US1154594A - Regulating device for mixed-pressure turbo-compressors. - Google Patents

Description

R. H. RICE.

REGULATING DEVICE FOR MIXED. PRESSURE TURBO COMPRESSORS.

APPLICATION FILED JULY23, 1914.

1,154,594. PatentedSept. 21, 1915.

Fig.1.

\X/itnesses: I17 Ab/Q. 1 A I g Rlchard .ce,

UNITED STATES PATENT OFFICE.

RICHARD H. RICE. OF LYNN. MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY. A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Sept. 2|. HHT.

Application filed July 23.1914. Serial No. 852.753.

To 17/ Il'll/II/l I! ///r/ run/'1 m1 Be it known that l. lturnann ll. then. a

-citi7.en ol' the tnited States. residing at Lynn. in the county of Essex. State of Masszwhusetts. have invented certain new and useful linprovenn-nts in Regulating l)evices for '.\lixed-lressure 'lurho-tompressors, of which' the following is a specification.

This invention relates to means for regulating the speed of a turlm-compressor set in which the turhine is actuated either by low pressure steam or by high pressure steam or by hoth. as may he desired. amt can he rcadily changed from one condition to another while running: the regulation ol' speed being etl'ected mainly by a constant 'volnme go\' ernor in the intake of the air compressor. but being subject also to a speed governor under certain conditions. There is also'a pressureresponsive device for keeping constant pressilre in an intermediate stage or chamber to which low pressuresteam is led and from which steam can he extracted from the turhine 'l'or industrial purposes. The constant volume. governor is operatively connected to the high pressure valve means and also to the low pressure valve means ot the turbine, operating them simultaneously and serving to govern the machine under normal working conditions. In case the speed becomes excessive. the speed governor hecomes operative and controls the two sets of valve means, acting as an auxiliary governor for the volume governor. When the turbine is operated as a mixed pressure machine, steam is admitted to an intermediate stage, as well as to the initial stage. \Yhen steam is extracted 'l'or industrial purposes it is with drawn from an internu-diate. stage. For both mixed pressure and extraction operation constant pressure is preferably maintained in said intermediate stage, and this is accomplished by a ,device responsive to the pressure in the stage, to which steam is admitted or from which it is extracted, and acting upon the low pressure valve means which control the flow of steam from said stage. to thenext lower.

The valve means which control the flow of motive lluid to the turhine are usually arranged to open and close a plurality of no'/.- '/.lcs. In order to he able to change from operation on high pressure strain to operation on low pressure steam. or to an intermediate condition of mixed pressure operation. I provide a hand device for adjusting the relative positions of the high pressure and low pressure valves so as to vary the ratio of the areas ol' their respective nozzle openings and thus permit thesleam to llow in such a manner as to maintain a constant pressure in the stage to he regulated. This gives a greater range ol regulation and by moving the hand lever to its extreme positions the turbine can hechanged from purely high pressure to purely low pressure conditions. The internu-diate positions ot the leve rcause the machine tooperate under mixed pressure conditions.

. ln the 'a'iccompanying drawings, Figure l "is a diagranmuitlc view ol the regulating device. and Fig. 2 aside. elevation of the turlio-compressor set.

It need hardly he. explained that a turbocompressor set comprises a steam turbine l and a centrifugal air compressor 2, the rotating elements of both machines being mounted on a common shat't It. to which is suitably geared a speed responsive device t. The compressor has an intake. 5 and a delivery pipe (3. The intake has an enlarged frusto-conieal portion 7 in which is located a volume. governor consisting of a disk 8 floating on the intlowing column of air and shifting its position up and down in the intake in :uzcordance with the varying volume of air passin through said intake. The movements oi this disk are relied upon to govern the admission of steam to the turbine and so vary its speed that a constant volume of air will he delivered by the compressor under varying conditions of service. The speed governor 4 is also placed in control of the. turbine to prevent ahn0rmal speed under emergency conditions.

The turhine is ol the multistage type, the drawing indicating this by showing a high pressure wheel 9 receiving steam from a plurality of nozzles 10 controlled by a valve 11,

till

and a low pressure wheel 12 receiving steam from a plurality of nozzles'13 controlled by a valve 14. The high pressure steam is supplied through a pipe 15, while the low pressure steam may he the exhaust from the wheel 9 entering the chamber 16, or it may be supplied to said chamber from some other source through a pipe 17. It will be under stood as a matter of course that the drawing is-merely illustrative, and does not pretend to show actual construction.

The valves 11 and 14: are plelerahly actuatcd, hy hydraulic motors, comprising cylinders 18, '15) containing pistons .20, 21 connected to the valve stems22, 23. Fluid pressure is admitted to the cylinders hy pilot valves 24,25 which are connected to levers 2(3, 27, which are pivoted at one end to extensions ofthe valve stems 22, 23. The other end of thele'ver 26 is connected by a link 2% with one end of a floating lever 29, while the corresponding end of the lever 27 is connected by a'link 30 with one end (if a lever 31 whose other end is articulated to the adjacent end of the lioatimg lever 29.

An intermediate point on the floating lever is connected both to the speed responsive device and to the volume governor, in such a manner that an increase eithe. the speed of the machine or in the volume of the air entering the compressor will -ause a lowering of the floating lever. The system of levers for this purpose shown in the drawing is merely illustrative and may be replaced hy other equivalent mechanism. As shown, the sliding collar 33 of the speed governor is connected hy'a short lever 34 iulcrumcd at an to one end of an arm 36 whose other end is connected by a link 37 to a lever 38 lulcriuncd at 39 and pivoted at its other end to the stem 40 on which the floating dish 8 is mounted. The arm 36 pivoted to a short plunger ll sliding in astationary guide in and pivoted to the floating lever 29 at the point 32.

A pressure responsive device is connected to the lever 31 and actuates it in correspondonce with variations in the steam pressure in a stage or chamber of the turhinc. The preferable construction is indicated in the drawinn, coniprisinc; a so-called sylphon dia phragm -lZ- attached to a rod it which is pivotally connected to the lever 31. A pipe 45 conveys fluid pressure from the stage or chamber 16 to the diapln'agrm, so that upon an increase of pressure in said chamhor the spring 46 will he. cmnprcs:-;ed and the lever 31 will he forced downwardly.

The means for positively tilting the floating lever 29 comprises a hand lever i7 fulcrumedat 48 and having a latch 49 coiiperating with a notched quadrant 50. The upper end of the hand lever is jointed to an arm 51 on the floating lever 29 in-such a way as not to interfere with the free up and down movements of the floating-1; lover, but at the same time enable theattendant to tilt the floating lever one way or the other by manipulating the hand lever. v l

The construction and arrangement of the mechanism having thus hhen demrihed, it remains to point out how these parts funo tion. Let us consider first what happens upon an increase in the volume of air entering the compressor. This occurs when the resistance otlered to the column o air decreased. as for instance when the fuel in a gas producer has heel consumed sulliciontly to allow the air to pass through it more freely. Any increase in the \"l',lll.ll'litl of air lifts the floating dish 8 and its em ill and thereby depresses the opposite end of the lever 38, carrying with it the arm 36, As this arm fulcrums on the end of the lever 34, which is held stationary by the speed governor, the 1 plunger all will he depressed,

dropping the eating lev'erfllyhodily. This movement forces down one end of the lever 26. which fulcrums at the upper end of the valve stem 22. The downward nmvement of the pilot valve 24 admits hydrzmlic or other fluid pressure under the piston :20, cruising it to move upwardly and lift the high or I'- sure valve 11, therehy closing some of the nozzles 10 and slowing down the machiiuary to lessen the volume of air. Simultaneously with this closing of the high pressure valve l.l,the low pressure valve 14 closed also, in the following manner: The hodily downward movement of the lever 29 carries have the adjacent end of the lever 31 which fulcrums on the rod 44 and thereby lifts the linlc 30, the lever 27 and the pilot valve 253, admitting fluid pressure on top of the piston 21 and forcing down the low presraare valve ll, thereby shutting oll' some of the nozzles .3 or decreasing the outlet area.

The ahove-dcscrihed movement of the pistons 20, gives the. levers do, iii a move ment in the opposite direction to that which they had previously received, that the pilot valves will be restored to an covering}; hoth ports leading to tlsm; cylmders and retaining the valves-1 ll and H in the oositions to which they have shi'l'ted stoning now an almornial crease of speed of the machine. due to a drop in load or other causes, the speed g ernor acts in. the following manner to throttle the steam and restore the speed to normal: The out ward movement of the tlydiails oi. the crown nor lifts the collar and that end of the lever 34, depressing the opposite end of said lever and with it the arm 36, which fidrvmm 0n the link 3'7 and pushes down it plan or 41, thereby causing a drop of this 1 29 and a partial closing of the valves 14 in the manner above described 1 The pressure in the intermediate chamber y 16 of the turbine is under the controlof the Mil pressure regulator lil. \vhieh operates the low pressure valve It only. Hhould the pressure in this ehamher inerease. the sylphon diaphragm will move do\\'n\\'al'dl oven eoming the tension of the spring 46 and pushing down the lever 23]. .\s this l'ull'rnms at the point where it is pivoted to the lloating lever 15 the link 3 \\'ill depress the lever 27 and the pilot valve 23. therehy admitting lluid pressure under the piston 21 aml lilting the low pressure valve It to open more of the nozzles l and permit a larger llovv of steam from the ehamher to to the lower stage l' the tnrhine. therehy relieving the exeess of pressure in said ehamher. i

'lhe pressure regulator has an important l'unetion in supplementing under eertain eonditions the ell'eets ol' the volume and speed governors. To make this plain. let it he assluned that the maehine is rmming only on low pressure steam derived from the exhaust of another engine or some similar souree. The load is earried solely hy the llllt'lttl \\'heel 1;. It. now. the-supply of low pressure steam is redueed the maehine \vill slowdown and the speed governor \\'ill aet to open up the high pressure valve 11 and admit live steam to the hueltet \vheel f to earry the load. Simultaneously. it tends to open the low pressure valve It still \vider.

lhlt the reduetion of pressure in the ehamher it: due to the t'ailure ot' the low pressure steam eauses the pressure regulator to operate in a manner to shut oll' some of the low pressure nozzles iii in an attempt to rester" the lost pressure. .\lmost immediately however. the steam.exhausting into the eln.mher it) from the wheel 9 builds up the pressure. aml passing to the wheel 1; eauses the latter to resume sueh portion of the load as the redueed area of the nozzles It permits. l'pon the slight. inerease in speed. due to the operation of both wheels. the volume governor arts to reduee the supply ot steam. and eauses the maehine to settle down to a mixed pressure rendition of operation.

It will he observed that the pressure regulator operates quiteindependently of the volume aml speed governors. and also that the operation of these two latter devices is not interfered with by the pressure regulator. 'lhis t'eature'is of importanee when the maehine is running as an extraction turhine. heeause the supply of steam from the ehamher It) for industrial purposes nmst be maintained at a eonstant pressure, irrespeetive ol' the variations of load on the c mpressor.

'lo ohtain the highest'ellieieney of the high pressure and low pressure eomhination. the hand lever 47 and its eooperating parts enable the pressure ratio hetween the high pressure and l()\\ pressure valves to be varied. By moving the lever to the right in Fig. 1 the floating lever 25) \vill'he tilted up at the left hand end. causing the normal nozzle opening for the high pressure valve 11 to he greater than that for the low, pressure valve ll. ll the handle 47 is carried to the extreme right. all the low pressure nozzles will he elosed and all the ltlfll pressure nozzles opened. and the machine will then operate as a simple high pressure tin hine. The pressure of the exhaust. entering the ehamher to will aet upon the sylphon diaphragm and eause it to open the low pressure valve means sutlieiently to permit the steam to pass to the eondenser. Any excess pressure will he taken eare of by the relief valve 52 in the pipe 17. When running in this manner on high pressure steam alone, themm-hine ean he used for extraction purposes. steani heing led otl" through the pipe 17. and a eonstant pressure being maintained hy the pressure regulator.

- it the handle 4? is thrown to the extreme left. the high pressure valve 11 will he closed and the low pressure valve 14 opened. and the maehine will run on low pressure steam supplied to the ehamher Itt through the pipe IT. in hoth ewes. \vhether high pressure or low pressure. the vohune governor. the speed governor and the pressure regulator maintain eomplete regulative eontrol ot' the maehine. although when the handle 47 is in either of its extreme positions it absolutely prevents 'the speed and volume governors from moving the eel-responding valve enough to open its ports. (onsetplentl v, if the maehine is running on low pressure. steam only. with the high pressure valve out of serviee. any serious reduetion in the Supply of low pressure steam must he met by the engineer. who must shift the handle 47 far enough tovvard the midposition to letthe movement of the high pressure valve hy the governor eause it to open some of the high pressure steam nozzles. 'hen the handle 47 oeeupies an intermediate position, the maehine will operate as a mixed pressure unit. suhjeet as be ore to the regulation of the vohnne and speed governors and the pressure regulator. The position of the. handle 47 determines the pressure ratio hetween the two valves. by determining the relative amounts of normal nozzle opening. Thus. it the handle oeeupies the position indieated hy the dotted line in Fig. 1. the lnaehine will operate normally on low pressure steam but will eall the high pressure steam into serviee when the load heeomes greater than the low pressure steam can earry. the speed governor operating to open the high pressure valve. It will he understood that there is more or less simultaneous. play of the valves all the. time, due to'tli'e aetion oi the two governors, but that the normal regulating movement is not enough to open the high pressure. valve when the handle e7 is in the dotted line position.

time. ."when the turbine is running);

, ciple of operation of my The machine can he need as a mixed preasure ti rbine, running partly on high pressure and pa" 1v on low jn'esiulre steam, but not under extraction conditions at the same under mixed or low pres-mire conditions, the low pressure steam enters through the pipe ll". Under extraction conditions, the high pressure-steam is used and the extracted steam isled'ofi' through the name, pipe'll', to a branch pipe having a suitable valve which is closed when the low pressure steam is used.

In accordance with tl i'HCH'lSlOliS of the patent statutesfl have described the prininveution, together with the apparatus which I now consider to repreaent' the beat emluulimcut thereof; but I desire tohave it understood that the up paratus shownie only illus ative, and that the invention can be carried out by other n'ieane.

l /hat L claim as new and desire to secure by Letters Patent of the lmted States, 19

- 1. The combmatlon with an air romprea 5 nor, driven by animated pressure turbine, of

a device responsive to variations in volume of the air passing through said compmsaor, high pressure and low pressure valves for said turbine, and meanswhereby said valves aresimultaneously operated by said device.

55.- The COll'lbiIlfilliUll with an air compressor, driven by a mixed pressure turbine, of a deviceresponsive to variations in volume of the air. paseing through said compressor,

5 high pressure and lo pressure valves for saidv turbine, operative connections between said deviee'and said valves, whereby boti valves are operated aimultaneouialy, and a epeod responsive device also connected to "Kl valves, and operatinp, them uimultw news-1y, i an 3, dl'ie combination with. an air compressor-,driven. by, a mixed pressure turbine, of volume governor in the intake of said coml5 pressor, high pressure and low pressure valves for said turbine, aetuating mocha niam for operating said valves sinmltane' ouslmand connections between said aetuab i means and said governor.

L c 0 4; 'lhe. combination. WLt-h an air comprew otngdriven by a mixed pressure turb? .e, of a speed governor driven by (52nd. turbine, a volume governor in the lllllltlm of said coma aid turbine, actuating; meciurmom for operating said valves simultaneously, andgopemtwe connections between aaid actuating means and both of Said gov QIIIIOFSV-I- a Thacomblnation with an air conmres sor, drivenby a mixed pressure turbine, of

a e vg-overnor driven by said turbine, at vo governor 1n the intake of said com- ,bierh pressure, and low 'prcaaure high pressure and low pressure volume governor in the intake of said compressor, high presume and low pressure valves for said turbine, actuating mechanism for operating said valves siu'mltaneously, operative connections between said actuab ing means and both of said governors, and means for varying the relative nozzle areas respectively controlled by said valves.

7. The combination with an air com rcs-- S01, driven by a mixed pressure turbine, of a volume governor in the intake of the compressor, high pressure and low pressure valves for the turbine, actuating mechanism for ol'ierating said valves simultaneously,

conneetions between said actuating means .and said governor, and a device responsive to intermediate stage pressure ha viug iudc pendent control of said low pressure valve.

8. The combination with an air comprcqn aor, driven by a mixed pressure turbine, of e, speed governor driven by said turbine, a volume governor in the intake of said compressor, high pressure and low pressure valves for said turbine, aetuatin mechanism for operating said valves siumltaneously,'

operative connections between said actuating means and both of said governors, and a dc vice I'GE-JPOHSH'Q tomtermcdlate stage pressure having: imlepcndent control of said low prt-ieaurc valve,

9. The combination with an air compressor, driven by a mixed pressure turbine, of a volume governor in the intake of said compressor, high pressure and low pressure valves for said turbine, mechanism controlling}; said valves coulprisinp a floating lever,

and connections whereby said lever is moved bodily in response to the varying positions of aaid g vernor. c

10, The combination with an air compresaor, driven by a mixed pressure turbine, of

a volume governor in the intake of said compressor, a speed governor driven by said turbine, high pressure and low pressure valvcu for said turbine, nurchanism controlling said valves con'lpriaing a floating lever, and conncetie whereby said lover is moved bodily in reaponse to the varyii'ig positions of either governor.

11. The combination with an air compres: sor, driven by a mixed pressure turbine, of a Ill) volume governor in the intake of said compressor, valves for stud turbine, mechanism controlhigh pressure and low pressure 121) g Q 302m "11 waives cemprising a floating er- In whegeof I br n; hereunto set 501:5 wwyi b;\"sm5d new? is moved 9052- my hand 32115; 16in day 0:; July, I 513* in r' spmnw m the: varyins p inns REUFARL HI RICE. said gm'ummg nmm' fim ci sue Way 02* can-in

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