US934915A - Elastic-fluid turbine. - Google Patents

Description

P. HODGKINSON.

ELASTIO QUID TURBINE.

APPLICATION FILED APR.12, 1905. RENEWED JUNE 7,1909.

Patented Sept. 21, 1909.

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@Wi/knew@ nel 3513K@ @Hoz/14 F. HODGKINSON.

ELASTIG FLUID TURBINB. APPLIOATION FILED APB. 12, 1905. EBNEWED JUNE 7, 1999.

934,93 5E Patented sept. 21, 1909.

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F. HODGKINSON. BLASTIG FLUID TURBINE. APPLICATION FILED APE. 12, 1905. RBNBWED JUNI: 1, 1909.

WITNESSES: 44

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TTORN EY fr caricia BRANCS HODGKINSON,

OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO THE VVESTENGHOUSE MACHINE COMPANY, A CORPORATIONOF PENNSYLVANIA.

ELASTICI-FLUID TUBBINE.

Specication of Letters Patent. .Patented Spt. 21, 1909,

Application filed April 12, 1905, Serial 110.255,113. Renewed June 7, 1509. Serial No. 500,737.

Zf'o all whom it' may oedeem:

lie it known that l, Francis HoDoKINsoN,

" /f )in object ot' this invention has been to provide eil'ective governing means for steam or other elastic iluid turbines, whereby a substantially uniform speed may through a wide range of load Variations. This, well as other objects which will be apparent to those skilled in this particular art, l attain b y means of the mechanism described in the specification and illustrated in the accompanying drawings in conjunction with a particularl type of steam turbine.

lt will be understood that this invention is not limitedin its application to any particular style or type o'lf turbine, and a particular type is here shown only for the sake of illustration.

Hereinafter the working fluid will be re- 'le red to as steam, with no intention, howover.. ot limiting the appended claims to steam turbines. l

in the drawings, Figure 1 is a longitudinal sectional view ot a steam turbine to which this invention may be applied: Fig. 2 is a longitudinal sectional view ot' the inlets portion ot tht turbine illustrated in Fig. l, showing the automatic valve forming a part of this invention` in position: Fig. 3 is an end view in elevation ot a portion of a turbine equipped with this invention, and Fig. 4 is a detail view oi a governor which may be utilized with this invention: Figs. 5 and`6 are diagrams hereinafter described.

'ihc turbine proper, as illustrated, consists ot tivo essential elements, a casing or stator 5 and a rotor or rotating` part (i.

The rotor is builtup of blade supporting drums mounted on shaft ends which project ihrou1 h the casing ends and are journaled within suitable bearings. rl`he drums, for reasons oi manufacture, are stepped and o'l' increasing diameters to provide for proper strani expansion.

be maintained v Opposed to the blade drums, the rotor is providedpwith balance-pistons rendered cft'ective by means of steam passages Y, one only of which is illustrated, and by a passage 8 subjecting the reverse sides of the baance-pistons to the exhaust pressure.

The internal portions of the easing correspond to the several dimensions of the rotor and its parts, and its inner surface is adapted to carry rings of fixed blades to alternate with the blades with which'the rotor is adapted to be provided.

f The governing mechanism is constructed and arranged so that the Ysteam enters the turbine in puffs, and not in a continuous blast. Speed regulating is, therefore, at.

complished by proportioning the duration ot' the puits to the load. This 1s done by means of a small pilot-valve 9, actuated directly by the governor which thereby controls the steam passing through the main puppet-admission-valve 10.

When the turbine is inv operation, the main or primary puppet-valve l0 is continually opening and closing at uniform intervals,

but the periods during which the valve is ali lowed to remain open are proportioned to the load on the turbine. At light load, the valve opens for a very short period and remains closed during the greater part of the interval. As the loadincreases the period lengthens until finally, at about full load, the valve does not reach its seat at all, and approximately continuous pressure is obtained in the high pressure end ot' theturbine,'or between the points r11-fn in Fig. 2 On the load becoming' further increased, an auxiliary orl secondary valve 1l begins to open and to admit steam tothe annular space l2 at the beginning of the intermediate drum of the rotor where the steam' working areas are greater; this increases in prgpoi.

tion the total power ot the turbine.

The operation of the secondary puppet# valve l1. is the same as that of the. main admission valve, so that the governor automatically controls the power and speed of the turbine from no load to such over-loads are usually beyond the limits of the generating apparatus with which they are generally utilized. With this method ot gow erning, the turbine operates at its best etliciency at or near full rated load, although tion, is raised from its seat duringr its reciplocations by means of a motor connected to its lstein' which motor consists of a steam-piston 14 and a spring 15. The piston is single-acting and the steam is admitted to its underside through a port or channel 16 and exhauster throi'igh the channel 1 62 under the control of pilot-valve 9. The channel 16 is materially smaller than the channel 16a and when the channel 16a is open to the exhaust,

steam admitted through they channel 16 is negligible. The 'seating of the valve is accomplished by means ofthe spring 15 acting in conjunction with a dash-pot or tiniiiigdevice formed by piston 17 located within a cylindrical portion 18 of the valve stem chamber. A hand-lever 19 is provided for opening the valve during the warming up operation.

The secondary acl/mission calva-The construction ol the secondary admission valve is similar to the primary admission valve in most respects, and its operation` is controlled by a pilot-valve 20. For the saire of visibly indicating' the operation of the secondary valve, the end of its stem is reduced and reciprocates within a sight-glass 2l provided 'foi-that purpose. 4

Any desirable kind" of a throttle-valve in the steam-linei between thel .boiler and the turbine may be utilized tocontrol the flow ot steam through the admission port'22. Duringr normal-load and all loads below normal, the secondary admission valve 11, as before said'. remains closed. During all loads above j normal, the steam passing` 'throughl the secondary admission valve, passes first through the primary admission valve, which remains open. v 1

It desired, a partition similar to the one indicated by dotted lines in Fig. 2 could separate the two .valve-chests and partition 22a' would be cut away,'so that the secondary admission valve would be supplied with ,steam direct from the admission port 22 without first passing through the primary admission valve. The construction shown, however, it is believed is preferable, owing to the 'fact that all oi' the steam passing to the turbine can be shut. oll'by the primary admission \'al\'e,'.\vhich would not be the case with thel alternative construction.

The governor, which is here shown otl the liy-ball type merely toi' the sake ot illustration, raises and lowers the Alulcruin 223 of the lever 24, which lever causes both of the pilotvalves to regularly reciprocate. i

v',lhe lever 24 is regularly reciproeated synchronously with the rotationl of the turbine rotor by means of a camy 25. driven from the turbine-shaft 26 through suitable geaI'-,

ing 27. The vstems of both pilot-valves, by

means of suitable links and lever connec.

tions, are reciprocated by a rock-shaft 28, operated by lever 24 through links 29 and 30 and the rock-shaft 31. A

It will be seen that as the lever 24 is regularly reciprocated, and as the position of its fiilcrum is dependent upon the posit-ion of .the fly-balls, the. planes of reciprocation of' the two pilot-valves will vary as the position of said fulcrum varies.

The connectingJ -neclianism between the 1ever 24 and both of said pilot-valves is such that the pilotfvalve controlling; the secondary admission valve 11 will reciprocate between ineffectiveA limits during normal' load and all 'loads under normal and the secondary admission valve will therefore re-v `main closed. When .the speed of the turbine drops below normal and the fulcrum 23 is lowered, the pilot-valve 2 0 for the secondary admission valve will reciprocate between effective limits, and thereby cause the sec. ondary valve to operate and to.openatregu-` lar' intervals. 1

The operationforl the primary admission valve is shown in Fig. 5, whicli represents some indicator cards taken on a'1250 k. w. turbine at various loads, the indicatorbeing attached'to the admission port 13, andthe indicator barrel -revolving at constant speed by suitable means. It is seen that at light loads the valve opens for-very short periods and remains closed during' the greater part.

of the interval. As ,the load increases, the

' valve remains open longer until finally continuous full pressure is obtained in the high pressure endl of the turbine,'and it lwill be seen that at this time the valve does not reach its seat at all, but is merely pulsating without sensibly reducing the pressure ofsteani in the turbine. On' the load being still further increased, the secondary admission valve will begin to open and admit high pressure steam tothe annular inlet 1,2.to the intermediate section, and the operation of this secondary valve While the primary valve is admitting continuous ful'l pressure, would be the same as the operation of the primary.,

'valve as4 indicated in Fig. 5.

The performance of a turbine 'equipped with a secondary valve embodyingr this in vention is illustrated in Fig.4 6, which shows an economy test on a turbine Where tests were made upto 7G per cent. overload'. vvThe economy, itvv will be observed, drops 'off slightly as the secondary valve opens, but, on the other hand, the range of load at which the turbine may be economically operated is greatly extended, in this case from 400 to over 1,00() BHP., with the steam consumption"varying from 13.2 to 14.3, or but slightly over S per cent. from that ot' maximum ef'- ficiencyl It will be understood that various changes in the mechanism may be made without departing from the spirit of this invention. The governor may be materially modified, and, if desired, a different type of governor may be utilized. For the primary and seeondary admission valves, Corliss valves may be substituted for the puppet valves, andthe 'alve motors changed to suit. Both theprimary and secondary valves maybe operated elerically, or either may beoperated di? reetiy from the governor through suitable mechanism, but v Having thus described my invention, what l claim as new and useful and desire to secure by Letters Patent is:

l1. In a multi-stage elastic fluid turbine, a fluid inlet to the hivhpressure stage, a supplemental fluidinlietl to an intermediate stage, valves regulating said inlets, means 'dependent on the turbine speed whereby said valves are automatically controlled, and mechanism whereby said valves are caused to give pulsations tothe entering fluid.

In a multi-stage' elastic fluid turbine, a fluid inlet to the high pressure stage, a supplemental fluid inlet to an intermediate stage, independent motor moved valves regulating said inlets, means dependent on the turbine speed whereby said valves are. auto- 'matieally controlled, and mechanism operatively connected to said means whereby the operation of the valve motors is such that the fluid passing said valves is caused to pulsate. v

3. In a multi-stage elastic fluid turbine, a primary fluid inlet to the high pressure stage, a secondary fluid inlet to an intermediate stage, independently operating valves regulating saidanlets, mechanism whereby at light loads the secondary'fluid inlet valve is held closed and the primary fluid inlet valve is caused to pulsate ,at constant intervals, the periods of which are proportional i to the turbine speed, and means whereby when the primary fluid inlet valve remains constantly open the secondary Huid inlet valve is caused to pulsate.

4. In an elastic fluid turbine, a main fluid inlet at the high pressure end, a pulsating valve controlling said inlet, a high pressure inlet intermediate of the main fluid inlet and the low pressure end, a .pulsating valve controlling said inlet, a speed governor and means between said governor and said' valves whereby the pulsationsof said valves are independently and automatically controlled by said governor.

5. ln an elastic fluid turbine, a main fluid linlet at 'the high pressure end, a supplemental fluid inlet nearer lthe low pressure l l l l end, a valve between the main inlet and the supplemental inlet for controlling the latter inlet, a valve controlling the fluid admitted to the main inlet and that passing the valve for the supplemental inlet, agents for causing said valves when in operation to pulsate,

a governor and means dependent thereon for automatically operating said Valves.

G. In an elastic fluid turbine, a secondary motor operated inlet valve and means movable within a transparent housing-for visibly indicating the operation of said valve.

7, In an elastic fluid turbine, a fluid inlet to the high pressure stage, a supplemental fluid inlet to an 'intermediate stage, a pulsating valve controlling said latter inlet, and means whereby the operations of Isaid latter valve is visibly indicated.

8. In a turbinehaving a plurality of inlet-ports, separate valves for said ports, and means operativelyconnected with the valves for opening and closing one at constant intervals wh-ile the other remains closed and' for allowing the first to remain open continuously while the second is open; said means including a governor device.v

9. The combination with a turbine-engine having a plurality of inlet-ports, of separate valves for said ports, means connecting with the valves and adapted to open and close one of said ports at intervals, and means to open and close the other port and permit the firstmen-t-ioned port to remain open continuously.

l0. The combination witha turbine-engine having a plurality of inlet-ports, of separate valves for said ports, means connecting with the valves for opening 'and closing one of the valves regularly, and a governor device for controlling the position of said means so as to regulate the time and degree of the valve-opening.

11. The combination with a turbine-engine having a plurality of inlet-ports, of separate valves for said ports, means for opening and closing one of said valves regularly, a variable fulcrum for said means, means for determining the position of the fulcrum, and means .for opening and closing a second valve while allowing the lirst valve to remain open continuously. v

12. The combina ion with a turbine-'engine` having a plurality t inlet-ports, of separate valves for said ports, means for opening and closing one of said valves at intervals, a variable fulcrum'for said means, and a gov- .'ernor controlling the. position of the fulrie lever, and a governor device controlling the position of the fulcrum so as to regulate the time and degree of the opening and closing of the valve.

14. The combination With a turbine-engine having a. plurality of inlet-ports, of separate valves for saldports, ay vibratinglev'er having a variable fulcruin and operating to open and close one of the valves, constantly.- acting means vibrating the lever, a governor controlling the position of' tlie. fulcruin to regulate the time and degree of tlie'opening of the valve, ,and means for openiiig and closing a secondl valve and allowing'tlie first to remain open continuously,.said means 'in-"- cluding a leveroperated by'tliesanie governor device.

15. 'lhecombination with a turbine-engine having two inlet-ports, of separate valves therefor, a lever-,having a variable fulcruni and operating to regularly open and close the rst valve, a governor device controlling the position of' the fulcruin, `a lever for opening and closing the second valve at such times as the opening-lever for the firstr valve becomes ineffective, and ineanswhereby the f same governor controls the action ofthe".

opening-lever for the second valve.

lt. 1n a governor device for .engines,'the combination 'with an Iengine organizedztc receive steam at,two points,"of a steam-chest 1 having a fixed port at each end of such points and connected with a source of supply,v separate valves for said ports-,means4 for opening and closing one of said'valves at intervals and-for allowing 1t to remain lcontinuously open at times, and means for opening'the second valve.

17. ln a multi-stage elastic fluid turbine, a primary admissiony valve ttor the high pressure stage, a secondary admission valve forv` an vintermediate stage, means whereby each of said valves when in operation .is caused vto pnlsate the fluid passing iti, a governorand mechanism whereby'the governing function is placed upon one or the other of said valves according to the turbine speed. A

18. A turbine divided into stages,`with blades or buckets Vfor the stages, in combination with a Huid-actuated valve controlling the passage of motive fluid through one stage and a fluid-actuated valve controlling `the passage of' motive fluid through a lower stage, said lower lstage valve receiving its operating fluid. when said first valve moves from its seat.

' 1t). A turbine divided into'stag-es, with blades or buckets forthe stages, in combination' with a valvevcaliiable ot' automatic and hand regulation for controlling the sage of i'i'iotivefliiid through one stage and a fluid-actuated valve controlling the passage -of motivefluid through a lower stage, the lower stage valve receiving its operating fluid when said first. valve moves from its seat. v

2t). A turbine divided into stages, with l blades or buckets for the stages, in combination with an automatic fluid actuated valve capable of hand regulation for controllingthe passage of fluid through one stage, and a valve for automatically by-passing motive fiuid around one or more stages.

2l. A turbine divided into stages, with blades or buckets for the stages, in combination with an automatic valve capable of fluid around one or more stages, and means',I

for causing said by-pass valve to operate under predetermined conditions. I

23.' A turbine divided into stages and provided with a speed-responsive governor, in

combination with a fluid-actuated valve controlling the passage ol motive fluid thr0i1, ),li

the first stage, and a Huid-actuated valve for automatically ley-passing motive fluid around.

one or more stages. l

Z-l. A turbine divided into stages and prov vided with a speed responsivey governor, in

combination with a Huid-actuated valve controlling the passage of motive fluid through a stage, and a flnid-actiuited valve t'or automatic-ally by-passing vfluid around one or more stages under pi'c(.letei.'niiiied conditions. f

25. A method olE operating a n'inlti-stage turbine consisting in admitting a substantially constant supply of motive-fluid Vto the liigli-l )i'essiii'e stage, in admitting a relatively liigli-pressure supply'of motive-Huid to an intermediate or low-pressure stage and in` pulsating the relatively liigli-pressl'ire `supply to the intermediate or low-pressure 'st-age.

2t3..i\ method of operating a nnilti-stage 'turbine dui-ing overloads consisting in ad- ,iuitting a substantially constant supply of motivefluid to a ,liigli-pressure stage, in'adniitting relatively high-pressure motive-fluid to an intermediate or low-pressure stage and in varyingthe relatively high-pressure 'motive-fluid adn'iitted to-tlie intci inediate or low-pressure stage with the variations in the overload.

Q7. A i'netliod ol operating` a, multi-stage turbine during -overloads which consists in admitting a substantially constant, supply

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