GIFT OF Arthur E. Moncaster lircular W. M. 501 The Westi nghouse The Westinghouse - Leblanc Condenser EAST PITTSBUR.G,RXV. Westinghouse-L/eblanc Condenser Standard Jet Type Driven by Westinghouse Steam Turbine Relative sizes, air and circulating equipments of like capacity The Westinghouse-Leblanc Condenser The Westinghouse-Leblanc Condenser represents The Type . , , - . ^ one or those developments in engineering that owes its stimulus to a radical improvement in another branch of the art. The steam turbine revolutionized steam engineering practice in half a dozen years. The Leblanc Condenser bears the same relation to the familiar type of condensing apparatus that the steam turbine does to the reciprocating engine. It is in fact a turbine type condenser. Like the turbine it occupies only a small fraction of the space formerly allotted. Like the turbine it develops superior efficiency, not by the multiplication of parts, but through a simple application of rotary motion, with no reciprocating or rubbing parts and no valves of any description. Recent At the time of the introduction of the steam Develop- turbine by the Westinghouse Machine Company, mejits t , : was announced that a very high vacuum would improve turbine" economies to an extent hitherto impossible ^wketv-^ap^li^do^to'vr^ciprocating engines. This condition nat- urally created an era of development among the condenser designers. It became evident at once that the old types that were good enough for 25" or 26" vacuum would be practically useless where the requirements called for a vacuum of 28" or 29". While many refinements thus far have been made in all features of condenser design, they have been generally along the lines of former practice. The principal improve- ment adopted by practically all manufacturers has been to apply a separate dry vacuum pump for the removal of air and non-condensible vapors. The dry vacuum pump, as commonly constructed, is a direct steam driven reciprocating unit, with its air cylinder and valve mechanism designed to reduce as far as possible the return to the condenser of the compressed air from the Westinghouse-I v eblanc Condenser serving a Curtiss Turbine at the plant of The Harwood Power Co., Harwood, Pa. A cooling pond with Koerting sprays is used for cooling the injection water clearance spaces. When it is realized that the air follow- ing back from the clearance will exceed many times the original volume, it becomes evident that the ideal vacuum will never be reached by the reciprocating type of pump. In the effort to overcome these inherent defects, builders have resorted to numerous refinements. Air cylinders are water- jacketed to prevent overheating. Mechanically operated air valves are introduced, to prevent the building up of a high back pressure in the condenser sufficient to lift voluntary valves from their seats. Two air cylinders are sometimes put in series, which manifestly improves the efficiency. An additional set of flash ports is sometimes introduced, which permits the air compressed in the clearance to be almost instan- taneously discharged, not into the condenser, but into the opposite end of the cylinder just before the suction valves open. This last expedient would at first blush seem to go a long way toward removing the bad effect of clearance, if it did not in a measure defeat itself. The sudden expansion resulting from this action causes a re-evaporation of the moisture always present on the walls of the cylinder, and hence, no air can enter from the con- denser until the piston has traveled far enough to equalize the pressure. The net result of the combination of such expedients is to impose a burden of first cost and maintenance that will overbalance the doubtful benefits to be secured by extreme complication . The most striking feature of the Leblanc system Essential c , ,. . ., -, . ,. ., P or condensation is its compactness and simplicity. While it employs the excellent feature of sep- arate removal of water and air, its functions are performed by a pair of small turbine type rotors on a common shaft, in a single unit casing, which is integral with the lower por- tion of the condensing chamber. The condensing chamber is of small diameter, being but slightly larger than the exhaust opening of the engine. These elements are all discernible at a glance, but the pre-eminent superiority of the Leblanc system over all others lies in the practically perfect removal of air and non-conden- sible vapors. The detailed description of the air pump on the follow- ing page shows how this result is obtained by a mechanism that is practically indestructible. SECTION N.-N. THROUGH AIR PUMP DISCHARGE. DISCHARGE. SECTION M.-M. THROUGH WATER PUMP. Sectional views of the standard Westinghouse-Leblanc Condenser are shown on the opposite page. Bxhaust steam enters at D and cooling water entering through pipe A is projected downward through spray nozzles B. The injection water and condensed steam flow to the centrifugal discharge pump M under a head of 2 or 3 feet, which insures positive filling of the pump. The exhaust steam is drawn downward and condensed by the water spray. The space E above the water is occupied by water vapor plus the air released from the injection water and from the exhaust steam. This space communicates with the air pump N through pipe K. The principle is entirely new, and it differs from p all ejector type pumps which depend on friction for the entrainment of air. The Leblanc pump projects a series of water pistons through the discharge nozzles, each one of which forces ahead of it a small pocket of air. This air, of course, mingles with the water in the lower portion of the nozzle, but the speed is such that no part of it ever finds its way back toward the condenser. In other words, there is no leakage past the pistons. The initial pocketing of the air between the successive layers of water is positive and, as will readily be seen, the neutralizing effect of clear- ance is entirely eliminated. The water supply for the air pump may be taken from the main water inlet or a supply may be placed in a tank and used over and over in the air pump. Since the air pump water is in communication with the con- denser, it is drawn by suction into an annular chamber G, which is overhung by the buckets of the pump rotor P. The water passes out of the chamber through the ports H and is projected downward in a rapid succession of water pistons. At the lower end of the air pump nozzle is placed an auxiliary ejector nozzle L,, to which is connected a steam pipe. In starting up the condenser, steam is turned into this auxiliary nozzle for a few moments, thus creating a sufficient vacuum to start the regular flow of water through the air pump. Where the level of the cold well is 3 or 4 feet above the basement floor, the air pump may be started without the use of steam. As will be seen from the illustration, the air pump rotor P and the main pump runner F are enclosed in a common casing and mounted on the same shaft. There are only two bearings and the shaft glands are made air-tight by water seals. Power The pumps are usually driven by a Westinghouse Require- steam turbine, and under ordinary conditions re- ments quire from 2 to 3 per cent of the power generated by the main engine. The exhaust from the condenser turbine is utilized for heating feed water, and when combined with the exhaust of other plant auxiliaries, the quantity is just about sufficient to maintain a feed temperature of 212 degrees Fahrenheit. In cases where economizers are used, or where there may be extra sources of exhaust steam, it would be advisable to operate either the condenser pumps or the exciter by means of an electric motor. The main pump is commonly designed to discharge against only a few feet head sufficient to over- come friction in the discharge line. If it is desired to ele- vate the water to the top of cooling towers, or other moderate elevations, the pump can readily be modified to meet the additional duty. This is the only moving element in the condenser Turbine driven condenser at the plant of the Bristol Gas & Electric Co., Bristol, Tenn. Motor driven condenser at the Municipal Lighting Plant of the City of Cleveland This condenser serves a 1000 kw. Westinghouse Turbine, injection water being cooled in a %"-acre pond with Koerting sprays 27 > -inch vacuum is maintained at full load during summer 10 Counter This term is often used in connection with various Current apparatus whose functions involve a transfer of Principle nea t. Aside from its application to surface con- densers, it is generally ignored by jet condenser builders, although sometimes vaguely referred to. In general terms, it may be said that counter current principle as applied to a cooling process consists in so disposing the cooling medium that the substance being cooled will at the instant of with- drawal be subjected to the full effect of the lowest temper- ature. Thus, in a surface condenser the water is introduced at the top and the steam at the bottom, the steam, rising to the top, is exposed to the entering cold water. The air, which is always present, being non-condensible, is little affected by this final cooling, but the effect on the final volume of steam is remarkable, a much greater proportion of it being condensed in the cooler region and the air pump, instead of handling a certain volume of air plus a relatively large volume of steam, is enabled to draw out a mixture from which a large part of the steam as such has been eliminated. This law may be illustrated arithmetically as follows: CASE I. Slight Counter Current Effect. Assume initial temperature injection water 70 Temperature at which air is removed 90 Vacuum (temperature 101.3) 28 Weight of air entering condenser per minute 1 Ib. In this case, owing to an excess of cooling water as ordin- arily supplied, the mixture of air and vapor is taken off in a partly cooled condition, i.e., from 101.3 degrees (the hot- test point) to 90 degrees. At this temperature and pressure the volume of the pound of air alone is 221 cubic feet, while the volume of the steam is 539 cubic feet. Therefore, the air pump, in order to extract a pound of air per minute, must have an effective displacement of 221 cubic feet plus 539=750 cubic feet per minute. CASE II. Full Counter Current Effect. Assume initial temperature injection water 70 Temperature at which air is removed 70 Vacuum (temperature 101.3) 28 Weight of air entering condenser per minute 1 Ib. 11 In this case, the full counter current effect is realized, the mixture of air and steam being taken off at 70 degrees tem- perature (a cooling of 31.3 degrees below the hottest part). At 70 degrees the volume of one pound of air alone is 213 cubic feet, while the volume of steam in the mixture is only 125 cubic feet, making a total of 338 cubic feet for the air pump to handle, or less than half the size required for case I. These relationships remain the same whether the cooling is done in a surface or a jet condenser, and the Leblanc air pump, as applied to either type, combines in its cold circula- ting water both the means of expelling the air and simul- taneously cooling the mixture to the point of minimum volume. 12 Small For units smaller than 300 Sizes horse power, it is customary to eliminate the main condensing chamber and pass all of the exhaust steam as well as the air through the air pump only. For this service, the air pump is slightly modified, a relatively greater amount of water being used, which serves both to expel the air and condense the steam in one operation. The sectional cut illus- trates a complete condenser of this type. The same high efficiency is maintained and the apparatus occupies scarcely more space than that required for the exhaust pipe alone. The accompanying cut illus- trates a vertical steam engine equipped with one of these small condensers. 13 For use with surface condensers, both stationary A . n and marine, and for application to barometric and Air Pumps . other types of jet condensers, evaporating pans, etc., the air pump is furnished separately. Embodying, as it does, the vital element of the Leblanc system, its application in any situation requiring an efficient vacuum will insure a marked improvement in the effectiveness of the entire equipment. In the case of new installations of surface condensers, the air pump and the circulating pump may be combined in a single compact unit substantially as shown by the cut below. It is not always logical to refer to European prac- C|i /"*/"* />o c tice as a criterion to be precisely followed in Abroad , , . , America, tor the reason that labor cost is lower and fuel cost much higher and, therefore, warrant the use of expensive and elaborate equipment which would fail to realize any ultimate economy when transplanted in the region of lower fuel cost and higher labor. In the present in- stance, however, where the whole tendency is in the direction of simplicity and ease of handling, the fact of the rapid adoption of the Leblanc system in England and on the Con- tinent possesses a useful significance for American practice. There are upwards of 400 installations in Europe, aggrega- ting one-half million horse power, many of the most prominent engine and turbine builders, including Prof. Rateau, having abandoned the older types formerly manufactured by them- selves and are installing the Leblanc system exclusively. Mr. Balcke, of Bochum, Germany, probably the largest con- 14 denser builder in Burope, is now turning out the Leblanc type exclusively, under a license arrangement. Naturally, the majority of these installations are in connection with steam turbines of various makes, but a considerable proportion is applied to stationary reciprocating engines, marine engines, vacuum pans, etc. The First At the present writing there has already been Year's contracted for in this country over 60 Leblanc Miowmg Condensers, aggregating 75,000 horse power. Most of these serve turbines of various types, while a few, espe- cially in small sizes, are used with reciprocating engines. Results obtained from some of these plants are set forth in the following tables. Efficiency is here expressed by the percentage of an ideally perfect vacuum actually obtained. For instance, if the dis- charge temperature is 100 degrees Fahrenheit, the corres- ponding ideal vacuum would be 28.08 inches. If, however, the observed vacuum is 27.75 inches, the efficiency percentage would be 27.75 28.08 = 98. i RELIEF VALVE. NLET TO WELL 15 Shop Test East Pittsburg No. 12 Condenser Capacity and Efficiency Steam Condensed Temperatures Vacuum Referred Per Cent of Lbs. Per Hour Injection Discharge to a 30 Barometer 11,400 65 79 28.76 99.5 18,300 70 92 28.09 98.8 25,000 71 97 27.96 99.3 32,100 70 104 27.59 99.3 38,600 70 112 26.81 98.8 11,300 55.3 72 29.06 99.5 18,400 56.5 86.3 28.44 99.4 25,000 62.3 94 28.21 99.7 32,100 65.5 103 27.51 99.0 37,500 54.0 102 27.56 99.0 Jersey Central Traction Company, Keyport, New Jersey No. 5 Condenser Capacity and Efficiency (Rated capacity 8380 Ibs. steam condensed at 27" vacuum and 90 degrees injection temperature) Steam Condensed Lbs. Per Hour Temperatures Vacuum Referred to a 30" Barometer Per Cent of Ideal Vacuum Injection Discharge 5,680 85.5 100.5 27.8 99.1 9,200 87.0 108.0 27.3 99.1 12,000 88.0 120.0 26.4 99.4 15,000 87.0 124.0 26.1 99.7 19,000 87.0 139.0 24.0 98.9 Union Sand and Material Company No. 5 Condenser Efficiency Only Temperature Discharge Vacuum Referred to a 30" Barometer Per Cent of Ideal Vacuum 75 28.9 99.2 80 28.7 99.1 82 28.7 99.3 78 2 8.. 6 98.5 (Practically full load was maintained during the above readings, viz., from 450 to 525 kilo- watts on the turbine) Jacksonville Oil Mill Co., Jacksonville, Ala. No. 1 Condenser Efficiency Only Temperature Discharge Vacuum Referred to a 30" Barometer Per Cent of Ideal Vacuum 102 106 95 27.86 27.66 28.18 99.6 99.8 99.5 16 500 kw. condenser at the plant of the Calhoun Light & Power Co., Jacksonville, Ala. 17 Relation between temperature and pressure of saturated steam a 'S J3 a g S w i> Q a J & | g a ~ "5 04 a a % aj &H rt V ^ 03 S t3 t a bi 03 eS a Q 04 * ^* c g Q 04 _g K* rj C-^ Q > c S H ^ iJ at a ij - at W i-3 - C8 a i-3 CS EH .S .5 .S h .S 70 0.3602 29.27 90 0.6925 28.59 110 1.2663 27.42 130 2.2119 25.50 71 0.3726 29.24 91 0.7146 28.55 111 1.3035 27.35 131 2.2719 25.38 72 0.3854 29.22 92 0.7372 28.50 112 1.3416 27.27 132 2.3333 25.25 73 0.3986 29.19 93 0.7605 28.45 113 1.3807 27.19 133 2.3961 25.12 74 0.4122 29.16 94 0.7844 28.40 114 1.4207 27.11 134 2.4603 24.99 75 0.4262 29.13 95 0.8090 28.35 115 1.4618 27.02 135 2.5261 24.86 76 0.4406 29.10 96 0.8342 28.30 116 1 . 5039 26.94 136 2.5932 24.72 77 0.4555 29.07 97 0.8601 28.25 117 1.5470 26.85 137 2.6619 24.58 78 0.4708 29.04 98 0.8867 28.20 118 1.5912 26.76 138 2.7321 24.44 79 0.4865 29.01 99 0.9140 28.14 119 1.6364 26.67 139 2.8040 24.29 80 0.5027 28.98 100 0.9421 28.08 120 1.6828 26.58 140 2.8774 24.15 81 0.5194 28.94 101 0.9709 28.02 121 1.7302 26.48 141 2.9525 23.99 82 0.5365 28.91 102 1.0004 27.96 122 1.7789 26.37 142 3.0292 23.84 83 0.5542 28.87 103 1.0307 27.90 123 1.8287 26.28 143 3.1076 23.68 84 0.5723 28.84 104 1.0619 27,84 124 1.8797 26.18 144 3.1877 23.51 85 0.5910 28.80 105 1.0938 27.77 125 1.9318 26.07 145 3.2696 23.35 86 0.6102 28.76 106 1.1266 27.71 126 1.9852 25.96 146 3.3532 23.18 87 0.6299 28.72 107 1.1602 27.64 127 2.0399 25.85 147 3.4387 23.00 88 0.6502 28.68 108 1.1947 27.57 128 2.0959 25.74 148 3.5260 22.83 89 0.6711 28.63 109 1.2301 27.50 129 2.1533 25.62 149 3.6152 22.64 The above vacua are referred to a barometer of 30 inches. In taking vacuum readings, a barometer reading at the same level as the condenser should be obtained, and in comparing temperatures allowance should be made for the barometer, adding or subtracting, as the case may be, the difference between the barometer readings and 30 inches. Thus, if the barometer reading is 30.3 inches, for example, subtract 0.3 inches from the vacuum reading to get the correct vacuum. If the barometer reads 29.6, for example, then add 0.4 to the vacuum reading to get the correct vacuum. 18 Relative volumes of air in a saturate mixture at various temperatures corresponding to different observed vacua Temperature Deg. Fahr. fl*. I* O C* M !_ OHH (B x M D 3 P ^Sl gg-S-fc (a5<<< Inches Vacuum Referred to a 30" Barometer, no Air Present Pounds per Square Inch Absolute .49 .98 1.47 1.96 2.45 j 2.94 14.697 Inches Vacuum Referred to a 30" Barometer 29 28 27 26 25 24 Per Cent Volume of Saturated Air Present in a Mixture of Air and Vapor of Water 60 70 80 90 95 100 105 110 112 114 116 118 120 122 124 126 128 130 132 134 136 138 140 0.2545 0.3602 0.5027 0.6925 0.8090 0.9421 1.0938 1.2663 1.3416 1.4207 1.5039 1.5912 1.6828 1.7789 1.8797 1.9852 2.0959 2.2119 2.3333 2.4603 2.5932 2.7321 2.8774 29.48 29.26 28.97 28.59 28.35 28.08 27.77 27.42 27.26 27.10 26.93 26.75 26.57 26.37 26.17 25.95 25.73 25.48 25.24 24.90 24.71 24.42 24.13 48.0 26.5 74.0 63.0 48.6 29.4 17.4 3.87 82.6 75.5 65.8 52.9 45.0 35.9 25.6 13.8 8.7 3.3 87.0 81.5 74.3 64.6 58.7 51.9 44.2 35.4 31.6 27.5 23.3 18.8 14.1 9.3 4.1 89.5 85.5 79.5 71.8 67.0 61.5 55.3 48.3 45.3 42.0 38.6 35.05 31.3 27.4 23.3 18.96 14.45 9.72 4.77 91.4 87.8 82.9 76.4 72.5 67.9 62.8 56.9 54.4 51.6 48.9 45.85 42.8 39.5 36.1 32.5 28.7 24.8 20.6 16.3 11.8 7.07 2.13 98.4 97.6 96.7 95.4 94.6 93.7 92.6 91.4 90.9 90.4 89.8 89.3 88.6 88.0 87.3 86.6 85.8 85.0 84.2 83.3 82.5 81.5 80.5 19 An Interesting Installation A 1000 kw. Westinghouse Exhaust Steam Turbine, with a Leblanc Condenser working in connection with a cooling tower at the plant of the Colorado Springs Electric Company, Colorado Springs, Col. 20 Cooling tower used in connection with the low pressure turbine and Westinghouse-Leblanc Condenser shown on the opposite page It is needless to remark that the free use of artificial cooling devices is made a commercial success only by combining with a highly efficient condensing equipment 21 A typical installation of a 500-kilowatt Westinghouse-L,eblanc turbine-driven condenser 22 The \Vestinghouse Machine Company General Offices, Works and Laboratory East Pittsburg, Pa. SALES OFFICES NEW YORK 165 BROADWAY ATLANTA CANDLER BUILDING BOSTON 131 STATE STREET CHICAGO 171 LA SALLE STREET CINCINNATI . . .. . . 1102 TRACTION BUILDING CLEVELAND NEW ENGLAND BUILDING SAN FRANCISCO . HUNT, MIRK & Co., -141 SECOND STREET DENVER 512 MCPHEE BUILDING PITTSBURG WESTINGHOUSE BUILDING PHILADELPHIA 1003 N. AMERICAN BUILDING ST. L/ouis . . . . . . . CHEMICAL BUILDING G. & O. BRANIFF & Co. .... CITY OF MEXICO THE CORDAY & GROSS Co. CLEVELAND 24 726302 W4 UNIVERSITY OF CALIFORNIA LIBRARY THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. THE PENALTY WILL INCREASE TO SO CENTS ON THE FOURTH DAY AND TO $1.OO ON THE SEVENTH DAY OVERDUE. AUG 1 1933