US910472A - Elastic-fluid turbine. - Google Patents

Description

o. 1111199119111 ELASTIG FLUID TURBINE. APPLICATION FILED JUNE 24, 1907;

Patented .191119, 1909.

2 SHEETS-SHEET 1.

O. JNGGRBN. ELAsTw FLUID TURBINB. APPLICATION FILED JUNE 24, 1907. 91 0,472, Patented Jan. 19, 1909. 2 SHEETS-SHEET 2.

INVENTUR Dim/m JUNGGREN UNITED sTATEs PATENT OEEIOE.

oscAR IUNGGREN, OE scEENEcTADY., NEW YORK, AssIcNoR- 'ro GENERAL ELEcTRIc;

COMPANY, A CORPORATION OE N'EwYo-RK.

ELAsTIc-FLUID TURBINE.

To all whom it may concern: Y

Beit known that I, OsoAR JUNGGREN, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Elastic-Fluid Turbines, ofwhich the following is a specification.

The present invention relates to elastic iiuid turbines and has for its object to improve their economy of operation by reducing the leakage at the shaft packing.

The invention is applicable to various types of turbines although it will be described in connection with a Curtis multi-stage turbine for which it is particularly intended. The high pressure end or" such a turbine isprovided with afpacking around theshaft -comprising a number of individual packing rings, usually three, each located in a separate compart-ment or chamber. One of these chambers, usually the one containing the lowest pressure, is connected by an open conduit or drain to a stage of the turbine of lower pressure than the first through which the leakage steam and water is free to pass. When the load on a turbine increases or decreases, the

pressure of the steam conlined by the pack.-v

ing increases or decreases as the case-may be, hence 1f tne draln or condult be of the proper size to satisfy one load condition, it will be 1ncorrect for the other. f In other words, steam.

will leak past the packing to the atmosphere when the pressure is above the predetermined normal, and when the pressure is below said normal air will be drawn in from the surrounding atmosphere and discharged into the stage or compartment to which the drain is connected. In ordinary cases the turbines are run under such variable load conditions that at light load the vacuum works up into the first stage. Obviously the admission of air under this or other conditions would impair the vacuum and increase the work to be performed by the air pumps. I overcome the objections above pointed out by controlling the effective area of discharge ofthe drain by a valve whose position bears a certain. re-

lation toi the ressure in the first stage and therefore to t at conned by the packing. This; drain is connected between the low pressure chamber of the packing and the last tur bine stage whose pressure is that of the condenser and therefore constant Within a small range. also provide a conduit for admit- Specification of Letters Patent.

Application'led .Tune 24, 1907. Serial No. 380,423.

Patented Jan., 19, 1909.

through the drain and the admission. of live steam to a packing chamber in a variety o ways, the simplest being to actuate the controlling valves therefor by the same governing mechanism that controls the turbine. As the load on the turbine increases the admission valves are opened one after the other, or

in the case of a throttle'. valve control the opening oi' said valve isf-increased and the drain controlling valve isgraduallyopened an: amountfsulicient. to take care of the leakage. When the load decreases the: governing mechanism decreases the steam admis sion, and the valve controlling'the admission of live steam to a packing chamber is so ade justed and arranged that. as the load decreases until a vacuum exists in Ythe iirst stage, it will open gradually or otherwise untll sufficient. steam is admitted to prevent the entrance of air from around the packingv to the turbine and condensen It sometimes happensowing tn faulty adjustment, lack of attention, etc., that steam will escape around the packing and where the turbines are directly connected to electric generators it may result inserions injury to the generator. This particular eature is true of any kind of mechanical packing. I avoid this objection by providing a fan contained in a casing, that causes the leakage steam to low through a conduit leading to a suitable point away from the generator windings. The rotating member of the fan so to speak, guards the space or clearance between the wall of the fan casing and the shaft-and prevents the outward iiow of. steam there through. The rotating member of the fan also prevents to a greater or less degree, the entrance of air to the turbine and condenser from around the packin In the accompanying i'aw-ingswhich-.illusz-f detail viewpartly in section and partly in elevation of lthe packing and governing mechanism; Fig. 4 is a detail view of a slight modification of the means employed to actuate the drain controlling valve Fig. 5 is a detail view of a yielding connection interposed between the actuator and the drain valve; Fig. 6 is a detail plan view of the fan for protecting the generator from escaping steam; and lig. 7 is a detail view showing the valve which controls the supply of steam to the packing.

l indicates the casing of a multi-stage turbine adapted to operate with a condenser. lt contains the usual` wheel and stationary buckets, nozzles, and diaphragms for dividL ing the casing into stages working at different pressure. On top of the turbine is the usual head 2 and resting thereon is a stool 3 which supports the stationary member 4 of the electric generator. 'he revolving member of the turbine and also that of the generator are mounted on the vertical shaft 5. lhe admission of steam to the nozzle or other fluid dis;harging device is controlled by a plurality of valves, each of whith is provided with an upright stem 6 and a lever 7 pivoted closing it.

at the right of the stem. Eath lever is raised and lowered at its free ends by a cam 8, and all of the cams are carried by the cam or rock-shaft 9. Eath valve has a spring for Near the end of the rock-shaft is a pinion 10 engaged by a rack l1, the latter forming a continuation of the piston rod of a hydraulic motor 12. ille piston in the motor moves forward or'backward under the control of a pilot valve and speed governor driven by the turbine shaft. On the end of the rock-shaft is a special cam 13 which gradually increases in diameter from the beginning to the end of its active surface. Engaging the cam is an anti-friction roller mounted in the end of a lever 14 which is pivotally supported in a bracket aiiixed to the main valve chest. To the lower end of the lever is connected a rod 15 u hich in turn is connected to the drain controlling valve 16 in the drain pipe 17. rhe drain pipe is connected to the packing and also to a point of low pressure.

Referring to Fig. 3, the specific form of packing used as illustrative of my invention, will be described. rhe head 2 of the turbine is cored out to form a chamber 18, and located therein and resting on the horizontal wall thereof is a carbon packing ring 19. 'Ihe ring is made in segments held together by garter springs 20, and closely surrounds the shaft without, however, making actual 'contact under normal running. 'Ihe packing is prevented from turning by the spline 21 which, however, permits it to move slightly to or fro to adjust itself to the proper position. 'lhe splineis carried b'y a plate 22,

and between the plate and the packing ring ing at all times to force the ring downward against its seat and against the pressure in the first stage or wheel compartment. Mounted on the plate is a casing or housing 24 containing a partition 25 which divides the same into chambers each containing a packing ring sirnilar'inl construction to the one described. It Will thus be seen that three chambers are rovided, each with a packing ring. the ower ring is pressed downward while the other rings are pressed upward. rihe drain 17 is connected to the outside or low pressure chamber and the escape of fluid therethrough is controlled by the' valve 16. Acting on the lever attached to the valve spindle is a spring 26 that tends at all times to close the' valve while the scroll cam 13 opens it.

In the connecting rod 1-5 is a spring coupling shown in Fig. 5, the purpose of which is to compensate for any inaccuracy in the length or adjustment of the parts. It comprises an outer tube 27 that is rigidly attached to the left hand end of the connecting rod and an inner tubular member 28 that is guided at the right end by a threaded head adapted to slide on the rod 29, the latter being pinned to one portion of the connecting rod. 'I he two tubes are adapted under normal conditions to move one Within the other. rhe left hand end of the inner tube. is provided with an internal shoulder whichengages the collar 30 on the rod. Between the opposite side of the collar and the threaded head is coiled compression spring 31. A second coiled compression spring 32 is located between a iixed abutment and the internal shoulder on the inner tube. 4'he internal shoulder has threaded holes to receive screws 33, the' latter working in slots in the tube 27. 105, The ends of these slots limit the relative movements of the parts under certain conditions. i" ssuming that the travel of the lower end of'the lever 14 and that of the upper end of the valve actuating lever are exactly right the springs may be disregarded, but if the parts are not set exactly right then one spring or the other will yield as the parts move and the inaccuracy be compensated f for. It will be readily seen that as the cam or rock-shaft turns so will the scrollcam and the latter acting through the lever 14 and connecting rod 15 will adjust the drain controlling valve 16.

The construction described has among others, the advantage that it can `be applied to existing machines with practically no modication.

In order to admit live steam to the packing, a conduit 35 is provided which extends 125 from the main valve chest to the intermediate chamber of the packing. 'lhe passage of steam through this conduit is controlled by a valve 44, lig. 7, of the same character are a number of compression springs 23 tendi as that described for regulating the passage 130 of motive Huid through the'turbirles, onlyit steam chest througha chamber 4 5'therein'to the conduit 35. rlhis valve-is located in line with the regulating valves and is operated in a similar manner by a cam 8 and a lever `7. 'Ihe cam 8 is so shaped that itsactive portion becomes operative to open the valve 44 n' hen under a decreasing or light load the .governing mechanism has closed all but two or three of the group of admission valves, and

that its inactive portion ermits the valve to close ifdesired when a .of the admission `valves are closed andl to close when. morev than two or three of them are opened by the governing mechanism to meet a-correspond- .ing increase in load. .That is, the valve 44 will admit sufficient steam to prevent the entrance of air to the turbine and condenser from around the packing when the load is so small that .the pressure in theiirst stage of the turbine is less than atmospheric ressure..

Under certain conditions it will not e necessary to regulate the passage of live steam to ,the packing, it being satisfactory to ermit of acertainlimited flow. at all times. nder these' conditions the steam flows directly .from the valve chest to the packing chanibel.l Itisfevidentthat-Whatever steam enters the low-pressure chamber of the packing, whether it be due to leakage or from the valve chest or both, it will be 'conveyed awayby the valved drain17, and further that the effective area of this drain will be greatest when all the admission valves are open and the initial stage "pressure at a maximum. Also that the enective area willbe gradually de.- creased'as vthegnumber ofopen admission valves is decreased and the initial stage pressure decreases.: f

In Fig. 4 is shown another means for actuating the Ad rain controlling valve, or a valve in the supply conduit 35. Mounted on the end of the cam shaft 9 is a crank-36 to the crank-pin of which is attached'a link 37 .v

The lower end of the link is attached to a bell-crank lever 38, and the latter is in turn connected by rod 15 to the valve 16 or to a valve in the conduit 35.- VVhen a valve is located in the conduit 35 as described, the valve 44 will be omitted. g

The fan for opposing the passage of any leakage steam from the packing through the generator will now be described, and it may be here stated that I can use the fan with or Without the particular packing described,

since it is of .utility in either case. When the packingis properly adjusted and cared for no leakage will occur vbut should any leakage occurdue to any abnormal condition of the packing, vthe fan prevents the leaking steam from injuring the generator. Mounted on the top of the packing housing is a casing 39 and located therein and mounted on the shaft in ean impeller orfan Wheel 4 0. Both'the-caslng and the impeller are preferably made in two principal parte t0 facilitate under side. As the impellerrotates it creates a pressure within the casing which opposes the leakage of steam through the clearance between tne main shaft and the bore of casing 39. Under certain conditions it may be desirable to turn the impeller over so that what is now the bottom will become the top. I may leave off the vane'connecting iange 42 under certain conditions. Connected to the casing is a discharge conduit 43 (ll igs. l and 2) through which leakage steam or air, or both, are driven by the action of the, impeller. The shape and arrangement of the fan parts can obviously be changed without departing from the spirit of my invention. The essential feature is to make the fan develop suHicient pressure to prevent leakage at the shaft and casing clearance. If it develops rather more pressure thanisnecessary for this pur pose no harm be done;

l .have described the valve 16. as being positively actuated as the stage pressure varies, but it may be actuated by a fluid pressure means if desired.

I n accordance with the provisions of the patent statutes, I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the ap'- paratus shown is onlyillustrative, and that the invention can be carried out by other means., Y What l claim as new and desire to secure byLetters Patent of the United States, isf-# 1. A prime mover and its shaft, in com bination with a packing for the shaft', a drain-for thepackmg, and means for varying the eective discharge opening 'of the drain asv the pressure of the fluid in the prime mover changes.

2. A multi-stage turbine and its shaft, in

vcombination with a packing for the shaft, a

drain for the packing which is connected to a low pressure sta e, and means for varying the edective disc arge opening of the drain asv the pressure vof the fluid in the stage which is restrained by the packing changes.

3. A prime mover vand its shaft, and a governing mechanism, in combination with a packing for the shaft, and a means under the control of the governing mechanism for regulating the passage of fluid through the packing.

4. A prime mover and its shaft, and a governing mechanism, combination with a packing for the shaft, a ain for the packing,

and a means under the control of the governing mechanism for varyingthe effective discharge opening of the drain.

5. A multi-stage turbine, and its shaft, in combination With a governing mechanism for regulating the supply of motive fluid to the turbine that includes a shaft which assumes different positions for different loads, a packing for the turbine shaft, a conduit connected to the packing, a valve therein, and an actuator therefor which is moved by the shaft of the governing mechanism.

6. A multi-stage turbine and its shaft, in combination with a packing for the shaft, a drain for discharging fluid from the packing, and a means for automatically increasing the effective discharge area of the drain as the pressure confined by the packing increases and decreasing said area as the pressure falls.

7. A multi-stage turbine and its shaft, inl

combination With a packing for the shaft, a drain for the packing, a valve in the drain, and a motor for moving the valve to regulate the passage of fluid through the drain.

8. A prime mover and its shaft, in combination with a packing for the shaft, and a 'means for admitting fluid under pressure to the packing at light load to prevent the vacuum in the prime mover from causing air to enter it.

9. A prime mover and its shaft, in combination with a packing for the shaft, and a means for admitting fluid under pressure to the packing at light load to prevent the vacuum in the prime mover from causing air to enter it, and a drain for conveying fluid away from the packing.

10. Amulti-stage turbine and its shaft, in combination with a packing for the shaft, a means regulating the admission of steam to the packing for preventing the vacuum in the turbine from drawing air through the packing, and a drain for the packing, the effective discharge area of which changes with changes in pressure in one of the turbine stages.

11. A multi-stage turbine and its shaft, in combination With a packing for the shaft, a drain for the packing, valves regulating the admission of motive fluid to the turbine, a shaft and cams for actuating the valves, a valve for controlling the drain, and means elo/iva actuated by the cam shaft for moving the drain controlling valve.

12. A multi-stage turbine and its shaft, in combinationwith a packing for the shaft comprising a plurality of rings located in separate chambers, a conduit admitting steam to one of the chambers to prevent air from passing through the packing into the turbine, a drain connected with a low pressure chamber of the packing through which fluid is discharged, and a valve in the drain whose position is changed as the pressure on the packing changes.

13. In combination, a prime mover, a shaft therefor, a i packing which normally prevents leakage along the shaft, and a fan comprising a casing, a discharge conduit, and an impeller which receives any leakage from the packing due to an abnormal condition of said packing and discharges it through the conduit to a point remote from said prime 14. In combination, a driving and a driven member, a shaft connecting them, a packing for the shaft located between said members which normally prevents leakage from the driving member along the shaft, and a fan comprising a casing, a discharge conduit, and a rotary impeller which receives any leakage from the packing due to an abnormal condition of said packing and discharges it through the conduit so that it will not affect the driven member. 15. In combination, a turbine, a shaft therefor, a member driven by the turbine, a packing which normally prevents leakage along said shaft, a casing mounted on the packing and outside of the turbine, a conduit extending from the casing-to the side of the machine, and an impeller located within the casing and on the turbine shaft Which by its rotation prevents leakage due to an abnormal condition of the packing from escaping through the clearance between the shaft and casing on the side away from the packing and affecting said driven'member.

In witness whereof, I have hereunto set my hand this 21st day of June, 1907.

OSCAR JUNGGREN. Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

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