US1619129A

US1619129A - Bleeder turbine

Info

Publication number: US1619129A
Application number: US644255A
Authority: US
Inventors: Josiah F Johnson
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1923-06-08
Filing date: 1923-06-08
Publication date: 1927-03-01
Anticipated expiration: 1944-03-01

Description

J, F. JOHNSON BLEEDER TURBINE March 1,1927. J 1,619,129

Filed June 8. 1923 5 Sheets-Sheet 1 UHF-Johnson INVENTOR ATTORNEY March 1 1927.

. 1,619,129 J. F. JOHNSON BLEEDER TURBINE Filed June 8, 1923 5 Sheets-Sheet 2 071mm ymsssz 1 n lNVENTOR Q1 ow fit I BY @024 ATTORNEY March 1,1927. 1,619,129

J. F. JOHNSON BLEEDER TURBINE Filed June 1923 5 Sheet-Sheet 3 1 v JZZJaZzmon WITNESS: I INVENTOR ATTORN EY March 1 1927. 1,619,129

' J. F. JOHNSON BLEEDER wuasnm Filed June 8. 1923' I 5 Sheets-Sheet 4 ATTORNEY J. F. JOHNSON Margh 1 1927.

BLEEDER TURBINE s sheets-sheet 5 n A 1 pm 1 m 2 E1. ,MV/WJ 0 m v. a a o 7% w )2 1 Z W M WWII 5- 7- ATTORNEY Lil Patented Mar. 1, 19 27.

UNIT ED STATES Application filed. June 8,

My invention relates to bleeder turbines and it has for an Object to provide, apparatus of the character designated which shall be capable of i'nai'ntaining a substantially constant and predetermined bleede'r pressure W'th a wide range of variation in the amount of motive fluid passing through the turbine or with a wide variation in the bleeder demand.

A further object of my invention isto provide interstage valve meansin a blee'der turbine to control the admission of motive fluid to the low-pressure end thereof and which is connected to a valve in the blee'der line in such a Way that the latter valve is fully opened and closed While the inter-stage valve is fully open and the interstage valve is opened and closed While the bleed'e'r line valve is approximately Wide open.

A further object of my invention is'to provide an inte'rstage valve fora bl'eedcr turbine which is connected to a valve in a bleeder line by means arranged internally of l the casing structure so that a minimum of exposed parts and packed joints is involved.

A further object of my invention is to provide, in connection ivith apparatus of the character referred to, means which is responsive to predetermined movements of the governor-controlled valves in either direction for the purposes of closing the bleeder line valve so that, in case of [excessive leads, all of the steam maybe caused to pass through the turbine and, in case of shutting down of the turbine, the latter is effectively isolated from the hleeder system, preventing the turbine from ovcrspeeding by steam supplied from the bleede'r system.

My present invention constitutes an improvement upon. the type of bleeder turbine disclosed my application, Serial No. 1%,827, filed June 8, 1921, assigned to the VJest-inghouse Electric and Manufacturing Company, and it has for its particular object to improve the valves and the valve-operating mechanisms in order to simplify them from a structural standpoint and to render them more practicable. Also, due to the connection of the valve-operating,mechanism to the governor-controlled valves, the closure of the bleeder line valve in case ofoverloads PENNSYLVANIA, ASSIGNOR "r MANUFACTURING COMPANY, A CORPORATlYON OF PENN- resistive. 1923. Serial No. 644,255.

or of shutting down of the turbine is as- Apparatus made in accordance w th my invention is illustrated in the accompanymg' drawings, forming a part of this application, in ivhich 1 is a side elevation of a turbine having my improvement applied thereto; Fig. 2 is a fragmentary sectional view of a bleeder ,turbi'ne shovving my improved valve mechanism applied thereto; Fig. is a sectional view taken along the line III- III of 2; Fig. 41 is a fragmen'tary View, someivl'lat, like F-igf 3, but showing the valves in a (lifferen't operative position; 5 is an enlarged sectional "view of the valve-"actuating mechanism; Fig. '6 is a top plan View "or the mechanism shown in Fig. 5; Fig. 7 is a sectional vieW of a steam chest and showing the goi Thor-controlled valves; and Fig. 8 is a diagrammatic view .shovving the operative relation of various parts relating to my invention.

Referring now to the drawings for a better understanding or my invention, I show a bl'eeder turbine comprising a casing 10 and a rotor 11 carrying the energy-abstracting 'el'en'ients of a first or high-pressure section, at 12, and the energyabstracting elements of a second oi loiv pre'ssure seotiomat 13. The sections, M12 and 13', are separated by means of interstage valve mechanism, at 14, and a bleeder conduit or connection 15 coinmunieates With the casing 10 at the highpressure side of the valve 14. A valve 16, preferably 'Of the butterfly type, is arranged in the bleeder line or conduit 15, and the valves 14 and 16 are operated by mechanism, at 17. which is responsive both to pressure in the bleeder line and to the positions of governor-controlled valve mechanism, shown at 18, the lat-t er being, iii turn, actuated by a governor, at

The interstage valve 14 consists of a stationary member 20 carried by the turbine casing 10 anda relatively movable, member 21, Which is retained in position with respect to the member 20 andivhich is provided with a gland ZZlitting with eloseclearanceuvith respect to the rotor 11. The stationary member 20 is provided With eti 'cumlerehtiel series of ports are relatively longer in a circumferential direction than a series of cooperative ports 2 1 arranged in the movable valve member 21. This diiference in the dimensions of the ports permits of movement of the valve member 21 before such valve member begins to restrict communication through the ports.

7 The butterfly valve 16 is pivoted internally of the bleeder line or conduit at 25 and it is providedat its top with a crank arm 26 which is pivotally connected to a link 27, the latter, in turn, being pivotally connected to a crank arm 28 carried by the movable valve member 21.

The relationship of the crank arms carried by the valve members and the connecting link will more clearly appear from an inspection of 3. From this view, it wil be seen that the

crank arms

28 and 26 define acute angles at opposite sides of the center line at), passing through the axes of the valve members so that, when the butterfly valve 16 is closed, its crank arm is in such a position as to receive a large tangential component of force transmitted from the arm 28 in order to open such valve.

As already pointed out, the ports 23 are longer in a circumferential direction than the ports 24; When the butterfly valve 16 is closed, the rear edges of the ports 24; are adjacent to the rear edgesof the ports 23 so that the movable valve member 21 may undergo such movementwithont restriction of communication through these ports as will be suiiicient to substantially fully open the butterfly valve 16.

In Fig. 3, clockwise movement of the movable valve member 21 results in movement of the forward edges of the ports 2st toward the forward edges of the ports 23, and when these edges substantially register, the butterfly valve will be moved to substantially its wide open position. Further movement of the movable valve member 21 takes place with very slight movement of the butterfly valve 1.6; and, as will be seen from Fig. 4:, the movable valve member 21 may reach a linal position entirely restricting communication through the ports without any sub stantial disturbance of the wide-open position of the butterfly valve. A

From the structure described, it will be apparent that. the butterfly valve 16 is opened and closed while the inter-stage valve let. is substantially wide open and that the intcrstage valve is opened and closed while the butterfly valve is approximately wide open. In other words, these valves are opcrated in a sequential manner so as to take care of wide variations in power and bleeder demands.

The movable valve member 21. of the in terstage valve is provided with a crank arm 30 which is operatively connected to the operating mechanism, at 17, which is responsive both to bleeder pressure and to the governor-control valve mechanism.

The operating mechanism, at 17, will be understood from a consideration of Figs. 3 and 5. It includes an operating piston 31, which is connected to the crank arm 30 by means of a piston rod 32. The operating piston 31 is arranged within an operating cylinder 33, and motive fluid is admitted to opposite ends of the latter, in order to move the piston 31 in both directions, by suitable pilot valve mechanism, at 34, which is under the control of a pressure-responsive device 35 connected to the bleeder line beyond the butterfly valve 16 by means of a conduit 36 and under the control of the governor, at 19, and the governor-operated valve mechanism, at 18.

The pilot-valve mechanism, at 3 1, comprises a cylinder 36 having motive fluid inlet passages 37 and motive fluid exhaust passages 38 and 38. The cylinder is also provided with passages 39 and 40, arranged between the passages 37 and 38 and between the passages 37 and 38, respectively. The passages 39 and 40 communicate with the passages 41 and 4-2, respectively, leading to the lower and to the upper ends of the op erating cylinder 33. A piston valve 4E3, hav ing piston portions 4 1, (see Fig. 5) is arranged within the cylinder 36 and it controls communication of the motive fluid supply passages 37 with the passages 39 and 1:0 and of the latter with the exhaust passages 38 and 38, respectively, so that motive fluid may be admitted to one side of the operating piston 31 and exhausted from the other side for moving the latter. The exhaust passages 38 of the cylinder 36 preferably connect with a common discharge passage 45.- V

The mechanism for securing operation of the pilot valve l3 in response to bleeder line pressures and in response to load conditions of the turbine will now be described. The pressureresponsive device 35 incl ndes a diaphragm member d7, which is subject to lluid pressure received from the conduit 36 and to the pressure of the spring 43 arranged above the diaphragn'i. The diaphragm is connected to a stem 49, whirh, at its upper end. bears against knife edges carried by the lever 51.. The lever 51 has knife edges 52 which bear aga nst a suitable hearing surface 53 of framework or stationary part of the apparatus. Suitable weights 5i are Carried by the lever 51 in order to vary the load on the diaphragm and consequently the required tluid pressure to move the latl *r upwardly.

The lever 51 is pivotally connected, at 55, to a link 56, which is pivotally connected, at 57, to a floating lever 58, the latter lever being pivotally connected, at 59,'to a link 60, which is pivotally connected, at 61, to a 'veloping' lever 62, fulcru'ined at 63,- and having its oiiter end connected, at 63, to the pilot valve 43. With this arrangement, upon predetermined upward movement of the diaphragm 47 in response to an increase in bleeder pressure, the stem 49 moves upwardly, the lever 51 is tilted upwardly about its ful crum 52, the link 56 moves upwardly, the floating l'ever 58 is tilted upwardly about the n'ion eiitary fulcrum 58', with, respect to a stein 31 carried by the operating piston 31, the link 60 moves upwardly, and the lever 62 tilts about the fulcrum 63 to move the )ilot valve 48 downwardly so as to supply motive fluid below the piston 81 and to exhaust fluid from above the latter, resulting in counterclockwise movement of the movable valve member 21 to restrict the flow o t motive fluid to theble'eder connection. This movement continues until the pilot valve is moved back to its cut-off position by the stem 31', the lever 58, the link 60, and the lever 62. In this way, the building up of bleeder pressure beyond a predetermined amount is limited.

In case the bleeder line pressure should fall slightly, the diaphragm 47 would move downwardly under the influence of the spring 48 and of the weight 54, with the result that the linkage connections referred to would cause the pilot valve 43 to move upwardly to place the space below the operating piston 3l in communication with the eizhaus't and the space above the operating piston in communication with the source of motive fluid under pressure, in which case the operating piston 81 would move clownwardly to move the movable valve member 21 in a clockwise direction so as to increase the supply of steam being bled in order to maintain the bleeder pressure, this movelllBllt-COIltlIllllllg until the pilot valve 43 is brought back to cut-oil position due to movement of the operatingpiston 81.

Referring again to the inter-stage valve 14 and to the butterfly valve 16, in Fig. 3, the valves are shown in such a position that the turbine is capable of developing the maximum amount of power, the bleeder connection being practically cut off, while in Fig. 4, 1 show the valves in such a position that the turbine has its minimum power-dc anda maxin'nnn bleederi vel'oping capacity capacity. These valves may, therefore, be moved by the mechanism just referred to in order to supply various power and bleeder demands over wide ranges.

It is desirable that the bleeder line should be cut oil from the turbine in case of peak loads in order that themaXimuin po\'ver-decapacity may be had and in case in order to b'ackfiow of steam from the bleeder linethrough the lowpressure section,- at 13. Accordingly, thereof shutting down of the turbine operation piston ment of the lever fore, I provide a connection between the lever 6201? the pilot valve 48 and the governor-controlled valve mechanism, at 18, in order to secure downward movement of the pilot valve 43, upward movement of the 31, and counterclockwise movement of the movable valve member 21 in order to secure closure of the butterfly valve 16 in case of a predetermined light load or a predetermii' ed overload.

The lever 62 is moved downwardly by meansot a lever 65 fulcrumed at 66 and pivotally connected, at 67, to the upper end of the stem 68 bearing the fulcrum connection 63; A spring 69 cooperates with the lowerend of the stem 68 in order to maintain the latter normally in an upper position. lVlienever the lever 65 is moved upwardly, the stem 68 is forced downwardly, compressing the spring 69, and the lever 62 is tilted downwardly about theepivotal con-' nection 61 to move the pilot valve 48 downwardly so as to secure upward motion of the operating piston 81 and closure of the butterfly valve 16. The governor-controlled valve mechanism tor securing operation of the lever 62 in this way will now be described; V v

' Referring to Fig. 7, the governor controlled admission valve mechanism,- at 18, consists of a primary vvalve 70 and a secondary valve 71 for controlling the passage of steam from the supply 72 to the turbine passages 7 3 and 74, respectively. The

valves

70 and 71 are connected to stems 74 and 75, respectively, and the latter are pivotally connected, at 76 and 77, respectively, to a lever 78. The lever 78 is pivotally connected, at

79, to suitable gover nor;operated mechanism,

at 80. For example, I show the governoroperated mechanism, at 80, consisting of downwardly extending links 81 which are pivotally connected to a lever 82, the latter, as may be seen from Figs. 1 and 8, being fulcrumed, at 88, and connected to the movable element of the governor, at 19.

spring 84 isconn'ec-ted to the lever in order to assure that, upon upward movement ot the governor-operated mechanism, at 80,

the primary valve shall first be opened. In

order that the secondary valve 71 may he opened after the primary valve 70 is wide open, it is necessary that the "upward move- 78 in the manner referred to should be limited. Therefore, I show an adj ust-able abutment 86 which limits upward movement of the left-hand end of the lever 78, so that the right-hand end of the latter may be moved upwardly against the force of the spring 84 to open the secondary valve 71 after the primary valve 70 is fully opened. The governor-controlled valve mechanism,

at 18, includes mechanism, whereby, upon extreme limits of adjustment of the primary and

secondary valves

70 and 71, the lever 65 is moved so as to tilt the lever 62 downwardly to secure closure of the butterfly valve 16 in the manner already referred to. I, therefore, provide a lever 87, fulcrumed at 68, and having one end pivotally connect- .ed, at 89, to a link 90, which is pivotally conner stated. The governor-operated lever 78 is arranged to tilt the lever 87 in this manner upon extreme limits of valve adjustment.

One end of the lever 87 is pivotally connected, at 92, with respect to a link 93 which is provided with an adjustable abutment 9d at its lower end. The lever 78 has a slidable connection 95 with respect to the link 93 so that, when the primary valve 70 is closed, the lever 78 comes in contact with the abutment 94 to pull down the link 93 and tilt the lever 87 about the fulcrum 88 in order to pull the link 90 upwardly and tilt the adjacent end of the lever 65 upwardly for the purpose of securing closure of the butterfly valve 16. The other end of the lever 78 has a slidable connection 96 with respect 'to the link 90 and the latter carries an adjustable abutment 9'7. Ience, after the secondary valve 71 is opened to a predetermined extent, the lever 78 comes in contact with the abutment 97 with the result that the link 90 and the adjacent end 01": the lever 65 are pulled up for the purpose of closing the butterfly valve 16.

The operation of apparatus made in accordance with my invention will be better understood from a consideration of diagrammatic Fig. 8 from which it will be seen that the prassure-responsive device 35 acts upon an increase or a decrease in bleeder pressure to move the lever 62 through the intern'iediary of the lever 51, the link 56, the lever 58, and the link in order to move the pilot valve 13 upwardly or downwardly to secure movement of the interstage valve 1% in one direction or the other. hen the butterfly. valve 16 is closed the ports 23 and 2t ot the interstage or grid valve atl'ord tull connnunication between the turbine sections, at 12 and 1?). This is the position tor maximum power development. Vith movement of the valve member 21 in a direction to close the interstage or grid valve 14-, the butterfly valve 16 is fully opened bet'ore restriction of the inter-stage or grid valve 14 commences; and, while the butterfly valve 16 is approximately wide open, further movement of thevalve member 21 may take place to secure closure and opening of the interstage or grid 'valve 1%. \Vith closure of the interstage or grid valve 1a the parts are in a position for the satis faction of a maximum bleeder demand,

The pressureresponsive device 35 there for serves to secure operation of the valves in such a way as to maintain the'bleeder line pressure as near as possible to a desired value. Upon a tendency otthe bleeder pressure to increase the inter-stage valve 1.4 is opened, or, it' the latter is opened the butterfly valve 16 is moved so as to restrict the tion takes place between the turbine sections I 12 and 13 and any diminution in bleeder pressure must occur by movement of the butterfly valve 16 in a closing direction. In cse of increasing bleeder demand, with the interstage or grid valve 14: wide open and with the butterfly valve 16 substantially wide open, a decrease in bleeder line pressure results in further clockwise movement of the valve membr 21 to restrict communication between the turbine sections, at 12 and 13, so that more of the steam may be diverted for passage through the bleeder line, the limit being reached when the lowpiessure section, at 13, is wholly cut off from the high-pressure section, at 12, and the butterfly valve at 16 is approximately wide open.

The governor-operated lever 78 for the primary and

secondary valves

70 and 71 serves to move the lever 87 so as to pull the link 90 and the adjacent end of the lever upwardly so as to push the lever 62 downwardly about the pivotal connection 61 in order that the operating piston 81 may be moved upwardly to secure closure of the butterfly valve 16 either when the primary and secondary valves are substantially closed, as when shutting down the turbine, or with such valves substantially wide open which occurs when the turbine is overloaded to a predetermined extent.

From the foregoing it will be apparent that I have devised a bleeder turbine which is capable of satisfying wide ranges of bleeder and power demands and which is capable of being automatically cut oil from too blender system when it is being shut down.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed there= 2. In a bleeder turbine, the combination of primary and secondary valves for the and means tor turbine, a bleeder line valve,

closin the bleeder line valve u on redetermined closing movement of the primaryf valve and upon predetermined opening movement of the secondary valve. 3. In a bleeder turbine, the combination of an admission valve, a bleeder line, avalve in the blee der line, a pressure-responsive device connectedto the bleefder linebeyond th l e ne "el' e me n erera ed by h pre u i ns e d vice t ee d v .0 he eeder n lva d n w Subject to sure j .he a m s i n ah' at- 9 th bleeder line valve. a In a bleeder turbinaihe cwl binationoi an interstage valve, ableeder line, a valve in the bleeder line, a pressurerrespoiisive dev e QQQ Q Q t h le r liae e e t bleeder line valve opera the intertee va a m an f a at n t bleeder line valve from the inter-stage valve. 5 In a bleeder turbine, the com n ation of an interstage valve, a bleeder'line, avalve in the bleederline,

. P 3 SPQ W i v l'l v connected to the bleeder line beyond its valve,

a fiuid relay interposed between the pressurei-esponsiv e' e c and the in e st ge v lve. a d me ns er C9. I'1,ecting the ini i s age valve and the bleeder line valve sothat the latter is operated by movement of the former. 6. In'ableegler turbine, the ,cq binationof a bleeder line, a valvein the bleeder line, pressure-responsive device connectednto the bleeder line beyondthe valve,"flu id relay mechanism subject to the pressnremespQllsive device for opening and closing the valve, an

. admission valve :toi the turbine, and means dependent upon: closure "of the admission valve to operatet e relay to close the bleeder line valve. Y i In a bleeder turbine, the eombina-tion of an interstage valve, a bleeder line, a valve 'in the bleeder line, a pressure-responsive ie vice connected tothe bleeder line beyond its valve, fluid relay mechanism subject to the .i s. u e-, sp n v de e f r c nven n the interstage valve, mechanism for transmitting mot onv f om the nterstage valve to the bleeder line lve, and adm ss on valve,

and means resoons veto-predeterm ne closing movement "of the admissipn valve to op.-

er ate onthe relay mechanism for closing the bleeder line valve.

' n ble d turb ne th e eh at ee of primary and secondary valves, a lever hav ng its ends connectedto said valves, means for bias ng the lever so that the pr mary valve is opened before the secondary valve and closed after the latter, a bleeder line,'a valve in the 'bleederfline, and means responsive to predetermined do'ivnivard movement of the primary-valve-end of the lever nd to predetermined upward move: ment of the secondary-v alve end of the lever fQr clQSingthe bleeder line valve;

9. In a bleeder turbine, the combination of a bleed'erline, a valve in the bleeder line,

primary and secondary valves forthe turbine, a lever connected to'the primary and secondary valves, and means for closingthe bleeder line valve upon predetermined downvard movement of the primary-valve end of the lever and jupon predetermined upward movement of the secondary valve end ofthe lgver. v I i n 10. In a bleeder turbin'e,'the combination of an interstage valve, a bleeder line, a valve in the bleede'r line, means for connecting the valves so that the bleeder line valve is moved by the interstage valve, a pressure-responsive device connected to tlie bleeder linebeyond its valve, a relay between the pressure-re sponsive device and the interstage valve, primary and secondary valves for the'turbine, and means dependent upon a predeten mined closing movement of the prin'iaryya'lve and upon a predetermined opening movement of the secondary valve 1101- rendering the relay operative to move the inter-stage valve in order to close the bleeder line valve.

11'. In a turbine, the combination of a high-pressure section, a 1ow-p1-e;suie section, a valve between the, sections 'having a greater range of movement than'its throttling range; a bleeder line conununicating with the turbine at the high-pressure side of sai'd'valve, a valve 'for controlling the ad:-

mission of motive fiuid to the bleeder line, and n'eans arranged'internally' ot the turbine forfopening and closing the bleeder line valve during"nonthrottling' movement of said firsttalvep 1 2. Ina turbine, the con'ibination of an interstage valve having a greater range of movement than its throttling range, a bleeder line, a valve in the blee der line, and means operated by the interstage valve for opening and closing the bleeder line'valve during non-throttling movements of the former. i i 13. In a turbine, the combination of a rotary interstage valve having a range of rotary movement greater than' its throttling range, a' bl eeder line, a butterfly valve in the bleeder line, crank valves, and a linlifor arms; 7' 1 L In a turbine, the combination of an interstage valve having a rotary member, a

connecting the crank arms carried by the 15. In a turbine, the combination of high and low-pressure sections, a valve between the sections, ableeder line communicatin with the turbine at the high-pressure side or the valve, a valve in the bleeder line, and means actuated by the first valve for opening and closing the bleeder line valve.

16. In a bleeder turbine, the combination of an inter-stage valve comprising a stationary member having one or more openings therein and a movable member having corresponding opening or openings of less extent in the direction of travel than the first opening or openings, a bleeder line valve, and means operated by the movable member of the interstage valve for opening and closing the bleeder line valve.

17. In a bleeder turbine, the combination of an interstage valve comprising a stationary valve member having a plurality of openings therein, and a movable member having corresponding openings or less extent in the direction of travel than the first openings, a bleeder line, a valve in the bleeder line, and means for actuating the bleeder line valve from the movable member of the first valve and so arranged that the bleeder line valve is closed when the interstage valve is in its extreme position of maximum opening.

18. In a bleeder turbine, the combination of an interstage valve having a greater range of movement than its throttling movement, a bleeder line, a bleeder line valve, and variable motion means for connecting the valves so that the bleeder'line valve is opened and closed during .nonthrottling movements of the interstage valve and the latter is opened and closed while the bleeder line valve is substantially wide open.

19. In a bleeder turbine, the combination of an inter-stage valve, a bleeder line, a bleeder line valve, a variable motion linkage means for connecting the valves so that the interstage valve is opened and closed while the bleeder line valve is substantially fully open. 7

20. In a bleeder turbine, the combination of a grid valve within the turbine, a bleeder line, a valve in the bleeder line and mechanism for transmitting motion from the grid valve to the bleeder line valve.

21. In a bleeder turbine, the combination of a grid valve within the turbine having a greater range of movement than its throttling range, agbleeder line, a valve in the bleeder line, and mechanism arranged between the grid valve and the bleeder line valve for opening and closing the latter during non-throttling movments of th former.

22. In a bleeder turbine, the combination of a rotary grid valve within the turbine,'a-

bleeder line communicating with the turbine, a valve in the bleeder line, crank arms carried by the valves, and a link for connecting the crank arms.

23. In a bleeder turbine, the combination of a rotary grid valve within the turbine having a greater range of movement than its throttling range, a bleeder line communicating with the turbine, a valve in the bleed-er line, mechanism for transmitting motion from the grid valve to the bleeder line valve, a pressure-rcspousive device connected to the bleeder line beyond the bleeder line valve, and means operated by the pressureresponsive device for moving the grid valve.

24L. In a bleeder turbine, the combination of an admission valve for the turbine, a. rid valve within the turbine, a bleeder line communicating with the turbine, a valve in the bleeder line, mechanism for transmitting motion from the grid valve to the bleeder line valve, a pressure-responsive device connected to the bleeder line beyond the bleeder line valve, a relay between the pressure-responsive device and the grid valve, and means dependent upon predetermined closing movement of the admission valve for rendering the relay operative.

25. In a bleeder turbine, the combination of a grid valve within the turbine, a bleeder line communicating with the turbine, a. valve in the bleeder line, mechanism for transmitting motion from the grid valve to the bleeder line valve, a pressure-responsive device connected to the bleeder line beyond the bleeder line valve, a double-acting motor device for the grid valve including a control valve, and means for operating the control valve from the pressure responsive device.

26. In a bleeder turbine, the combination of a grid valve within the turbine having a greater range of movement than its throttling range, a bleeder line'communicating with the turbine, a valve in the bleeder line, mechanism for transmitting motion from the grid valve to the bleeder line valve so; that the latter is opened and closed during nonthrottling movements of the grid valve, a pressure-responsive device connected to'the bleeder line beyond the bleeder line valve, a double-acting motor device connected to the grid valve and including a control valve, and

withthe turbine, a valve in the bleeder line,

mechanism for transmitting motion from the grid valve to the bleeder line valve, a pressure-responsive device connected to the bleeder line beyond the bleeder line valve, a double-acting motor device connected to the grid valve and including a'control valve,

means for operating the control valve from the pressure-responsive device, and means rendered operative by predetermined closing movement of the admission valve for moving the control valve to move the grid valve to secure closure of the bleeder line valve.

28. In a bleeder turbine, the combination of primary and secondary valves, a grid valve Within the turbine having a greater range of movement than its throttling range, a bleeder line communicating with the turbine at the high-pressure side of the grid valve, a valve in the bleeder line, mechanism for transmitting motion from the grid valve tothe bleeder line valve so that the bleeder line valve is opened and closed during nonthrottling movements of the grid valve and the grid valve is opened and closed While the bleeder line valve is substantially Wide open, a pressure-responsive device connected to the bleeder line beyond the bleeder line valve, a double acting motor device connected to the grid valve and including a control valve, means for operating the control valve from the pressure-responsive device, and means rendered operative upon predetermined closing movement of the primary valve and upon predetermined opening movement of the secondary valve for moving the control valve so that themotor device moves the grid valve to secure closing movement of the bleeder line valve.

29. In a bleeder turbine, the combination of an interstage valve, a bleeder line, a bleeder line valve, means for controlling one of said valves, and variable motion means separate from said control means for connecting the valves so that the interstage valve is opened and closed While the bleeder line valve is substantially fully open.

In testimony whereof, I have hereunto subscribed my name JOSIAH F. JOHNSON.

this 1st day of June,