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July v23, 1946. D. BRADBURY 2,404,428 TURBINE APPARATUS _ Filed JanfSl, 1944 2 Sheets-Sheet Kl 0 60 00mm BRADBURY BY .> QJKBKRM , ATTORNEY ' July 23, 1946- D. BRADBURY 2,404,428. TURBINE APPARATUS Filed Jan. 51, 1944 2 Sheets-Sheet 2 Fm. 7‘ Emly. _n! FIG. 6 INVENTOR v wnuessas: WM. WM I DONALD Bmosukr BY QKBSPWA'. ATTORNEY Patented July 23, 1946 2,404,428 ‘ UNITED- STATES PATENT ()FFICE." 2,404,428 . TURBINE APPARATUS Donald Bradbury, Prospect Park, Pa,v assignor to Westinghouse Electric Corporation, East Pitts burgh, Pa., a corporation of Pennsylvania Application January 31,1944, Serial No. 520.565 (CI. 60-41) 1 Claim. ' 1 tional speed of a gas turbinevand to prevent the motive ?uid entering the turbine from. exceeding This invention relates to power plants and par ticularly to a control system, for protecting ,a gas turbine power plant from overspeeding and from a predetermined safe value. > These and other objects are effected by vthe excessive temperatures, and it has'for an object to provide an improved device of the character invention as will be apparent from the- follow ing description and claim taken in connection with the accompanying drawings,:forming apart setforth. The present invention, while not limited there~ to, isyparticularly adapted to be. used=to control of- this application, in which; Fig. 1 is a side elevational view of a gas turbine a gas turbine power plant like that ‘disclosed power plant inwhich the present invention has in the copending application _of Stewart Way, l0 been incorporated, a-portion. of the outer- casing Serial No. 482,533, ?led April 10, 1943 and as~ structure being broken away toshow certain de_ signed to the assignee of the presentv invention. tails of construction; ' A power plant of the type disclosed in the men Fig. 2 is an enl-argedview of the controlape tioned Way application includes an axial-flow air paratus, the parts thereof being shown insec compressor, an air heating apparatus, a gas tur 15 tion for the sake of clear-ness; . blue, and a propulsion jet nozzle all'housed in Fig. 3 is averticalsectional view taken sub-. line within a streamlined tubularcasing. A plant stantially on the line III..—-III of Fig.- 2; of this character is particularly suitable for pro Fig. 4 is an elevational view ;of a camfor-ining pelling aircraft at high speeds and operates gen a part of the control valve; erally as follows: Air enters the forwardvend of Fig. 5 is a developed side elevational. view of-the . the tubular casing, which is pointed in the direc oamshown in Fig. 4; ' 7 tion of ?ight, and is compressed in the compres Fig.6 is a vsidelelevational view of the. control sor, the compressed air is then heated in the valve looking from the right of Fig. 3; heating apparatus by the-combustion oi?v fuel sup ported by the compressed air. The resulting 25 ‘Fig. 7 is an enlarged ‘vertical sectional View taken substantially onthe line VII—-VII of Fig. 1 motive ?uid comprising the products of combus and showing in detail the temperature-respon tion and the excess compressed air drives the sive device; and a turbine and is then discharged through the pro Fig. 8 is a sectional view of aportionwof the pulsion nozzle as a jet, the reaction of .which control valve. illustrating. a, modi?ed ‘construction serves to propel the aircraft. The turbine ex 30 thereof, 7 tracts at least sufficient power from the motive The power plant shownin Fig. 1 comprises in ?uid to drive the compressor and auxiliaries. general an outer tubular casing structureJll, The fuel is supplied to the air heating apparatus, open from end to end and having a centralv core under the control of a throttle valve-by means of a positive displacement pump which is pref 35 ll providing with the casing an annular‘?ow passage I42 which, if the plant is to be usedfor erably driven by the turbine. propelling an airplane, is adapted to extend fore In the copending application of Donald Brad bury et al., Serial No. 520,564, ?led January 31, and aft with respect to theairplane. The cen supplied to the air heating apparatus and which ?ow compressor E8, the ?xed blades of which are tral core structure H is supported by the outer 1944 and assigned to the assignee of the present casing structure along its longitudinal axis and invention, there is disclosed a control which auto iii) includes ‘a hollow fairing cone I3 de?ning with matically prevents dangerous overspeeding of the the forward or left end, asviewedin Fig. 1_, of turbine by limiting the rate at which fuel is sup the casing l0 anairli-nlet l4. The fairing cone plied to the air heating apparatus. However, it l3 houses a fuel pump, generally indicated I5, is important also to prevent the temperature of and other auxiliaries (not .shown) and is sup the motive ?uid entering the turbine from ex ported fromthe casing ID by hollow compressor ceeding a safe value. In accord-ance'with the guide vanes [6. present invention, a single control valve is pro The core I I also includes a rotor ll of an axial vided which regulates the rate at which fuel is is actuated to reduce the rate of flow of fuel in _ response to overspeeding of the turbine and ex cessive temperature of the motive ?uid entering the turbine. ' It is, accordingly, a further object of the in vention to provide means for limiting the rota 55 carried by the casing 10, a rotor IQ of a gas tur bineZl and a longitudinally adjustable conical _ tailpiece 22 which de?nes with the rear end of the casing Ii] an adjustable propulsion nozzle 23. The intermediate portion'of the core structure between the compressor l8 and the turbine. 2| " 2,404,428 7' V 3 4 ’ comprises an inner tubular wall structure 24 which houses a shaft 25 connecting the turbine rotor I 9 and compressor rotor H. The inner wall structure 24 de?nes with the casing in an annu lar chamber26 connecting the compressor blade pressure between the inlet andrthe throat of a Venturi tube 44 interposed between the outlet of the pump | 5 and the throttle valve 42 and is also actuated by a temperature-measuringdevice gen erally indicated, 45.v It is to be understood that the control valve 43 may be actuated by the pres sure difference between the throat and exit of passage and the turbine blade passage. I The chamberri? is provided with suitable air heating means, such‘ as shown, in the copending application of Way et a1. SerialNo. 511,468; ?led November 23, 1943 for heating the air compressed by the compressor. In the embodiment shown, a plurality of perforated, tapered burner- tubesZ‘l the Venturi tube 44, if desired. *- 1 . ' The rate of flow of fuel to the burners is de termined by the pressure drop across the atomiz ing nozzles 32. This pressure drop is controlled by the total resistance to ?ow of the constant are mounted in the annular chamber 26 with volume of fuel output of the pump I5 and is de their large open ends 28 directed‘ downstream. termined bythe area of the nozzles plus that of Fuel is supplied to the burner ‘tubes 21 from‘ a 15 the throttle valve by-pass. Absolute pressure in manifold 29,.connected to a fuel supply as here the combustion chamber varies widely depending inafter described, and is fed through branch on operating’ conditions, i. e. pressure ratio and pipes’ 3| to atomizingnozzles 32 extending into atmospheric pressure. Thus the pressure in the 1 the ‘burner tubes. Suitable means, including fuel ‘supply system ?uctuates over a range from spark plugs 34 extending into the burner tubes, near atmospheric pressure to the rated pressure are provided'for igniting the air-fuel mixture in of the pump. In the particular embodiment ' the burner tubes.‘ ' ‘ ' shown, the maximum pressure necessary for max- ‘ Thepresent invention is not concerned with imum flow through'the burner nozzles, atmaxi the speci?c‘ design of the apparatus thus far referred to, although itris preferably constructed mum pressure in the combustion chamber, is the maximum rated ?ow of the pump. Thus the present control device as it relates to limiting the rotational speed of ‘the turbine must have a very small total pressure drop as well as be independ in accordance with the disclosure of the men tioned Way and Way et al. applications. ‘ The power plant operates substantially as fol lows: ' V ' - ' ' Air enters the casing I 0 at the inlet I4, is com pressed by the ‘compressor l8, and flows into the , ent of the pressure level. so annular chamber 26 which may function as‘ a di?user to effect further compression. The com pressed air then passes through the‘ openings in V the walls of'the burner tubes 21 and mixes with the atomized fuel supplied by the nozzles 32. The air and fuelmixture is ignited by the spark plugs 34 andburns steadily thereafter. The mo The Venturi tube 44 satis?es both of these last mentioned requirements. The total output of the pump passes through the Venturi tube and by measuring the pressure drop from the inlet to the throat thereof, which is a function only‘ of the volume of the fuel ?owing therethrough, a measure of the speed of the turbine shaft is ob tained since the speed of the turbine determines _ the pump output. This pressure drop in the Ven tive ?uid comprising the products of combustion turi' tube is used to control the flow of fuel to the and the'excess air flows from the burner tubes 21‘ 40 burners, so that when the speed reaches a pre and is directed by ?xed guide vanes or nozzles 35 determined maximum, fuel is by-passed by the into the blade passage of the turbine rotor I9. control valve from the outletof the pump to the The tu‘rbineZl extracts at-least suf?cient energy inlet thereof and in this Way prevents the ture from the motive fluid to drive the compressor l8, bine from exceeding this predetermined speed. 7 pump l5 and other auxiliary apparatus that may Similarly, the control valve is actuated by be housed in the fairing cone I4. The spent gases means of a suitable temperature-responsive leaving the turbine are discharged through the mechanism to reduce the amount of fuel ?owing propulsion nozzle 23Vat 'a'high velocity so that 7* to the burners in the event that the motive ?uid the remaining energy in the motive ?uid is avail discharging from the burners attains a tempera able to propel ‘the aircraft. The tailpiece 22 is 50 ture which might causedamage to the turbine. preferably axially movable with respect to the By reducing the rate of flow of fuel to the burners ‘ casing I ll so'that the back pressure on the turbine under this condition, a corresponding 1owering of and the jet effect produced by the nozzle may be the temperature'of the motive fuel is obtained. 45 varied. _ j ' » The fuel, such as gasoline, for the burner tubes ‘ The present invention is particularly concerned 55 ZT?ows from‘ a suitable tank (not shown) car with maintaining the turbine speed and the tem ried by the aircraft into a main supply pipe 45 perature of the motive fluid entering the turbine to the inlet side of the pump [5. The outlet or within safe limits by regulating the fuel supplied discharge side of the pump is‘ connected by means to the burners 21. ' _ of a pipe 47 to the Venturi tube 44, which in turn ratus which regulates the. fuel supply may con, 60 is connected to inlet 43 of the four-way, rotary throttle valve 42. One outlet 49 of the valve 42 veniently, be housed within‘ a tunnel 4| formed in _ .The speed and temperature controlling appa the top of the casing in, which tunnel also houses lubricating and fuel oil pipes and ignition wires. Thejfuel supply system for the burner tubes is connected by a pipe 5|.to the manifold pipe 29 of the burner tubes. 7 , . Manual regulation of the rate of flow of fuel comprises the pump l5, which is of the constant 65 to the burner tubes to vary the speed of the tur bine is effected by adjusting the throttle valve displacement type and driven by the turbine so 42 to by-pass more or less of the fuel ?owing-into‘ that its output is independent of pressure and the inlet 48to the inlet of the pump by means depends only on the rotational speed of the tur of a pipe 52 leading from a second outlet 53 of the . bine shaft, a manually adjusted throttle valve 42, 70 of the'by-pass type, and a control valve 43 which. when open, also by-passes fuel to the inlet side. of the pump l5 to reduce the amount of fuel go ing to theburners. As will appear later, the con trol valve 43 is actuated. by the differential in 76 throttle valve to the pump inlet pipe 46. _ The'throttle valve 42 comprises‘ a valve ‘body in which a rotatable valve member 54 is received. The valve member is manually rotated,rtol regu late the amount of oil?owing to the burners and through the by-pass pipe 52 by suitablemeans, 5 such’ as the wheel 55z?xed-rtheretoandeeonnected by - a cable '56 to a > pulley 'li‘L-to which 1 is ?xed .a ' handv throttle-lever 58. The throttle lever£58¢is located for-convenient manipulation by the pilot of - the‘ aircraft. In Fig.2, the throttle valve“ isshown in closed position so that all of the iueliis by~passedor re turned tothe pump I15 through ‘ pipe .52 .. ' 1In=this any one. .01. a .pluralityzzof notches" a2 ,providedin an .externalr?ange £3- otthe nut. The outer pointed end 940i the member 85 isadaptedgtoxengage a stem .95. on the valve mem ' ber lZ-sothat movement of the piston ‘II is trans mitted to the .valve member. The overspced control operates-as follows: Whent-he rate. of ?ow of fuel-zthroughthe .ven- , turi reaches a value resultingin a;pressure drop position, a 'pin‘519 ea-rriedlby the wheel 155<engages 1.0 fromtheinlet to tthegthroat thereof Su?icient to a stop BI ?xed-on the valvebody. Thervaliveiis displace the piston .11 to the right against ‘the fully opened when the pin 59~engages¢a~second force ‘exerted :by the compression spring 8.6 and stop ?62 on the valve body. ‘It will be-noted that the basing. spring 1.5,thevalvestenn95 is engaged fromelosed position to‘fullyopen position of the by the pointedend Mot. member "=85ncausing the throttle valve, a'thi-rd outlet 13-3 of the valve body 1.5 valve, member 5112 to be shifted to the rightand always remains open. ' gradually uncover the ‘ports v14. Thisprovidcs The outlet 634s connected by axpipe 64 to the direct communication between the .byepass pipes control valve 43, which, in turn, communicates 84 and 6.6, thusreducing the amountof fuel-?ow th-roug‘h'a pipe ‘66 ‘and pipes Bland“ tothe inlet ingtothe burners and; thereby effecting. a-reduc of vpump I5.‘ If desired, the outlet 63-may be. dis tion . in . the: speedof . the: turbine since‘: its speed ‘is pensed‘ with and'the pipe ‘Ell connected to the out 20 dependent upon the energy‘ added. to the come let of the Venturi tube ‘M. ‘Thercontrol valve” pressed air by the burning fuel. _' is normally closed but is opened, as will appear later, to by-pass vfuel ?owing vinto the throttle valve“ and thereby re'ducethe ‘amountof fuel ?owing to the burners in the-event-overspeeding of the turbine or excessivetemperature of the The valve ‘member-:1 25is=a1soa shifted to the right to uncover the ports 'Mintheevent the tempera ture. of the motive .?uid. enteringithe. turbine sex-i ceeds .a predetermined value. This is accom The valve .43 comprises a .valve body '61 having plished by :means of suitable temperature-re sponsive meansrwhichmay be located between; the an annular chamber“ into‘rwhich’the'pipe 6.4 Any suitable temperature-‘responsive ~means motive ?uid occurs. ‘ discharges and a second annular chamber "H which communicates with ‘ the outlet 'pipe 66. Communication between the chambers 168' ‘and ‘II and, therefore, between the'inlet and outlet pipes 64 and 66‘is controlledbyrmeanszofa valve mem ber'l-Z which is-slidable ina2 sleeve 173.11‘! a central bore of thevalve body'?l. Thezs‘leeve :13 is pro vided with ports ‘14 and ‘I15 connecting. the ‘cham her-s68 and ‘H, respectively, with theinterior of the sleeve. burner‘tu‘bes 2.1 and the turbineizl . ‘ may be employed. which will .a‘ctuate'the. control valve .43 and, .therefore,:the invention is not toibe construed - as limited. to "the particular type dis closed. Referring particularly: tofFig."'-7,jthere is shown a temperature-responsiveidevice, generally indicated 91, which comprises ~a*high tempera ture metal tubei98' having a. quartz rod” ‘received therein. ‘The tube £8 and rod‘ 98~ aresuspended from ‘the outer casing I10 , the upper. end I0 I ofzthe The valve ‘member ‘I2 is biased to valve-closing position by means of ‘a compression 40 sleeve '98 ‘being threaded and received in a threaded hole in ‘the casing. "The’invention "is spring 16 so that itnormally closes‘ ports '14. not restricted‘tostheiemployment of ‘a. metal tube The valve member '12 is adapted to :beshifted andquartz rod since any‘hightemperature re to the right, ‘as-viewed in ‘Fig; 2,‘to»gr.adually un sisting materials having di?'erent. coefficients of cover the ports ‘I4 and thereby‘bymassrfuellirom expansion may be vemployed. the-Venturi tube to theinlet side of: thepump and 45 ‘ The-upper end 'ofrthe'quartz rod=l99 is ‘engaged . reduce the amount of fuel ?owing tothe burners by .a 'freelyrsliidable ‘member I502‘ having a pointed in the event of over-speeding of 1 the .turbineor upper --end‘I'034 providing a'lcnife edge on which a overheating of the-motive'?uid enteringxthe tur lever 150:4 ‘is fulcrumed. "The *lever I04, member bine. intend-quartz rod59'9-are biased downwardly, so Overspeeding ' of the turbine is controlled by 60 that-the quartz rod engages the bottom I05 of means of a piston "I7 housed within-a cylinder 18 the tube £98 bymeans ofia compression‘ spring’IOB mounted on a base ‘I9'common to the valvebody disposed ‘within a housingv I01 secured to the ‘up 61. The pistori‘l‘l: is shiftedrto the right, as viewed per ‘end of ther'tube- 98. .A .second'knife- edge I00 in Fig. 2, when-the rate of flow of fuel through the Venturi tube exceeds a ‘predetermined value. 05 spaced laterally ifrom theikn'ife ‘edge -' I 03 engages tn; lever I04 at the sideoppositethe knife edge Pipes ~81 and Y82 extendirom the inlet :and throat, respectively, of the Ventnri tube M and ‘The outer end of = the lever IMiis connected by open into the cylinder 18 on opposite sides of the a ‘link "39 toac-rankarm I II carried'by a torque piston TI. The piston-is provided .witha stem 83 having a pointed end 184. adapted to engage a 60 tubevl I52 fextendingi'from thetemperatureeresponp sive device to the con-trolvalve43. spring-biased memberxBiwhich is slidable in the ‘As the quartz rod 199 andmetal tube 98 ‘are cylinder block. Themember 85 isbiasedto‘the I0 . ~ ’ heated, the tube, having a higher ~‘coei‘licient- or left, as viewed in Fig. 2, by means of a compres expansion ‘thanthe rod, increases in length at a sion spring 86, one end of which engages a ?ange 65 greater rate than the quartz rod so that the rod 81 on the member 85 while the other end engages moves downwardly intQ the tube, and the lever an internally-?anged nut 88 which is adjustably I04, maintained in engagement therewith by the threaded into the cylinder block. From this spring I06, swings in a counterclockwise direction, structure, it will be clear that by turning the nut as viewed in Fig. 7, about knife edge I08. Thus, 88 into or out of the cylinder block, the amount 70 under the conditions mentioned, the lever I04 of pressure acting on the piston 11 and necessary will cause the crankarm III to turn the torque tube H2 in a clockwise direction as viewed in to shift it to the right may be readily varied. The Fig. ‘I. nut 88 is locked in adjusted position by means This rotation of the torque tube is transmitted of a dog 09 removably secured to the cylinder block and having a ?ange 9| adapted to engage 75 to the control valve ‘43 by means of mechanism 2,404,428. 7 8 ,. shown in Figs; 2 to 6, inclusive.‘ Theforward end of the torque tube-is journaledrin'brackets H3 carried by theibase' 19 of the control valve 43. The end of the torque tube has ?xedly secured starting position with'the'slide rod I26 pulled ‘out ~ , so that thelow surfaces I25 ,of the cam are in a position to be engaged by the cam-follower-?n-i I thereto an arm ‘I I4 to which'is ?xed a tension ' spring H5 attached to the bracket H3 at H6. 7 The spring H5 cooperateswith the compression gers H9. Afterthe turbine: hasybeen started; the cam is manually'shifted by meansv of:the slide rod I26 to bring the high surfaces_I24 into controlling position: A spring-pressed detent- I29 spring I96 to bias the ‘quartz rod 99 against the mounted in one, of the brackets‘ I I3_may»be~pro bottom of tube 98. vided for selective, engagement with=notchesI3I A second arm H1 is rigidly clamped to the 10 provided in the'rslide rod to maintain the slide 7 torque tube between the brackets H3 .asishown The arm H1 is bifurcated providing rod Inand Fig.r8,rthere cam in either is shown of=its positions. a slight modi?cation - a arms H8, the lower ends of which straddle the valve stem 95 and terminate substantially at an of ‘the ‘control valve 43 in Whichthe piston 11 is replaced by a piston 11' to which is secured in-Figl 3. axial plane of the stem. The face of the lower 15 ?exible bellows I32. The bellows’ I32 together ends of these arms I I8, at the side opposite that with the piston 11’ and the‘ end walls of the visible in Fig.v 3, is provided with cam follower cylinder 18 de?neexpansible chambers into which ?ngers H9 as shown by dottedlines' in Fig. 2, the pipes -8I and/82', leading from the inlet; and adapted to engage the face of a cam' I2I. The throat respectively of the Venturi tube, discharge. cam I2I isin the form of a disc and is threaded 20 Except for this difference, the modi?edcontrol onto an externally-threaded sleeve ‘I22 which is valve is identical with and operates like'that ?xed by means of “a set'screw I 23 to the'valve stem 93; The'cam I2I is adjustable along the . While the invention has been shown in sev sleeve I22, so that its position with respect to the eral forms, it will be obvious ‘to those skilled in camfollower ?ngers I I9 may be changed in‘ cali the art that it is not so limited, but is susceptible brating the temperature control apparatus. of various other changes and modi?cations with: Referring to Figs. 4 and 5, it .will be noted out, departing from the spiritthereof, and it is that the cam I2I is provided with diametrically desired, therefore, that only such limitations shall opposed high surfaces I24 and low surfacesl25. be placed thereupon as are speci?cally set forth In" normal operation, the cam is positioned so 30 in the appended claim. 2_ . that the ?ngers 'I I9: of the arm H1 are aligned Whatisclaimedis: I %.f < a» '" showninFig.2.' ' with and adapted. to engage the high surfaces I24.» The apparatus is calibrated so that" when a' predeterminedtemperature is reached in the ' w '1 - A system for controlling the supply of fuel to the combustion ‘apparatus of, a gas turbine or the like, comprising a constant displacement annular chamber96, the arm I I1 is moved to a 35 pump, a throttle valve having an inlet and a position to engage the high surfaces I24 and ef-' plurality of outlets, means including a Venturi fect movementof the valve member 12, to the tube connecting the outlet of the pump to the ' right as viewed in Fig. 2, to uncover the ports inlet of the throttle valve, means for connecting 15 and ‘thereby provide by-passing of the-fuel one of said valve outlets to the combustion appa around the burners. For example, in'gas tur— 40 ratus for supplying" fuel thereto, means for con bines as now known,»the temperature-responsive necting a second valve outlet to the inlet of the device may be calibrated to effect opening of the pump, said valve including an adjustable valve ports '14 when the temperature’ in the chamber member ‘for ‘by-passing a selectable amount of 96/reaches 1200“ Fr 5 . ' , However, it was found necessary to. change the temperature limit at which thetemperature-re sponsive device opened the control valve when starting the'gas turbine so that at starting and fora short interval thereafter, the temperature of the-motive ?uid will reach a higher value such as 1500° F. before thetemperature-responsive de vice 45 opens the control valve 43. This is ac: complished by. shifting the cam I2I to bring‘ the low surfaces. I25, in line with the cam follower ?ngers II9 so that greater travel of the arm I I1 is required before the temperature-responsive‘ de vice begins to open the ports 14. As shown particularly in Fig.3, this adjust fuel through said second outlet to the. pump inlet ' for varying the rate of ?ow of fuel to the com bustion apparatus, a controlvalve communicat ing with the discharge end of said Venturi-tube and opening to the inlet of said pump, ‘said con trol valve including a valve member for regu lating'the ?ow of fuel therethrough, means for positioning said valve member in accordance with the pressure differential between the inlet and throat of said. Venturi tube and arranged so that an increase in the pressure diiferential between the inlet and throat of the Venturi tube tends to open said control valve, and means responsive tothe temperature of the motive ?uid generated by said combustion apparatus for positioning said ‘ V ment of the cam for the starting period of the valve member 'in'accordance with the tempera ' gas turbine is e?‘ected by.means of a slide rod 60 ture of 'said motive ?uid and arranged so that I25 having an‘opening I21 therein which‘re (an increase in temperature of said ?uid above a ceives a’ lug I28 projecting from the periphery of the cam:I2I. ‘4 ' ' ‘ In Figs. 2 and‘ 3, the apparatus is shown in, ~ predetermined value tends to open said control valve. DONALD BRADBURY.