TJ WO -NRLF B M S3D M5b GIFT OF Arthur E. Mono aster ircular WM No. 506 Westinghouse Turbo- EAST PITTSBUR.G.F'A. E", Westinghouse Turbo- cy DURING the 17 years that have elapsed since the American rights for the manufacture of the Parsons steam turbine were acquired and the Westinghouse Ma- chine Company and the Westinghouse Electric & Manufacturing Company jointly commenced the building of turbo-generators there has been a complete revolution in the design of electric power plants. The superior economy of the turbo-generator unit, not only in steam consumption, but in first cost, attendance and in mainten- ance as well, and the reduction it has effected in general plant investment, in real estate, buildings, and foundations, has practically eliminated the large slow-moving reciprocating engine-driven sets from the serious consideration of the modern power plant engineer and designer. A 10,000-kilowatt turbo-generator set readily fits into the space required by a reciprocating engine-driven set of one-third the capacity, and its cost does not exceed the average price paid for such a reciprocating engine-driven set. To provide for extensions in metropolitan plants, in congested districts, where 726303 Westinghouse Turbo- Alternators the cost of real estate is unusually high, it is now considered justifiable to discard reciprocating engine and generator equipment of the most efficient ,and, serviceable character and to replace it with turbine-driven apparatus. The Steam Turbine The'gefiefai idea' of a steam turbine engine is almost as old as history itself. But it lay dormant for many centuries, because there was no machinery of sufficiently high speed to be suitable for driving with this type of motor. Inventive genius requires a definite stimulus, and in the case of the steam turbine the stimulus was undoubtedly furnished by the introduction and rapid development of alternating-current electrical machinery another of the many examples of Westinghouse pioneering that has so completely justified itself that the bitterness of the opposition it encountered is almost forgotten. The American people as a nation are much more conservative than is generally believed; they are inclined to regard innovations rather skeptically until their worth is established. However, when the utility of any device of a mechanical nature is once recognized, it is adopted in no half-hearted war and its application and further development are carried out on a scale of unprecedented magnitude. When, in 1895, the Parsons steam turbine was first introduced into this country, it was not received with much enthusiasm. It was practically five years before it was accorded any general public approval, and it would doubt- less have been considerably longer in obtaining recognition, had it not been that one of the allied Westinghouse interests The Westinghouse Air Brake Company had the courage to install a plant of four 400-kilowatt units. This plant, which is still in operation, was watched with the utmost interest by leading engineers and soon demonstrated the reliability, economy, and general attractiveness of the steam turbine as a prime mover for direct connection to alternating-current generators. From that time on the growth in public favor of the Westinghouse Parsons turbo-generator units has been phenomen- ally rapid and extensive. While the Westinghouse Machine Company commenced its turbine work under the American patents of the Honorable Charles A. Parsons, which it purchased outright, it has been no mere copyist, but has from the first worked along original and progressive lines. For example, it first demonstrated the practicability of single-cylinder units of large powers. In 1901, it built and installed for the Hartford Electric Light & Power Company, Hartford, Conn., a turbine of 2000 kilowatts capacity in one cylinder. Up to that time no single- cylinder turbine of larger than 500 kilowatts capacity had been built, and even with separate high and low-pressure cylinders, 1000 kilowatts was then the record size. Notwithstanding predictions of failure, this machine broke down the barriers of ultra-conservatism, and established the confidence that has made possible the mammoth engines that are in common use today. It has made the Company willing to assume the responsibility for the still larger units that are in contemplation. The combination impulse and reaction turbine, and the double-flow design, which makes it possible to build turbines of larger capacities and higher rotative speeds than would otherwise be possible, are both instances Westinghonse Turbo- A Iternators Westinghouse Turbo- Alternators of Westinghouse progress! veness and originality. This Company also intro- duced the governor-controlled by-pass for automatically taking care of over- loads. Reaction vs. Impulse Turbines The elementary principles of the steam turbine are now so generally known, and there is so much literature on the subject available, that any extended theoretical discussion would be superfluous. Broadly speaking, steam turbines are of two general classes; those employing the reaction principle and those employing the impulse principle. In the reaction turbine, approximately one-half of the expansion in any one stage takes place in the stationary blades, imparting to the steam a velocity substantially equal to that of the moving blades, so that it enters them without impact. The remainder of the expansion takes place in the moving blades, the spaces between which gradually grow smaller from the inlet to the exit side of the turbine forming a ring of moving nozzles. The velocity imparted to the steam by reason of the expansion occurring in the moving blades, produces a reactive effort on these blades which turns the rotor of the turbine. This effect is very similar to that produced by water issuing from an ordinary hose nozzle. In turbines of the impulse type the complete expansion for any one stage takes place in the stationary blades or nozzles, and the steam is delivered to the moving blades with a velocity somewhat more than double that of the blades. The passages between the moving blades are of uniform or even slightly increasing cross section from inlet to outlet. The moving blades check and reverse the velocity of the steam current and the reluctance of the steam current to having its direction and velocity altered gives rise to a force against the blades which sets the rotor in motion. Each of these two general classes of turbines has its partisans, and doubt- less always will have. In Westinghouse later practice a combination of the two principles is utilized in such a way that all the advantages of both are obtained with none of the disadvantages of either. The use of a single-impulse element for the first stage of the expansion is desirable, inasmuch as it replaces without any appreciable sacrifice of economy, a considerable number of rows of reaction blading in the least efficient part of a reaction turbine, and makes possible a shorter and consequently stiff er rotor. For the intermediate and low-pressure sections, in which the volume of the steam is sufficient to require reasonably long blades moving at considerable velocities, an extended experience confirms the belief that reaction blading has a decided economic advantage. The all-impulse type necessitates a rotor built up of discs mounted on a shaft of small diameter, in order that the circumferential clearance between the shaft and the diaphragms separating the pressure chambers may be as small as possible, so that the considerable pressure drops between adjacent stages will not cause too much leakage. In the reaction type the pressure drops between adjacent stages are very much smaller, and the body of the rotor may be built up in the form of a hollow drum. The drum construction is much stiffer than the shaft and disc design, and, it is believed much safer. When a disc is heated it develops internal Westinghouse Turbo-Alternators Fig. 2 A 10,000-Kva., 11,000-Volt, Three-Phase, 60-Cycle, 1800 R.P.M. Unit at the Plant of the City Electric Company, San Francisco Fig. 3 Three 5500-Kva. and Two 8000-Kva., 11,000-Volt, Three-Phase, 25-Cycle, 750 R.P.M. Units and Two 3000-Kva., 11,000-Volt, Three-Phase, 60-Cycle, 1200 R.P.M. Units. Generating Station of the Pennsylvania Tunnel & Terminal Railroad Company, Long Island City, New York Westinghouse Turbo-Alternators strains that are impossible of calculation, and which are liable to start cracks in the metal, resulting in many instances in complete rupture. On the other hand, in a rotor made up of a comparatively thin cylindrical drum of con- siderable diameter, and rings of large bore, no such strains are encountered. Again, the drum construction of rotor makes the turbine very much more accessible for examination and repairs. In most of the later designs of West- inghouse turbines, the upper half of the cylinder can be lifted without inter- fering with the governor, steam chest, or pipe connections. With the special lifting gear furnished with each turbine as a part of the tool equipment, the rotor is removed in a very short time. A comparison of the actual operations of dismantling a Westinghouse turbine and a multi-stage impulse turbine of any standard design whatsoever, will demonstrate the superiority of the former as regards general accessibility in the most forcible and convincing manner. In the Westinghouse combina- tion impulse and reaction turbines, only one impulse element is used so that no interstage packing is required, and consequently the drum and ring con- struction of the rotor can be maintained. Variations in Design The development of high-speed alternating-current generators of large capacities, has made it desirable to make certain radical departures from the By-pass Sfeam Inlet- Inlet. - Dummies Equilibrium Pipe Fig. 4 Section of a Parsons Type Single-Flow Turbine conventional Parsons design. The original Parsons design, and three West- inghouse variations thereof, are shown diagrammatically in Figs. 4, 6, 9 and 11. The Single-Flow Type Fig. 4 illustrates the original single-flow Parsons type. Steam is admitted at A to an annular chamber in the casing. From this point the steam passes alternately through rings of fixed and moving blades, of progressively increasing lengths, on the small diameter of the drum or rotor, expanding in volume as it passes through the successive rings of blades. When the volume of the steam has increased to the extent that the blades on this small diameter of drum and casing would have to be inconveniently long to provide passageway for it at a sufficiently moderate velocity, the diameters of the drum and casing are increased for the next stage of the expansion. The available area of the steam passage through the blades is a fairly constant Westinghouse Turbo-Alternators Fig. 5 100,000 Kw. in One Room Kent Avenue Station of the Brooklyn Rapid Transit Company Westinghonse Turbo-Alternators percentage of the product of the mean circumference of the blade ring multi- plied by the height of the blades. If the mean diameter of the blades in the second stage be increased to about 1.42 times that of those in the first stage, the area through each blade ring per inch of blade height will be 1.42 times that through the first stage rings. On account of the larger diameter, the mean speed of the blades will also be 1.42 times that of the blades in the first stage and consequently the velocity of the steam through the blades in the second stage may be 1.42 times that in the first stage. Now if the area through the second stage blades per inch of height and the velocity of the steam through the blades, are both 1.42 times as great as in the first stage, then to pass the same volume of steam per second the blades in the second stage need be only one-half as high as those in the first stage. As the steam expands in the second stage, its volume will increase until the blade heights required again become excessive. The drum diameter is Reaction Element Exhaust - No2Zle Chamber --Impulse Wheel - - Dum my Fig. 6 Section of a Combination Impulse and Reaction Single-Flow Turbine again increased, and the blade heights on the enlarged diameter are reduced. Expansion proceeds along this third or low-pressure stage through progres- sively increasing blade rings until the pressure of the steam falls to that of the exhaust. Impulse and Reaction Single-Flow Type Fig. 6 illustrates a modifica- tion of the single-flow design in which the smallest barrel of reaction blading is replaced by an impulse wheel. Steam is admitted to the nozzle block A, is expanded in the nozzles and discharged against a portion of the periphery of the impulse wheel. The intermediate and low-pressure stages are identical with the corresponding stages in the design illustrated in Fig. 4. The sub- stitution of the impulse element for the high-pressure section of reaction blading has no influence one way or another on the efficiency. That is to say the efficiency of an impulse wheel is about the same at the least efficient section of reaction blading. This design is attractive, however, in that it shortens the machine materially, and gives a stiffer design of rotor. The entering steam is confined in the nozzle chamber until its pressure and temperature have beet, materially reduced by expanding through the nozzles. As the nozzle chamber is cast separately from the main cylinder, the temperature and pressure differences to which the cylinder is subjected are correspondingly lessened. However, probably on account of its small 10 Westinghouse Turbo-Alternators Fig. 7 Two 500-Kva. and One 625-Kva., 600-Volt, Three-Phase, 60-Cycle, 3600 R.P.M. Units Pressed Steel Car Company, McKees Rocks, Pa. Fig. 8 An H80-Kva., Two-Phase, 440-Volt, 40-Cycle, Low-Pressure Turbo-Generator Unit, American Iron & Steel Company, Lebanon, Pa. 11 Westinghouse Turbo-Alternators diameter at the high-pressure section, the straight Parsons type has always shown itself to be adequate for all of the steam pressures and temperatures encountered in ordinary practice. The principle advantage of the high-pres- sure impulse element, is that without any sacrifice of economy, it shortens the rotor to such an extent as to make a double-flow design practicable. The Double-Flow Turbine The maximum economical capacity of a single-flow turbine is limited by the rotative speed. The economical velocity at which the steam may pass through the blades of the turbine depends on the velocity of the moving blades. The capacity of the turbine depends on the weight of the steam passed per unit of time, which in turn depends on the mean velocity and the height of the blades. For a given rotative speed, the mean diameter of blade ring practicable is limited by the allowable stresses due to centrifugal force, and there is a practical limit for the height of the blades. Now if we make the rotative speed only half as great, the maximum diameter of the rotor may be doubled and, without increasing the height of Reaction Element Impulse., Wheel Reaction Element Exhaust - -I-*- --Exhaust Fig. 9 Section of a Double-Flow Turbine the blades, the capacity of the turbine will be doubled. So with the single- flow steam turbine as well as with the single-crank reciprocating engine, there is a practical limiting economical capacity for any given speed. If this limit is reached with a single-crank reciprocating engine, we may produce a .unit of double the power at the same speed by coupling two single-crank engines to one shaft. We accomplished similar results by making a double-flow tur- bine which is in effect, as will be seen from Fig. 9, two single-flow turbines made up in a single rotor in a single casing with a common inlet and two exhausts. Steam enters the nozzle block A, acts on the impulse element, and then the current divides, one-half of the steam going through the reaction blading at the left of the impulse wheel ; the remainder passes over the top of the impulse wheel and through the impulse blading at the right. Semi-Double-Flow Type Fig. 11 is a modification in which the inter- mediate section of reaction blading is single-flow, and the low-pressure section only is double-flow. This would be analogous to a triple compound recipro- cating engine with one high-pressure, one intermediate pressure and two low- pressure cylinders a design not at all uncommon in very large engines in which the required dimensions of a single low-pressure cylinder would be prohibitive. Such turbines are useful for capacities greater than is desirable for a single-flow turbine, and which are still below the maximum possibilities of a double-flow turbine of the same speed. In such machines the best efficiency is secured by 12 Westinghouse Turbo- Alternators tfS i I Kg a ll = a 13 Westinghouse Turbo-Alternators making the intermediate blading in a single section large enough to pass the entire quantity of steam. A "dummy" similar to those used on the single-flow Parsons type, shown at the left of the impulse wheel, compels all of the steam to pass through the single intermediate section of the reaction blading, and balances the end thrust due to this section. When the steam issues from the intermediate section, the current is divided, one-half passing directly to the adjacent low-pressure section, while the other half passes through the holes shown in the periphery of the hollow rotor and through the rotor itself, beyond the dummy ring, into the other low-pressure section at the left-hand end of the turbine. There are sound logical engineering reasons for the existence of these several types, viz., single-flow, double-flow, and semi-double-flow. The double- flow turbine is not offered as a design that is inherently superior to the single- flow design, but it is offered for use under conditions for which the single-flow Single Flow Reaction Element Reaction Element -- Impulse Wheel ~" Dummy Reaction Element Exhaust - .-- Exhaust Nozzle Chamber Fig. 11 Section of a Semi-Double-Flow Turbine machine is unsuitable. Similarly, the semi-double-flow is recommended only for conditions which it can meet more satisfactorily than either of the other types. Special Turbines While this publication is devoted to a consideration of the steam turbine solely as a prime mover, taking steam at boiler pressure, and using all of its steam for producing mechanical energy, the turbine principle is nevertheless so flexible as to be capable of many special adaptations. Two of these, viz: low-pressure or exhaust turbines, and "bleeder" turbines are very important and interesting. Low-pressure turbines use exhaust steam from non-condensing engines and are valuable as an adjunct to existing plants for the purpose of increasing economy and capacity with a minimum outlay for new equipment. Examples of low-pressure turbine installations are shown in the illustrations on pages 25 and 31. Bleeder turbines are for use in plants which are required to furnish, not only power, but also considerable and varying quantities of low-pressure steam for heating purposes. In these turbines a part of the steam after it has done work in the high-pressure stages may be diverted to the heating system, and the remainder expanded through the low-pressure blading and exhausted into 14 Westinghouse Turbo-Alternators 15 Westinghouse Turbo-Alternators the condenser. In this way none of the energy of the heating steam, due to the difference of pressure between the boiler and the heating system, is wasted. On the other hand if no steam is required for heating purposes, the' turbine operates just as efficiently as though the bleeder feature were absent. A general view of the bleeder turbine is shown in Fig. 30. The weighted valve on the top of the cylinder regulates the pressure and quantity of steam bled to the heating system. ^ - ^^^ ^^^ji^j^rfta*"""*' Fig. 13 A Single-Flow Rotor Fig. 14 A Double-Flow Rotor Some Details of Construction Rotors Figs. 13, 14 and 15 illustrate respectively single-flow, double- flow, and semi-double-flow rotors. These rotors are built up of hollow steel shafts or drums, which are machined on the inside as well as on the out- side. The shaft sections are enlarged or flanged at one end and securely fixed in the drums. The drum diameter corresponds to the root diameter of the smallest rings of blading. The larger diameters of blading sections are mounted in groups on separate steel drums which are carefully balanced and pressed on the central drum. The "dummies" on the single-flow Parsons type, and on the Westinghouse semi-double-flow design are also made up- of separate steel rings pressed on the central drum so that if they should be injured by careless adjustments, they can be easily removed and replaced by new ones. Westinghouse Turbo- Alternators The Westinghouse impulse blading is shown in detail in Fig. 16. It is made of extruded metal and is of generous section. The blades are sepa- rated by steel packing pieces, and blades and packing pieces are locked together Fig. 15 A Semi-Double-Flow Rotor by steel pins so arranged as to present the strongest possible resistance against shearing. The method of assembling the components is evident from the illus- tration. The grooves in the impulse wheel are somewhat wider than the blades, and have an overhanging shoulder on one side. The blades and packing pieces are notched oruone side, and when in place the notches engage with the overhanging shoulder on the one side of the ring groove. The other side of the ring groove is slightly undercut in dovetail Fig. 16 Westinghouse Impulse Blading fashion. When the blades and packing pieces are set in their grooves, the space between the blades and the dovetail side of the groove is filled in with a series of pairs of steel wedges. These wedges are beveled in both directions viz., lengthwise and crosswise, so that when set up in pairs they fit snugly 17 Westinghouse Turbo-Alternators against the side of the blades, and the undercut side of the ring groove, so that they cannot be loosened or thrown out by centrifugal force. The section of the blade at its root is cut away much less than any with other form of fastening, and consequently, it has greater strength to resist centrifugal strains. The wedges, while affording the utmost security as a means of locking the blades in place, can nevertheless be easily removed without special appli- ances, in case it should be necessary to replace or repair the blading. The impulse blades are shrouded to prevent the steam from spilling over the ends, as shown in Fig. 17, which is a view of a portion of a single-double flow Fig. 17 Portion of a Combination Impulse and Reaction Rotor Fig. 18 Guide Blade Section rotor showing a section of the finish impulse blading, and also a little of the reaction blading and the ' 'dummy' ' ring. There are two rows of blades on the single-impulse element, and the steam issuing from the first row is redirected onto the second row by a short section of stationary guide blades shown in Fig. 18. The reaction blading exhibits a marked improvement over older practice. It is made of phosphor-bronze, drawn to the proper section, heat treated and cut to length. The root ends are slightly "upset" in a "bulldozer" and a small hook or shoulder formed on one side as shown in Fig. 20. The grooves in the rotor and cylinder are of dovetail section, and have a small auxiliary groove of rectangular cross-section in the bottom. The steel packing pieces are beveled on the sides to fit snugly in the dovetail grooves and the shoulders formed on the lower ends of the blades project down into the auxiliary grooves, and hook under the packing pieces so that they could not be pulled out without actually shearing the metal. The slight thickening at the roots, caused by 18 Westinghouse Turbo- A Uernators 19 Westinghouse Turbo-Alternators TWO- 1250 KVA.,600 VOLT. 60 CYCLE, TURBINE GENERATOR UNITS. DARTMOUTH MFG. CORPORATION, NEW BEDFORD, MASS. THREE 2000 KVA., 6600 VOLT. 25 CYCLE,A.C. TURBINE GENERATOR UNITS. CON6PESSIONAL POWER PLANT, WASHINGTON, D.C. Westinghouse Turbo-Alternators Z500 W*,t WOO KVA.,2 PHASE,440 VOLT, 60 CTOE, TURBINE 6CNERATOR UNITS. B.F. GOODRICH COMPANY, AKRON, OHIO. JBBINE GENERATOR WOT. .KANSAS CITY. MO. 750 W.,240 VOLT, 60 CYCLE, A.C JURBJNE GENERATOR UNIT. BROWN & SHARP MF6.CO. PROVIDENCE. R.I . Westinghouse Turbo-Alternators the "upsetting" in forming the hook or shoulder, adds very greatly to the strength of the blades. With the largest sizes of reaction blading, double wedges are used- in one side of the blading groove, which are similar to those used for securing the im- pulse blades. The outer ends of the blades are tied together with the now well- known ' 'comma' ' lashing, The blades are punched with comma-shaped holes as shown in Fig. 23 and a wire of the same section is threaded through these holes. After the blades are straightened and gauged, the part of the lashing wire that in section corresponds to the tail of the comma, is curled over, forming a rigid separator, or distance piece between the blades. For the longest reaction blades, two lashings are used, one at the middle of the blade and one near the outer end. Cylinder In the cylinder design, care has been taken to eliminate inso- Packing Pieces Assembly Fig. 20 Reaction Blading Figs. 21 and 22 Two Views of Nozzle Chamber with Stationary Guide Blade Section Attached far as possible, all ribs, equalizing ports, and other features, which would result in an unnecessarily complicated and irregular casting that would be likely to be affected by strains resulting from temperature changes. Whenever dummy packings are used, as in the semi -flow Parsons type and in the semi-double- 22 Westinghouse Turbo-Alternators flow combination type, they are made up in removable rings as illustrated in Fig. 24. In the combination impulse and reaction turbines, the nozzle cham- Original Calked Blade Punched Blade Lashed Fig. 23 Westinghouse Comma Lashing bers are also independent castings. The nozzle chamber is illustrated in Figs. 21 and 22. The root section of stationary guide blades between the first and second rows of impulse blades, is attached to the nozzle chamber. Figs. 21 and 22 show respectively the front and rear views of the nozzle chamber with the guide blade sec- tion attached. There are two noz- zle chambers in each turbine, the primary and the secondary. The secondary comes into action only when the turbine is loaded above its normal or rated capacity. Spindle Gland Packing The various metallic and fibrous pack- ings which give excellent results both as to wear and tightness in a stuffing box for a reciprocating pis- ton rod, are not at all satisfactory when applied to a stuffing box on a shaft rotating several thousand times a minute. In general, the packing in a steam turbine is sub- jected to only a moderate pressure difference, i.e., the difference be- tween the pressure of the atmo- sphere, and the vacuum at the exhaust end of the turbine. Instead of preventing the escape of steam from the turbine, the office of the packing is to prevent air leaking into it; and as a properly designed turbine makes profitable use of the last fraction of an inch of vacuum attainable, it is particularly desirable that this packing should be tight. In the Westinghouse turbines, the spindle gland is packed by an annular ring of water, which is absolutely tight, and which does not cause any wearing Fig. 24 Dummy Packing 23 Westingkouse Turbo-Alternators of the shaft. A bronze casting like the runner of a small centrifugal pump (see Fig. 13) is pressed on the shaft, and rotates in an annular chamber surrounding the opening in the end of the turbine cylinder through which the shaft projects. Water is fed to this annular chamber, and under the action of centrifugal force, it builds up a fluid ring or wall between the bronze runner and the turbine casing, which effectually seals the opening, and which is strong enough to resist a pressure of more than 30 pounds per square inch. The grooved hubs on the bronze runner constitute an ordinary labyrinth packing that may be temporarily sealed with water or low-pressure steam while the turbine is being started, and before it has attained the speed required to make the centrifugal water packing effective. Governing Fig. 25 is a view of the governor, with the casing removed. It is driven from the main shaft through a worm gear, and is unusually powerful. The ball levers and the links connecting these levers to the governor sleeve, are all pivoted on hard chrome steel knife edges, which elim- inate frictional disturbances. The main spring surrounds the spindle and bears directly on the governor sleeve. A small auxiliary spring, with a manually or electrically-operated tension gear for making small speed adjustments while running, is con- nected to the governor linkage. It is used in synchronizing the alternators or in distributing the electrical load among them. In the smaller turbines, the gover- nor acts directly on the steam admis- sion valves, opening first the primary valve, and then, if necessary, the secondary valve, after the primary is fully open. In turbines of the single-flow Parsons type, the governor actuates two small valves controlling ports leading to steam relay cylinders which operate the admission valves. The little valve controlling the relay cylinder for the secondary valve has more lap than the other and consequently does not come into action until the primary valve has attained its maximum effective opening. Fig. 28 shows the general design of this type of valve gear. Governors for the larger turbines, particularly those of the combination impulse and reaction double, or single double-flow type, employ an oil-relay mechanism, illustrated in Fig. 29 for operating the steam valves. In these turbines the lubricating oil circulating pump, maintains a higher pressure than is required for the lubricating system. The governor controls a small relay Fig. 25 Turbine Governor 24 Westinghouse Turbo- A Iternators Fig. 26 A 937-Kva., Three-Phase, 600-VoIt, 60-Cycle Turbo-Generator Unit, Lorain Manufacturing Company, Pawtucket, R. I. Fig. 27 An 8000-Kva., Two-Phase, 60-Cycle Turbo- Genera tor Unit, Peoples Power Company, Moline, 111. 25 Westinghouse Turbo- Alternators valve A , which admits pressure oil to, or exhausts it from the operating cylinder. When oil is admitted to the operating cylinder raising the piston, the lever C lifts the primary valve E. The lever D moves simultaneously with C, but on account of the slotted connection with the stem of the secondary valve F, the latter does not begin to lift until the primary valve is raised to the point at which its effective open- ing ceases to be increased by further upward travel. A common fault of most oil-relay governing systems is that they are sluggish in Fig. 28 ValvelGear With Steam Relay their action. In the West- inghouse designs, the oper- ating valve A is connected not only to the governor, but also to a vibrator, which gives it a slight but continuous reciprocating motion, while the gov- ernor controls its mean position. The effect of this is manifested in a slight pulsating throughout the entire relay system, which, so to speak, keeps it ' 'alive' ' and ready to respond instantly to the smallest change in the position of the governor. The oil relay can be made sufficiently powerful to operate valves of any size, and it is also in effect a safety device in that any failure of the lubricating oil supply will automatically and immediately shut off the steam and stop the turbine. Safety Stop Governor Every Westinghouse turbine is fitted with a simple, reliable speed- limit governor, which is wholly independent of the main regu- lating governor and its driving gear. Whenever the turbine at tains the over- speed limit to which this safety- stop governor is adjusted, an au- tomatic stop valve is tripped, Fig ^^ Gear With ou Relay and the steam supply is shut off. When it is desired to shut the turbine down, the oper- ator, instead of closing the throttle by hand, can, by exerting a pull on the governor linkage, make the turbine speed up until the limit governor trips 26 Westinghouse Turbo-Alternators Fig. 30 A 625-Kva., 600-Volt, 60-Cycle, Three-Phase Automatic Bleeder Turbo-Generator Unit, Lowell Bleacheries, Lowell, Mass. Fig. 31 A 300-Kva., 440-Volt, 60-Cycle, Three-Phase, Turbo -Genera tor Unit Installed In the Bernon Mills Plant, Georgiaville, R. I. 27 Westinghouse Turbo- A Iternators the automatic stop valve and in this way assure himself that the safety-stop mechanism is in condition to act with promptness and certainty in case its protection should be needed. Bearings In turbines running at speeds of more than 3000 revolutions per minute the spindle tends to rotate on its gravity axis instead of on its geometric or mechanical axis; of course, these two axes are made to coincide as exactiy as possible, but a difference so small as to be within the limit of error of the most refined methods of balancing, might set up disagreeable vibrations when the turbine is running at full speed. To compensate for this possible condition, the bearings on high-speed turbines are made up of several concentric tubes with slight clearance between them. The lubricating oil fills these clearances with a viscous film which forms an elastic cushion, and allows the spindle to find its true center of rotation. This nest of tubes is carried in a cast-iron sleeve which rests in a pedestal. In Fig. 32 the nest of tubes is shown at the left, and the supporting sleeve at the right. On the outside of the sup- porting sleeve are four steel blocks fitting in slots spaced 90 degrees apart and secured with screws. These blocks ex- tend above the outer circumference of the casting and are machined to form a section of the surface of a sphere. The pedestal has a corresponding spher- ical bore, so that the combination forms Fig. 32 Turbine Bearing a self-aligning ball and socket bearing. The steel blocks referred to above, are backed up with a few rolled-steel shims, the thickness of which are multi- ples of five one-thousandths of an inch. By transferring these shims from one side of the bearing to the other, the final adjustments for centering the spindle in its casing can be affected with the utmost nicety. In the larger and slower-running turbines, the so-called critical speed is never reached and consequently the concentric oil-cushioned tubes are not required. The bearings for these turbines are very like the supporting sleeve for the high-speed turbine bearings, except that they are babbitt-lined and made in halves. Lubrication A closed oiling system through which a continuous circulation is maintained by means of a pump geared to the main shaft of the turbine, keeps the turbine and generator bearings flooded with oil at a very moderate pressure. From the bearings, the oil drains through a strainer into a col- lecting reservoir, whence it is pumped through a cooler, and back to the bear- ings. No water-cooled bearings are used on Westinghouse turbo-generators. It is believed to be safer, more convenient, and more efficient to water-cool the oil in the course of its travel through the system. In the turbines in which the oil-relay governing system is employed, and a higher pressure is maintained by the pumps, the comparatively small quantity of oil required for operating the valve mechanism passes to the relay cylinder, whence it exhausts into the cooler. The remainder of the circulating oil dis- 28 Westinghouse Turbo-Alternators Fig. 33 A 937-Kva., Three-Phase, 600-Volt, 60-Cycle Turbo-Generator Unit, Corr Manufacturing Company, East Taunton, Mass. Fig. 34 A 4000-Kva., Three-Phase, 2300-Volt, 60-Cycle Unit and- a 3500-Kva. Unit of the Same Characteristics, Narragansett Electric Lighting Company, Providence, R. I. 29 Westinghouse Turbo-Alternators 5:?? Water Rates- Lbs/KWHR. 5500K.W WP Turbine 74 th St. Station, N.Y Tested by H. G. Staff \-l907-ISOLbs, SB'Vacumn 3- 19/0- 176 &s. ?S"?a'B Vtoc. 2- B Corrected to HSLbs 8"Vac D-B" Corrected to ISOLbs. ?S" Vfcc charges directly into the cooler through a spring-loaded pressure-reducing valve, so that pressure in the main circulation is therefore the same, whether the oil- relay governing system is employed or not. Economy This is a matter that depends more on scientific proportions than on the general type of turbine. Published reports of tests, are apt to be misleading, unless one is especially skilled in interpreting the data obtained. Until the principles of turbine design become more extensively, and more exactly a matter of public information, the purchaser will have to rely more on the knowledge, experience, and integrity of the builder, than on any theo- retical discussion of the subject. The Westinghouse Machine Company has the most extensive steam-turbine testing plant in the world. It has conducted more actual tests of steam turbines than any other manufacturer, and its files of test records, constitute the most comprehensive collection of dependable information on turbine efficiencies in existence. Efficiency guarantees as to the performance of Westinghouse turbines are made with the expectation that they may have to be demonstrated, and not with the hope that they may never be questioned. Better guarantees may be offered, but in point of actual performance the only thing that really counts Westinghouse turbines are still distinctly in the lead. Those who are interested in examining in detail, arid analyzing efficiency tests, are referred to a series of trials on the 10,000-kilo- watt unit installed for the City Electric Company, San Francisco, Cal., shown in the illustration on page 5. These tests were con- ducted by the J. G. White Com- pany, and were reported in a paper presented by Mr. S. L. Napthaly, at the annual meeting of the American Society of Mechanical Engineers, at New York, in December, 1910. A reprint of this paper will be sent on request. Permanency of Efficiency Most important of all, however, is the question of the permanency of the efficiency. In this connection the diagram, Fig. 35, above is particularly interesting, in that it shows graphically the results of a test of a 5,500-kilowatt Westinghouse turbine at the 74th Street station of the Interboro Rapid Transit Company, New York City, in comparison with the results of a test of the same machine made three years earlier. These tests were made under the direction of Mr. H. G. Stott, Superintendent of Motive Power, and at the date of the last test the unit had been in service five years and two months, and its total output had been 168,614,075 kilowatt-hours, or 70 per cent of the total number of hours multiplied by the rated capacity of the unit. The last test, far from indicating any deterioration in efficiency, shows even better results than the one made three years earlier. Naturally, this record reflects the highest type of good management and intelligent supervision, but at the same time it is evidence that the Westing- house turbines possess the inherent qualities that make this sort of manage- ment and supervision worth while. 30 4000 5000 6000 Load KW Fig. 35 Curves of Turbine Performance Westinghouse Turbo- Alternators The Generator Although the principle of operation of the steam turbine and that of the reciprocating engine are decidedly unlike, the principle of operation of the high-speed turbine-driven generator does not differ from that of generators designed for being driven by other types of engines or by water-wheels. There are, therefore, with the turbine-driven generator, no new ideas for the operator, who is familiar with the older forms to acquire. That the proportions of such high-speed machines must be very different from those permissible in generators of much slower speeds is obvious. In the high-speed machines ' the rotor Fig. 36 Westinghouse Generator for Turbine Drive diameter is small and is of relatively greater length than in low-speed generators. Special ventilation is necessary. The high peripheral rotor speeds involve new ideas and ideals in material, design, and workmanship. Westinghouse turbo-generators have, from the time they were the pioneers in the field, formed a part of the most efficient turbine units operating in America. Their present development is the result of unremitting investiga- tions, exhaustive tests, the advantages of a splendid shop equipment and the efforts of superior engineering talent. Type From the first, Westinghouse turbo-units have been of the hori- zontal type. They are the result of a long and consistent development of this one type. That sound judgment was used in selecting this construction is evidenced by rapidly decreasing use of the vertical units. Armature Construction Frame and Core A pleasing appearance results from the use of a cast- iron frame having cast-iron end-bells bolted to each of its ends. The frame is of the box girder construction which provides the rigidity required to firmly 31 Westinghouse Turbo-Alternators hold the laminated core. It also provides passages through which the warm air is conducted away from the generator. Ventilation The turbo-generator gives a very large output from relatively little material in a small space. Therefore the losses in these generators that must be disposed of as heat are very large per unit area. This necessitates plenty of cooling air. Well designed, well located devices for effectively guiding its flow must be provided. No one design of air-circulating device will effi- ciently serve for turbo-generators of all sizes and speeds. The Westinghouse method is to affix a special blower (See Fig. 44) to the rotor. It creates a flow of air which is guided by enclosing end-bells (Fig. 37) through the fan- D Fig. 37 Generator with Half of End-Bell Removed shaped end turns of the armature coils (Fig. 40), thence into the interior of the machine. Most of it flows through the air-gap between the stator and the rotor. Because the laminations are very deep and the volume of air forced through is large, the ducts (Fig. 42) must be of just the right proportions and must be accurately located to insure, with economy of air and power, uniform temperatures. The warm air collects in the large annular spaces (Fig. 41) within the frame casting and is ejected downwardly. Very large generators are sometimes ventilated by a motor-driven fan. In very large stations the installation of such an auxiliary is justified because its blower is more efficient than that on a generator shaft. Winding Because of the small number of coils in a turbo machine as compared with that in a slow-speed generator of the same kilovoltampere rating, each turbo-generator armature coil carries an enormous amount of power on large loads, particularly at times of short-circuits of grounds on the external circuit. The "throw" of the coils is large, leaving a considerable part of the winding in the end turns unsupported by the armature core. For these reasons great stresses, which are dangerous if, effective means are not 32 Westinghouse Turbo-Alternators Fig. 38 Two 625-Kva., Two-Phase, 450-Volt, 60-Cycle, Turbo-Generator Units, Sherwin Williams Company, Kensington, 111. Fig. 39 A 750-Kva.. Three-Phase, 2400-Volt, 60-Cycle, Low-Pressure Turbo-Generator JJnlt, Penn Mary Coal Company, Possum Glory, Pa. 33 Westinghouse Turbo-Alternators adopted to withstand them, may exist between the coils. An absolutely unique and perfectly secure form of armature winding has been invented for use in Westinghouse turbo-generators. Fig. 40 Armature with End-Bells Removed Showing Method of Bracing Fig." 41 Dovetail Grooves in Stator Casting Fig. 42 Laminations in Position in Stator Casting The copper conductors in the coils are of such cross-section that they can be made rigid and insulated satisfactorily. The manufacturer is more inter- 34 Westinghouse Turbo- Alternators ested than any one else in seeing that none but the best insulation is used. It is his insurance. Then the end turns are given the fan-like (Fig. 43) form peculiar to Westinghouse turbo- generator armature coils. This con- struction affords thorough ventila- tion and with it the disposition of the coils is the very best for effective bracing (Fig. 40). Cord lashings are, except in the smallest frames, used only for hold- ing in the small spacing blocks be- tween the coils. They are not depended on to support the coils. Malleable iron braces, hard maple blocks, and brass or steel bolts with brass washers are used to withstand the mechanical stresses imposed on the armature coils by external short circuits. Field Construction Precedent has not influenced the Westinghouse Company to try to adapt one form of field structure construction for all capacities and speeds. The radial or parallel slot, the integral or separate shaft; and the semi-laminated or solid disc body form of construction is each used for rotors of the capacities and speeds for which it is best fitted. A record of entire freedom from any operating difficulty has been maintained for several years for fields built within that period. Insulation Every field is insulated solely with fire-proof materials mica and asbestos although guaranteed for the usual low-temperature rise. Fig. 43 Armature Partially Wound Fig. 44 A Two-Pole, Parallel Slot Field Radial Slot Construction Very small generators, have fields of the radial slot construction shown in Fig. 45. The rotor diameters are so small that the end turns of the winding can be effectively bound into place, such binding being necessary with a radial slot machine. The shaft and disc are a one- piece forging of steel. 35 Westinghouse Turbo-Alternators The parallel slot design of field construction, developed only by the Westinghouse Company, is best utilized in two-pole field generators up'to Fig. 45 A Two-Pole, Radial Slot Field Fig. 46 A Four-Pole, Parallel Slot Field Fig. 47 A Four-Pole, Radial Slot Field 10,000-kilovoltampere capacity or thereabout. Fig. 49 shows parallel slot cylinders, wound and ready for assembly. The large holes near the circumfer- ence of the cylinder are for the accommodation of the bolts that hold the bronze end disks and stub shafts. In winding, the cylinders are mounted on a horizontal turn-table that rotates in a horizontal plane. The copper strap field coil winding is wound turn by turn under pressure and strip insulation is wound in between. When completed the turns are held rigidly in position with heavy 36 Westinghouse Turbo- Alternators brass wedges. In Fig. 44 the rotor has been completed. A perfectly compact unit, almost indestructible and one in which the end turns are securely sup- ported, results. An end disc, made of bronze to prevent magnetic leakage, holds the stub shaft and is bolted to each end of the steel center. When the leads are attached to the collector rings the field is complete. No instance of operating trouble Fig. 48 A Two-Pole, Parallel Slot Field (either mechanical or electrical) with rotors of this type of construction has ever been reported to the Westinghouse Company. Hundreds are in service. Multipolar fields are illustrated in Figs. 46 and 47. Construction such as shown in Fig. 46 is entirely satisfactory except for the large sizes for which Fig. 49 Parallel Slot Field Cores Fig. 50 Armatures Under Construction it is difficult for the manufacturer to obtain castings promptly. It is unneces- sary to make special provision for end turns. The shaft is integral with the field center. For very large fields the radial slot construction is used. Through the use of this construction the use of large steel castings is avoided. Fig. 47 illus- trates a field of this type. 37 Westinghouse Turbo- Alternators S a a f u o 2 a II 38 Westinghouse Turbo- A Iternators 39 The Westinghouse Machine Co, New York Atlanta Boston Chicago Cincinnati Cleveland - San Francisco Denver Pittsburgh - Philadelphia St. Louis City of Mexico General Offices and Works East Pittsburgh, Pa. SALES OFFICES Ijp Broadway ff ^ - Candler Building 201 Devonshire Street 39 South La Salle Street 1102 Traction Building 1117 Swetland Building Hunt, Mirk & Co., 141 Second Street Gas and Electric Building - Westinghouse Building 03 North American Building - Chemical Building era, Importadora y Contratista, S. A. Circular W. M. 507 November, 1912 TheWestinghouse SMALL TURBINE-DRIVEN OUTFITS Pumps For All Purposes Generating Units fr^X I Centrifugal Blo\vers EAST PITTSBUR.G.RA. A Non-Condensing Turbine Driving the Air and Circulating Pumps of a Westinghouse Leblanc Condenser Westinghouse Small Turbine Outfits THAT turbines are by all means the most satisfactory form of drive for auxiliaries and small generating units, is generally conceded by all who have used them or have had opportunity to observe their performance. By every measure which the station owner or operator applies to his apparatus, they surpass reciprocating machinery, and just as the large turbine effected a complete change in main unit practice, so now this type of prime mover is becoming the standard for exciter, blower, or pump drive. Without enumerating the self-evident advantages of tur- bines for such service, this pamphlet deals in a general way with the product of The Westinghouse Machine Company in this field, including not alone the driving, but also the driven part of the unit. Westinghouse Small Turbine Outfits Centrifugal Pumps For fire or water service, irrigation, condensing, or general purposes, the centrifugal pump has almost unlimited application, and in a great majority of cases the turbine furnishes the desirable form of drive. This is particularly true of such pumps when used in and about power houses. The Westinghouse Machine Company is accordingly prepared to furnish centrifugal pumps in any capacity for power house work, including boiler- feed, hot-well, circulating and general service pumps. A brief descrip- tion of the types built, with general information as to capacity and size, follows. Boiler Feed Pumps As indicated by the sectional view opposite, the centrifugal boiler-feed pumps built by this Company are of the multi-stage, double-suction type. This construction has several decided advantages over the single-suction pumps, largely employed in the past. End thrust, a constant source of trouble, is practically eliminated, no balancing pistons being necessary. The double-suction pump may also be operated at higher speeds for equal capacity and efficiency, thus improving the economy of the driving turbine appreciably. Floor space requirements also favor this construc- tion. A particular feature of the design is the ease with which the machine may be inspected in all its parts. The casing and its heads are horizon- tally split, and the upper half can be lifted and the whirl chambers and runner shaft removed without disturbing any pipe connections. The use of large shaft diameters is made possible by the ample suction passages, insuring a rigid, smoothly operating unit. The bearings are ring-oiled, large reservoirs being provided to carry the oil. The glands are soft packed, the problem of evenly packing a revolving shaft being overcome by a simple but effective system which involves a mini- mum of wear on the shaft and very infrequent necessity of re-packing. Westinghouse Small Turbine Outfits It is accurate to state that the pump here described represents the latest development in the building of centrifugal boiler-feed appara- tus, and that the features of its construction embody most fully the advantages of rotating over reciprocating pumps for this service. A list of standard sizes with closely approximate dimensions follows: Westinghouse Small Turbine Outfits Boiler Feed Pumps INLET a 1 Head in Feet Pressure in Lbs. Per Sq. In. Stages Length (A) With Turbine Drive Width (B) Height (C) PIPE SIZES Inlet (1) Discharge (2) 150 to 230 192-460 287-690 I 384-920 83-200 125-300 166-400 2 3 4 7' 11" 8' 6" 9' *0" 2' 10" 3' 4" 5" 4" 225 to 350 192-460 287-690 384-920 83-200 125-300 166-400 2 3 4 7' 11" 8' 6" 9' 0" 2' 10" 3' 4" 5" 4" 295 to 458 192-460 287-690 384-920 83-200 125-300 ](i(i 100 o 3 4 8' 8" 9' 5" 10' 1" 3' 5" 4' 7" 6" 5" 371 to 570 192-460 287-690 384-920 83-200 125-300 166-400 2 3 4 9' 0" 9' 9" 10' 3" 3' 5" 4' 7" 6" 5" . 450 to 700 192-460 287-690 384-920 83-200 125-300 166-400 2 3 4 9' 6" 10' 4" 11' 1" 3' 10" 4' 11" 8" 6" 590 to 920 192-460 287-690 384-920 83-200 125-300 166-400 2 3 4 10' 3" 11' 1" 11' 10" 3' 10" 4' 11" 8" 6" 750 to 1160 192-460 287-690 384-920 83-200 125-300 166-400 2 3 4 11' 2" 12' 2" 13' 3" 4' 10" 6' 4" 10" 8" 840 192-460 to 287-690 1190 384-920 S3 200 125-300 166-400 2 3 4 12' 2" 13' 5" 14' 8" 6' 6" 7' 10" 12" 10" 1480 192-460 to 287-690 2300 384-920 83-200 2 125-300 3 166-400 4 12' 2" 13' 5" 14' 8" 6' 6" 7' 10" 12" 10" Westinghouse Small Turbine Outfits Circulating and General Service Pumps In connection with jet and surface condenser work, this Company has built a large number of centrifugal pumps which are particularly adapted to low-head service. The runners are of the double-suction type, giving large ca- pacity for small diameter, which results in good efficiency at economical speeds. These pumps, one of which is shown by the photo- graph, may be driven by tur- bines, motors, or by belt. While primarily de- signed to handle water for con- densers, they are available for any moderate head service, and their high efficiency, the ease with which they may be inspected, and their rugged construction, make them generally desir- able. These pumps are built in a complete list of sizes given by the following table: DISCHARGE (1) Gals. Per Min. Head in Feet Length A Width B Height C Discharge Piping 750- 1000 20 to 30 4' 5" 3' 2" 2' 10" 6" 1500- 2000 20 to 30 5' 6" 3' 2" 2' 10" 10" 2500- 3000 6' 7" 3' 2" 2' 10" 12" 4000- 5000 20 to 30 4' 9" 3' 5" 3' 0" 14" 6000- 7500 20 to 30 6'0" 3' 5" 3' 0" 16" 8000-12000 20 to 30 7' 3" 3' 5" 3' 0" 18" 15000-20000 20 to 30 5' 9" 4'0" 3' 6" 24" 23000-28000 . 20 to 30 7' 2" 4'0" 3' 8" 32" 30000-37500 20 to 30 8' 7" 4'0" 3' 6" 36" Westinghouse Small Turbine Outfits High Efficiency Low-Head Pumps For Large Capacities One reason for the popularity of steam turbines for auxiliary drive is that the exhaust is uncontaminated by oil, and is therefore pure water for boiler feed. As, however, relatively high speeds should be used for good efficiency, they are sometimes unfitted for direct connection to pumps, particularly where the working head is small. An example of this condition is the centrifugal circulating pump for surface con- densers, where large volumes of water are to be handled against total heads seldom exceeding 30 feet. To overcome this inconsistency in speeds and at the same time retain high efficiency in both pump and turbine, this Company makes use of the Flexible Reduction Gear first employed in connecting turbines and direct-current generators. A circulating unit built on this plan, is shown above. The efficiency of the gear is approximately 97 per cent, and of the pump 70 to 75 per cent, with heads as low as 15 feet. Of course, the use of the gear permits of any turbine speed required for high efficiency. These outfits are built with one, two or three double- suction runners on a common shaft, depending upon the desired capacity. A sectional view of a two-runner pump is shown herewith. Westinghouse Small Turbine Outfits If it is desired, motor drive may of course be employed instead of the turbine and gear. The following table gives closely approximate data on these pumps. I o Capacity Gal. Per Min. Head Speed Number LENGTH Width B Height C Discharge Piping ners A | P 8000-13000 10.0-25.0 200-325 1 16' 3" 6' 3" 7'0" 6' 1" ] 8000-13000 11.5-28.5 200-325 1 j 16' 5" 6' 5" 7' 2" 6' 6" i 30" 8000-13000 12.8-32.0 200-325 1 i 16' 7" 6' 7" 7' 4" 6' 11" ] 16000-26000 10.0-25.0 200-325 2 19' 1" 8' 7" 7'0" 6' 1" ] 16000-26000 11.5-28.5 200-325 2 19' 5" 8' 11" 7' 2" 6' 6" i 36" 16000-26000 12 . 8-32 . 200-325 2 19' 9" 9' 3" 7' 4" 6' 11" i 24000-39000 10.0-25.0 200-325 3 22' 0" 10' 11" 7'0" 6' 1" 1 24000-39000 11.5-28.5 200-325 3 22' 6" 11' 5" 7' 2" 6' 6" 42" 24000-39000 12. 8-32. O 1 200-325 3 23' 0" 11' 11" 7' 4" 6' 11" J Westinghouse Small Turbine Outfits Condensate and General Service Pumps In applying Westinghouse Leblanc Air Pumps to surface condensers it is often convenient to handle the condensate by a centrifugal pump mounted on the same shaft. These small centrifugal pumps are also arranged for separate motor or turbine drive. They are built with single-stage, double-suction run- ners, and the design is such that direct or alternating-current motor speeds are suitable. The total head in handling condensate averages about 60 feet. With slight modification, these pumps are therefore available for small and medium capacity general purposes against heads not exceeding 125 feet. A list of sizes with approximate dimensions, is given below. CAPACITY Speed Head Length A Width B Height C Discharge Piping Lbs. Per Hour Gals. Per Min. 20000 401 ! 1400-2000 50-125 36" 34" 24" 3" 30000 601 1400-2000 50-125 36" 34" 24" 3" 50000 lOOi 1400-2000 50-125 38" 31" 25" 4" 75000 l.W 1400-2000 50-125 38" 31" 25" 4" I 00000 200 1400-2000 1400-2000 50-125 40" 34" 2(5" 5" 150000 300 50-125 40" 34" 26" 5" 200000 400 1400-2000 50-125 40" 35" 2S" 6" 300000 600 1400-2000 50-125 42" 35" 28" 6" 400000 800 \ 1400-2000 50-125 42" 35" 28" 8" Westinghouse Small Turbine Outfits Small Capacity Centrifugal Blowers For Low and Intermediate Pressures The turbine or motor-driven blowers built by The Westinghouse Machine Company, are of the shallow vane centrifugal type. The machines are particularly suited to forced draft work, gas- blowing, or furnishing blast for cupolas. The distinctive characteristic of the blowers is their efficiency, which averages 60 per cent at rating. ^ *^>s 65 *- F/ 6 / X ^. \ 60 5 / ^L, . _ -^ * 5A VOL. \ 55 Q: UJ 4 / / JJ ^ & ^. ^ ^^ 50 \0 fe 3 / < ^ 45 6 X v. 2 tt 40 O UT A/G :F/= 7C/ NCY kl Q. c > c > > 1 c c_ > c > ) o cf o c> M 00 4000 5.8 15.0 14,000 22,400 3' 4" 4' 8" 4' 3" 30" 30" 2B 39" 800 1900 5.3 30.0 28,400 ,, . 68,000 81 nil / 8' 0" 36" 36" 3B 39" 800 1600 5.3 21.3 35,500 ,, q// 70,800 81 nil A S'O" 40" 40" 50" 4B 39" 800 1600 5.3 21.3 42,600 85,000 4' 2" 8' 2" S'O" 50" 2C 22^" 2f)0() 4000 12.5 32.0 16,600 36,800 3' 4" 4' 8" 4' 3" 30" 30" 2C 3C 4C 39" 800 1000 11.4 65.0 32,000 76,000 3' 4" 81 nn S'O" 36" 36" 39" 800 1(H)() 11.4 46.0 40,000 80,000 3' 9" 81 nil 1 S'O" 40" 40" 39" 800 1600 11.4 46.0 48,000 96,000 4' 2" S' 2" S'O" 50" 50" 2D 22^ 2 " 2500 4000 17.3 (4. r, 22,000 35,600 3' 4" 4' 8" 4' 3" 30" 30" 2D 39" 800 1900 16.0 90.0 40,000 94,600 3' 4" 8' 2" S'O" 36" 36" 3D 39" 800 1600 16.0 64.0 50,000 100,000 3' 9" 8' 2" S'O" 40" 40" 4D 39" 800 1600 16.0 64.0 60,000 120,000 4' 2" 8' 2" S'O" 50" 50" 10 Westinghouse Small Turbine Outfits Single-Flow Overhung Type Class Runner Diam. Speed Press. In. of Water Capacity Length A Width B Height C Discharge Opening I II 1A 22^" 2500 4000 2.4 6.2 5,500 8,900 10" 4' 8" 4' 3" 20" 20" 1A 39" 800 1900 2.2 12.6 ~2.2 8.9 11,050 26,500 10" 8' 2" 8'0" 26" 26" 2A 39" 800 1600 16,600 33,000 1' 8" 8' 2" 8'0" 30" 30" IB 22K" 2500 4000 5.8 15.0 7,000 11,200 14,200 34,000 10" 4' 8" 4' 3" 20" 20" IB 2B 39" 800 1900 5.3 30.0 10" 8' 2" 8' 0" 26" 26" 39" 800 1600 5.3 21.3 21,300 42,500 1' 8" 8' 2" 4' 8" 8'0" 30" 30" 1C 22)4" 2500 4000 12.5 32.0 8,300 13,400 10" 4' 3" 20" 20" 1C 39" 800 1900 11.4 65.0 16,000 38,000 10" O/ f)lt o A 8'0" 26" 26" 2C 39" 800 1600 11.4 46.0 24,000 48,000 1' 8" 8' 2" 8'0" 30" 30" ID 22^" 2500 4000 17.3 44.5 11,000 17,800 10" 4' 8" 4' 3" 20" 20" ID 39" 800 1900 16.0 90.0 20,000 47,300 10" 8' 2" 8'0" 26" 26" 2D 39" 800 1600 16.0 64.0 30,000 60,000 1' 8" 8' 2" 8' 0" 30" 30" 11 Westinghouse Small Turbine Outfits Generating Units As an auxiliary in large stations, where it is important to reduce attendance to a minimum, or as a main unit in smaller plants where reliability is highly essential, the small turbine generating unit is now generally accepted as the standard. The Westinghouse Machine Com- pany builds a very complete line of these units which are described below. The particular characteristic of the apparatus is its co-ordination of turbine and generator design. This most important factor in the success of such units is well exemplified in those built by this Company. Direct-Current Sets These units are built in sizes from 1 to 150 kilowatts for non-condens- ing service. The 100 and 150-kilowatt machines are also built in the 12 Westinghouse Small Turbine Outfits condensing type. The standard voltage is 125, although from 75-kilo- watts up, 250-volt generators, either two or three-wire, are furnished if desired. A 25-kilowatt, 125-volt set and a 100-kilowatt, 250-volt set are shown by the cuts. Although somewhat different in detail, these machines are all of the same type. The turbine wheel is mounted on the generator shaft and overhangs one of the two self-aligning bearings. These are ring-oiled in the smallest machines, and in the larger, are flooded by a pump driven from the shaft. The operation of the units is, therefore, entirely automatic, a safety stop being provided which would shut the machine down if the governor became disabled. The following table gives closely approximate data on these units. Non-Condensing PIPE SIZES Capacity Speed Voltage Length (1) (2) 1-kw. 4000 125 3' 1" 14" 19" W 1" 10-kw. 6000 125 5' 0" 2' 0" 2' 5" IK" 3" 25-kw. 3500 125 5' 9" 2' 8" 3' 3" 2K" 4" 50-kw. 3000 125 7' 10" 4' 6" 4' 7" 2^" 6" 75-kw. 2750 125 8' 4" 4' 6" 4' 9" 4" 9" 75-kw. 2750 250 8' 4" 4' 6" 4' 9" 4" 9" 100-kw. 2400 125 9' 6" 5' 1" 5' 1" 4" 9" 100-kw. 2400 250 9' 6" 5' 1" 5' 1" 4" 9" 150-kw. 2200 125 11' 3" 5' 1" 5' 6" 4" 12" 150-kw. 2200 250 9' 7" : 5' 1" 5' 6" 4" 12" Condensing 100-kw. 100-kw. 150-kw. 150-kw. 2400 125 11' 3" 4' 11" ! 5' 7" 3" 14" 2400 250 11' 3" 4' 11" 5' 7" 3" 14" 2200 125 14' 2" 5' 1" 5' 9" 3" 14" 2200 250 11' 6" 5' 1" 5' 9" 3" 14" 13 Westinghouse Small Turbine Outfits Alternating Current The cut below shows a 100-kilowatt, 60-cycle, alternating-current turbo-generator set with a direct-connected exciter. The machine shown is designed for condensing service. A non-condensing unit is shown opposite. There is a small constructional difference between the two units. For non-condensing service, the turbine wheel is of the overhung type, as is the case in the direct-current units. The condensing units have three bearings, two outboard and one between the turbine and generator. The rotor of such a unit is shown below. As the steam volumes at vacuum pressures are considerably greater, it is also necessary to use larger casings and nozzles. In operating principle, the machines are the same, consisting of a single impulse wheel upon which the steam is directed several times in order to entirely absorb its velocity energy. Sixty cycles being practically invariably employed in America as the standard frequency for small units, these machines all operate at 3600 r.p.m. They can be equipped with direct-connected exciters or not, as is desired. 14 Westinghouse Small Turbine Outfits Capacity LENGTH Width (B) Height (C) PIPE SIZES Unit (A) Exciter (D) Steam (1) Exhaust (2) 100-kw. 150-kw. 200-kw. 300-kw. 14' 1" 14' 5" 16' 8" 17' 6" 3'0" 3'0" 3' 2" 3' 6" Non-Condensing 4' 9" 4' 9" 5' 6" 5' 6" 4' 4" 4' 4" 5' 5" 5' 5" 4" 4" 5" 5" 10' 10' 18' 18' Condensing 100-kw. 14' 8" 3'0" 4' 5" 4' 6" 3" 14" 150-kw. 15' 0" 3'0" 4' 5" 4' 6" 3" 14" 200-kw. 16' 8" 3' 2" 4' 6" 4' 6" 4" 18" 300-kw. 17' 6" 3' 6" 4' 6" 4' 8" 4" 18" 15 Westinghouse Small Turbine Outfits Small Turbine Construction The apparatus described on the various pages of this catalogue, although now available for motor drive, was originally to be driven by Westinghouse small turbines. In order to completely cover the power turbine field, this Company builds small turbines of the impulse type ranging in normal capacities from 10 to 500 horsepower, for any condition of speed, steam pressure, and vacuum or back pressure. The first consideration in the design of these machines has always been simplicity. The cut shows the active principle of the machines. In each case they consist of a single disc of boiler-plate steel, carrying on the periphery nickel-iron blades. Steam, after expansion in a suitable nozzle, passes through these blades, delivering to them part of its velocity energy. On leaving the blades it enters a reversing chamber which again redirects it onto the blades. This process is repeated as many times as necessary to make efficient use of the energy in the steam. This is diagrammatically shown by the figure below. Where it is necessary to handle large volumes of steam, as in the case of condensing operation, it is convenient to use STEAM INLET a wheel such as is shown opposite, which wheel is of the condensing type. In any event, however, the power of the turbine is developed 1 on a single wheel, and all the complication of several wheels with 16 Westinghouse Small Turbine Outfits diaphragms and trouble- some packing between them is eliminated. This simplicity of connstruction involves practically no sacrifice in efficiency of the machine, and is undoubtedly the prime factor in the suc- cess of turbine drive for auxiliary apparatus, since, as a rule, this is installed in more or less inaccessible places. The most satis- factory unit, assuming reasonable efficiency, will therefore be the one re- quiring the least atten- tion, which in turn is, of course, the one operating upon the simplest principle. The blades, which as noted before, are made of nickel iron, have roots which set in a groove turned in the edge of the disc, and steel pins are driven through and riveted into place, forming a particularly strong construction and one which is little subject to deterioration. The bearings are of the plain ring-oiled type, and ample reservoirs are provided so that filling is not frequently necessary. A sectional view shows the gen- eral details of con- struction. It will be noted that the governor is of the plain centrifu- gal type mounted on the turbine shaft, and is connected through a simple lever direct to the stem of the steam valve. In ad- dition to this, a safety device is applied to each turbine which will shut off the flow of steam whenever the speed exceeds a certain safe limit, irre- spective of the action of the governor. The operation of the tur- bine is, therefore, en- tirely automatic. The materials used in the construction of 17 Westinghouse Small Turbine Outfits these turbines are, of course of the highest quality, and they are built in the same shop with our large turbines. The workmanship is, therefore, beyond question. As to sizes and capacities, it is not possible to list these on account of the great number, but as stated above, The Westinghouse Machine Company is prepared to furnish power turbines of this type in any size up to 500 horsepower for any operating conditions. 18 \ \ The Westinghouse Machine Company V- Designers and Builders of Steam Turbines Stokers s A Steam Engines ~ ^Ga.s Producers Gas Engines Pumps Condensers Blowers r .- Turbo Compressors SALES OFFICES A New York ^W . 165 Broadway Chicago .' . . . .39 South La Salle Street Pittsburgh Westinghouse Building Philadelphia 1003 North American Building Boston 201 Devonshire Street Atlanta Candler Building Denver Gas & Electric Building Detroit 27 Woodward Avenue Cleveland 1117 Swetland Building Cincinnati 1102 Traction Building San Francisco Hunt Mirk & Co., 141 Second St. City of Mexico Cia Ingeniera, Importadora y Contratista, S. A. Havana, Cuba '. Galban & Company San Juan, Porto Rico Porto Rico Construction Co. Iquique, Chile , J. K. Robinson & Co. Toki'o, Japan Takata & Company Caracas, Venezuela H. I. Skilton GENERAL OFFICES, AND WORKS EAST PITTSBURGH, PA. 726303 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 5O CENTS ON THE FOURTH DAY AND TO $I.OO ON THE SEVENTH DAY OVERDUE. MAY 16 1935 ccf , o 1939 Fto M ' fiPfl win 1 JUK fc 19^ DEC 75 1040 10Dec'57CS| RECTO l~U HFC 1 v