US1311615A - Steam-turbine - Google Patents

Description

1. F. M. PATITZ.

STEAM-TURBINE.

APPLlCATION FILED MAR. 24. 1913.

Patentml J My 29, 1919.

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9 illivxrlull r INVNTDR- WITNES s EEs- ATTDR NEY- all "UNITED STATES PATENT OFFICE.

waukee, in the county of Milwaukee and State of Wisconsin, has invented a certa-in new and useful Improvement in Steam-- Turbines, fication. p

This invention relates to improvements in the construction of steam turbines and particularlv to improvements in devices for retaining t 'e speed of a turbine and mechanism driven thereby, within safe limits.

An object of the invention is to provide asteam turbine especially adapted to drive a generator furnishing current to locomotive headlights or .for similar purposes, lwhieh is simple in construction and efficient in operation. Another object is to provide a simple means for retaining the speed attainable by the turbo-generator unit within safelimitsf thereby preventing destruction of the apparatus due to excessive speeding up caused by a sudden release of the load on the generator. It is a further object of of which the following is a specithe invention to provide a turbo-generator set in which-a predetermined constant setting of the throttle means for admitting motive fluid to the prime mover may be maintained for-all loads of the variable load generator, the speed of the unit under all load conditions beingautomatically retained within predetermined limits. Still another object of the invention is to provide common f neans for both controlling the speed of the iinit and for cooling the driven elements which. may be subjected to undesirable heating during normal operation.

I A clear conception of an embodiment of the invention may be had by referring to the drawing accompanying and iorming part of this specification in which like reference characters designate the same or similar parts in the various views.

' Figure 1 is a side elevation of a turbo-generator set showing a central vertical section through the turbine and auxiliary po consuming means or. fan.

Fig. is an end elevation of a turbo-generator set showing the turbine inlet throttle and theturbine exhaust.

' Fig. 3 is an enlarged development of a frag nent of the turbine bucket wheel showing the nozzles for directing the motive fluid Specification of Letters Patent.

Application filed March 24, 1913.

Patented July 29, 1919. Serial No. 757,261.

therethrough and the turbine exhaust, in section.'

The turbo-generator set consists essentially of a main shaft 3, having a power consuming means such as an electric generator 1, connected to an end thereof, and having a power furnishing means or prime mover, such as a steam turbine, connected to the opposite end thereof. The electric generator 1 may be of any of the well known types, the generator herein disclosed being especially adapted to furnish a limited. amount of power for furnishing current to locomotive headlights and for similar purposes. The generator 1 is mounted upon a suitable base 2 and is preferably direct connected to the prime mover which drives same.

The steam turbine consists essentially of a bucket wheel which is secured to an overha ging end of the shaft extension 4.. The shaft extension 4 is provided with a socket which fits over the end of the main shaft 3. The socket i is firmly secured to the main shaft 3 by any suitable means, such as a set screw, and the bucket wheel 10 may, if desired, be' secured directly to the end 'of the main shaft 3. The bucket wheel 10 carries a. series of radialbuckets 11 which, as -disclosed, are of the impulse type. The turbine casing 8 and end cover 12, completely inclose the bucket wheel 10 and are removably secured to each other by means of ca screws 20. The casing common base plate 2 by means of cap screws 17. The main shaft 3 and shaft extension 4 are prevented from floating or movin longitudinally by means of a "s ui.table adjustable cap screw 13 which forms a thrust bearing" and which is capable of being locked to the cover 12 in a predetermined position. The high pressure inlet pipe 16, through which the motive fluid is admitted to the turbine, is controllable by means of a suit able throttle means disclosed as a valve 20. The discharge from the inlet pipe 16 is directed into the high pressure admission nozzle 19, which is capable of transforming the steam pressure. into velocity and of directing the steam at high velocity against the vanes or buckets 11 carried by the bucket wheel 10, see Fig. 3. The return nozzle casing having the return nozzle passage 18 formed therein, is secured to the turbine casing 8 and is capable of receiving the 8 is secured to the steam discharged from the buckets 11 after mission of the high -pressure steam to the Wheel 10. The turbine exhaust 14' receives the steam exhausted. after its second passage through the Wheel and conveys same to any suitable source of low pressure, such as a condenser or directly to the atmosphere.

The means for automatically causing the resistance to the rotation of the shaft 3 to vary inversely as the load on the generator 1 varies, consists of a fan 5 having a series of radially extending vanes or blades 6. The fall 5 is secured directlyto the shaft extension 4: and may be secured directly to the shaft 3 if desired. The fan 5, as disclosed, is formed of a pair of sheet metal plates which are riveted together and have portions thereof bent outwardly to form the blades (5. The baliie plate 7 is provided Witha cent al opening forming an air duct Q'rvhich forms a means for conducting the supply of air to the fan'5 from a point adjacent the generator'l.

During the operation of the device, the throttle valve 20 is opened to a predetermined setting, thereby admitting a substantially constant amount of motive fluid to the steam turbine for. a given speed. The steam admitted to the nozzle 19 through the inlet pipe 16 is directed against the buckets 11 and upon having its energy partially abstracted during passage through the wheel 10, is discharged from the buckets 1 1 into the return nozzle passage 18. in the return nozzle passage 18 the directions-f the. steam is changed to again become eiiective indriving the bucket Wheel 1.0 in the proper direction. Upon being discharged from the return nozzle passage 18, the steam is again passed through the buckets 15., after winch it is dischargedfroni the turbine inclosing casing through the exhaust n.

' The power furnished by the steam turbine and controllable by means of the throttle valve 20 is sufficient to normally drive the generator 1 and the fan 5 at a desired speed with normal full load on the generator 1. If, however, the load on the generator 1 decreases; thesetting of the throttle valve 2-0 in the meantime remaining constant, the tendency of the shaft 3 will be to increase in speed. .Such increase in speed is, however, rapidly checked by the fan the power consumed by which being directly proportional to the cube of the speed at which it is driven. It will thus be noted that as the load onthe generator 1' decreases, the power consumed by the fan 5 will rapidly increase, thereby retaining the total load on the shaft 3- substantially constant and preventing excessive overspeeding of the bucket wheel 10. This automatic increasing of the power consumed by the fan 5 carried by the shaft extension 4: automatically causes the resistance to the rotation of the shaft 3- to vary inversely as the load on the generator 1 varice, and by properly designing the fan blade 6, the maximum attainable speed of the shaft 3 can be readily maintained within the desired safe limits.

During the rotation of the fan 5, the blades 6 are constantly drawing air through the air duct 9 and discharging same'from the periphery of the fan 5. By arranging the air duct 9 so as to receive its supply of air from a point adjacent the generator 1, the air supply drawn through the duct is drawn directly through the generator 1., thereby servingto cool the elements 'of the generator which may'be subject to undesired heating.

It should be understood that it is not desired to be limited to the exactdetails of construction shown and described, for obvious modifications will occur to a person skilled-in the art.

It is claimed and desired to secure by Let'- ters -Patent, y 1

. 1'.- In! combination, an electric generator having, 3 shaft, hearings for said shaft on opposite sidesjof' said generator, a single bucketvvheel associated with an overhanging end of closely adjacent said bucket Wheel, said fan rotation of said shaft to vary asthe load on said generator varies and constituting the sole means for automatically controlling the speed'of said bucket Wheel.

2. In combination, an electric generator haying a shaft, bearings for said shaft on opposite sides of and closely adjacent said Intestimony whereof, the signature of the inventor is ffixed hereto in the presence of,

two" witnesses.

JGHANN F. M. PATITZ.

Witnesses:

H. LIEBE G F. DE VEIX.

said shaft anda fan associated- With said overhanging shaft end and located automatically'causing the resistance to the

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