCO CO -3-CO CO co co co co COM II 00 O O LO L( M d-LOCO L< | LOO LOLO I 1 1 LOCO 1 rj- uo ^J-LOCO L ->VO O O M ICO ^-co M 1 O 1 H- I 1 I I LO 1 3- 1 1 3> | Jo >** vo oo oo H M CO rJ-CO t-CO CO M M jj ^ u 'fi < If 1 !! : :f : : : jjlfl &< j wi '&, ' ^ 5 'C V* " '' ' ft g-^Sg dSo^ 2 o^'^J iiliiii!illi I d rt ti r 2-4-'p S S^ iil l p4SftpLiPk^PUPHcy] REFRIGERATION AND ICE-MAKING. 1 g in o U w s g PH % 1 rt o 00 O LO 1 LO 1 N M 1 CO N Ti- | *$ \ zj--*? \ I O N N 1 S^ M I I 1 1 1 1 ! Tl 1 Mill K 00 CO w OO LO co ^- 1 1 1 LO 1 LOLO 1 1 CO CO CO LO O a^ 1 ^o 1 1 co ^ LOLO ^ w co rh ^ rt to M ||| 1 1 1 1 1 1 1 rh co 1 1 rj "S o OO LO LO VO 1 CO CO 1 co CO VO O O M co co co co w CO i i i iT 4J M LO LO ^d <* ^t-co i o CO 1 1 1 1 1 Ml CO INN O 00 I i i i i M T i i CO i i iTT O LO Wallis- Tayler. OO LO Tl Tl 31 IS 3 3- O LON Tt- Tfro 1 fO 1 *3- O LO CO ^-04 4> & .2 :::::::: w> s J5 C/3 C^ C/3 C^H H H > II COLD STORAGE. MEAN TEMPERATURES OF PRINCIPAL CITIES OF THE WORLD. CITIES. Spring. Summer. Autumn. Winter. Annual. ENGLAND. Degs. Fahr. Degs. Fahr. Degs. Fahr. Degs. Fahr. Degs. Fahr. Birmingham . . 48-0 62-0 5' 34'2 48-2 Bristol.. Liverpool 497 48-8 63-0 62-9 SI'S SI'S 40-0 39'8 5I-05 50-8 London . . 49' 62-8 5i-3 39'5 50-6 Manchester . . 48-0 62-0 50-5 34-8 48-8 SCOTLAND. Edinburgh 457 57-9 48-0 38-5 47'5 Glasgow 47'9 60-9 50-5 39'9 49-8 IRELAND. Belfast.. 52-1 Dublin 50-1 FRANCE. Bordeaux 57'0 Boulogne 54'4 Marseilles 58-3 Nice 55'9 72-5 63-0 487 60- 1 Paris .. S*'3 GERMANY. Berlin 46-4 63-1 47-8 30-6 47'5 Breslau 46-7 Buda Pesth . . 47'5 Dresden 49-1 Frankfort 49-6 Hamburg 48-0 Leipsic 46-4 Munich 48-4 Trieste 53-8 7^5 56-6 39'S 55'8 Vienna 49*5 63-9 52-8 39'9 ITALY. Florence Genoa 59-2 01*1 Milan 55* 1 Naples 59'5 74'5 62-5 49-9 61-6 Palermo 59'5 74'5 65*9 52-0 63-1 Rome 57'4 73'2 61-7 46-6 597 Turin 53'i 71-6 53-8 33*4 53'i Venice "~"~ 55-4 86 REFRIGERATION AND ICE-MAKING. MEAN TEMPERATURES OF WORLD. PRINCIPAL CITIES OF THE (Continued.} CITIES. Spring. Summer. Autumn. Winter. Annual. SPAIN & PORTUGAL. Fahr. Degs. Fahr. Degs. Fahr. Degs. Fahr. Degs. Fahr. Barcelona 63*0 Madrid 57-6 74-1 567 4 2-I 57-6 Lisbon 59*9 71-1 62-5 61-4 SWITZERLAND. Berne 45'8 60-4 47'3 30-4 46-0 Geneva 527 HOLLAND. Amsterdam . . 49'9 Rotterdam 51-0 BELGIUM. Brussels 507 NORW AY & SWEDEN. Christiania 39-2 59'5 42-4 25-2 41-7 Stockholm . . 61-0 43-8 DENMARK. Copenhagen . 437 63-0 48-5 31'5 46-8 RUSSIA. Moscow 43'3 62-6 34*9 13-5 38'S Nicolaief 49 '3 72-2 50-0 25-9 487 St. Petersburg.. Warsaw 44-6 60-3 63-5 4'5 46-4 16-6 27-5 38-3 45'5 TURKEY. Bucharest _ _ 46-4 Constantinople. SI'S 73'4 60-4 40-6 567 PALESTINE. Jerusalem 60-6 72-6 66-3 49-6 62-2 EGYPT. Cairo . . 1 71-6 84-6 74'3 58-5 72-3 ALGERIA. j Algiers 63-0 74'5 70'S 50-4 64-6 Tunis .. ~~ 68-8 COLD STORAGE. MEAN TEMPERATURES OF PRINCIPAL CITIES OF THE WORLD. ( Continued.} CITIES. Spring. Summer. Autumn. Winter. Annual. NORTH AMERICA. Degs. Fahr. Degs. Fahr. Degs. Fahr. Degs. Fahr. Degs. Fahr. Baltimore 60 -o 83-0 64-6 43'5 54*9 Boston 48-0 66-0 53'O 28-0 49-0 Chicago S 2-8 74'5 61-3 38-5 45'9 Cincinnati 63-2 81-8 66-4 46*6 Mexico 53-6 63-5 65-1 60-2 60-5 Montreal 44'2 69-1 47-1 I7-5 43'7 New Orleans . 73'0 84-0 72-0 58-0 72-0 New York 50-0 72-0 56-0 53' Philadelphia . 52-0 76-0 57' 34-0 55-0 Quebec 4'3 San Francisco . 58-0 59' 60-0 53'Q 57'5 St. Louis 84-6 67-8 44-6 46-0 55' Washington . . 69-0 79-0 58-0 38-0 SOUTH AMERICA. Buenos Aires . . 59*4 73' 64-6 S2-5 62-5 Lima .. 63-0 73' 2 69-6 59' 66-2 Quito .. Rio Janeiro . . 60-3 72-5 60- 1 79-0 62-5 74*5 60- 1 Valparaiso 64-0 EAST INDIES. Bombay ' 81-3 Calcutta 82-6 83-3 80-0 67-8 78-4 Madras 81-9 WEST INDIES. Havanna , . 79-1 Kingstown 78-3 81-3 80-0 76-3 79* Port of Spain . . 81-5 CHINA. Canton . . 69-8 82-0 72'9 54'8 69-8 Pekin .. 56-6 77-8 54'9 29-0 52-6 AUSTRALASIA. Melbourne 57' Paramatta 66-6 73'9 64-8 54*5 64-6 Sydney 65-8 CANARY ISLANDS. Funchal . . 63-5 70-0 67-6 61-3 657 NEW ZEALAND. Auckland . , 60- 1 66-7 58-0 53'5 59*6 88 REFRIGERATION AND ICE-MAKING. w o - w J m sit O r^ ^ W ^ 'N M H c>i CO O Op rh u-> o ^f. oo O OO w v) 01 O t^ 5 ' VO sO ^O O O NO O *H *-* IO v to 10 to ** ^ W & S ^ "R "u ^C3 s |c/2 COLD STORAGE. 8 9 to fc o j vO^N^J-OOOOvON 3 1^* CO O CO ^O CJ Tt" ^i" LO O H CO ^ N* cj ro W C^ ro >-< ^ ^O fO -sj Ci H W H _ H w ^ * S, 2. 2 2[ ] '"" s S o^oooooooo * I 73 3 TfMOOvO fOr^vO rt- ^ 7 C c s & it & 4r & $i & * $4 ^ . cr^ be *n 1 g % fc > ^ h fe fe s it H ^ g MIC ^ fe c, ^ 1: S 2 S^St-'S Jo^^ rffc S ^ -O a &> | q P^ V T X ** S COrt-rj-N-OCOMwONO c: \ ^ ?s , <^ w ^ ^s 1 O "^OO C\vO ^ O N M Q W ^ 3S3 i ^J" CO CO CO ^J" ^O CO *^ ^ O C/3 w n u W 5? ~jj ^H ^v H H *a ...... W *g W ^ >* O ^ &&.'? ^ -S 58 *iQ *.& 5 P^ ^^ ^^^ S 8 ? F B w i : -| *.*f.* 5 H g 55 S M 1 0) 1 V a | IJ ;l | | 3 | | i ^. N sZ. "vT Sos.1'5 sT "'^'"''^S'^rt'^^ S ri|.i^Pi|i|illlPl8 1 <^(^ct;ct;(^(^^^h^ QO REFRIGERATION AND ICE-MAKING. COLD STORAGE CHARGES (England], Cambria Cold Storage and Ice Co., Ltd. MEAT. First Each p 24 Hours. ~cl We. Beef, Quarters, each .. .. i/- .. 6d. .. 2/- Sheep and Lambs, each . . . . 6d. . . 3d. . . 1/6 Pigs and Calves, each . . . . i/- . . 6d. . . 2/- Beasts' Heads (with tongues), each i Jd. per week or any part thereof. (without ), id. Sheeps Heads and Plucks \ Beasts' Livers .. . . [ id. ,, Beasts' Plucks, &c. . . ) Beasts' Tails, per doz. .. .. 4d. ,, ,, Pieces of Meat, in packages . . ^d. per Ib. Minimum Charge, 3d. FISH, GAME, AND POULTRY. Fish (wet), small quantities 9d. per cwt. per week or any part thereof. large quantities 6d. ,, Kippers & Finnon, per box 2d. each and upwards per week or any part thereof. Loose Fish ...... 2d. each and upwards per week or any part thereof. Poultry and Game . . . . i/- per cwt. per week or any part thereof. Frozen Poultry, in large quantities . . . 2O/- per ton for 28 days Chickens, loose Rabbits, in hampers Rabbits, loose Rabbits, Frozen, in cases . i Jd. per couple per week .pd. per cwt. per week .id. per couple per week ,, small quantities, 6d. per case j per case per week or any part thereof. Rabbits, Frozen, large quantities, 17/6 per ton for 28 days or any part thereof. Pheasants, i|d. per brace ist week, id. per brace each succeeding week. Partridge and Grouse, id. per brace per week or any part thereof. Hares, Turkeys and Geese, 2d. each Minimum Charge, 3d. PROVISIONS. Butter, small quantities, 6d. per cwt. per week or any part thereof. ,, 2O/- per ton for 28 days or any portion thereof. 2 tons and upwards, 1 6/- Bacon 14;- Cheese 12/6 Lard I5/- Eggs I7/- COLD STORAGE. CONDITIONS OF DEPOSIT AND REGULATIONS. The Conditions of Deposit are as follows : The Cambria Cold Storage and Ice Co., Ltd., receive goods on the following conditions only : I . No goods will be given up without the production of a ticket, which is delivered to the person when goods are brought to Stores, or satisfactory evidence of ownership. 2. All consignments to the Stores must be plainly marked with the owner's name and address, and date. 3. All payments for storage must be made when the goods are delivered. 4. The Company will not be responsible for any loss or damage to goods stored by them, through maintaining too high or too low a temperature in the Stores, failure of machinery, fire, or any other cause whatsoever ; but the Company will always, and at all times, use their utmost endeavours to prevent any such damage, and will render all assistance in their power to properly preserve and keep goods entrusted to their care. 5. The Company reserve to themselves the right to refuse any goods that, in the opinion of the Manager, or his representative, are unfit to store. 6. The Company will hold all goods stored by them subject to a feneral lien for all debts due by Depositors on account of torage. 7. Stores open for receiving and delivering goods: "Week-days, 6 a.m. to 5 p.m. ; Saturday, 6 a.m. to 5 p.m., and 10.30 p.m. to ii.30jp.rn." COLD STORAGE CHARGES (United States]. Substance. Temperature. Degrees. Month. For the Season. Remarks. Salt meat 32 to 36 25 to 3 5 cents Per tierce. > 32 to 36 20 tO 25 Per barrel. Dried beef 32 to 36 35 i Fresh meat 38 Per pound. 38 25* Per quarter. Veal .. 36 25 Per pound. Lamb . . 36 ^ Game . . 32 to 36 15 cents H Below 20 i Per Ib. gross. Venison and poultry Below 20 I* ,, Ducks, grouse, and quail 32 to 35 15 Per dozen. Quails Below 20 pf Fish 25 to 30 i t o 4- Storage Room 25 dollars Per 1,000 and upwards cubic feet. 92 REFRIGERATION AND ICE-MAKING. S i 1 I *N * ts^ *o .& M ^ s -o o 6 b~ o HIM O< v 4'-'l-l-irip|p'--l|pP'-' j^b b b b b b b b ' b b b b ' b b b C/2 r-lfa rH|M M< r ^ .M bb bbbbobbbbboobbbb S j^ . .^d ..... OT*- B ^ _^ rtlao - ^ i^ . < H t-iO 1 - 1 I O I-" IwwMOOO'-iOO I ?Pr 1 P ? I 1 /^ /-\ /-\ I /-\ y-\ I o Hbbbbbbbbb i-W LnO M O roOooONto ^b bbbbb 8 b o'~ l b l ~'b bbbbb bbbbb 8 8 b o a ^ rfT-g sV5 tftf 2^2*11 8 S^b s 'B SriOrt2a3^^^ttiri !U ^2( :L <& l i ^ V It V l i s 41 OOO 94 REFRIGERATION AND ICE-MAKING. IIS . II Us a T 4 1 I U w o o & Q 8 u Season Rate per Barrel of 100 Ibs. b o o b b b ^ooooooooooooooooooooo o bbbbbbbbbbbbbbbbbbbbb ^::::::::::::::::::::: o COLD STORAGE. 95 > I I I I I > I " I I I I I O O o & O 1 K 1 is 1 1 1 1 i 1 2 II 1 1 1 OLOOOOMIOOOO >-ooo I I a ^ j> b b b b b b b b b b b 1 OLOOOOLOO'IN in'o* O O LO o b b b b b b b b b b b b b b O O *-O O *-O O *-O *-O O O ^o *-O w> O bbbbbbbbbbbbbb 8 CO 3 6 96 REFRIGERATION AND ICE-MAKING. RATES FOR FREEZING POULTRY, GAME, FISH, MEATS, BUTTER, EGGS, ETC., UNITED STATES. The rates for freezing goods, or for storing goods at a freezing temperature when they are already frozen, are as follows : POULTRY, GAME, ETC., IN UNBROKEN PACKAGES. Poultry, including turkeys, fowl, chickens, geese, etc., and rabbits, squirrels, and ducks when picked. Four rates, A, B, C, and D, for storing poultry, and the rate to be charged will be determined by the amount of such goods as may be frozen and stored during a season of six months, usually from October or November ist to April or May ist. RATE A. For customers storing fifty or more tons of poultry, the rate to be one-third cent per pound for the first month stored, and one-fourth cent per pound for each month or fraction of a month, including the first month, if stored for more than one month. RATE B. For customers storing five or more, but less than fifty tons of poultry, the rate to be one-third cent per pound for the first month stored, and one-fourth cent per pound for each month or fraction of a month thereafter. RATE C. For customers storing one or more, but less than five tons of poultry, the rate to be three-eighths cent per pound for the first month stored, and one-fourth cent per pound for each month or fraction of a month there- after. RATE D. For customers storing less than one ton of poultry, the rate to be one-half cent per pound for the first month stored, and three-eighths cent per pound for each month or fraction of a month thereafter. Venison, etc., and ducks when unpicked, one to one-half cent per pound per month, according to quality and length of time stored. Grouse and partridges, three cents to five cents per pair per month. Woodcock, one cent to two cents per pair per month. Squabs and pigeons, four cents to six cents per dozen COLD STORAGE. 97 per month. Quail, plover, snipe, etc., three cents to five cents per dozen per month. When a portion of the goods is removed from a package, storage to be charged for the whole package as it was received, until the balance of the package is removed from the freezer. For goods received loose, when to be taken out of the packages in which they are received, or when to be laid out, the following rates to be charged : Poultry, including turkeys, chickens, geese, etc., and rabbits and squirrels, one-half cent to one-fourth cent per pound extra, according to quality and length of time stored. Grouse, partridges, woodcock, squabs, pigeons, quail, plover, and snipe, 50 per cent, more than the rates as above specified. Ducks weighing less than two pounds each, two cents to three cents each per month. Ducks weighing two pounds or more each, three cents to four cents each per month. For all kinds of poultry and birds not herein specified, the rate from one cent to one-half cent per pound per month, according to quantity and length of time stored. SUMMER FREEZING RATES. Freezing rates for the summer months, 50 per cent, more than the specified winter rates for the first month stored, and the same as the winter rates for the second and succeed- ing months. STORING UNFROZEN POULTRY, ETC. For holding poultry, game, etc., which are not frozen, at a temperature which shall be about 30 Fahr., the rate to be one-fifth cent to two-fifths cent per pound according to quantity, for any time not exceeding two weeks. FREEZING RATES FOR FISH AND MEATS. Salmon, blue fish, and other fresh fish in packages, one- half cent per pound for the first month stored, three- eighths cent per pound per month thereafter. 98 REFRIGERATION AND ICE-MAKING. Fresh fish of all kinds when to be hung up or laid out, three-fourths cent per pound for the first month stored, one-half cent per pound per month thereafter. Fish in small quantities, 50 per cent, more than the above rates. Special rates for large lots of large fish. Scallops, three-fourths cent per pound, gross, per month. Sweetbreads, and lamb fries, one cent per pound, gross, per month. Beef, mutton, lamb, pork, veal, tongues, etc., three- fourths cent to one-half cent per pound, net, for the first month stored, one-fourth cent to three-eighths cent per pound per month thereafter. BUTTER FREEZING RATES. For freezing and storing butter in a temperature of 20 Fahr. or lower, the rate to be charged will be determined by the amount of such goods that may be frozen and stored during the season of eight months from April ist to December ist, or from May ist to January ist. There will be three rates, A, B, and C. RATE A. For customers storing thirty-five (35) or more tons of butter, the rate to be fifteen cents per 100 pounds, net, per month. RATE B. For customers storing five or more, but less than thirty-five tons of butter, the rate to be eighteen cents per 100 pounds, net, per month. RATE C. For customers storing less than five tons of butter, the rate to be twenty-five cents per 100 pounds, net, per month* EGG FREEZING RATES, j For freezing broken eggs in cans, the charge to be one- half cent per pound, net weight, per month, and for a season of eight months the rate to be one and one-half cents per pound, net weight. RENT OF ROOMS. For freezing temperatures, four cents to five cents per cubic foot per month. COLD STORAGE. 99 TERMS OF PAYMENT OF COLD STORAGE AND FREEZING RATES. All the above rates are to be charged for each month, or fraction of a month, unless otherwise specified ; and in all cases fractions of months to be charged as full months. Charges to be computed in all cases when possible upon the marked weights and numbers of all goods at the time they are received. All storage bills are due and payable upon the delivery of a whole lot, or balance of a lot of goods, or every three months, when goods are stored more than three months. Unless special instructions regarding insurance accom- pany each lot of goods, they are held at owner's risk. COLD STORAGE CHARGES (France). Public Abattoir j Chambery. Rent of cold storage chamber 500 francs (20) per annum. An ordinary cold storage chamber contains 17 or 1 8 hooks, each capable of supporting about 100 kilo- grammes (220*4 Ibs.) of meat, and 17 or 18 S-hooks, each capable of receiving 10 kilogrammes (22*04 Ibs.), in small pieces. The weights of the meat suspended from the hooks and S-hooks are never to exceed the above. In all cases where such weights are exceeded the butchers will be held responsible for any damage and breakages which may result. Where a cold storage chamber is let to a number of persons, the rent to be per hook, at the rate of 40 francs (32 shillings) a year, that is to say, for the time during which the cold store is in operation. The S-hook situated above is included with each hook. SECTION III. ICE-MAKING AND STORING ICE. ICE-MAKING. ARTIFICIAL ice is either what is known as clear, trans- parent, or crystal ice, or milky, opaque, or tombstone ice. The latter is generally used where appearance is of no consequence, and cheapness is the main consideration, and it does not necessarily possess any unwholesome qualities, but it has the objection of very considerably reduced keeping powers, and should be used immediately. The opacity of ice is mainly due to rapid freezing pre- venting the air contained in solution in the water from escaping. Clear or crystal ice can be made by using distilled or de-aerated water, or by agitation of the water during the freezing process. This latter has been carried out in a number of different ways, of which the most common and practical is the reciprocating movement of agitators or paddles in the ice can or mould, or in the ice-box, accord- ingly as the can system or the stationary cell system is in use. Many other devices have, however, been used, amongst which may be mentioned the imparting of a rotary motion to the freezer, rods or plungers moving up and down in cans, oscillating rods or agitators, forcing cold air through the freezing water, shaking cans or moulds, removing water and refilling it by pumping, water injection with pressure reduction, taking water from one point of one can and pumping it into another, rotating stirrer or agitator, freezing ice in very cold air, freezing ice very slowly, freezing ice in very thin slabs. A white core in ice is due to the presence of carbonite of lime and magnesia or other minerals in the water. A red core in ice is due to the separation of oxide of iron in ice which was maintained in solution in the water in the form of carbonate of iron, and the sediment usually comes from ICE-MAKING AND STORING ICE. IOI the iron of the plant. Pure distilled, carefully filtered water should be alone used for making ice intended for domestic consumption. The three most used types of ice-making apparatus are those working on the can system, the station- ary cell system, and the plate or wall system. In ice-making, where it is important to secure the maxi- mum production at the minimum cost, it is necessary to work both day and night so as to render the operation a continuous one. Likewise such routine must be followed as will ensure the largest possible output and the best quality. With this purpose in view, great care must be exercised to maintain all the parts of the apparatus per- fectly clean, and in first-class working order. A regular and systematic plan of drawing the ice must be settled upon and strictly adhered to, and with this object a dis- tinctive number or letter should be stamped or painted upon each can or mould, and so many drawn regularly per hour. TABLE GIVING SIZES AND CAPACITIES OF ICE-MAKING PLANTS, ETC. (H. H. Kelley, The Engineer," New York.} Tons *per 24 Hours. Size of Engine. i Pd Size of Com- pressor. Size of Blocks of Ice. Gallons of Water per Hour. "S,. No. of Engineers. No. of Firemen. 1 No. of 1 Labourers. | I 7x 9 90 +5* 10 8 x 8 x 28 5 i I . , 3 8x 16 80 8 x 15x28 15 i 2 2 2 5 lox 20 75 6x 18 8 x 15x28 20 *i 2 2 2 f II X 22 X 28 \ 10 12x30 70 8x20 1 II X II X 28 j 3 2 2 2 3 10} 14x30 65 8x2 5 { II X 22 X 28 II X II X 28 J35 *i 2 2 3 15 14x30 65 10 X 20 { II X 22 X 28 II X II X 28 } 4 o 3 2 2 4 20 16 x 30 55 10 x 30 J II X 22 X 28 II X II X 28 j 50 4 2 2 5 30 16x42. 52 iix3o{ II X 22 X 28 II X II X 28 J6o 5 2 2 6 40 18x36 5 12 X 3O II X II X28 90 6J 2 2 7 20 X 36 50 15x30 II X II X 28 94 8 2 2 8 60 24 x 36 45 1 6 x 36 II X II X28 96 10 2 2 9 80 26x48 45 20x36 II X 22 X 28 100 13 2 2 10 * 2,000 pounds. J One cylinder. 1 02 REFRIGERATION AND ICE- MAKING. DIMENSIONS OF ICE-MAKING TANKS. Table compiled by E. T. Skinkle, giving sizes of some Freezing Tanks, Piping and Moulds, in actual operation. (From " Compend. of Mechanical Refrigeration") , 1 ^ # * * Average of i-in. pipe per ton, 327 feet. Average of i^-in. pipe per ton, 272 feet. * Twenty-ton tanks are duplicate lo-ton tanks ^ Thirty-ton 15 v Dimensions of one tank only are given in each instance. Sixty-ton 30 ) 'Pl n W qa^ 3 Suizaaij joj sinojj jaquin^ ,,, s ^ s XjpBdB^ Sui -^Hui-aoj no; jbd o o o b M b b b \o Vvo qoBa uioaj aoj jo ?q3pA\. ? 3 N oooooooooooooooo oooooooooooooooo SEW. XXXXXXXXXXXXXXXX xxxxxxxxxxxxxxxx jju^x at spinoj\[ SDJ jo agquin^i .a^^H^iH XjpBdt;} J9d' 9dis nD jo q;StK>i noo o o o oooo ^tl I 1 1 [III H, M M M H H M M M M N qSijj S9di j jo -o^j VQ VO VO OO OO 00 OO OO OO O OO saqDut ut odijjoazjs KHHM M H M H Wff SHOD jo -ox -S^2 S? 5J EJ X? P; ? SIZES OF TANKS. sgqoui u; jo ssau^otqx \OVOvO ^ ^ ^ ^ -, < , ,^ A,A,A, sgqoui ui jo q^dad ^^,0 ^ ^ ^ 0000000 sgqoui 33 ijaaj rrr f T r r ? ?n VOON't-ON ON ON ON ONOOO MM M M M M fO saqouj ^ ^38.1 >3 l aB X Jj" H? nT M Jo 5 w ? ?io? S^UBIJO-OX M M M M H M N CM M N IN sa "Sr M N f>u-> O'M'IOO OOOO M H M M ^ t*5\O NO ICE-MAKING AND STORING ICE. IO3 PURE WATER. If properly distilled water, or ice made from such water, be evaporated slowly on a piece of platinum foil over a spirit-lamp or a Bunsen gas-burner, there should be no residuum whatever. In the manufacture of ice intended for domestic con- sumption, the use of pure water is a matter of paramount importance, consequently it is well to define what pure water is, and as very much the same requirements that are made by authorities with respect to potable water, also apply to ice, we will give some of the demands made in the former case. Pure water is soft, is transparent, has a certain amount of sparkle, is sufficiently aerated, has no matter held in suspension that is visible, is completely tasteless, and is either entirely colourless or has a slight bluish tint. The requirements of some authorities in the United States in this direction great care being there exercised are given by Prof. Siebel as follows : " i. Such water should be clear, temperature not above 15 C. 2. It should contain some air. 3. It should contain in 1,000,000 parts: Not more than 20 parts of organic matter. Not more than 0*1 part of albuminoid ammonias. Not more than o'5 part of free ammonia. 4. It should contain no nitrates, no sulphuretted hydrogen, and only traces of iron, aluminium, and magnesium. Besides the mentioned substances, it should not contain anything that is precipit- able by sulphuretted ammonia. 5. It must not contract any odour in closed vessels. 6. It must contain no sapro- phites and leptothrix, and no bacteria and infusoria in notable quantities. 7. Addition of sugar must cause no development of fungoid growth. 8. On gelatine it must not generate any liquefying colonies of bacteria." SIMPLE RULES FOR ASCERTAINING THE QUALITY OF SO- CALLED MINERAL WATER. {Frick Company!) Water turning blue litmus paper red.jbefore boiling, which after boiling will not do so ; and if the blue colour can be restored by warming, then it is carbonated (con- taining carbonic acid). If it has a sickening odour, giving a black precipitate 104 REFRIGERATION AND ICE-MAKING. with acetate of lead, it is sulphurous (containing sulphuretted hydrogen). If it gives a blue precipitate with yellow or red prussiate of potash by adding a few drops of hydrochloric or muriatic acid, it is chalybeate (carbonate of iron). If it restores blue colour to litmus paper after boiling, it is alkaline. If it has none of the above properties in a marked degree and leaves a large residue after boiling, it is a saline water (containing salts). TESTING BY REAGENTS. If water becomes turbid or opaque by using the following reagents, it is not pure : With baryta water, indicating carbonic acid. With chloride of barium, indicates sulphate. With nitrate of silver, indicates chloride. With oxalate of ammonia, indicates lime salts. With sulphide of hydrogen, slightly acid, indicates presence of antimony, arsenic, tin, copper, gold, platinum, mercury, silver, lead, bismuth, and cadmium. With sulphide of ammonia, alkaloid by ammonia, indi- cates nickel, cobalt, manganese, iron, zinc, alumina, and chromium. With chloride of mercury or gold and sulphate of zinc, indicates organic matter. FREEZING TANK OR Box. These are constructed of sheet iron and steel, and also of wood and cement. The amount of pipe required is about 250 feet of 2-inch pipe, or 350 feet of i-j-inch pipe, or their equivalent per ton of ice per twenty-four hours, in accordance with the temperature of the brine and the capacity of the machine. Less pipe than the above, says Prof. Siebel, is employed in the United States, even as low as 150 feet of 2-inch pipe, and 200 feet of i^-inch pipe per ton of ice-making capacity (in twenty-four hours), but in that case the back pressure must be carried excessively low, which duly increases the consumption of coal and the wear and tear of the machinery. The brine in the freezing tank may be cooled on either the brine circulation or the direct expansion system. ICE-MAKING AND STORING ICE. 105 The size and length of pipe in the brine tank, it is recommended by the above-mentioned authority, should be arranged in such a manner that each row of moulds or cans is passed by an ammonia pipe on each side, preferably on the wide side of the mould or can. The series of pipes in the ice tank or box are connected by a manifold, the liquid ammonia entering the manifold at the lower extremity, and the vapour leaving by the suction manifold placed at the higher extremity of the refrigerating coils. When working with the wet vapour of ammonia, the liquid must be admitted at the upper extremity of the refrigerating coils, and be drawn off to the compressor at their lower extremity. BRINE FOR USE IN REFRIGERATING AND ICE-MAKING PLANTS. A brine suitable for the above purpose can be made with from 3 to 5 Ibs. of chloride of calcium, or muriate of lime, in accordance with its degree of purity, dissolved in each gallon of water. The density of this solution is about 23 Beaume', its weight about 13% Ibs. per gallon, and the freezing-point is 9 Fahr. As the above standard of density must be kept up, in order to prevent the brine from becoming congealed in the refrigerator, or the ice- making tanks or boxes, it is desirable to test it periodically with a salinometer. In the best American practice first quality medium ground salt, preferably in bags for convenience of handling, is employed, the proportions being about 3 Ibs. of salt to each gallon of water. The brine is made in a brine mixer, consisting of a water-tight box or tank about 4 ft. X 8 ft. x 2 ft., having a suitably perforated false bottom, and a small compartment, partitioned off at one extremity, communicating with the main compartment through an overflow situated at the upper end of the partition, and fitted with a large strainer, to prevent the passage into the small compartment of salt or foreign bodies. The water is admitted through a perforated pipe situated beneath, and running the full length of the false bottom, and the brine is removed through a pipe from the io6 REFRIGERATION AND ICE-MAKING. upper part of the end compartment, at the lower extremity of which latter pipe is a strainer-box and strainer through which the brine passes before delivery into the brine-tank. A salt gauge, salinometer, or hydrometer is also placed in the small or end compartment. The salt should be dissolved in the water until it reaches a density of about 90 by the hydrometer. To facilitate dissolution it is desirable to stir the salt in the mixer with some handy implement, the salt being shovelled in as fast as it can be got to dissolve. By the use of this mixture the settlement of salt on the bottom, and on the coils in the brine tank, which inevitably results when the dissolution is effected directly in the latter, is avoided. To maintain the strength of the brine it is recommended to suspend bags filled with the salt in the brine tank, or to pass the return brine through the above-described brine maker or mixer. A cheap and easily constructed apparatus for mixing brine can be made out of an old barrel in which a perforated false bottom is fixed a short distance above the bottom, the water to form the solution being delivered to the space between the two bottoms, and an overflow pipe fitted with a suitable strainer and a well to receive a salinometer being provided near the top to draw off the brine. SOLUTIONS OF CHLORIDE OF CALCIUM (CaCh). (Manufacturer of Chloride of Calcium, U.S.) Specific Gravity at 64 Fahr. Degree Beaume at 64 Fahr. Degree balino- meter at 64 Fahr Per cent, of Chloride of Calcium. Freezing- point Degrees Fahr. Ammonia Gauge. Lbs. per square inch at Freezing-point. 007 I 4 0-943 +31-20 46 014 2 8 1-886 +30-40 45 021 3 12 2-829 -29-60 44 028 4 16 3772 -28-80 43 35 20 4715 -28-00 42 43 6 24 5-658 -26-89 4i 050 7 28 6-601 - -25-78 40 058 8 3 2 7'544 +24-67 38 065 9 34 8-487 + 2 3-56 37 1-073 10 40 9-430 -j-22-09 35-5 ICE-MAKING AND STORING ICE. 107 SOLUTIONS OF CHLORIDE OF CALCIUM (CaCte). (Manufacturer of Chloride of Calcium, U.S.} 'Specific Giavity at 64 Fahr. Degree Beaume at 64 Fahr. Degree Salino- meter at 64 Fahr. Per cent, of Chloride of Calcium. Freezing- point Degrees Fahr. Ammonia Gauge, Lbs. per square inch at Freezing-point. I-oSl II 44 10-373 -j-20-62 34 1-089 12 4 8 11-316 -f-19'14 32-5 097 13 52 12-259 + 17-67 30-5 105 H 56 13-202 +15-75 29 114 15 60 H'MS + 13-82 27 112 16 6 4 15-088 +II-8 9 25 131 17 68 16-031 + 9-96 23-5 140 18 72 16-974 + 7-68 21-5 149 19 76 17-917 + 5-40 20 158 20 80 18-860 + 3-12 18 167 21 84 19-803 - 0-84 15 I 7 6 22 88 20-746 - 4-44 12-5 186 23 9 2 21-689 - 8-03 10-5 196 24 96 22-632 -11-63 8 205 25 100 23-575 -15-23 6 215 26 104 24-518 -19-56 4 225 27 108 25-461 -24-43 i-5 236 28 112 26-404 -29-29 1 66 vacuum 246 2 9 116 27-347 -35-30 5 66 257 30 120 28-290 -41-32 8-566 268 31 29-233 -47-66 I2 66 279 32 30-176 -54-00 i5 66 290 33 31-119 -44-32 I0 66 1-302 34 32-062 -34-66 4 65 I-3I3 35 ~* 33-000 25-00 1-5 Ibs. PROPERTIES OF SOLUTION OF CHLORIDE OF CALCIUM. (Prof, Siebel, " Compend. of Mechanical Refrigeration.'"'} Percentage by Weight. Specific Heat. Specific Gravity at 60 Fahr. Freezing- point Degrees Fahr. Freezing- point Degrees Cels. I 0-996 00 9 31 -0-5 5 0-964 043 .27-5 2*5 10 0-896 087 22 -5-6 15 0-860 134 15 -9-6 20 0-834 182 5 -14-8 25 0-790 234 -8 22-1 io8 REFRIGERATION AND ICE-MAKING. 5 c. 1 ho u N to ON T^-M 1 ' ' 77 c *N ^""^ i S Vbo oo !* ' 2 t^ M 10 1030 .^ 1 Heat of Solution. -l P-H (C 4-1 g H^ONr^ so c^ *-o w oo I rt 3 C^OO OO OO t** C/2 *3 o o o o o 3 CO t^ ro too >- b b ~ M 1 r OO fO M O 1^ rt rt JD LO o o ro s c/2~ O M >- N M "8 -I s 1" OO \O ^- CNJ ON k ~ ON ON ON CNGO ^"* J to O to O to V C < CJ CJ 1 a ^ M (C "u- (2j co r>. >-i to ON ?9r r r W C $ J 13 Twaddell. w W CO PO 1 1 too to ON TJ- 1? S _ .- _ r< PQ & inometer. 85-SS8 i 1 ICE-MAKING AND STORING ICE. IOQ COMPARISON OF VARIOUS HYDROMETER SCALES. (Yaryan.) .:f.c Gravies. 6 A Ji Jo 5 ^z. ~* .j %g -.^ -r o - = ~3 1 '-'. - s* a d | 1 . .1- - > t '- z , J*~" - i ^ C till *j i s 3i c||_| ^ " -', _. e \** I |) jl Piy.uvs P.M. \ r ii O I -000 I -0000 o-o o-o o-o o-o o-o o-o I 1-007 1-0070 0-7 1-4 2-8 1-2 1-8 0-4 2 1-014 1-0140 2-8 5-5 2"3 3-6 3 I-02I 1-0215 2*1 4*2 8-2 3-5 5'4 2-1 4 1-028 1-0285 2-8 5*6 10-9 4*6 7-1 2-7 5 I-036 1-0380 3-6 7-2 13-9 5*9 9-0 3*5 6 1-043 I-C--55 4*3 8-6 16-5 7-0 10-7 i 9 I-05I 1-058 1-066 1-0510 1-0585 1-0665 8 10-2 n-6 13-2 19-4 21-9 24-8 8-3 9*3 10-4 12-6 14-3 16-1 4*8 il 10 ii 1-074 I-082 1-0745 1-0825 K 14-8 16-4 27-5 30-3 11-7 12-9 18-0 19-8 % 12 I-090 1-0905 9-0 18-0 33-0 14-1 21*5 8-3 13 1-098 1-0990 9-8 19-6 36-0 15-2 23-3 8-9 '4 107 1075 10-7 21-4 39;o 164 25-2 9*7 3 '"5 124 -1160 1245 -5 12-4 23-0 24-8 44-2 17-6 18-8 27-0 28-9 10-3 n-o 17 133 -1335 13-3 26-6 46-5 20-0 30-7 11-7 18 142 1425 14-2 28-4 49'7 21*2 32-6 12-4 20 IIS 1607 To 30-2 32-0 52-5 55*2 22-3 34*4 36-2 '3*1 13-8 21 169 -1705 16-9 33-8 57-8 2^-6 38-0 '4*5 22 23 24 179 188 -198 1795 1895 1995 ! 9 '8 35-8 3 '*6 60-7 63-3 66-1 2 5 -8 26*9 28-1 40-0 43*6 15-2 15-8 16-5 25 -208 -2095 20-8 4?-6 68-9 29*3 45*5 17-2 26 -218 -2195 21-8 43-6 71-6 30-4 47'3 17-9 27 -229 2300 22-9 45-8 74*5 3 / 49*4 18-6 28 239 2405 23-9 47-8 77'2 32-8 51-2 19-3 29 2515 50-0 79*3 34'0 53*2 20-0 30 -261 -2625 26*1 52-2 82-8 35*2 55*1 20-7 3' 272 2735 27-2 54-4 85-5 36-4 57*o 21-4 32 33 283 -295 2850 52960 28-3 29-5 56-6 88-3 91-1 III 60-9 22*1 22-8 34 Jrf 3080 30-6 6?-2 93*7 39'9 62-7 23*4 35 -318 3200 31-8 63-6 96-5 41-0 64-7 24-1 110 REFRIGERATION AND ICE-MAKING. COMPARISON OF VARIOUS HYDROMETER SCALES. (Continued.) Specific Gravities. u 1 1 ' u 'B "3" to. p^x. ^ Q 1 s , H 3 M o *C J Iff V? ^ rt rt i b 1 *I-T cl 1 -a ? 1* Hill d M f 11 J5*i a I o o U o | g 8 tw"l M" MO X V rt | U Z* Q H n't, ** i 6 '! | ti O g j & 2 g <8 o || w W o fej ($4 a> ^ c || * gS S> MH 8 g w & w 2^ rt C/5 * 1 Q I' 3 | O 36 1-330 3320 33-o 66-0 99-2 42-2 66-7 24-8 37 1-342 3445 34*2 68-4 101-9 43-3 68-6 25-5 38 -355 '35/0 35'5 71-0 104-7 44*6 70-7 26-2 39 40 'ili 3700 3830 36-8 38-1 73-6 76-2 107-6 110-3 45-8 46-9 747 26-9 27-6 394 '3955 39-4 78-8 113-5 48-0 76-7 28-3 42 408 4100 40-8 81-6 115-9 49'3 78-8 28-9 43 421 4240 42-1 84-2 118-5 5;4 80-8 29-6 44 436 438o 43'S 87-0 121-3 82-9 30-3 45 46 47 450 465 '479 4525 4675 4827 45*0 48-0 90-0 93 -o 96-0 124-1 126-7 129-7 52-8 53-9 87-2 89-4 31-0 32-4 48 '495 4980 49'5 99-0 132-4 56-3 91-5 33-J 49 510 5135 51-0 102-0 135-1 57-4 93'6 33-8 50 526 5300 52-6 I05-2 137-9 58-6 , 34'5 542 5460 54'2 I08-4 140-6 59-8 . 35-2 52 '559 5630 55'9 111-8 143-4 61-0 . 35'9 53 5/6 5800 57-6 115-2 146-2 62-2 . 36-6 54 593 5965 59-3 118-6 148-9 6 3 ' 3 . 37-2 55 611 -6150 61-1 122-2 151-7 . 37-9 56 629 6335 62*9 I25-8 154-5 65*7 . 38-6 57 648 6520 64-8 129-6 157-3 66-9 . 39'3 58 666 6715 66-7 I33-4 160-0 68-0 . 40-1 59 686 6910 68-6 137-2 162-8 69-2 . 40-7 60 706 7110 70-6 I4I-2 165-5 70-4 , 41-4 61 726 7315 72-6 I45-2 168-3 . 42-1 62 '747 7525 74-7 149-4 171-0 727 . 42-8 63 768 7740 76-8 153-6 173-8 73-8 . 43-4 64 790 795 79' I58-0 176-5 75' . 44-1 65 812 8185 81-2 162-4 76-2 , 44-8 66 835 8420 83*5 I67-0 182-0 77'4 t 45'5 67 859 8660 85-9 I7I-8 184-8 78-6 . 46-2 68 883 8910 88-3 176*6 187-5 797 t 46-9 69 907 9151 I8I-4 190-2 80-9 t 47-6 70 1-933 9410 93'3 186-6 193-0 82-1 , 48*3 72*5 2-000 2-0085 loo-o 2OO-O 200-0 85-0 So-o ICE-MAKING AND STORING ICE. Ill FREEZING TIMES FOR DIFFERENT TEMPERATURES AND THICKNESSES OF CAN ICE. (Siebert.) C c G c a a c a a c a g H N 10 * 10 VO ** oo o> H H H H Temperature 10 0*32 !*28 2*86 S'xo 8'oo "'5 I.V6 20*4 25-8 3i'8 38*s 45-8 12 I-40 3'i5 5*60 8*75 12-6 i7'3 22*4 28*4 42*3 50*4 14 3*5 b'22 Q'70 14-0 iq-o 25-0 39' 47-0 56-0 16 18 20 22 24 0-44 0-50 o'70 0-88 i'75 2'00 2-32 2-80 3'5o 3 '94 4]50 6-30 7*86 7-00 8'oo 11*2 14*0 II'O 12*5 14-6 17*5 2I'O i5' i8'o 21*0 25-2 31*5 21-5 24'5 28-5 3 4' 3 42-8 28*0 32-0 37'3 44-8 56*0 35'5 4'5 47-2 567 71*0 43*7 &1 I?, 106*0 72*0 84-0 lOO'O 126-0 TIME REQUIRED FOR WATER TO FREEZE IN ICE CANS. (The Triumph Ice Machine Company, Catalogue.} Cans, size, 6 in. by 12 in. by 24 in. Weight of cake, 5olbs. Time to freeze, 20 hours. Cans, size, 8 in. by 1 8 in. by 32 in. Weight of cake, 100 Ibs. Time to freeze, 36 hours. Cans, size, 8 in. by 16 in. by 40 in. Weight of cake, 150 Ibs. Time to freeze, 36 hours. Cans, size, n in. by 22 in. by 32 in. Weight of cake, 200 Ibs. Time to freeze, 55 hours. Cans, size, 1 1 in. by 22 in. by 44 in. Weight of cake, 300 Ibs. Time to freeze, 60 hours. Cans, size, II in. by 22 in. by 57 in. Weight of cake, 400 Ibs. Time to freeze, 60 hours. NOTE. Temperature of bath 14 to 18 degrees Fahrenheit. Asa rule, the higher the bath temperature the slower the process of freezing, but the finer and clearer the ice. STORING ICE. For storing purposes ice should be clear, solid, and devoid of core. In America some persons insist that ice for storage should not be made at temperatures higher than 10 to 14 in brine tank. The first requisite for a storage house for artificial ice, as also for natural ice, is of course the best possible insulation; other necessary points to be attended to are drainage and ventilation. The best shape for an ice storage house is squargg^oras nearly approaching this form 112 REFRIGERATION AND ICE-MAKING. as possible, and the roof should have a good pitch. An ante-room or lobby is also desirable, as by the provision of this latter the necessity for the frequent opening of the main store is done away with. To preserve the ice, the storage rooms as well as the ante-chambers or lobbies must be refrigerated, and the amount of the latter required may be roughly estimated, according to Prof. Siebel, at from about ten to sixteen British thermal units of refrigeration per cubic feet con- tents for twenty-four hours. About one foot of 2-inch pipe (or its equivalent in other size pipe) per fourteen to twenty cubic feet of space is frequently allowed, says the same gentleman, in ice storage houses for direct expansion, and about one-half to one-third more for brine circulation. The pipes should be located on the ceiling of the ice storage house. The ventilation of an ice storage house should be carefully attended to, and ventilators fitted with suitable regulators should be provided both in the highest part of the roof and also in the gable ends. The drainage should be such as to absolutely prevent the accumulation of any moisture beneath the bed of ice. It is recommended to paint an ice store white, preferably with a mineral paint such as barytes, or patent white. Respecting the best method to adopt for packing the ice in the store, considerable diversity of opinion seems to exist. It is well to provide a bed of from eighteen inches to two feet of cinders, as this tends to improve the drainage of the house. In one method the blocks are placed on edge and as closely packed together as possible, the blocks in each succeeding layer being placed exactly over those beneath and all breaking of joints being avoided. The ice is covered between the times of storing with dry sawdust or soft wood shavings, and the uppermost layer is invariablv covered with dry sawdust or shavings. Mr. R. Thompson, writing to the Canadian Farming World, says that in filling the house he puts the ice on edge, placing every alternate layer crossways, which plan, he claims, enables ice to keep better and come out easier. Others recommend that the ice be stored with alternate ends touching, and alternately from one and a half to two ICE-MAKING AND STORING ICE. 113 inches apart, so as to prevent the ice from freezing together. The cakes or slabs of ice should not be parallel to each other, and storage should only be made when the tempera- ture is at or below freezing. Or, again, inch strips placed between the layers of ice in the store so as to separate the cakes or blocks top, side, and bottom, from all others in the house. For packing the ice, sawdust, rice chaff, straw, hay marsh or prairie hay being said to be preferable are em- ployed, the latter materials being the best, and rice chaff being capable of being dried and re-used. Six inches of well-packed hay should be placed between the ice and the walls, and no covering until the store is full. A cubic foot of ice is taken to weigh 57-5 Ibs. approxi- mately at 32 Fahr. A cubic foot of water frozen at 32 will make 1*0855 cubic foot of ice, thus showing an expan- sion of 8*5 per cent, due to freezing. A cubic foot of pure water at 39 Fahr., its point of greatest density, weighs 62*43 Ibs. Fifty cubic feet of ice, as usually stored, equals about one American or short ton of ice (2000 Ibs.), or 62 cubic feet one English ton. In small ice houses, in which the ice is closely packed, a short ton of ice can be got into from 40 to 45 cubic feet. When withdrawing ice from a store, breaking out bars for bottom and side breaking are required, and if properly skilled assistance is not available a considerable amount of the ice will in all probability be broken up and wasted. The wastage of ice in an ice store not artificially cooled from January to July is, in the United States, at the rate of about o-i Ib. of ice per twenty-four hours for each square foot of wall surface, or say from 5 to 10 per cent, of the ice stored during the six months. The amount of heat that will pass through a square foot of ice one inch in thickness is put at 10 British thermal units per hour for each degree Fahrenheit difference between the respective temperatures on each side of the sheet of ice. In handling and selling ice, the waggons should be clean and sanitary, the men in charge should avoid walking about in them with dirty boots, and blocks of ice should not be deposited and slid about on filthy pavements. These 114 REFRIGERATION AND ICE-MAKING. matters are attended to in the United States, but here they are totally neglected. In the United States the selling and delivery of ice is generally done by the coupon system, which is thus described by Prof. Siebel : " It is a system of keeping an accurate account with each customer of the delivery of and the pay- ment for ice by means of a small book containing coupons, which in the aggregate equal 500 or 1000 or more pounds of ice taken by the customer every time ice is delivered. These books are used in the delivery of ice in like manner as mileage books or tickets are used on the railroad. A certain number of coupons are printed on each page, each coupon being separated from the others by perforation, so that they are easily detached and taken up by the driver, when ice is delivered. Such books are each supplied with a receipt or due bill, so that if the customer purchases his ice on credit, all that is necessary for the dealer to do is to have the customer sign the receipt or due bill and hand him the book containing coupons equal in the aggregate to the number of pounds of ice set forth in the receipt or due bill. The dealer then has the receipt or due bill, and the customer has the book of coupons. The only entry which the dealer has to enter against such purchaser in his books is to charge him with coupon book number, as per number on book, to the amount of 500, 1000, or more pounds of ice, as the value of the book so delivered may be. The driver then takes up the coupons as he delivers the ice from day to day." SECTION IV INSULATION. IN addition to non-conducting qualities, a good insulating material should be non-odorous, non-hygroscopic, not liable to silt, and both vermin and fire-proof. Perfect insulation would be attained when there was absolutely no transmission of heat through the walls of the building, which state of things is practically an impossibility. Every one should, however, endeavour to secure as near an approximation to the above as possible, and it should be remembered that poor insulation is a constant drain upon the machinery and pocket of the owner, as a very large percentage of the actual work of a refrigerating machine is that required to make up for the transfer of heat through the walls, floor, and ceiling of the cold store, resulting from defective insulation. In the following tables the results of a number of tests as to the values of different insulating materials are given, and from these tables may be deduced sufficient .information to enable an intelligent choice to be made. In Australia pumice stone is much used, and is said to give good results. In this country and the United States silicate cotton or slag- wool; cork, in slabs, bricks, and granulated; and char- coal are employed, and there is something to be said in favour of each of these materials. When charcoal is employed it should be well dried, and packed as nearly as possible to a consistency of 1 1 Ibs. per cubic foot. Silicate cotton or slag-wool is usually packed to a consistency of about 1 2 Ibs. per cubic foot, one ton equalling about 187 cubic feet. Some engineers prefer, however, to use 13 Ibs. per cubic foot. An advantage possessed by granulated cork is its extreme lightness. One cubic foot weighs only 4-| Ibs., and one ton occupies about 450 cubic feet. REFRIGERATION AND ICE- MAKING. TRANSMISSION OF HEAT THROUGH VARIOUS INSULATING STRUCTURES. (Starr, American Warehouse-merits Assoc.} Col. I. gives B.T.U. per square foot per day per degree of difference of temperature. Col. II. gives meltage of ice in pounds per day by heat coining through 100 square feet at a difference of 40. Col. I. Col. II. One f-in. board, 2-in. mineral wool, paper, one f-in. board 3-62 101-9 Two -in. double boards and two papers, i-in. hair-felt 3*318 93-4 Two |-in. boards and paper, i-in. sheet cork, two -in. boards and paper .. .. .. .. .. 3-30 92-9 One f-in. board, paper, 2-in. calcined pumice, paper, and ^-in. board .. .. .. .. .. 3-38 95-2 One f-in. board, paper, 3-in. sheet cork, paper, one ^-in. board .. .. .. .. .. .. 2'io 60*0 Double boards and papers, 4-in. granulated cork, double boards and paper .. .. .. .. .. 1-70 48-0 RESULTS OF TESTS TO DETERMINE THE NON-CONDUCTIVE VALUES OF DIFFERENT MATERIALS. (H. F. Donaldson, M.I.C.E., Proceedings, Inst. C.E.) EXPERIMENT No. i. Weigh t after Thickness . . Loss after of Insulating Material. Weight of Ice. Twenty- four Seventy- two Seventy- two Hours. Hours. Hours. Peat (compressed Inches. Ozs. Ozs. Ozs. Per cent. and set in Fossil Meal) . . 9 95 8l 59 37-89 Charcoal .. ii 79 56 4**97 Silicate Cotton . 4* 9 2 I 73 4l 56-21 Magnesia and As bestos Fibre . 4* 93 73 4J 5 6 '45 NOTE. The author thought it undesirable to consider further com- pressed peat set in fossil meal, as he found by experiment its powers of absorption of moisture to be so great as to constitute in his opinion a source of danger. INSULATION. EXPERIMENT No. 2. 117 Weight after Thickness Original Loss after of Insulating Material. Weight Ice. Twenty- four Forty- eight Ninety- six Ninety- six Hours. Hours Hours. Hours. Inches. Ozs. Ozs. Ozs. Ozs. Percent. Silicate Cotton 6 104 88f 76| 5i 4375 Sawdust 9 I03l 86J 71 4 8 52-62 Peat 9 104 77& 56 26 74*75 Charcoal 9 104 88f 78* 60* 41-82 EXPERIMENT No. 3. Weight after Thickness of Insulating Material. Original Weight of Ice. Loss after Seventy- two Hours. Twenty- four Seventy- two Hours. Hours. Silicate Cotton . . Inches. 9 Ozs. 9 2 Ozs. 83 Ozs. 7*i Per cent. 2I-I9 Charcoal II 9 2 fej 70* 23-36 EXPERIMENT No. 4. Thickness of Insulating Material. Original Weight of Ice. Weight after Loss after Ninety- six Hours. Twenty- four Hours. Ninety- six Hours. Silicate Cotton (loosely packed) Silicate Cotton . . Charcoal Vegetable Silica . . Diatomite Inches. 9 9 II II II Ozs. 1 10 1 10 no 110 110 Ozs. I0 3 lOlf I00| I0l 99 Ozs. 8 4i & 731 Per cent. 23-41 26-59 28-18 30-22 32-95 REFRIGERATION AND ICE-MAKING. RESULTS OF TESTS TO DETERMINE THE NON-CONDUCTIVE VALUES OF VARIOUS MATERIALS. (Dr. Wm. Wallace.} Cubic MATERIALS. Centimetres (grammes) of water melted Average c.c.'s per day. in 12 days. Silicate Cotton 9.470 789 Flake Charcoal 11,010 917 Felt .. 11,760 980 Fossil Meal .. 12,530 ,044 Twig Charcoal I3>590 ,132 Plain Cork Slabs 14,020 ,168 Tarred Cork Slabs I4,6lO ,217 Broken Lump Charcoal I59l6 ,326 Ashes 23,316 ,943 Coleman's method was used in making the above tests, with walls 6 in. thick. RATE OF PASSAGE OF HEAT THROUGH VARIOUS MATERIALS. (Alex. Manet.) British Thermal Units per hour per superficial foot through materials 6 in. thick. T = 60 T = 50 T = 4 o Dry. Wet. Dry. Wet. Dry. Wet. Silicate Cotton 4-11 2-14 8-57 I-I7 670 Cow Hair . . Charcoal .. Sawdust . . Infusorial Earth 4-11 4-70 6-75 10-00 8-80 12-30 15-60 2'34 2'93 6-18 5'30 9-60 I-I7 1-76 2'34 3*57 3-50 4-40 5*50 Cork Bricks 5-87 ~ 3*20 -~ 2-90 ~~ T = The Difference of Temperature (Fahr.) on material. the two sides of the INSULATION. IIQ RESULTS OF TESTS ON THE HEAT CONDUCTIVITY OF DIFFERENT SUBSTANCES ( Various authorities.) (Silicate Cotton being taken at 100.) SUBSTANCE. C.E. Emery, 1881. J.J.Cole- man, 1884. W. H.' Collins, 1891. Prof. Jamieson 1894. Silicate Cotton or Slag Wool . . 100 100 100 100 Hair- Felt or Fibrous Composition 117 114 112 Papier-Mache J 47 III Kieselguhr Composition ijs 112 Sawdust . . . . 122 163 142 Charcoal 132 140 __ Cotton Wool 122 ___ Sheep's Wool 136 __ Pine Wood (across the grain) ISO Loam . . ___ Gasworks Breeze or Coal Ashes 24O 230 299 Asbestos 22 9 179 ~~~ TABLE GIVING THE RELATIVE HEAT CONDUCTIVITY OF VARIOUS BOILER-COVERING MATERIALS. (The "American Engineer.") 100 117 Silicate Cotton or Mineral Wool Hair Felt .. .. _ .__ ,. CottonWool .. ^.. ,122 Sheep's Wool 136 Infusorial Earth Charcoal . . Sawdust Gasworks Breeze Wood and air space 136 140 163 230 280 I2O REFRIGERATION AND ICE-MAKING. RESULTS OF EXPERIMENTS REGARDING NON HEAT-CON- DUCTING PROPERTIES OF VARIOUS SUBSTANCES. (Prof.J. M. Ordway.) Coverings i inch thick. Pounds of Water heated 10 F. per hour by i sq. foot. II " Silicate Cotton" or " Slag Wool " 13-0 2 Paper 14-0 3 Cork Strips, bound on 14-6 4 Straw Rope, wound spirally 18-0 5 Loose Rice Chaff 187 6 / 7 Blotting Paper, wound tight Paste of Fossil Meal and Hair 21'0 167 i 8 Loose Bituminous Coal Ashes 21'0 J 9 Paste of Fossil Meal with Asbestos 22-0 t 10 Loose Anthracite Coal Ashes 27-0 11 Paste of Clay and Vegetable Fibre 30-9 \ I2 Dry Plaster of Paris 30-9 13 Asbestos Paper, wound tight 217 14 Air alone 48-0 I< Fine Asbestos 49 'O 16 Sand 2-16 * These substances are not well suited for covering heated surfaces owing to their nature they soon become carbonised. t Hard substances that, with the action of the heat, break, powder, and fall off. N.B. The Asbestos of 15 had smooth fibres, which could not pre- vent the air from moving about. Later trials with an Asbestos of exceedingly fine fibre have made a somewhat better showing, but Asbestos is really one of the poorest non-conductors. By reason of its fibrous character it may be used advantageously to hold together other incombustible substances, but the less the better. NON HEAT-CONDUCTING PROPERTIES OF VARIOUS SUB- STANCES. (From " Engineering."} Prepared Mixtures, for Covering Boilers, Pipes, &c. Pounds of Water heated 10 Fahr. per hour, per square foot. Slag Wool (Silicate Cotton) and Hair Paste Fossil Meal and Hair Paste Paper Pulp alone Asbestos Fibre, wrapped tightly Fossil Meal and Asbestos Powder Coal Ashes and Clay Paste, wrapped with Straw Clay, Dung, and Vegetable Fibre Paste . . Paper Pulp, Clay and Vegetable Fibre lO'O 11 10-4 147 17-9 26-3 29-9 39-6 44-6 )S. INSULATION. 121 RESULTS OF EXPERIMENTS REGARDING NON HEAT-CON- DUCTING PROPERTIES OF VARIOUS SUBSTANCES. (Walter Jones, "Heating ly Hot Water.") Frame Filled with Left for Highest Temp. Registered. Leroy's Boiler-covering Composition . . Asbestos Powder 3 hours 4 94 86 Hair Felt 9 77 Silicate Cotton . . 9 76 HEAT IN UNITS TRANSMITTED PER SQUARE FOOT PER HOUR THROUGH VARIOUS SUBSTANCES. (Peclet.) Materials. Units of heat trans- mitted. Materials. Units of heat trans- mitted. Gold . ^ 625 Guttapercha '37 Platinum 600 India-rubber 36 Silver . 595 Brickdust, sifted . '33 Copper 520 Coke, in powder . 29 Iron 230 Iron filings . 26 Zinc 225 Cork . !5 Tin 178 Chalk, in powder 0-86 Lead Charcoal (wood) in pow Marble 24 der . 0-63 Stone Glass r '-3^3^ a f-H H S|l ||| Jl 11 ^^ o| o H Ibs. oz. Degr. Cent. Dry air . 6-0 0-0000558 i-oo Fossil meal composition . Cement with hair felt* . 7 2 5 15 M-5 30-0 0-0002689 0-0003613 4-82 6-47 Silicate cotton, f or slag wool .... 29-0 0-0003875 6-95 Kieselguhr J composition Papier mache composition Fibrous composition (flax, hemp, cow-hair, and clay) Papier mache composition|| 7 13 7 6 9 9 8 12 29-0 35'5 34'5 37'5 0-0004336 0-0004424 0-0004550 0-0005019 7'77 7'93 7-98 8-99 * The outside diameter of this sample was about in. smaller than the inside diameter of the middle tin-case or vessel, and it had consequently a slight advantage over ths other samples in having a thin layer of air between its outer surface and the latter. f The silicate cotton was pressed together tightly, and thus its conductivity appears greater than would have been the case had it been more loosely packed. J The Kieselguhr employed consisted on the average of Silica 83-8, Magnesia 0-7, Lime O-8, Alumina ro, Peroxide of Iron 2-1, Organic Matter 4-5, Moisture and Loss, 7-1. It was employed in conjunction with 10 per cent, of binding material, viz., fibre and mucilaginous extract of several vegetable matters. Papier mache composition, consisting of paper pulp mixed with clay and carbon, together with hair and fragments of hemp rope. || A lighter modification of above. The quantity of heat in units, transmitted through one ^quare foot of plate per hour, may be found thus : Subtract INSULATION. 123 the temperature of the cooler side from that of the hotter side of the plate, then multiply the result by the number in the table on p. 121 corresponding to the material used, and divide the product by the thickness of plate in inches. Thus an iron plate 2 in. thick, having a temperature of 60 on one side and 80 on the other, will transmit 80 60 X fMp- = 2300 units of heat per square foot per hour. HEAT-CONDUCTING POWER OF VARIOUS SUBSTANCES, SLATE BEING 1000. (Molesworth.) Slate .... 1,000 Lead . . . .5,210 Flagstone . . .1,110 Portland stone . . 750 Brick . . . 600 to 730 Fire-brick . . . 620 Chalk Asphalt . Oak . Lath and plaster Cement . 564 45i 336 255 200 TESTS REGARDING CONDUCTIVITIES OF ASBESTOS AND KIESELGUHR. (/. G. Dobbie.) RESULTS OF TESTS. Asbestos. Kieselguhr Com- position. Water Condensed in Inches. Water Condensed in Inches. After 15 minutes . 30 45 60 . Totals in one hour . 4 3! 3t 31 a| 2 f 2 I Hi 9i 124 REFRIGERATION AND ICE-MAKING. RESULTS OF DIFFERENT EXPERIMENTS ON THE HEAT CON- DUCTIVITIES OF VARIOUS SUBSTANCES. (W. H. Collins?) (Silicate cotton being taken as 100.) Substance. fl M Woo e rt if H^ | .00 it 70 Cement with hair-felt . Silicate cotton or slag wool . Hair-felt or fibrous composition 83 IOO IOO 117 IOO 114 147 93 IOO 112 III Kieselguhr composition . 122 136 14.2 112 Charcoal 140 122 Pine wood (across the grain) . Loam Gasworks breeze or coal ashes Asbestos 240 229 230 299 179 EXPERIMENTS BY T. B. LIGHTFOOT AND G. A. BECKS. EXPERIMENT No. i. Duration of experiment, 48 hours. Average temperature of room or chamber, 90 F. A piece of ice 23 Ibs. in weight was placed in a zinc box 12 in. cube, and covered with 2 in. silicate cotton, this latter being provided with an outer cover, also of zinc. When the ice was taken out it weighed io Ibs., showing a loss of i2 Ibs. i2\ Ibs. x 142 (latent heat of ice) = 1775 thermal units passed through in 48 hours, ^-p = 36*979166 thermal units passed through in i hour. Difference in temperature between inner box and outer air = 58 F. - - = 0*63 thermal unit transmitted per hour per degree difference in temperature. Area of zinc boxes : inner box, 6 sq. ft. ; outer, 10*6 sq. ft. ; mean, 8'i sq. ft. INSULATION. 125 Thermal units transmitted through the three areas O'lOfj) O*O7) = O'O^Q o 8*1 1 0*6 which being multiplied by 2 for the thickness of cotton, gives thermal units per hour, per degree difference in temperature, per square foot, per inch of thickness, as follows : o'2io inner tin, q'ii8 outer tin, 0*14 mean. EXPERIMENT No. 2. Duration, 48 hours. Average temperature of room, 90 F. A piece of ice 26 Ibs. in weight, covered with 6 in. of charcoal. When taken out it weighed 7^ Ibs., showing a loss of i8|- Ibs. 18-5 X 142 = 2627 thermal units in 48 hours. -Hip- = 54*72 thermal units per hour. *-$$* = 0*94 thermal units per hour, per degree difference in temperature between inner box and outer air. Area of tins : inner box, 6 sq. ft.; outer, 24 sq. ft.; mean, 13-5 sq. ft. The number of thermal units transmitted per hour, per degree, per square foot -6* = ' IS> 7?-5 = ' 69 ' ^ = ' 39 which being multiplied by 6 for the thickness of charcoal, gives thermal units transmitted per hour, per degree, per square foot, per inch of thickness; 0*90 inner tin, 0*234 outer tin, 4*14 mean. FORMULA FOR ASCERTAINING UNITS OF REFRIGERATION (R) REQUIRED IN 24 HOURS, TO CARRY OFF HEAT RADIATED THROUGH SQ. FT. (/) OF WALL, FLOOR, AND CEILING. HU = heat units of 772 ft. Ibs., / = internal temperature, /! = external temperature, and n - heat units transmitted per 24 hours per sq. ft. of surface for difference of i Fahr. between internal and external temperature. 126 REFRIGERATION AND ICE-MAKING. TRANSMISSION OF HEAT THROUGH VARIOUS INSULATING STRUCTURES. (Starr, American Warehousemen, 's Assoc.) Insulating Structures. B. T. U. per sq. ft. per day per deg. of difference of tempera- ture. Meltage of ice in Ibs. per day by heat coming through 100 sq. ft. at a difference of 40. jj-in. oak, paper, i-in. lampblack |-in. pine (ordinary Stock family refrigerator) 57 160*7 ^-in. board, i-in. pitch, |-in. board 4-90 138-0 Four |-in. spruce boards, two papers, solid, no air-space 4-28 I20'0 Two double boards and paper (four J-in. boards), and one air-space 37i I05'0 |-in. board, 2-in. pitch, |-in. board 4*25 II9-7 ^-in. board, 2^-in. mineral wool, paper, |-in. board 3-62 101-9 Two ^-in. double boards, and two papers, i-in. hair felt 3*3*8 93*4 Two ^-boards and paper, i-in. sheet cork, two |-in. boards and paper 3'3o 92*9 2-in. board, paper, 2-in. calcined pumice, paper, and |-in. board 3-38 95'2 Four double |-in. boards with paper between (eight boards), and three 8-in. air-spaces 27 76-0 Hair quilt insulator, four boards, four quilts hair 2-517 70-9 7 -in. board, 6-in. pat. silicated straw-board, air-cell finished inside with thin layer of patent cement 2-48 69-8 g-in. board, paper, 3-in. sheet cork, paper, |-in. board 2'10 6o'o Two |-in. boards and paper, 8-in. mill shavings and paper, two ^-in. boards and paper . . _ Same, slightly moist II 38;3 Same, damp 2'10 6o'o Double boards and paper, I -in. air, 4-in. sheet cork, paper, $-in. board I'2O 33'6 Same, with 5-in. sheet cork o % 9O 25-3 J-in. board, paper, i-in. mineral wool, paper, g-in. board. . 4'6 130-0 Double boards and papers, 4-in. granulated cork, double boards and paper 17 48-0 INSULATION. 127 WALLS FOR COLD STORES. The following materials and dimensions have been re- commended for walls of cold chambers : 14 in. brick wall, 3^ in. air space, 9 in. brick wall, i in. layer of cement, i in. layer of pitch, 2 in. by 3 in. studding, layer of tar paper, i in. tongued and grooved boarding, 2 in. by 4 in. studding, i in. tongued and grooved board, layer of tar paper, and, finally, i in. tongued and grooved boarding, the total thickness of these layers or skins being 3 ft. 3 in. 36 in. brick wall, i in. layer of pitch, i in. sheathing, 4 in. air space, 2 in. by 4 in. studding, i in. sheathing, 3 in. layer of mineral or slag- wool, 2 in. by 4 in. studding, and, finally, i in. sheathing ; total thickness, 4 ft. 7 in. 14 in. brick wall, 4 in. pitch and ashes, 4 in. brick wall, 4 in. air space, 14 in. brick wall ; total thickness, 3 ft. 4 in. 14 in. brick wall, 6 in. air space, double thickness of i in. tongued and grooved boards, with a layer of water- proof paper between them, 2 in. layer of the best quality hair felt, second double thickness of i in. tongued and grooved boards, with a similar layer of paper between them ; total thickness, 2 ft. 2 in. 14 in. brick wall, 8 in. layer of sawdust, double thickness of i in. tongued and grooved boards, with a layer of tarred waterproof paper between them, 2 in. layer of hair felt, second double thickness of i in. tongued and grooved boards, with a similar layer of paper between them ; total thickness, 2 ft. 4-| in. Brick wall, 3 in. scratched hollow tiles, 4 in. silicate cotton or slag-wool, 3 in. scratched hollow tileSj and layer of cement plaster. Brick wall, i in. air spaces between fillets or strips, i in. tongued and grooved boarding, two layers of insulating paper T in. tongued and grooved boarding, 2 in. by 4 in. studs, 1 6 in. apart, spaces filled in with silicate cotton, i in. tongued and grooved boarding, two layers of insulating paper, air spaces between fillets, or strips i in. by 2 in. spaced 16 in. apart from centres, i in. tongued and grooved boarding, two layers of insulating paper, and i in. tongued and grooved boatding. 128 REFRIGERATION AND ICE-MAKING. Brick or stone wall, well coated on inside with pitch or asphaltum, 2 in. by 3 in. studding, 24 in. centres spaces between filled in with silicate cotton, f- in. rough tongued and grooved boarding, two layers waterproof insulating paper, f- in. rough tongued and grooved boarding, 2 in. by 3 in. studding 24 in. centres in spaces between, f in. rough tongued and grooved boarding, two layers of waterproof insulating paper, f in. rough tongued and grooved boarding, 2 in. by 3 in. studding, 24 in. centres spaces between filled in with silicate cotton, in. rough tongued and grooved boarding, two layers of waterproof insulating paper, and J in. tongued and grooved match-boarding. Paper to be laid one-half lap and cemented at all joints. Brick wall 2 in. air space, 2 in. thicknesses of tongued and grooved boards with three layers of paper between, 2 in. air space, 2 in. thicknesses of tongued and grooved boards with three layers of paper between, 2 in. air space and 2 in. thicknesses of tongued and grooved boards with three layers of paper between. Brick wall well coated with pitch, 2 in. air space, 2 in. thicknesses of tongued and grooved boards with three layers of paper between, 2 in. space filled with slag-wool or cork, 2 in. thicknesses of tongued and grooved boards, with three layers of paper between, 2 in. space filled with slag-wool or cork, 2 in. thicknesses of tongued and grooved boards with three layers of paper between. Shelving should be fixed horizontally in the spaces packed with slag-wool or cork at about 16 in. apart. Brick wall, i in. air space, f in. match-boarding, 9 in. slag-wool or silicate cotton, layer of insulating paper, and J in. match-boarding. Brick wall, i in. air space, 6 in. slag-wool or silicate cotton, i in. silicate of cotton slab, layer of insulating paper, i- in. air space, and j in. match-boarding. Brick wall, i in. air space, i in. silicate of cotton slab, 4 in. silicate of cotton, i in. silicate of cotton slab, -^ in. air space, and J in. match-boarding. Brick wall well coated with pitch, 2 in. air space, | in. tongued and grooved boarding, two layers of paper, J in. tongued and grooved boarding, 4 in, slag-wool or silicate cotton, & in. tongued and grooved boarding, two layers of INSULATION. 129 paper, -J in. tongued and grooved boarding, 2 in. air space, - in. tongued and grooved boarding, two layers of paper, and % in. tongued and grooved boarding. Brick wall, 2 in. air space, in. tongued and grooved boarding, two layers of paper, -J- in. tongued and grooved boarding, 2 in. air space, J- in. tongued and grooved board- ing, two layers of paper, and | in. tongued and grooved boarding. Brick wall, 2 in. air space, -| in. tongued and grooved boarding, one layer of paper, 4 in. slag-wool or silicate cotton, J in. tongued and grooved boarding, one layer of paper, 4 in. air space, -J in. tongued and grooved board- ing, two layers of paper, and | in. tongued and grooved boarding. Brick wall, layer of pitch, f in. tongued and grooved boarding, 2 in. air space, J in. tongued and grooved board- ing, one layer of paper, 3 in. cork dust, f in. tongued and grooved boarding, two layers of^ paper, and | in. tongued and grooved boarding. Brick wall, 2\ in. air space ventilated by air-bricks every 5 feet in all directions, i in. tongued and grooved boarding, layer of insulating paper, i in. tongued and grooved boarding, 12 in. charcoal supported by horizontal shelving 28 in. centres apart, i in. tongued and grooved boarding, two thicknesses of brown paper, and i in. tongued and grooved boarding. Wall of cold storage room when made of wood : 2 in. thicknesses of tongued and grooved boarding with three layers of paper between, 2 in. air space, 2 in. thicknesses of tongued and grooved boarding with three layers of paper between, 2 in. air space, 2 in. thicknesses of tongued and grooved boarding with three layers of paper between, 2 in. air space, 2 in. thicknesses of tongued and grooved boarding with three layers of paper between, 8 in. slag-wool or silicate cotton, and i in. tongued and grooved boarding. 2 in. boards, $\ in. by 3 in. uprights, spaces between filled with carefully dried wood charcoal, i-| in. boarding, layer of insulating paper, and i in. boarding. Outside siding, two layers of insulating paper, i in. tongued and grooved boarding, 2 in. by 6 in. studdings, 1 6 in. apart from centres, i in. tongued and grooved boarding, 130 REFRIGERATION AND ICE-MAKING. two layers of insulating paper, i in. tongued and grooved boarding, 2 in. by 4 in. studding 16 in. apart from centres, spaces filled in with silicate cotton, i in. tongued and grooved boarding, two layers of insulating paper, 2 in. by 2 in. fillets or strips 16 in. apart from centres, i in. tongued and grooved boarding, two layers of insulating paper, and 1 in. tongued and grooved boarding. DIVISIONAL PARTITIONS FOR COLD STORES. Tongued and grooved match-boarding, wire netting, 6 in. silicate of cotton or slag-wool, wire netting, tongued and grooved match-boarding. The object of the netting is to render the partition fire-proof by supporting the silicate of cotton after the match-boarding might have burnt away. % in. match-boarding, ^ in. air space, i in. silicate cotton slab, 4 in. of silicate of cotton or slag-wool, i in. silicate of cotton slab, J in. air space, and i in. silicate of cotton slab. 2 in. tongued and grooved boarding, with three layers of paper between, 2 in. silicate of cotton or cork, 2 in. tongued and grooved boarding with three layers of paper between, 2 in. silicate of cotton or cork, 2 in. tongued and grooved boarding with three layers of paper between. in. tongued and grooved boarding, two layers of paper, in. tongued and -grooved boarding, 4 in. silicate cotton or slag-wool, J in. tongued and grooved boarding, 2 in. air space, J in. tongued and grooved boarding, two layers of paper, and in. tongued and grooved boarding. | in. tongued and grooved boarding, two layers of paper, | in. tongued and grooved boarding, 6 in. silicate of cotton or slag-wool, in. tongued and grooved boarding, two layers of paper, J in. tongued and grooved boarding, 2 in. air space, J- in. tongued and grooved boarding, two layers of paper, and -J in. tongued and grooved boarding. | in. tongued and grooved boarding, 2 in. silicate cotton or slag-wool, f in. tongued and grooved boarding, 2 in. air space, in. tongued and grooved boarding, two layers of paper, and in. tongued and grooved boarding. { in. tongued and grooved boarding, two layers of paper, | in. tongued and grooved boarding, 2 in. air space, J in. INSULATION. 131 tongued and grooved boarding, two layers of paper, and J in. tongued and grooved boarding. J in. tongued and grooved boarding, two layers of paper, |- in. tongued and grooved boarding, 8 in. silicate cotton or slag-wool, | in. tongued and grooved boarding, two layers of paper, and -| in. tongued and grooved boarding. |- in. tongued and grooved boarding, two layers of paper, -| in. tongued and grooved boarding, 4 in. silicate cotton or slag-wool, -| in. tongued and grooved boarding, two layers of paper, and | in. tongued and grooved boarding. -J in. tongued and grooved boarding, two layers of paper, ! in. tongued and grooved boarding, 2 in. hair felt, |- in. tongued and grooved boarding, 2 in. silicate cotton or slag- wool, |- in. tongued and grooved boarding, two layers of paper, and J in. tongued and grooved boarding. FLOORING FOR COLD STORES. 2 in. flooring, two layers of paper, -J in. tongued and grooved boarding, 2 in. air space between fillets or scant- lings, -f in. tongued and grooved boarding, 12 in. joists, spaces between packed with silicate cotton or slag- wool, | in. tongued and grooved boarding, two layers of paper, | in. tongued and grooved boarding, 2 in. air space between fillets and scantlings, J- in. tongued and grooved boarding, two layers of paper, and -f in. tongued and grooved boarding. 2 in. cement, 3 in. concrete, -J in. tongued and grooved boarding, two layers of paper, 2 in. flooring, 4 in. silicate cotton between fillets or scantlings, -J in. tongued and grooved boarding, two layers of paper, and 2 in. flooring boards on fillets or scantlings set in concrete. 2 in. asphalte, -J in. tongued and grooved boarding, two layers of paper, J- in. tongued and grooved boarding, 2 in. air space between scantlings, f in. tongued and grooved boarding, 3 in. silicate cotton or slag-wool between fillets or scantlings, J- in. tongued and grooved boarding, 2 in. air space between fillets or scantlings, concrete. i in. asphalte, 2 in. concrete, in. pitch, 2 in. concrete, brick arches. i-j in. tongued and grooved flooring, layer of insulating 132 REFRIGERATION AND ICE-MAKING. paper, 2 in. by 9 in. joists, 12 in. centres apart, spaces filled with silicate cotton or slag-wool, wire netting, layer of insulating paper, f- in. match-boarding on 2 in. by 2 in. fillets or scantlings air spaces between, existing wooden or concrete flooring. The wire netting secured to the under side of the joists serves to retain the silicate cotton in case of fire. 1 in. tongued and grooved boarding, three layers of insulating paper, i in. tongued and grooved boarding, 2 in. by 9 in. joists, spaces between filled in with silicate cotton or cork, i in. tongued and grooved boarding, three layers of insulating paper, and i in. tongued and grooved boarding. ij in. tongued and grooved flooring, layer of insulating paper, 2 in. by 9 in. joists, 12 in. centres apart, spaces between filled in with silicate cotton or slag-wool, i in. silicate cotton slab on ! in. by 2 in. fillets air spaces between, and f in. match-boarding. The i in. silicate of cotton slab is nailed on the under side of joists and is claimed to render the floor fire-proof, and to prevent radiation through the joists. 2 in. matched flooring, two layers of insulating paper, i in. matched sheathing, 4 in. by 4 in. sleepers 16 in. apart from centres, spaces between filled in with silicate cotton, double i in. matched sheathing with twelve layers of paper between, and 4 in. by 4 in. sleepers 16 in. apart from centres imbedded in 12 in. of dry underfilling. Ground, concrete, layer of asphalte, i in. tongued and grooved match-boarding well tarred, two layers of stout brown paper, i in. tongued and grooved match-boarding, floor joists 3 in. by n in. spaced 21 in. apart, binder joists ii in. by 4 in., bearing edges of floor joists protected by strips of hair felt ^ in. thick and spaces between joists filled in with flake charcoal, and ij- in. tongued and grooved flooring boards. As a further example of methods that have been actually successfully employed for insulation, it will be interesting to know that the cold storage chambers built at the St. Katherine Dock, London, were constructed as follows : On the concrete floor of the vault, as it stood originally, a covering of rough boards ij in. in thickness were laid INSULATION. 133 longitudinally. On this layer of boards were then placed transversely, bearers formed of joists 4^ in. in depth by 3 in. in width, and spaced 21 in. apart. These bearers supported the floor of the storage chamber, which consisted of 2\ in. battens tongued and grooved. The 4^ in. wide space or clearance between this floor and the layer or covering of rough boards upon the lower concrete floor was filled with well-dried wood charcoal. FLOORING FOR ICE HOUSES. Floor to incline 3 in. towards central drain, and cross channelled fillets or scantlings on i^ in. flooring, 2 in. cement, 6 in. concrete, ground. i in. tongued and grooved match-boarding, three layers of paper, i in. tongued and grooved match-boarding (to incline 3 in. towards central drain) on fillets or scantlings, air spaces between, i in. tongued and grooved match- boarding, three layers of paper, i in. tongued and grooved match-boarding, 2 in. by 9 in. joists spaces between filled with 4 in. silicate of cotton or slag-wool kept in position by f in. boards secured by cleats to joists. CEILINGS FOR COLD STORES AND ICE HOUSES. i in. tongued and grooved match-boarding, three layers of insulating paper, i in. tongued and grooved match- boarding, 2 in. air spaces between strips or fillets, i in. tongued and grooved boarding, three layers of insulating paper, i in. tongued and grooved boarding, joists spaces between filled with silicate cotton or cork, i in. tongued and grooved match-boarding, three layers of insulating paper, and i in. tongued and grooved match-boarding. Insulated flooring, joists, -| in. tongued and grooved match-boarding, two layers of insulating paper, |- in. tongued and grooved match-boarding, 2 in. spaces between strips or fillets filled in with silicate cotton or cork, % in. tongued and grooved match-boarding, three layers of in- sulating paper, and f in. tongued and grooved match- boarding. i in. tongued and grooved boarding, two thicknesses of 134 REFRIGERATION AND ICE-MAKING. brown paper, i in. tongued and grooved boarding, joists with spaces between packed with silicate cotton, i in. tongued and grooved boarding, Willesden paper, and i in. tongued and grooved boarding. Concrete floor, 3 in. book tiles, 6 in. dry underfilling, double space hollow tile arches and layer of cement plaster. Double i in. floor with two layers of insulating paper between, 2 in. by 2 in. strips or fillets 16 in. apart from centres, spaces filled in with silicate cotton, two layers of insulating paper, i in. tongued and grooved match-board- ing, 2 in. by 2 in. strips 16 in. apart, spaces filled in with silicate cotton, two layers of insulating paper, i in. tongued and grooved match-boarding, joists and double i in. flooring with two layers of insulating paper between. DOOR INSULATION. i in. tongued and grooved match-boarding, three layers of insulating paper, i in. tongued and grooved match- boarding, 2 in. by i in. fillets or strips, with spaces between filled in with silicate cotton or cork, i in. tongued and grooved match-boarding, three layers of insulating paper, i in. tongued and grooved match-boarding, 2 in. by i in. fillets or strips, spaces between filled in with silicate cotton or cork, i in. tongued and grooved match-boarding, three layers of insulating paper, and i in. tongued and grooved match-boarding. i in. tongued and grooved match- boarding, two layers of insulating paper, i in. tongued and grooved match-boarding, 1 2 in. space filled in with silicate cotton, i in. tongued and grooved match-boarding, two layers of insulating paper, and i in. tongued and grooved match-boarding. WINDOW INSULATION. Windows are better dispensed with in cold stores and artificial light resorted to; where present, three sashes spaced a few inches apart and glazed at both sides should be used. INSULATION. 135 TANK INSULATION. Tank sides: 4 in. air space between studding, i in. tongued and grooved match-boarding, three layers of insulating paper, i in. tongued and grooved match-board- ing, 4 in. space filled with cork, i in. tongued and grooved match-boarding, three layers of insulating paper, i in. tongued and grooved match-boarding, 2 in. air space, i in. tongued and grooved match-boarding, three layers of insulating paper, and i in. tongued and grooved match- boarding. Bottom : i in. space between strips, fillets or studding, well tarred before tank is placed in position, i in. tongued and grooved match-boarding, three layers of in- sulating paper, i in. tongued and grooved match-boarding, i in. air space between strips, fillets or studding, i in. tongued and grooved match-boarding, three layers of insulating paper, i in. tongued and grooved match-boarding, and 2 in. by 9 in. joists on concrete or ground spaces between filled with cinders. Tank : 2 in. air space between fillets, f- in. tongued and grooved match-boarding, two layers of insulating paper, in. tongued and grooved match-boarding, 4 in. silicate cotton or slag-wool, f- in. tongued and grooved match- boarding, two layers of insulating paper, and in. tongued and grooved match-boarding. Tank: 2 in. air space between studding, layer of in- sulating paper, 2 in. flooring, two layers of insulating paper, | in. tongued and grooved boarding, joists, spaces between filled with charcoal for three-quarters depth, in. tongued and grooved match-boarding, two layers of insulating paper, J in. tongued and grooved match-boarding, ground or concrete. SECTION V. TESTING AND MANAGEMENT OF REFRI- GERATING MACHINERY. TESTING. THE testing of a refrigerating plant is carried out for the purpose of ascertaining what it is capable of performing under comparable normal conditions, and as to the amount of refrigeration produced in relation with the expenditure of work, and the coal consumption. To determine the efficiency of an installation on the compression system, the following instruments and fittings are required, viz. : An indicator, so that diagrams can be taken from the compressor ; stroke counters, to enable the number of strokes made by the steam-engine and brine pumps to be ascertained; and mercury wells to admit of the temperature being obtained at various points through- out the system. In making a test it is desirable that it should last at the very least for fully 12 hours, and it is better to carry it on for 24 hours. The number of readings which it is desirable should be taken from the various in- struments will vary in accordance with whether or not the work is steady or otherwise, and the person carrying out the test will have, of course, to use his own judgment on this head. Where artificial ice is made, for example, twice an hour will be sufficient, whilst on the other hand, four or more readings per hour should be taken in cases where the variation in the temperature of the materials to be cooled is wide. Indicator diagrams should be taken from both the steam-engine cylinder and the compressor cylinder every two hours. TESTING AND MANAGEMENT OF MACHINERY. 137 A mercury well, for an horizontal pipe, when the latter is of sufficient dimensions, consists usually in a short piece of tubing closed at its lower end, and fitted into the pipe by means of a suitable bushing. It is filled about three parts full of mercury, and the thermometer, which should have an elongated cyclindrical bulb, is held in position therein by means of a perforated cork. For vertical pipes, or pipes of very small dimensions, where this arrangement would be impracticable, the well is generally formed by means of a wooden or other block, one side of which is shaped to the outline of the pipe to which it is to be applied, and has a suitable recess formed therein. This block is firmly secured against the pipe by metal strips in such a manner that a portion of the wall of the well will be formed by the pipe, the latter being scraped perfectly clean at that part. The joint between the block and the pipe must be made perfectly tight, which can easily be effected by means of a little white-lead paint, there being no pressure, and the whole should be surrounded by a thick layer of non-conducting composition, through which the stem of the thermometer is permitted to project. The points in the system where it is desirable to locate the mercury wells are : The suction pipe just at its connection with the compressor; the discharge pipe, as close as possible to its connection with the compressor; the ammonia discharge pipe from the condenser, as near the latter as practicable. Where a brine circulation is employed : The pipe or manifold supplying the various coils or sets of pipes in the refrigerator ; the discharge pipe of the refrigerator ; the brine discharge pipe, at the point where it connects to the refrigerator ; and the brine return pipe in proximity to where it connects with the refrigerator. INTERPRETATION OF COMPRESSOR DIAGRAM. The interpretation of a compressor diagram with respect to the working, valves, defects, etc., of the latter are given as follows by Hans Lorenz, in " Neuere Kuehlmaschinen," Muenchen and Leipzig, 1899. Assuming all the parts of the machine to be in good order, then the diagram will have the general appearance 138 REFRIGERATION AND ICE-MAKING. shown in Fig. 23. The suction line S is only slightly below the suction pressure line V, and the pressure line D is only slightly above the condenser pressure K. Small projections at the pressure and suction line indicate the work required to open the compressor valves, and the effect of clearance is shown by the curve R, which latter cuts the back pressure line after the piston has commenced to perform its return or back stroke, and consequently reduces the suction volume to that amount. It can also be seen from this diagram that the vapours are taken in by the compressor, not at the back pressure, but at what may be called the suction pressure, which is somewhat lower. This is the reason that the compression curve C does not intersect the back pressure line until after the piston has changed its direction of movement. The theoretical volume of the compressor, as indicated by the line V, is consequently reduced in practical working for vapours possessing a certain tension. In Fig. 24 is shown a diagram taken from a compressor having an excessive amount of clearance. In this case, it will be seen, the back expansion line R passes through a flat course, and thereby reduces the useful volume of the compressor. Fig. 25 is a diagram which indicates the binding of the pressure valve, which may be due to an inclined position of the guide rod of the valve. This deficiency also fre- quently causes a delay in the opening of the pressure valves, a state of things indicated by a too great projection in the pressure line. As soon as the valve is once opened the pressure line pursues its normal course until the piston commences its return stroke, when the defect is again manifested in the back pressure line, as mentioned. Fig. 26 shows a diagram indicating too great a resistance in the pressure and suction pipes respectively, when the valves are over-weighted. In this case the pressure and suction line are at a comparatively great distance from the condenser pressure line and the back pressure line. The remedy for this is to replace the valve springs by weaker ones ; and should there be then no marked effect, then the pipe-lines and shutting-off valves should be inspected, and, if found necessary, cleaned. TESTING AND MANAGEMENT OF MACHINERY. 139 FIG. 23. Diagram from Compressor with all parts in good order. FIG. 24. Diagram from Compressor with excessive amount of clearance. ATMOSPHERIC LINE. FIG. 25. Diagram from Compressor indicating the binding of the Pressure Valve. FIG. 26. Diagram from Compressor indicating too great a resistance in the Pressure and Suction Valves. I4O REFRIGERATION AND ICE-MAKING. FIG. 27. Diagram from Compressor indicating the binding of the Suction Valve. MMOSPHERIC LINE. FIG. 28. Diagram from Compressor indicating leaking of Compressor Valves. Vr- ATMOSPHCRIC LINE. J FIG. 29. Diagram from Compressor indicating Defective Packing of Piston. TESTING AND MANAGEMENT OF MACHINERY. 141 Fig. 27 indicates the binding of the suction valve by which a considerable decline is caused in the pressure at the beginning of the suction, which is consequently shown by an increased projection in the commencement of the suction line. At the beginning of compression this defect makes itself felt by causing a delay in the latter, which effect is also shown on this diagram. Fig. 28 shows leaking of the compressor valves. In this diagram the projections in the compression and suction line do not appear, but the compression line gradually merges into the pressure line, and the back expansion line passes gradually into the suction line. If the leak in the pressure valve is the predominant one, then the compres- sion curve will be almost in a straight line and very steep ; if, on the contrary, the leak in the suction valve is the predominant one, then the compression line will run a rather flat course. Fig. 29 indicates that the piston is not well packed, and, being leaky, the vapours are permitted to pass from one side of the piston to the other, thus causing a very gradual compression, and as a result a compression line having a flat course. On the other hand, a longer time will be taken before the suction line reaches its normal level on the return or backward stroke, inasmuch as the suction valve is prevented from opening until such time as the velocity of the piston becomes such that the amount of vapours leaking past the piston is insufficient in amount to fill the suction space. The pressure then gradually diminishes and the suction valve then begins to act, as is shown on the diagram. It is to be understood that several of the defects above mentioned may exist at the same time. MANAGEMENT OF AMMONIA COMPRESSION MACHINES. Every particular type of machine working on this prin- ciple has, as a rule, certain distinctive or characteristic features, and will, of course, so far at least as these are concerned, require special care and adjustment, and it would consequently be totally impossible to lay down an arbitrary set of rules for working that would be suitable to 142 REFRIGERATION AND ICE-MAKING. all; nor is this necessary or required, as full particulars relating to the manipulation of each particular machine are invariably supplied by the makers. The following points, however, are more or less applicable to all machines working on the ammonia compression principle, and should therefore be familiar to those in charge of the same. Before charging an empty machine with anhydrous ammonia, all air must first be carefully expelled. This is effected by working the pumps so as to discharge the air through special valves which are usually provided on the pump dome for that purpose. The entire system should have been previously to this thoroughly tested by working the compressor, and per- mitting air to enter at the suction through the special valves provided for that purpose, and it should be perfectly tight at 300 Ibs. air pressure on the square inch, and should be able to hold that pressure without loss. Whilst testing the system under air pressure, it should be also carefully blown through and thoroughly cleansed from all dirt, every trace of moisture being also removed. It is totally impossible to eject all air from the plant by means of the compressor, therefore it is advisable to insert the requisite charge of ammonia gradually and not all at once, the best practice being to put in from 60 to 70 per cent, of the full charge at first, and cautiously permit the air still remaining to escape through the purging-cocks with as little loss of gas as possible, subsequently inserting an additional quantity of ammonia once or twice a day, until all the air has been got rid of by displacement, and the complete charge has been introduced. To charge the machine, the dryer or dehydrator of the apparatus for manufacturing or generating anhydrous am- monia, or where no such apparatus is included in the installation, the drum or iron or steel flask of anhydrous ammonia should be connected, through a suitable pipe, to the charging valve; the expansion valve must be then closed, and the valve communicating with the dryer or dehydrator, or that in the flask or bottle, opened. The machine should be run at a slow speed when sucking ammonia from the drier, or whilst the flask is being emptied, with the discharge and suction valves full open. TESTING AND MANAGEMENT OF MACHINERY. 143 In the latter case, when one of the said flasks or bottles has been completely emptied, it must be removed, the charging- valve having been first closed, and another placed in position, until the machine is sufficiently charged to work, when the charging- valve should be finally closed, and the main expansion valve opened and regulated. A glass gauge upon the liquid receiver will show when the latter is partially filled, and the pressure gauges, and the gradual cooling of the brine in the refrigerator (in the case of a brine circulation or ice-making apparatus), and the expansion pipe leading to the refrigerator coils becoming covered with frost, indicate when a sufficient amount to start working has been inserted. It is sometimes advisable to slightly warm the vessels or bottles containing the anhydrous ammonia by means of a gas jet, or in some other convenient manner, whilst transferring their contents to the machine, as otherwise, if frost forms on the exterior of the said bottles, they will not be completely discharged, and loss of ammonia will ensue. The flasks, bottles, or other receptacles containing the anhydrous ammonia should be always kept in a tolerably cool and a perfectly safe situation, and they should more- over be moved and handled with the utmost caution and care. In the event of an accident occurring, and any con- siderable quantity of the ammonia becoming spilt, it is well to remember that it is so extremely soluble in water that one part of the latter at a temperature of 60 Fahr. will absorb some 800 parts of the ammonia gas, therefore water should be employed to kill or neutralise it, and any person attempting to penetrate an atmosphere saturated with this gas should not fail to place a cloth well saturated with water over his nose and mouth. The machine having been started, and the regulating valve opened, it is essential to note carefully the tempera- ture of the delivery pipe on the compressor, and if it shows a tendency to heat, then the said regulating valve must be opened wider; whilst, on the contrary, should it become cold, this valve must be slightly closed, the regulation or adjustment thereof being continued until the normal 144 REFRIGERATION AND ICE-MAKING. temperature of the delivery pipe is the same as that of the cooling water leaving the condenser. When the charge of ammonia in the machine is insufficient, the delivery pipe will become heated, and that even when the regulating valve is wide open. There are many additional signs of the healthy working of the apparatus other than the fact that it is satisfactorily performing its proper refrigerating duty, which soon become easily recognisable to those in charge ; for example, every stroke of the piston will be clearly marked by a corre- sponding vibration of the pointers or indexes of the pressure and vacuum gauges. The frost visible on the exterior of the ammonia pipes leading to and from the refrigerator will be about the same. The liquid ammonia can be distinctly heard passing in a continuous and uninterrupted stream through the regulating valve. The temperature of the condenser will be about 15 higher than that of the cooling water running from the overflow. And finally, the tem- perature of the refrigerator will be about 15 lower than the actual temperature of the brine or the water being cooled. Air will find its way into the system through leaky stuffing-boxes, improper regulation of the expansion valve, etc. Its presence in any considerable volume is shown by a kind of whistling noise, the liquid ammonia passing through the expansion valve in an intermittent manner, a rise of pressure in the condenser, and also loss of efficiency thereof, and other obvious signs. In this case the above air must be got rid of through the purging-cocks in a similar manner to that which remains in the system when first charging the machine. The presence of any considerable amount of oil or water in the system, which may result from careless distillation, will cause a reduction in efficiency, and will be evidenced by shocks within the compressor cylinder. The temperature can be regulated either by running the machine at a higher speed or by increasing the back pressure, or by a combination of both. The back pressure can be regulated by means of an expansion valve or valves fitted between the receiver and the refrigerator evaporating coils or pipes in the main liquid pipe. TESTING AND MANAGEMENT OF MACHINERY. 145 LEAKS IN AMMONIA APPARATUS. Leaks are readily detected by the smell of the escaping ammonia gas when the machine is being filled ; at a later stage, when working, their detection is not so easy. During the operation of the machine, when the liquor or brine in the tanks commences to smell of ammonia, it indicates a considerable leakage. It is recommended to test the liquor or brine periodically with Nessler's solution or otherwise. Nessler's reagent, which is the best to use for the dis- covery of traces of ammonia in water or brine, consists of 17 grms. of mercuric chloride dissolved in about 300 cc. of distilled water, to which are added 35 grms. potassium iodide dissolved in 100 cc. of water, and constantly stirred until a slight permanent red precipitate is produced. To the solution thus formed are added 120 grms. of potassium hydrate dissolved in about 200 cc. of water, allowed to cool before mixing ; the amount is then made up to i Itr., and mercuric chloride added until a permanent precipitate again forms. After standing for a sufficient time, the clear solution can be placed in glass-stoppered blue bottles and kept in a dark place. If a few drops of this reagent be added to a sample of the suspected brine or water in a test-tube, or other small vessel, and the slightest trace of ammonia is present, a yellow colouration of the liquid will take place; a large quantity of ammonia will produce a dark-brown. When the leaks are comparatively insignificant they can be closed in the usual way, by solder, using as a flux muriatic or hydrochloric acid killed with zinc. In some instances electric welding may be resorted to with advantage, or the leak may be closed by means of a composition of litharge and glycerine mixed into a stiff paste, bound with sheet-rubber, and covered with sheet-iron clamped firmly in position. When, however, the leak is at all serious, it is usually the better plan to at once put in a new coil, or a new length of pipe. LEAKS IN CARBONIC ACID MACHINES. To detect these, smear the joints with a solution of soap and water, and any leakage of gas will be evidenced by the 146 REFRIGERATION AND ICE-MAKING. formation of bubbles. Carbon dioxide or carbonic acid being a completely inodorous gas, precautions are required to prevent the unnoticed occurrence of leakage. Before closing this chapter, a few words upon the excess condensing pressure invariably found in ammonia com- pression machines will not be out of place. This excess of the actual working condensing pressure over the theo- retical is caused by the ammonia gas being imprisoned in the comparatively confined space afforded by the coils or pipes in the refrigerator, and the excess pressure is more marked in a horizontal compressor running at a high speed of, say, 140 revolutions per minute, than it is in vertical ones having only a tow speed of from 35 to 60 revolutions per minute; it varies, moreover, in almost every make of compressor. At a low suction pressure of about i5lbs. it should not be more than iolbs., but with a suction pressure of, say, 27 or 28 Ibs. it may rise to 50 Ibs., or even more. The condensing pressure affords a means of ascertaining whether or not the apparatus contains the proper full charge of ammonia, or if the losses sustained by leakage are sufficient to render it necessary to insert an additional supply. For this reason it is advisable for the person in charge to keep a record in a proper book, suitably ruled for the purpose, of the temperature of the condensed ammonia when leaving the condenser, and also of the condensing and suction pressures, at regular intervals of, say, three hours. This will enable him to follow the state of the ammonia charge; for example, if the condensing pressure is found to be gradually falling during a three months' period, as compared with the average condensing pressure of the previous three months, whilst at the same time the condensing temperature and the suction pressure remain constant, it will be evident that the charge of ammonia has become reduced by leakage to a sufficient extent to require replenishing. This reduction in the condensing pressure is caused by the diminution in the charge of ammonia giving larger condenser space, the gas having thus a much more extended worm, coil, or tube space wherein to condense and liquefy, and hence the decrease. As a general rule, it may be taken that, when- ever the condensing pressure is found to have fallen about TESTING AND MANAGEMENT OF MACHINERY. 147 81bs., enough ammonia to restore the original condensing pressure should be inserted into the machine. LUBRICATION OF REFRIGERATING MACHINERY. This important point is apt to be as much neglected by users of refrigerating machinery as it is by those of other types of machinery. It would be well for these gentlemen to at once dismiss from their minds the idea that low-priced inferior quality oils are really the cheapest, and understand that, on the contrary, not only are high-grade oils necessary to ensure the .highest efficiency of the machinery, but that they are also the least expensive in the long run. In refrigerating machinery the use of three different kinds of oil is demanded, viz. steam cylinder oil ; oil for general use ; and compressor pump oil : Oil for the steam cylinder. Good cylinder oil is entirely free from grit, does not gum up the valves and cylinder, and does not evaporate rapidly on exposure to the heat of the steam. The quality of a cylinder oil is demonstrated on removal of the cylinder head. If the oil is of good quality, the wearing surfaces should appear well coated with lubricant, which will not show a gummy deposit, or blacken on the application of clean waste. Oil for general use on all the bearings and wearing surfaces of the machine proper : This may be any oil that will not gum, is not too limpid, possesses a good body, is free from grit and acids, is of good wearing quality, and flows freely from the oil-cups at a fine adjustment without a tendency to clog. For the larger bearings it is well to use a heavier grade of oil. Oil for use in compressor pumps : This should be what is known as zero oil, or cold test oil, that is to say, it should be capable of withstanding a very low temperature without freezing, and it should be of the best quality. American makers recommend the use of the best paraffin oil, and clear West Virginia crude oil 148 REFRIGERATION AND ICE-MAKING. rf 1 Gallons to date. I suopjpuoo 4J C s ajn^BaadaisjQ 3 i J8SU9pUOD Ul'E9}S JSuiA'Bgf UO 91^M ;0 9jniBJ9dtU91 '['BUI J P- 1 -^ s uasugpuoD uiB9^s Suua; n TD us uo jaiBM. }0 gjn^Bjgduiaj N U U9SU9pUOO BlUOUI g? UIOOH z* -o M Is B.S ujoo-a ii - ON uioo>i 01 'ojvj w u , c; tuoo'jj 6 'o^j jj 1, 1 moo^ 8 -o N & ^ ft uioo>[ L 'o^ "rt ^ S uioo-g 9 -O^Q; U * 1 y uioo~jj S 'o^ 15 "o ^ 'C H .t 1 >. E s ^ moon e . ON . c uioo~g z 'N l| g uioo-a i -o N n w uinnDBA uiBa^g M ^ ~ a uuinjoD jg^M JI^BS Jo auug 2 jine Roor < '9ui3u3 ^ -OK "3 ~g '9uiSa3[ z 'O^j . c i o H *^ H fl -amSug i -o^i a M % 9jnss9Jd uopong w Pft^ Qj aanssgad ^39JiQ c ano H a TESTING AND MANAGEMENT OF MACHINERY. 149 LIGHTING COLD STORES. It is desirable that daylight should not be allowed to enter a cold store, and therefore artificial light is usually resorted to, electric light being invariably employed, owing to there being practically an absence of heat therefrom. Incandescent lamps should be always used inside the cold stores, but arc lamps may be placed, if desired, in the engine-room, and employed for the external lighting of the premises. Lower voltage lamps are the most durable, and serve the purpose quite as well as those of a higher voltage. The mains should be kept as far as practicable in the corridors, and tinned cables of high conductivity and with rubber insulation should preferably be employed. Iron piping, steel conduits, or wood casing, may be used for carrying the main cables, the latter being the cheapest both in cost of material and in fixing, and also lending itself more] readily to any subsequent alterations that may become necessary. Steel conduits, however, possess several important advantages. The steel-armoured insulating con- duit material now much used is installed in a similar manner to ordinary gas-pipe construction, the principal difference in electric piping being that specially insulated boxes, bends, elbows, etc., are substituted for the ordinary tees or angles of a gas-pipe system. The use of the conduit system ensures a mechanically and electrically protective duct for the installation of the electric conductors. When wood casing is used, the interior should be painted with asbestos paint, and the cover fixed with brass screws on each edge, not in the central fillet. Iron piping has an internal lining of suitable insulating material, and is, as a rule, coated with a bituminous com- pound of some description intended to act as a preservative. There are two systems of carrying out wiring now in use, viz. the tree system, and the distributing-board system. In the first of these, or the tree system, two main cables are carried through the building, the branch circuits being all taken from these cables or mains. In the second, or distributing-board system, a main switchboard is placed close to the dynamo, from which main switchboard cables are carried to supplementary distributing boards located at convenient points, from which the lamps are wired. 150 REFRIGERATION AND ICE-MAKING. An obvious advantage of this latter plan is that all the joints are readily get-at-able, being at the distributing boards and fittings. The insulation of the cable is left completely intact. In fixing wood casing all joints should be united, and no sharp edges or corners left for the cable to pass over. The casing is ordinarily secured by screws to the walls, floors, and ceilings, and either on the surface, partially sunk, or sunk flush therewith. In very damp situations, however, the casing should be supported, so as to be clear of the surfaces, by means of small porcelain insulators. The circuits may be arranged either on the series system or on the parallel arrangement, the latter being the most common, and the former being, as a rule, only employed where a number of arc lamps are used. The series circuit and parallel circuit are shown in the diagrams (Figs. 30 and 31), the dynamos, main cables, lamps, and switches being indicated thereon. In the series circuit the current is maintained constant in value, the difference in pressure varying with the work on the circuit. In the parallel circuit all the lamps are connected as separate paths between the two main leads, each path being quite independent of the other paths. The difference of electrical pressure is maintained constant, the current varying with the work that is on the circuit. The switching off of a lamp causes a break in the wires connecting the lamp to the circuit. MAIN CABLE FIG. 30. Diagram illustrating Arrangement of Electric Lighting on the Series Circuit System. CABLE. CABLE FIG. 31. Diagram illustrating Arrangement of Electric Lighting on the Parallel Circuit System. SECTION VI. GENERAL TABLES AND MEMORANDA. EXPERIMENTS IN WORT COOLING. THE following tabulated experiments of the performance of a tubular refrigerator for wort cooling are gleaned from Engineering. The water and wort are moved in opposite directions, the former through thin metallic tubes, which are surrounded by the wort to be cooled : fi ' WORT. WATER. 11 1* i t i fi i p, si" ~ H H u |l H H * Square Feet. Bbls. Fahr. Fahr. Fahr. Bbls. Fahr. Fahr. Fahr. No. i. 881 33'9 212 72 140 61-1 6.5 169" 104 No. 2. 514 i -104 36-1 i.55 59 96 75'5 54 100 46 No. 3. 514 1-188 36-6 191 59 132 99'5 54 100 40 No. 4. 514 1-035 47'3 193 59 134 90-7 54 100 4 b No. 5. 514 1-018 48-0 178 59 119 102-0 54 100 46 NOTE I. A barrel contains thirty-six gallons, or 360 Ibs. of water. NOTE 2. The temperature of the air in Nos. 2 and 4 was 44 F. t and in Nos. 3 and 5, 40 F. 152 REFRIGERATION AND ICE-MAKING. TABLE SHOWING THE TENSION OF AQUEOUS VAPOUR IN MILLIMETRES OF MERCURY, FROM 30 C. TO 230 C. (Siebert.) Temp. Tension. Temp. Tension. Temp. Tension. Temp. Tension. -30 0'39 18-5 94'o 610-4 104 876 -25 o'6i 22 197 94*5 622-2 i5 907 10 0-9 23 20-9 95*0 633-8 107 972 -15 i'4 24 227 95-5 645-7 no 1,077 10 2'I 25 23-6 96-0 657-5 "5 1,273 -5 3'i 26 25*0 96-5 66 9 - 7 1 20 1,491 2 4-0 27 26-6 97-0 682-0 125 1,744 I 4*3 28 28-1 97-5 694-6 130 2,030 4-6 2 9 29-8 98-0 707-3 135 2,354 I 4'95 30 31-6 98-5 721-2 140 2,717 2 5*3 35 41-9 99-0 732-2 US 3,125 3 57 40 55-o 99-1 735'9 150 3,58i 4 6-1 45 7i'5 99'2 738-5 155 4,088 5 6-5 5o 92-0 99-3 741-2 1 60 4,55i 6 7-0 55 ii7'5 99'4 743-8 165 5, 2 74 7 7'5 60 148-0 99-5 746-5 170 5,96i 8 8-0 65 186-0 99-6 749-2 175 6,717 9 8-6 70 232-0 99-7 75I-9 1 80 7,547 10 9-1 75 287*0 99-8 754-6 185 8,453 ii 97 80 354'Q 99'9 757-3 190 9,443 12 10-4 85 432-0 loo-o 760-0 195 10,520 13 ' u-i 90 525H lOO'I 762-7 200 11,689 H 11-9 90-5 535-5 100-2 765-5 205 12,956 15 127 91 - o 545-8 ioo"4 772-0 210 M,3 2 5 16 13*5 9i'5 556-2 100-6 776-5 215 15,801 17 14-4 92-0 566-2 lOI'O 787-0 220 17,390 18 19 It:] 92-5 93 -o 577'S 588-4 102-0 103-0 816-0 845-0 225 2 3 19,097 20,926 20 17-4 93*5 599'5 DegreesC 120 134 144 152 159 171 180 190 213 235 Atmospheres 2 3 4 5 6 8 10 15 20 25 GENERAL TABLES AND MEMORANDA. 153 T3 1 1 Ill^ll Co 1 3 ; 3 3 3 3 3 D 3 3 : : 000 0~-r o "3 "3 S'oMM-o'B U U UU OCJ |'||l *b * J b H ' b oT c5 ! M - M ^ Cj "; en o^d ^ 00 N cO ^D ^ ^ ^ ^ S ~ l|l i r^H^ : : r , | 111 Freezing- point Centigrade. B | ^ . >p s p oo r o s T T ? T r fa i 1 " 1 o 6 D Q r. ll!S |^]jppp-p|^ a s&E V-V^ --^ ' A iSiS O O O O O >OVO O OO ON 8" S|f ^ s s s&as^s g; 1 * d "^O 10 O oo tnoo ^ r 1 " " i S 9/2 48.1 SKJJ sfj??f!!^ S; 1 1 1| "a 1 3s 1 I 1 IQ q "'^ ? a s ' ; : s ; ; ; : ; .s: : :i::' z g .0 j * 5 ' 'o| <"" K s" ** " 1 *s S 'S i o ^2 B q c ra H fe ow W Scj'S'^oSS W E 154 REFRIGERATION AND ICE-MAKING. TABLE SHOWING PROPERTIES OF SATURATED STEAM. Yaryan. Absolute Pressure from Vacuum. Above Atmosphere. Tempera- ture. Deg. Fahr. Total Heat in British Units. Heat of Vaporiza- tion or Latent Heat. Ibs.per Square In. Inches of Mercury. Ibs. per Square In. Inches of Mercury. I 2-0355 -I3-7 -27-886 101-99 III3-I 1043-0 2 4-0710 -12-7 -25-851 126-27 II20-5 1026-1 3 6-1065 -11-7 -23-815 141-62 1125-1 1015-3 4 8-142 -10-7 21-780 I53-q9 II28-6 1007-2 5 10-178 -9'7 -I9-744 162-34 II3I-5 iooo-8 6 12-213 -8-7 -I7-709 170-14 II33-8 995-2 7 14-249 -7'7 -I5-673 176-90 II35'9 990-5 8 16-284 -6-7 -I3-638 182-92 II37-7 986-2 9 18-320 -5'7 I I -602 188-33 II39-4 982-5 10 20-355 -4'7 -9'567 I93-25 II40-9 979-0 ii 22-319 -3'7 -7-531 I.97-78 1142-3 975-8 12 24-426 -2-7 -5-496 201-98 1143-6 972-9 13 26-462 -1-7 -3-460 205-89 II44-7 970-1 14 28-497 -07 -1-425 20^-57 II45-8 967-5 I 4 7 29-922 o-o O'OOO 212-00 1146-6 965-8 15 30-533 0-3 0-611 213-03 1146-9 965-1 16 32-568 i'3 2-646 2I6-32 II47-9 962-8 17 34-604 2'3 4-682 219-44 1148-9 960-6 18 36-639 3'3 6-717 222-40 II49-8 958-5 19 38-675 4'3 8-753 225-24 II50-7 956-6 20 40-710 5'3 10-788 227-95 II5I-5 954-6 21 42-746 6-3 12-824 230'55 II52-3 : 952-8 22 44-781 7'3 I4-859 233-06 II53-0 951-0 23 46-787 8-3 I5-895 235-47 II53-7 949-2 2 4 48-852 9'3 18-930 237-79 II54-4 947-6 25 50-888 10-3 20-966 240-04 H55' 1 946-0 26 52-923 11-3 23-007 242-2I 1155-8 944-6 27 54-972 12-3 25-043 244-32 ii5 6 -5 943-1 28 57-oo8 I3-3 27-079 246-36 1157-1 941-7 29 59-044 I4-3 29-115 248-34 ii57-7 940-3 30 61-080 I5-3 3IT43 250-27 1158-3 938-9 31 63-116 16-3 33-I87 252-I5 1158-8 937-5 32 65-152 I/-3 35-223 253-98 II59-4 936-3 33 67-188 18-3 37-239 255-76 II59-9 935' 34 69-224 I9-3 39-295 257-50 1160-4 933-7 35 71-260 20-3 41-321 259-19 1161-0 932-6 36 73-296 21-3 43-367 260-85 1161-5 93I-5 37 75-33I 22-3 45-3!9 262-47 1162-0 930-3 38 77-367 23-3 47-397 264-06 1162-5 929-2 39 79-403 24-3 50-463 265-61 1163-0 928-2 GENERAL TABLES AND MEMORANDA. 1 55 TABLE SHOWING PROPERTIES OF SATURATED STEAM. Yaryan.- Continued. Absolute Pressure from Vacuum. Above Atmosphere. Tempera- ture. Deg. Fahr. Total Heat in British Units. Heat of Vaporiza- tion or Latent Heat. Ibs.per Square In. Inches of Mercury. Ibs. per Square In. Inches of Mercury, 40 81-439 25-3 5!'499 267-13 1163-4 927-0 41 83*475 26-3 53-534 268-62 1163-9 926-0 42 85-5II 270-08 1164-3 925-0 43 87;547 28-3 57*619 27I*5I 1164-8 924-0 44 S9'655 272-91 1165-2 923-0 45 91-619 30-3 61-691 1165*6 922-0 46 93-655 63-727 275-65 Il66*O 92I-O 47 95-691 32-3 65-763 276-99 1166-4 920-1 48 97*727 33-3 67-799 278-30 II66-8 919-2 49 99-763 34-3 69-835 279-58 II67-2 918-3 50 101-799 35-3 71-871 280-85 Il67*6 917-4 55 111-98 40-3 82-050 286-89 1169-4 913-1 60 122-16 45-3 92-230 292-51 II7I-2 909-3 65 I32-34 50-3 102-410 297-77 II72-7 905-5 70 142-52 55-3 112-59 302-71 "74*3 9O2T 75 152-70 60-3 122-77 307-38 ii75*7 898-8 80 162-88 65*3 132-95 3II-80 1177-0 895*6 85 173-06 7'3 I43-I3 316-02 1178-3 892*5 90 185-24 75*3 I53-3I 320-04 1179-6 889-6 95 I93H2 80-3 163-49 323-89 1180-7 886*7 100 203-06 85-3 173-67 327*58 1181-9 884-0 105 213-78 90-3 185-85 33I-I3 1182-9 881-3 no "5 223-96 95-3 100-3 194-03 203-67 334-56 337-86 1184-0 1185-0 878-8 876-3 120 244-32 105-3 214-39 34I-05 1186-0 874-0 125 130 254-50 264-68 110-3 "5*3 224-57 234-75 344*13 347-12 1186-9 1187-8 871*7 869-4 135 274-86 120-3 244-93 350-03 1188-7 867-3 140 285-04 125-3 352*85 1189-5 865-1 H5 295-22 130-3 265-29 355-59 1190-4 863-2 150 305-40 I35-3 275-47 358-26 1191-2 861*2 1 60 325*76 145-3 295-83 363-40 1192-8 857-4 170 345-82 I55-3 316-19 368-29 "94*3 853*8 180 366-48 165-3 336-55 372-97 "95*7 850-3 190 386-84 I75-3 356-9 1 377-44 1197-1 847-0 200 407-20 185-3 377-27 1198-4 843-8 5 6 REFRIGERATION AND ICE-MAKING. M 3 H * " 8,1 21^1 t^t^-OO CO Tt- covO <-< vo O O "* CO ^vO 1>.00 O H M TJ- ITNVQ t^ fe wit * 00000 MHHM " M "" 1 iiii^ f^H c^ ro Ti~ i-Oi^.CO QNO M C^ rOrf i ^3 P* b b b b b b b b b b b b b b 8 N o rf-g* j^fr" ON C^ d ^O OO OO vO ^f-O N M t-i rfvC 00 N VD t^ ^~ rj-oo "O t~ O ""> O O CO H Q 55 >ii|^ CN M 1 =7 ..J* . N ^ SB *T 1 OO vr> O 00 ^^^^^^^^^ H fc ? W| N M M ooooooooo .|= S ^X W "rt O Tt-oo CNVT N co O Th>O vo v> N 00 O >> p/ DH ^i g rf\O t^ t^OO H 5 | H i g . LO W> PH c/2 S> < I W g rt Q ** ' rt K H ro I-H ONiO"- t-- ON COOO COOO Tf- O MD 2 1 H m COO t-iOri-CON - M C/3 3 g, CNTJ-CON WNMMMMM ^ M 5 B O t^ ON t^ -coco.0~r.O P< 1 H M N CO COOO O VO ON c^ o o ONt^^i-t-ii^Noo rj- to u">vQ t^-OO OO ON ON WNMMMNNMN h || cooo r^>O if O "H co vot- N ro M H-I oo t^.vo 10 co * ON ** co T^N^O oo O c^ ^i* a 1 11 "^ es O O O O -i N CO Tj - vovO t^OO ON O >-i N co M M Mt M PH o (4 PH ui -bs aqj ud -sq[ ui M M C 5?RS*!f&IM^ GENERAL TABLES AND MEMORANDA. 157 > 6- M . 'I'? Jj'Ks O N i-or^ON>-i co^ot-^ONO M -^-vo ON O ** C*i CO '-OVO t^OO ON >H C^ CO ^ wO 1"! * NN-i t-i O ON ONOO "-VO t^OO ON O "-> N corhvounvo t^ o- j " oooooooooooooo 1*0! ^ -w a O 03 4> filii O oo *-o T^ cs O ^oO vo ^-O T^ ro ^o c^ ^^^^^f^f,,^^^^^^^^,^ rt 5, O O b b b b b b b b b b b " COOO M rJ-vO OO ON O O O O ONOO t> r^ vg g. ON O "- N co "^vo r^oo 00 ON O WNNNNNNNMNNNNN 1 B u ri-fOMrorh^M^rhOON^vo^ Q g h |l CO O ^* ^ *^ OO VO CO >* ONvO ^* N O O O ON ON ONOO OOOOOO t^t^r^t^fC. ON ONOO 0000000000000000000000 Id H .*S " O ON ONOO 00 00 t>. t-^Q VO VO VO VO V) 3 & &M b b b b b b b b b b b b b I o ON mO n N *H 00 covO O M N N O H N t^MVO O Thr~xi-i Vj-OO M r^ t^ b fOCOCOCOCOCOCOCOCOCOCOCOCOCO ll ^ N 1-1 vo l~>.vo 10 CO co >-i OO t-vO VOOO O i-< cOiot-^ONiH co xovo 00 O H u H O 3 22 s M" iovO r^oo ON O "-" N co rj- iovo tv. P *JJ Ps-''^NNcOfO 158 REFRIGERATION AND ICE-MAKING. O H Q 5 I if 8 * I 2" W 1 i ".M tf rt \g W l^>. ON ^ ^- W t->* O ^O LO t^-* O N LO OO O^ O *^ ^" LO I^CO O O N PO *^" ^ I"! * rocOCOfO^^^r)-^-^^-^^- Ij: j. a y OO O^ O *" C^ ro Tt- -OO r^*CC OO O^ *' I Q * bbbbbbbbbbbob ill illfif *8&SSfi*&3*8fc |jg .g> 2 g- 13 pjjbbbbbobbbbbbb 3 LOThN OCOO POO^rJ-i-.<^i-H POLO 11 ii 'n^rt MV o LO LO LO LOO O O O vO O t^O r-^. OO O"\ O M N PO Tj- uoO t^OO O^ O P-5 m 'bs 9qj no *sqi UT Tj- -^- LO LOO O t^ t^OO OO ON C\ O GENERAL TABLES AND MEMORANDA. 159 HEAT OF COMBUSTION OF VARIOUS FUELS. Equivalent Total Evaporative Air Chemically Heat of Power, from Fuel. Consumed Combustion and at 212 per Ib. of Fuel. of i Ib. F., Water of Fuel. per Ib. oi Fuel. Ibs. Cub Ft. at 62 Units. Ibs. F. Asphalt 11-85 156 17,040 17-64 Coal of average composition 107 140 14,700 15-22 Coke I0-8l 142 I3.54 8 14-02 Lignite 8-85 146 13,108 !3'57 Peat, desiccated 7-52 99 12,279 12-71 Peat, 30 per cent, moisture. . Peat charcoal, desiccated . . 5-24 9'9 69 130 8,260 12,325 9'53 12-76 Petroleum .. .. ^.. I4'33 188 20,411 21-13 Petroleum oils I7-93 235 27,531 28-50 Straw 4-26 56 8,144 8 '43 Wood charcoal, desiccated . . 9'5 I I2 5 13,006 J 3'46 Wood, desiccated 6-09 80 10,974 11-36 Wood, 25 per cent, moisture 4'57 60 7,95i 8-20 Coal gas, per cubic foot at 62 F ~ ~ 630 0-70 PERCENTAGES, HANDY RULE. Regard percentages as a decimal fraction, and with it multiply the whole number wanted. For example, 16 per cent, of 80 is 80 X 0-16 = 12 '8. l6o REFRIGERATION AND ICE-MAKING. SPECIFIC HEAT OF WATER AT VARIOUS TEMPERATURES. Units of Heat Units of Heat Tempera- ture. Dee. Fahr. Specific Heat. required to raise i Ib. of Water from 32 F. to given Tempera- ture. Deg. Fahr. Specific Heat. required to raise i Ib. of Water from 32 F. to given Temperature. Temperature. 32 oooo O'OOO 248 I-OI77 217-449 50 0005 I8-004 266 "O2O4 235791 68 'OOI2 36-018 284 0232 254-187 86 'OO2O 54*047 3O2 "0262 272-628 104 0030 72-090 3 20 0294 291*132 122 OO42 90-I57 338 0328 309-690 140 0056 I08-247 356 0364 328-320 158 0072 126-378 374 '0401 347-004 I 7 6 0089 144-508 392 0440 365-760 I 94 0109 I62-686 410 0481 384-588 212 I-OI30 180-900 428 0524 403-488 230 I'OI53 I99-I52 446 0568 422-478 SPECIFIC HEAT OF METALS, ETC. METALS. STONES (contd.) Antimony Bismuth 0-0507 0*0308 Chalk Quicklime 0-2148 0*2169 Brass 0-0939 Magnesian limestone 0*2174 Copper 0-0951 Cymbal metal 0*086 Gold 0-0324 CARBONACEOUS. Iridium Iron, cast wrought 0-1887 0-1298 0*1138 Coal Charcoal Cannel coke 0*2411 0*2415 0*2031 Lead Manganese .. Mercury, solid liquid Nickel 0-0314 0-1441 0-0319 0-0333 o'io86 Coke of pit coal Anthracite Graphite, natural . . ,, of blast furnaces 0*2008 0*2017 0-2019 0*197 Platinum, sheet 0-0324 spongy . . 0*0329 Silver 0-0570 SUNDRY. Steel 0-1165 Glass 0*1977 Tin 0*0569 Ice 0*504 Zinc 0-0959 Phosphorus 0-2503 Soda 0-2311 STONES. Sulphate of lead . . 0*0872 Brickwork & masonry 0'20 ,, of lime 0-1966 Marble 0*2129 Sulphur 0-2026 GENERAL TABLES AND MEMORANDA. 161 SPECIFIC HEAT OF LIQUIDS. Alcohol 0-6588 Turpentine . . 0*4160 Benzine . . 0-3932 Vinegar 0-9200 Mercury 0-0333 Water at 3 2 F. I'OOOO Olive oil 0-3096 212 F. . 1-0130 Sulphuric acid 32t02I2F 1-0050 Density, 1-87 I-30 0-3346 0-6614 Wood spirit . . Proof spirit . . 0*6009 0-973 SPECIFIC HEAT OF GASES. For Equal Weights. (Water = i.) At Constant Pressure. At Constant Volume. Air 0-2377 0-1688 Carbonic acid (CO 2 ) 0*2164 0-1714 oxide (CO) 0-2479 0-1768 Hydrogen 3-4046 2-4096 Light carburetted hyd ogen 0-5929 0-4683 Nitrogen 0*2440 0-1740 Oxygen 0-2I82 0-1559 Steam, saturated 0-3050 Steam gas 0-4750 0-3700 Sulphurous acid 0-1553 0*1246 BRITISH THERMAL UNIT, OR HEAT UNIT. Amount of heat necessary to raise the temperature of i Ib. of water i by the Fahr. scale when at 39*4 (temp, of max. density). Mech. eq. 778 ft.-lbs. FRENCH CALORIE, ENGLISH EQUIVALENT. Unit of heat used on the Continent with the metrical system. Amount of heat required to raise i kilo, of water through i Cent. B.T.U. X 0-252 = calorie. Calories X 3-968 = B.T.U. 162 REFRIGERATION AND ICE-MAKING. Loss OF PRESSURE BY FRICTION OF COMPRESSED AIR IN PIPES. F. A. Halsey. 'A Cubic feet of Free Air compressed to a Gauge Pressure of 60 Ibs. per Square Inch and passing through the Pipe per Minute. o 50 75 100 125 ISO 200 250 300 400 I 600 rt 3 Loss of Pressure in Pounds per Square Inch for each 1,000 Feet of Straight Pipe. ins. Ibs. Ibs. Ibs. Ibs. Ibs. Ibs. Ibs. Ibs. Ibs. Ibs. I 10-40 jl 2-6^ 5 '90 l| 1-22 275 4-89 7-65 II'OO 2 35 79 1-41 2'2O 3' 1 7 5-64 878 2 \ 14 32 '57 90 1-29 2-30 3-58 5'i8 9'20 3 ii 20 31 44 78 1-23 177 3*14 7-05 3^ 15 21 "38 '59 "85 i*5* 3*40 4 2O '45 80 1-81 1 10 15 26 59 23 FRICTION OF AIR IN TUBES. Unwin, " Min. Proceedings Inst. C.E? k = coefficient of friction = - + b, a and b being constants, and v = velocity of air feet per second. Diameter of tube, ft. 1-64 1-07 *3 338 266 164 Value of a 00129 00972 01525 03604 0379 04518 .....- 00483 0064 00704 00941 00959 01167 ifz>=ioo 00484 0065 00719 00719 00997 OI2I2 GENERAL TABLES AND MEMORANDA. 163 COEFFICIENTS FOR EFFLUX OF AIR FROM ORIFICES. (Molesworth). Vena contracta . . . . 0-98 Conical converging . . ... ; 0-9 Cylindrical rounded at ends . . * 0*9 Cylindrical throughout . . ' . , o'8 Thin plates o'6 CENTRIFUGAL FANS. Molesworth. D = Diameter of fan. V = Velocity of tips of fan in feet per second. P = Pressure in Ibs. per square inch. V= v/P X 973- 97300 POWER REQUIRED FOR FANS. Molesworth P = Pressure of blast in Ibs. per square inch. A = Area of the sum of the tuyeres in square inches. V = Velocity of tips of fan in feet per second. HP = Indicated horse-power required. HP = 0-000016 V 2 A P. PROPORTIONS OF FANS. Molesworth. Length of vanes Width of vanes = Diameter of inlet = Eccentricity of fan = 2 10 Length of spindle journal = 4 diameters of spindle. 164 REFRIGERATION AND ICE-MAKING. HYDRAULIC RAM PROPORTIONS OF THE SUPPLY PIPES AND DELIVERY PIPES TO THE NUMBER OF GALLONS. (Hutton.) Number of gallons to be raised in 24 hours . . . 500 1,000 2,500 4,000 6,000 Diameter of fall or supply pipe, in inches .... I* 2 2 3 4 Diameter of rising main or delivery pipe, in inches . 1 I I| 2 2 EFFICIENCY OF HYDRAULIC RAMS. (Hutton) Number of times the height to which the water to be raised is contained in the fall . 4 5 6 7 8 9 10 ii 12 13 *4 15 16 18 19 20 25 Efficiency per cent. . . 75 72 68 62 57 53 48 43 38 35 32 28 23 17 15 13 POWER REQUIRED TO DRIVE CENTRIFUGAL PUMPS. Diameter of suction and delivery pipes in inches. Quantity of water delivered per minute, in gallons. Horse-power required for every foot in height the water is raised. I 16 O'OI 2 50 O'O2 3 IOO O'O5 4 200 0'08 300 o'i6 6 500 0-25 I 7OO 800 o'35 0-40 9 I,OOO '5 10 1,500 075 ii 1, 800 o 12 2,000 01 13 2,3OO 08 H 2,500 *2O 15 3,OOO 31 16 3.500 60 17 3,800 75 18 4,200 2'0 TABLE OF POWER REQUIRED TO RAISE WATER FROM DEEP WELLS. (Appleby.) Gallons of water raised per hour . 200 350 500 650 800 1,000 Height of lift for one man work- ing on crank, in feet .... 90 S 2 36 28 22 18 Height of lift for one donkey working on gin, in feet . . . 1 80 1 02 72 56 45 36 Height of lift for one horse work- ing on gin, in feet .... 630 357 252 I 9 6 154 126 Height of lift for one horse-power steam-engine, in feet .... 990 56. 396 308 242 198 TABLE GIVING QUANTITY OF WATER DISCHARGED PER MINUTE BY BARREL PUMPS. (Hutton.} Diam. of pump. Length of stroke. Single barrel. Double barrel. Treble barrel. 30 strokes per min. 40 strokes per min. 30 strokes per min. 40 strokes per min. 30 strokes per min. 40 strokes per min. Inches. Inches. Galls. Galls. Galls. Galls. Galls. Galls. ii 9 If 2j 3i 4* 4* 6| 2 9 3 4 6 8 9 12 *i 9 4f 61 9* 12 H 19 3 9 ft 9 i|i 18 20 27 3i 9 9* izi i8f 25 28 37 4 9 12* 16 24^ S 2 36 48 4 9 15* 20| 32 42 4 6 62 5 9 19 25! 38 50 57 76 \\ 9 2 3 i 32 46 62 69 92 6 9 2 7 i 37 55 73 82 no 2 10 3 4 6 9 10 13 2 10 .5* 7 10 14 15 22 3 10 71 10 15 20 22 30 3 10 i of i3l 20 27 3 2 42 4 10 13* 1 8 27 36 40 54 4 10 17 23 34 45 52 68 5 10 22 28 42 56 63 84 5 10 Si 34 51 68 77 102 6 10 30* 40 62 82 92 122 2 12 4 5 8 10 12 16 2 12 6* 8 12 17 19 25 3 12 9 12 18 24 27 36 3^ 12 12* 16 24 33 37 5 4 12 i6i 22 32 43 49 65 4i 12 20 27 42 55 62 82 5 12 25i 33 50 68 76 IOO 5* 12 3i 42 62 82 92 123 6 12 361 49 73 97 no 146 6 12 43 57 86 114 129 172 7 12 50 66 100 134 149 199 7 12 57 76 114 152 171 229 8 12 65 87 130 174 195 262 9 12 82 no 165 220 246 330 10 12 102 134 202 268 303 404 12 12 146 195 294 390 440 588 DIAMETERS, AREAS, AND DISPLACEMENTS. Worthington Pumping Engine Company. Diameter. S Displacement in Imperial Gallons per foot of Travel . Diameter. d 8 in >-; | Tre^S Q-SOJ 0122 OOO5 71 41-28 I-783 26I-5 11-297 0490 0021 7} 44-17 1-908 268-8 11-612 IIO4 0047 71 47-17 2-037 276-1 11-927 1963 0084 8 50-26 2-I7I 19 283-5 12-247 3068 0132 8 53-45 2-309 i9i 291-0 12-571 4417 0190 8| 56-74 2-45 1 19! 298-6 12-900 I 6013 0259 8? 60-13 2-597 I9f 306-3 13-232 7854 0339 9 63-61 2-747 20 3H' 1 13-569 4- 0940 0429 67-20 2-903 20| 33o-o 14-256 i 1-227 0530 91 70-88 Vo62 21 346'3 14-960 | 1-484 0641 9f 74-66 3-225 2I| 3 6 3-o 15-681 i 1-767 0763 10 78-54 3-393 22 380-1 16-420 | 2-073 0895 I0 f 82-51 3-564 22J 397-6 17-176 If 2-405 1038 10^- 86-59 3-740 23 4I5-4 17-945 '$ 2-761 1192 iof 90-76 3-920 23i 433-7 18-735 2 3'I4I T356 II 95-03 4-105 24 452-3 19-539 2 i 3'546 1531 JI i 99-40 4-294 24i 4/ I% 4 20-364 2 i 3-976 1717 n| 103-8 4-484 25 490-8 2I-2O2 2f 4-430 1913 ii| 108-4 4-682 25i 510-7 22*062 2\ 4-908 2120 12 113-0 4-881 26 530-9 22-935 2| 5-4" 2337 I2 T 117-8 5-o88 26| 551-5 23-824 2| 5-939 25<>5 \2\ 122-7 5-300 27 572-5 24-732 21 6-491 2804 I2f 127-6 5-5I2 27* 593-9 25-656 3 7-068 3053 13 1327 5-732 28 615-7 26-598 3i 7-669 3313 i3i 137-8 5-952 28J 637-9 27-567 si 8-295 3583 J 3 H3'i 6-182 29 660-5 28-533 3t 8-946 3864 '3f 148-4 6-410 29| 683-4 29-522 3i 9-62I '4^6 H '53*9 6-649 30 706-8 3 0> 533 3f IO-32 4458 *ti '59*4 6-886 31 754-8 32-607 3f II-O4 4769 i4i 165-1 7-132 32 804-2 34741 3i 11-79 5193 I4| 170-8 7-388 33 855-3 36-949 4 12-56 5426 15 176-7 7-633 34 907-9 39-221 4i 14-18 6125 i5i 182-6 7-888 35 962-1 41-562 4? 15-90 6868 iqi 188-6 8-147 36 1017-9 43-973 4t 17-72 '7655 isl 194-8 8-4I5 37 1075-2 46-448 5 19-63 8480 16 2OI-O 8-683 38 1134-1 48-993 5; 21-54 9348 1 61 207-3 8-955 39 1194-6 51-607 5^ 2375 1-026 i6i 213-8 9-236 40 1256-6 54-259 Sf 25-96 121 i6f 220-3 9-516 4 1 1320-3 57-037 6 28-27 221 17 226-9 9-802 42 1385-4 59-849 oi 30-67 325 171 233-7 10-095 43 1452-2 62-735 6| 33-i8 433 J 7 240-5 10-389 44 1520-5 65-686 6|- 35-78 '545 7f 247-4 10-687 45 T59 -4 68-688 7 38-48 662 18 254-4 10-990 46 1661-9 71-794 In estimating the capacity of Worthington (and other duplex) Pumps (i.e., the delivery in gallons per minute or per hour) at a given rate of piston speed, it should be noted that they have two double-acting water plungers : the capacity, therefore, is double that of any ordinary double- acting pump of same size, or four times as large as a single-acting pump. PRESSURE OF WATER. Worthington Pumping Engine Company. The pressure of water in pounds per square inch for every foot in height to 270 ft. By this Table, from the pounds pressure per square inch the feet head is readily obtained, and -vice -versa. Feet Head, Pressure per sq. in. | Feet Head. | Pressure per sq. in. Feet Head. Pressure per sq. in. Feet Head. Pressure per sq. in. 1 W "3 & Pressure per sq. in. Feet Head. Pressure per sq. in. I o-43 46 19-92 91 39H2 136 58-9I 181 78-40 226 97-90 M 0-86 47 20-35 92 39-85 137 59-34 182 78-84 227 98-33 3 1-30 48 2079 93 40*28 138 59-77 183 79-27 228 98-76 4 i-73 49 21'22 94 40-72 139 6O' 2 I 184 79-70 229 99-20 5 2-16 50 21-65 95 4I-I5 140 60-64 J 85 80-I4 230 99-63 6 2-59 5 1 22-09 96 4I-58 141 6l-07 1 86 80-57 2 3 I 100-06 7 3-03 52 22-52 97 42-01 I 4 2 61-51 187 8roo 232 100-49 8 3-46 53 22-95 98 42-45 143 61-94 188 8i-43 233 100-93 q 3-89 54 23*39 99 42-83 144 62-37 189 81-87 234 101-36 10 4-33 55 23-82 IOO 43-31 145 62-8I 190 82-30 235 101-79 ii 4-76 56 24-26 101 43-75 146 63-24 191 82-73 236 102-23 12 5-20 57 24-69 IO2 44-18 147 63-67 192 83-17 237 102-66 13 5-63 58 25-12 103 44-61 148 64-10 193 83-60 2 3 8 103-09 H 6-06 59 25-55 104 45"5 149 64*54 194 84-03 239 I03-53 15 6-49 60 25-99 105 45-48 15 64-97 195 84-47 240 103-96 16 6-93 61 26-42 1 06 45-9I 151 65-49 196 84-90 241 104-39 I 7 7-36 62 26-85 107 46-34 IS 2 65-84 197 85-33 242 104-83 18 7-79 63 27-29 1 08 46-78 153 66-27 198 85-76 243 105-26 19 8-22 64 27-72 109 47-21 *54 66-70 199 86-20 244 105-69 20 8-66 65 28-15 1 10 47-64 155 67-14 200 86-63 245 106-13 21 ,9-09 66 28-58 III 48-08 IS 6 67-57 2OJ 87'07 2 4 6 106-56 22 9-53 67 29-02 112 48-51 157 68-00 202 87-50 247 106-99 2 3 9-96 68 29-45 H3 48-94 158 68-43 203 87-93 248 107-43 24 10-39 69 29-88 II 4 49-38 159 68-87 204 88-36 249 107-86 25 10-82 70 30-32 H5 49-81 1 60 69-31 205 88-80 250 108-29 26 11-26 71 375 lib 50*24 161 69-74 206 89-23 251 108-73 27 11-69 72 3I-I8 117 50-68 162 70-17 207 89-66 252 109-16 28 12-12 73 3I-62 118 51-11 163 70-61 208 90-10 253 109-59 29 12-55 74 32-05 119 5f54 164 71-04 209 90-53 254 110-03 30 12-99 75 32-48 120 51-98 165 71-47 210 90-96 255 110-46 3 1 13-42 76 32-92 121 52-41 1 66 71-91 211 9I-39 256 110-89 32 13-86 77 33*35 122 52-84 167 72-34 212 91-83 257 111-32 33 14-29 78 33-78 I2 3 53-28 168 72-77 213 92*26 2 5 8 111-76 34 14-72 79 34-21 124 53-71 169 73-20 214 92-69 259 112-19 35 15-16 80 34^5 125 54-I5 170 73-64 215 93-I3 260 112-62 36 t5-59 81 35-08 126 54-58 171 74-07 216 93-56 26l 113-06 37 16-02 82 35-52 127 55' 01 172 74-50 217 93-99 262 II3-49 38 16-45 83 35-95 128 55'44 J 73 74-94 218 94'43 263 113-92 39 16-89 ^ 3639 129 55-88 174 75-37 219 94-86 264 114-36 40 17-32 85 36-82 I 3 56-31 175 75-80 220 95-30 265 114-79 4i 17-75 86 37-25 131 56-74 176 76-23 221 95-73 266 115-22 42 18-19 87 37-68 132 57-i8 177 76-67 222 96-16 267 115-66 43 18-62 88 38-12 133 57-61 178 77-10 22 3 96-59 268 116-09 44 19-05 89 38-55 134 58-04 179 77-53 224 97-03 269 116-52 45 19-49 90 39-98 135 58-48 1 80 77*97 225 97-46 270 116-96 168 REFRIGERATION AND ICE-MAKING. DIMENSIONS, ETC., OF STANDARD WROUGHT-!RON PIPES. a 4 rt . - t S B'.S .5 e L )-, V P.1 | a I L Jj -0^2 Si .2.3 .2 2 II Jj .11 1 -f o 2 rs ^ rs *T> ^ (D G r^ c5 'S c * t S " -i H l_ ^1 _ 3 i 0-27 O'2O _ 0-40 0-0572 1-272 9'44 0-24 27 i 0-36 0-29 "54 0*1041 1-696 7-075 0-42 18 i 0-49 0*42 0-67 0-1916 2-I2I 0-56 18 i 0*62 0-54 0*24 0-84 0-3048 2-652 4-502 0-85 H 0-82 0-73 0-42 1-05 0-5333 3' 2 99 14 i 1-04 0-95 0-58 1-31 0-8627 4-134 2-903 1-67 Hi ij 1-38 1-27 0-88 1-66 1-496 5-2I5 2-301 2-25 III ji 1-61 1-49 i -08 1-90 2-038 2-01 2-69 ill 2" 2-06 i'93 1-49 2-37 3-355 7-461 i'6n 3-66 ul 2* 2*46 2-31 175 2-87 4-783 9-032 1-328 577 8 3 3"6 2-89 2-28 3-50 7-388 10-996 1-091 8 3'54 3'35 2-71 4-00 9-887 12-566 '955 9-05 8 4~ 4-02 3*81 3"!3 4-50 12-730 H-I37 0-849 10-72 8 5 5-04 19-990 I7-475 0*629 14-56 8 6 6"oo 6*62 28-889 20-813 o-577 18-77 8 7 7-02 7-62 38-737 23*954 0-505 23-41 8 8 7-98 8-62 50-039 27-096 o-444 28-35 8 9 9-00 9-68 63-633 3o;433 o-394 34-07 8 10 lO'OI ~ 10-75 78-838 o-355 40-64 8 STRENGTH OF ICE. Ice of a thickness of i-| inch will support a man ; 4 inches in thickness will support cavalry; 5 inches in thickness will support an 84-pound cannon ; 10 inches in thickness will support a multitude ; 18 inches in thickness will support a railroad train. GENERAL TABLES AND MEMORANDA. 169 FRICTION IN PIPES. Friction loss in pounds pressure for each 100 feet in length of cast-iron pipe discharging the stated quantities per minute. (G. A. Ellis, C.E.} TS* M HI pj (N roro'^-^-i-oc^O P* iot^-0 icO o HMHHPlPiroro 1 ^' H " t-T M" M" cT pT oT co ro ? i? ICNO" 00 ICH ooo O -^-wvo t>.O * ro rooo ic 8H pi pj rt- 10 r^co O ic O X O ro O oo o o o o ,o p jB .* * s H * y> b b b b b b b b b b b b b o o ON ONNO \0 M ic ro rooo t^ ic p) ro o o 8 O O o" S" O^ M IT'S *S ^ro ^ ?) K H oooooooooooooo V H ro^o O^ rooo ro ONNO M r> M p p M r (N .cV 50 ICvp <0 N b o b b o o o o o o o b * 1C I^ 88 o b b o p) -^oo ro O O"NOO ON ro r^ M H PI p) co^vo t^ M b b b b b b b o b b M M ro -rt- to^O 00000 30 O>oo M ON O 10 ro O O M ro-^-c^ONP4 00000 OOOOOOOH s * N ro ic t^ ON M ic M M ^ro^NOOx *J oo 1 o o o o o o o M P) 9 10 t^ O rh fxvo t-x O C Q Q M H M (N ro ic*O H NO MOO u OOOOOOOOO O w m '1 ON H ro H ON ic P) ON\O ic ro O N tf) 'CO ON M 00 NO NO t^ ?ro u? OOOO OO MMNCO-* txj ft, '5. *. 2 a 2-a-B-sjsftSw'w S'R.s s s, O O Ooo a OOOOOOOHHW rO^>.M JCON fffe 8 *, c^^^-tcNgcScggc^S^^^^ - c/3 N M M M ro TJ- a b b b b b M M V) ' V M co r^ '^. t S^o^ovglQo^fc^S^oS H H N ro ICNO CO Pj ONCO_ 5 roO~o5-^-1-HP,ONM M H Oi Tf-vO O^ N vO O ^MD ^-NOTO g O^g g H r V 2 ? cT ro^ *. m ^? c S &) 1 ?. suojpjS -^ScT^^^^^^gpTls The frictional loss is increased by bends or irregularities in the pipes. COMPARISON BETWEEN THE SCALES OF CENTIGRADE AND FAHRENHEIT THERMOMETERS. Centigrade. Fahrenheit. Centigrade. Fahrenheit. -73 100-0 -2 4 -II-2 -72 -97-6 -23 - 9'3 -95'8 22 - 7-6 -70 -94-0 21 5"8 -69 -92-2 20 - 4-0 -68 -90-4 19 2-2 -67 -88-6 -18 O*4 -66 -86-8 -17 4- I'4 -65 -85-0 -16 + 3' 2 -64 -63 -83-2 -81-4 -14 + 6-8 -62 -79-6 -13 + 8-6 -61 -77;8 12 + 10-4 -60 II + 12-2 59 -74-2 10 + H'O 58 -72-4 - 9 + I5-8 -57 -70-7 - 8 + I7-6 -56 -68-8 - 7 + 19-4 -55 67-0 - 6 + 21-2 -54 ~6 5 : 3 5 + 23-0 -53 - 4 + 24-8 -52 -61-6 - 3 + 26-6 -59-8 + 28-4 -5 -58-0 i + 30-2 -56-2 + 32-0 148 -54'4 + i + 33-8 -47 -52-6 4- 2 + 35*6 -46 -50-8 + 3 + 37-4 -45 -49-0 4- 4 + 39-2 -44 -47-2 + 5 + 41-0 -43 -45'4 4 6 + 42-8 -42 -43' 6 + 7 + 446 -41 -41-8 4- 8 + 46-4 -40 40-0 + 9 + 48-2 -39 -38-2 4 IO + 50-0 -38 -36-4 411 + 51-8 -37 -54-6 4-12 + 53-6 -30 -32-8 + 13 + 55'4 -35 31*0 4-14 + 57-2 -34 29-2 4- 15 + 59-0 -33 -3 2 -27-4 -25-6 + 16 4-17 + 60-8 + 62-6 -23-8 4- 18 + 64-4 30 22 -O 4-19 4-66-2 -29 20'2 4-20 + 68-0 -28 -18-4 4-21 + 69-8 -27 -16-6 + 22 + 71-6 -26 -14-8 + 2 3 + 73'4 -25 -13-0 4-24 4 75-2 GENERAL TABLES AND MEMORANDA. I/ 1 To CONVERT DEGREES CENTIGRADE OR REAUMUR INTO DEGREES FAHRENHEIT, ETC. Let F = degrees Fahrenheit ; C = degrees Centigrade ; and R = degrees Reaumur. *-f+ 3 *-? + 3. c = ^i> R = 4(F - 3 2 ) 9 USEFUL INFORMATION. A gallon of water contains 231 cubic in., and weighs 81 Ibs. (U.S. standard). A cubic foot of water contains 6J gallons, and weighs 62^ Ibs. The friction of liquids and vapours through pipes increases as the square of the velocity. Sensible heat of a liquid is the amount indicated by the thermometer when immersed in it. Specific heat is the amount of heat absorbed to produce sensible heat. Latent heat is the amount of heat required for the con- version into vapour after a liquid has reached its boiling- point. The latent heat of vapour is given off whilst condensing to a liquid ; the sensible heat is retained. One U.S. gallon = 0*133 cubic ft. ; 0*83 imperial gallon ; 3*8 litres. An imperial gallon contains 277-274 cubic in. ; 0*16 cubic ft.; 10*00 Ibs.; i'2 U.S. gallons; 4*537 litres. A cubic inch of water = 0*03607 Ib. ; 0*003607 imperial gallon; 0-004329 U.S. gallon. A cubic foot of water = 6*25 imperial gallons ; 7*48 U.S. gallons; 28*375 litres; 0-0283 cubic metre; 62*35 lbs - '> 0*557 cwt. ; 0*028 ton. A Ib. of water = 27*72 cubic in. ; 0*10 imperial gallon; 0*83 U.S. gallon; 0-4537 kilo.^ One cwt. of water = 11*2 imperial gallons; 13*44 U.S. gallons ; i *8 cubic ft. 172 REFRIGERATION AND ICE-MAKING. A ton of water = 35*84 cubic ft.; 224 imperial gallons; 298*8 U.S. gallons; 1,000 litres (about); i cubic metre (about). A litre of water = 0-22 imperial gallon; 0-264 U.S. gallon; 6 1 cubic in.; 0*0353 cubic ft. A cubic metre of water =220 imperial gallons ; 264 U.S. gallons ; 1*308 cubic yard ; 61-028 cubic in. ; 35*31 cubic ft. ; 1,000 kilos; i ton (nearly); 1,000 litres. A kilo of water = 2*204 Ibs. A vedros of water = 2*7 imperial gallons. An eimer of water = 27 imperial gallons. A pood of water = 3*6 imperial gallons. A Russian fathom = 7 ft. One atmosphere = 1*054 kilos per square in. One ton of petroleum = 275 imperial gallons (nearly) ; 360 U.S. gallons (nearly). A column of water i ft. in height = 0-434 Ib. pressure per square in. A column of water i metre in height = i "43 Ib. pressure per square in. One Ib. pressure per square in. = 2*31 ft. of water in height. One U.S. gallon of crude petroleum = 6-5 Ibs. (about). According to Prof. Siebel, about ten B.T.U. of heat will pass through a square foot of ice i inch thick in one hour for every degree Fahrenheit difference between the temperatures on either side of the ice sheet. A cubic foot of ice weighs approximately 57*5 Ibs. A cubic foot of water frozen at 32 makes 1*0855 cubic ft. of ice. One French horse-power = 75 kilogrammetres (542*533 foot-pounds) per second. One force de cheval = 0-986337 horse-power. One horse-power = 1-01385 force de cheval. Indicated French horse-power = 3-49 D 2 PRS. D = dia. of cy. in metres, S = length of stroke in metres, R = number of revs, per minute, and P = average pressure on piston in kilogs. per square centimetre. GENERAL TABLES AND MEMORANDA. 173 FRACTIONS OF AN INCH AND DECIMAL EQUIVALENTS. Fractions. Inch. Fractions. Inch. Fractions. Inch. I- 3 2 0-03125 3-8 o-375 23-32 0-71875 1-16 0*0625 13-32 0-40625 3-4 0-75 3-32 0-09375 7-16 Q'4375 25-32 0-78125 1-8 0-I25 iS-32 0-46875 13-16 0-8125 5-32 0-15625 1-2 0-5 27-32 ' 8 4375 3-i6 0-1875 17-32 0-53125 7-8 0-875 7-32 0'2l875 9-l6 0-5625 29-32 0*90625 1-4 0*25 19-32 0-59375 15-16 0-9375 9-32 0-28125 5-8 0*625 31-32 0-96875 5-16 0-3125 21-32 0*65625 11-32 0-34375 11-16 0-6875 COMPARISON OF BRITISH MEASURES WITH U.S. United States Standard. British Standard. i gill = 0-833565 imperial gill. 4 gills = i pint = 0-833565 pint. 2 pints = i quart = 0*833565 quart. 4 quarts = i gallon = 0*833565 gallon. An imperial gallon = 4*5435 litres = 1-19968 U.S. standard gallons. An imperial gallon contains (Act of Parliament, 1878) 10 Ibs. of water at a temperature of 62 Fahr. Its accepted volume is 277*274 cubic in. SPECIFIC GRAVITIES OF GASES. Gas at 32 and below one atmosphere. Specific gravity. Cubic feet in ilb. Air . . '" I -000 12-38 Ammonia 0-589 2I'OI Carbonic acid 1-529 8-10 Chlorine 2-440 5 '07 Nitrogen 0-978 12-72 Oxygen . . . 1-105 1 1 -20 1/4 REFRIGERATION AND ICE-MAKING. INFORMATION REQUIRED BY MANUFACTURERS TO ENABLE THEM TO ESTIMATE FOR THE COST OF A REFRIGERATING PLANT. 1. The length, breadth, and height of the cellars, rooms, or stores to be refrigerated. If the ceiling or roof is vaulted, the height to the centre and spring of the arch will be required. Full particulars of the means of insulation adopted, or, if none exist, of the materials from which the chambers are built. 2. Whether it is desired to refrigerate on the direct expansion, on the brine circulation, or on the cold-air system. 3. The temperature desired to be maintained in each chamber or store. 4. The nature of the substance which it is desired to refrigerate. 5. In the case of a packing-house, or an abattoir, the largest number of carcases to be cooled daily, and their average weight. 6. In the case of a freezing chamber for beef, mutton, or other produce, the number of carcases, etc., to be frozen in each 24 hours, and their average weight. 7. When a liquid is to be cooled, the number of gallons, or barrels, to be dealt with per hour, and from what tem- perature down. 8. The nature, quantity, and temperature of the water supply available for use. 9. Rough dimensioned plan of the establishment, show- ing the most convenient spot to locate the refrigerating machine. INFORMATION REQUIRED BY MANUFACTURERS TO ENABLE THEM TO ESTIMATE FOR THE COST OF AN ICE-MAKING PLANT. 1. Number of tons of ice that it is desired to produce per 24 hours. 2. If clear, crystal, transparent ice is required, or whether opaque ice will do for the purpose. 3. The nature, quantity, and temperature of the supply of water procurable for use. GENERAL TABLES AND MEMORANDA. 175 4. Whether there is an available source of steam supply on the premises ; and if spare steam-power, then how many horse-powers could be utilised. 5. When the installation is to be erected in existing buildings, a rough dimensioned plan of same. 6. Where an estimate of cost of making ice is required, price and quality of fuel ; wages of engine-drivers, stokers, and common labourers, for 12 hours day work, and for 12 hours night work ; if water has to be bought, cost of same. VARIOUS HORSE-POWERS IN USE. Kilogrammetres per second. Foot-pounds per minute. Ratio to British H.P. Austria 76-II9 33><>34 I'OOI Baden 75"ooo 32,552 0-986 France 75-000 32,552 0-986 Great Britain 76-041 33,000 I -000 Hanover . 75-36i 32,705 0-990 Prussia 75'325 32,689 0-990 Saxony 75*045 32,568 0-986 Wurtemburg 75-240 32,637 0-988 EXPANSION IN STEAM PIPES. The expansion and contraction of steam pipes is about i inch in 50 feet by reason of temperature variations. This expansion and contraction may be provided for in the case of long lengths of pipe between fixed abutments, by spring bends or lengths, or by expansion sockets. In the latter case, guard bolts should be fitted to prevent the pipes from being drawn out of the sockets. INDEX. A BSORPTION machines, 2-11 J\ Air co-efficients for efflux of, from orifices, 163 Air condensers, open, 33 Air, compressed, loss of pressure by friction of, in pipes, 162 Air, determination of moisture in, 75, 76 Allowance per ton capacity to be made when selecting machinery for refrigerating purposes, 33 Ammonia and carbonic acid ma- chines, comparative tests of, 22 anhydrous, boiling point and latent heat of, 36, 37 apparatus, leaks in, 145 compression machines, manage- ment of, 141-144 compression plant, efficiency of, under different conditions, 61 gas, cubic feet of, per minute to produce one ton of refrigera- tion per day, 75 gas, refrigerating effect of one cubic foot at different con- densing and suction (back) pressures in B.T. units, 59 gas, saturated, properties of, 44 gas, temperatures to which raised by compression, 41-44 gas, volume of, one pound at various pressures and tem- peratures, 45-47 gas, volume of, at high tempe- ratures, 48 Ammonia, saturated, "Wood's table of, 49-58 solubility of, in water at differ- ent temperatures, 38-40, 143 solubility of, in water at different temperatures and pressures, 39 solutions, yield of anhydrous ammonia from, 41 useful efficiency of, 50 Amount of refrigerating pipes necessary for chilling storing and freezing chambers, 69-72 refrigerating required in cold storage, 69-72 Analyser, The, 43, 44 Anhydrous ammonia, boiling point and latent heat of, 36, 37 ammonia, yield of, from am- monia solutions, 41 Apparatus, ammonia, leaks in, 145 refrigerating, 2-11 Application of the entropy or theta- phi diagram to refrigerating ma- chines, 1 1 -20 Approximate allowance per ton capacity when selecting machine for refrigerating purposes, 33 Aqueous vapour in air, table of, 78 vapour, tension of, 152 Areas, diameters and displacements, 167 Argentine Republic, mean tempera- tures and extremes for the year, 88,89 Atmospheric condensers, 33 178 INDEX. BARREL pumps, quantity of water discharged by, per minute, 165 Boiling point, latent heat, etc., of anhydrous ammonia, 36, 37 point of liquids available for use in refrigerating machines, 35 Box or tank, freezing, 104, 105 Breweries, estimate of refrigeration in, 70, 72 Brine circulation, loss of efficiency with, 23 Brine for use in refrigerating and ice- making plants, 105, 1 06 British measures, comparison of, with U.S. standards, 173 British thermal unit, 161 Butter freezing rates, 98 CALCIUM chloride, solutions of, V_, 106, 107 Calorie, 161 Can ice, freezing times for different temperatures and thicknesses of, in Cans, ice, time required for water to freeze in, 1 1 1 Capacities of ice-making plants, 101 refrigerating, 73 Capacity, etc., of refrigerating machine, variations in, 74 of compressor in cubic inches, 27-30 of refrigerating machines, 25, 26 Carbonic acid and ammonia ma- chines, comparative tests of, 23 acid gas, saturated, properties of, 62 acid machines, leaks in, 145-147 Cascade system of producing very low temperatures, 23 Ceilings for cold stores and ice- houses, 133, 134 Centrifugal fans, 163 Centrifugal pumps, power required to drive, 164 Chemical or liquefaction process, 2, 3 Chloride of calcium, solutions of, 106, 107 of calcium, properties of solu- tion of, 107, 108 of sodium, properties of solu- tion of, 1 08 Cities of the world, mean tempera- tures of principal, 85-87 Co -efficients for efflux of air from orifices, 163 Cold-air machines, 5, 6 air machines, formula for cal- culating amount of air de- livered by, 67 air machines, results of test experiments with, 22 storage, 68-99 storage, amount of refrigerating pipes necessary for chilling storage and freezing cham- bers, 69 storage and freezing rates, terms of payment of, 99 storage charges, England, 90, 91 storage charges, France, 99 storage charges, United States, 91-95 storage.of various articles, tem- peratures adapted for, 80-84 stores, divisional partitions for, 130, 131 stores, floors for, 131-133 stores, lighting, 149, 150 stores, walls for, 127-130 Combustion of various fuels, heat of, J 59 Common salt, see Chloride of sodium Comparative efficiency of various refrigerating machines, 20 tests as to efficiency of ammonia and carbonic acid machines, 2 3 Comparison between scales of Cen- tigrade and Fahrenheit thermo- meters, 170 of British measures with U.S. standards, 173 of various hydrometer scales, 109, no Composition and specific heat of victuals, 75 INDEX. 179 Compressed air, loss of pressure by friction of, in pipes, 162 Compression machines, 9-11 machines, management of am- monia, 141-144 plant, efficiency of, under differ- ent conditions, 6 1 temperatures to which ammonia gas is raised by, 41-43 Compressor, capacity in cubic inches, 27-30 mean pressure of, 31 diagram, interpretation of, 137- 141 capacities, relative, 23 Condensers, 33 Conditions of deposit and regula- tions, cold storage, 91 Constant of gases, physical, 153 Convert degrees, Centigrade or Reaumur, into Fahrenheit, to, 171 Cooler, fore, 38 Cooling wort, experiments in, 151 power, effective, 21-23 Cork, see Insulation Correct relative humidity in egg- rooms, 99 Cubic feet of ammonia gas per minute to produce one ton of refrigeration per day, 75 feet of gas that must be pumped per minute, at different con- denser and suction pressures, to produce one ton of refrige- ration in 24 hours, 32 Cubic feet of space per running foot of 2 -inch pipe, 70 feet covered by one foot of I- inch iron pipe, 71 Curves, efficiency, of perfect re- frigerating machine, 64 DAILY report, suggested form of engineer's, 148 Decimal equivalents of fractions of an inch, 173 Deep wells, power required to raise water from, 165 Degrees, Centigrade or Reaumur, to convert into Fahrenheit, 171 Deposit and regulations, cold stor- age conditions, 91 Diagram, compressor, interpretation of, 137-141 Diameters, areas and displacements, 166 Dimensions of ice-making tanks, 102 of standard wrought-iron pipes, 1 68 Displacements, see Diameters, areas, etc. Divisional partitions for cold stores, 130,131 . Door insulation, 134 Double pipe condenser, 34 T7FFECTIVE cooling power \_j obtainable from expenditure of one pound of steam in theoreti- cally perfect machines, 22 Efficiency, comparative, of various refrigerating machines, 22 of ammonia, useful, 60 of ammonia, compression plant, under different conditions, 6 1 Efficiency curves of perfect refrigera- ting machine, 64 Efficiency of ether machines, 66, 67 of hydraulic ram, 164 Efflux of air from orifices, co- efficients of, 163 Egg freezing rates, 98 rooms, correct relative humi- dity in, 79 Engineer's daily report, suggested form of, 148 Entropy or theta - phi diagram, application of, to refrigerating machines, 11-20 Ether machines, efficiency of, 66, 67 properties of saturated vapour of, 6$ Evaporation of liquids, 34 Expansion in steam pipes, 175 Experiments in wort cooling, 151 Extreme limits of cubic feet of space per running foot of 2 -in. pipe, 70 i8o INDEX. FANS, centrifugal, 163 power required for, 163 proportions of, 163 Fish, freezing rates for, 97, 98 Flooring for cold stores, 131-133 for ice houses, 133 Fore cooler, 38 Form of engineer's daily report, suggested, 148 Formula for ascertaining units of refrigeration required to carry off heat radiated through walls, etc., 125 Formula for calculating amount of air delivered per hour by cold- air machines, 67 Fractions of an inch and decimal equivalents, 173 Freezing mixtures, 4, 5 Freezing rates for butter, 98 rates for eggs, 98 rates for fish and meats, 97, 98 rates for poultry, game, fish, meats, etc., 96-99 rates, summer, 97 tank or box, 104, 105 Friction in pipes, 169 of compressed air in pipes, loss of pressure by, 162 of air in tubes, 162 GAME, rate for freezing in un- broken packages, 96, 97 Gases, physical constant of, 153 specific gravities of, 35, 173 specific heat of, 161 General tables and memoranda, I5I-I75 Gravities, specific, and percentages of ammonia, 35 H EAT, mechanical theory of, 1-3 of combustion of various fuels, J 59 specific, of gases, 161 specific, of liquids, 161 specific, of metals, 160 specific, of water at various temperatures, 160 Horse-powers, various, 172, 175 Humidity of air, relative, 77 Hydraulic ram, efficiency of, 164 ram, proportions of the supply pipes and delivery pipes to the number of gallons, 164 Hydrometer scales, comparison of various, 109, no Hydrometers, 78 ICE-houses, ceilings for, 133, 134 houses, flooring for, 133 making, loo-Hi making and storing ice, 100-114 making plants, brine for use in, 105, 106 making plant, information re- quired to estimate for, 174, 175 making plants, sizes and capa- cities of, 101 making tanks, dimensions of,io2 storing, 111-114 strength of, 168 Inch, decimal equivalents of frac- tions of, 173 Information required to estimate for cost of ice-making plant, 174, 175 Information required to estimate for cost of refrigerating plant, 1 74 useful, 171, 172 Insulation, 115-135 door, 134 tank, 135 window, 134 Interpretation of compressor dia- gram, 137-141 LATENT heat, boiling point, etc., of anhydrous ammonia, 36, 37 Leaks in ammonia apparatus, 145 in carbonic acid machines, 145- H7 Lighting cold stores, 149, 150 Lineal feet of i-inch pipe required per cubic foot of cold storage space, 70 INDEX. 181 Liquefaction process, chemical or, . 2 3 Liquid receiver, 60 Liquids, evaporation of, 34 specific heat of, 161 Liquor ammonia, strength of, 40 Loss of efficiency with brine circula- tion, 23, 74 Loss of pressure by friction of com- pressed air in pipes, 162 Low temperatures, production of, 24-26 Lubrication of refrigerating machi- nery, 147 TV MACHINERY, refrigerating, lu- IVl brication of, 147 Machines, absorption, 7-9 carbonic acid, 145-147 cold-air, 5, 6 compression, 8-n leaks in ammonia, 145 vacuum, 6, 7 Management of ammonia compres- sion machines, 141-144 of refrigerating machinery, 136- 148 Manufacturers, information required by, to enable them to estimate for the cost of an ice plant, 174, 175 Manufacturers to estimate for the cost of refrigerating plant, 174 Mean pressure of compressor, 31 temperatures of principal cities of the world, 85-87 temperatures and extremes of the year, Argentine Re- public, 88, 89 Meats, freezing, rates for, 97, 98 Mechanical theory of heat, 1-3 Memoranda, general tables and, 151- 175 Metals, specific heat of, 160 Mineral water, rule for ascertaining quality of, 103 Mixtures, table of freezing, 4, 5 Moisture in air, determination of, NON-conductive values of various substances, results of tests as to, 116-125 Number of cubic feet covered by one foot of i-inch pipe, 71 covered by one ton, refrigerat- ing capacity for 24 hours, 71 of cubic feet of gas that must be pumped per minute, at different condenser and suc- tion pressures, to produce one ton of refrigeration in 24 hours, 32 PEN- AIR condensers, 33 Orifices, co-efficients for efflux of air from, 163 PARTITIONS for cold stores, 1 divisional, 130, 131 Payment of cold storage and freez- ing rates, terms of, 99 Percentages, handy rule, 159 of ammonia, see Specific gravities and percentages Physical constant of gases, 153 Pictet's liquid, 67 Pipes, friction of water in, 169 loss of pressure by friction of compressed air in, 162 Poultry, game, etc., rates for freez- ing in unbroken packages, 96, 97 storing unfrozen, 97 Power required for fans, 163 required to drive centrifugal pumps, 164 required to raise water from deep wells, 165 Pressure and boiling point of liquids available for use in refrigerating apparatus, 35 5 loss of, by friction of compressed air in pipes, 162 of compressor, mean, 31 of water, 167 ratio of, sulphurous acid, am- monia, and carbonic acid, 23 182 INDEX. Principal cities of the world, mean temperatures of, 85-87 liquids employed in refrigera- tion, qualities of, 1 1 Production of very low tempera- tures, 24, 25 Properties of saturated ammonia gas, 44 of saturated carbonic acid gas, 62 of saturated steam, 154-158 Proportions of fans, 163 Psychrometers, 76 Pumps, barrel, quantity of water discharged per minute by, 165 Pure water, 103 QUALITIES of principal liquids ^ employed in refrigeration, 1 1 Quantity of water discharged per minute from barrel pumps, 165 RADIATION through walls, etc., 125, 126 Ram, see Hydraulic ram Rates for freezing poultry, game, etc., 96-99 Ratio of pressure of sulphurous acid, ammonia, and carbonic acid, 21 Reagents, testing by, 104 Receiver, liquid, 60 Refrigerating apparatus, 2-11 and ice-making plants, brine for use in, 105, 106 capacities, 72 capacity in B.T.U. required, per cubic foot of storage room, in 24 hours, 72 effect of one cubic foot of am- monia gas at different con- denser and suction (back) pressures in B.T. units, 89 machinery, lubrication of, 147 .machinery, testing and manage- ment of, 136, 137 machines, capacity of, 25, 26 machines, comparative efficiency of, 22 Refrigerating machines, variations in capacity of, 74 plant, information required to estimate for, 174 Refrigeration in general, 2-11 Regenerative process or self-inten- sive refrigeration, 23-25 Relative humidity of air per cent., 77 humidity in egg-rooms, correct, 79 Rent of rooms, 98 Report, suggested form of engineer's daily, 148 Results of test experiments with cold-air machines, 22 of tests to determine the non- conductive values of different materials, 116-127 Rooms, rent of cold storage, 98 Rough estimate of refrigeration in breweries, 73 SALT, common, see Chloride of sodium Saturated ammonia gas, properties of, 44 ammonia, Wood's table of, 49-58 carbonic acid gas, properties of, 62 steam, properties of 154-158 sulphur dioxide gas, 63 vapour of ether, properties of, 65 Scales of Centigrade and Fahrenheit thermometers, comparison of, 170 Self-intensive refrigeration, 23- 25 Sizes and capacities of ice-making plants, 101 Slag-wool, see Insulation Sodium, properties of solution of chloride of, 108 Solubility of ammonia in water at different temperatures, 38-40 of ammonia in water at different temperatures and pressures, 39 INDEX. 183 Solutions of chloride of calcium, 96, 97 of chloride of calcium, pro- perties of, 107, 1 08 of chloride of sodium, properties of, 108 Specific gravities and percentages of ammonia, 35 Specific gravities of gases, 35, 173 Specific heat and composition of victuals, 79 heat of gases, 161 heat of liquids, 161 heat of metals, etc., 160 heat of water at various tem- peratures, 1 60 Standard wrought-iron pipes, dimen- sions of, 1 68 Steam pipes, expansion in, 175 Steam saturated, properties of, 154, J 58 Storage charges, cold, England, 90, 9 1 charges, cold, United States, 92-95 cold, 68-99 Stores cold, ceilings for, 133, 134 cold, divisional partitions for, 130. I3 1 cold, flooring for, 131-133 cold, walls for, 127-130 Storing ice, 111-114 unfrozen poultry, etc., 97 Strength of ice, 168 Strength of liquor ammonia, 40 Submerged condensers, 33 Suggested form of engineer's daily report, 148 Sulphur dioxide, useful efficiency of, 64 Summer freezing rates, 97 TABLES and memoranda, gene- ral, 151-175 Tank insulation, 135 Tank or box, freezing, 104, 105 Temperatures adopted for the cold storage of various articles, 80-84 mean, of principal cities in the wprld, 85-87 Temperatures, mean and extremes of year, Argentine Republic, 88,89 to which ammonia gas is raised by compression, 41-43 Tension of aqueous vapour, 152 Terms of payment of cold storage and freezing rates, 99 Testing, 136, 137 Testing and management of refrige- rating machinery, 136-148 Testing by reagents, 104 Tests of ammonia and carbonic acid machines, comparative, 23 Tests to determine the non-conduc- tive values of various substances, 116-127 Theory of heat, mechanical, i, 3 Thermometers, comparison between scales of Centigrade and Fahren- heit, 170 Theta-phi diagram, application of, to refrigerating machines, 11-20 Time required for water to freeze in ice cans, 1 1 1 Transmission of heat through insula- ting structures, 115, 126 Tubes, friction of air in, 162 T TNFROZEN poultry, etc., U storing, 97 United States Standards, compari- son of British measures with, 173 Units of heat, 161 Units of refrigeration to carry off radiation through wall, 125 Useful efficiency of ammonia, 60 efficiency of sulphur dioxide, 64 information, 171, 172 VACUUM machines, 7, 8 Vapour, aqueous, in air, 78 Vapour, aqueous, tension of, 152 of ether, properties of saturated, 65 Variation in capacity of refrigerating machine, 74 1 84 INDEX. Various articles, temperatures adapted for cold storage of, 80-84 fuels, heat of combustion of, 159 hydrometer scales, comparison of, 109 Very low temperatures, production of, 23-25 Victuals, specific heat and composi- tion of, 79 Volume of ammonia gas at high temperatures, 48 of one pound of ammonia gas at various pressures and tem- peratures, 45-48 WALLS for cold stores, 127-130 radiation through, 1 25, 126 Water, friction of, in pipes, 169 Water, mineral, rule for ascertaining quality of, 103, 104 Water power required to raise from deep wells, 165 pressure of, 167 pure, 103 quantity discharged per minute by barrel pumps, 165 solubility of ammonia in, 38-40, 143 specific heat of at various tem- peratures, 1 60 time required for, to freeze in ice cans, m Window insulation, 135 Wood's table of saturated ammonia gas, 49-58 Wort cooling, experiments in, 151 Wrought-iron pipe, dimensions, etc., of, 1 68 "\ riELD of anhydrous ammonia j[ from ammonia solutions, 41 OF THE UNIVERSITY PRINTED BY WILLIAM CLOWES AND SONS, LIMITED, LONDON AND BECCLES. 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