US815154A - Turbine. - Google Patents

Description

H. 1"..'PULLAGA-11. l TURBINE. l' APPLIQATION HLBDAUG. 1s, 1904.

PATBN-TBD MAR. 13, 1906.y

2 SHEETSTSHEBT 2.

f i STcfr-FESk fNo s155154.:

l' Toni-all' tbm/ty concern: y'

'PATENT OFFICE i 'HUGH FRANCIS FULLACAE, CF NEWCAsr-LE-UPoN-TYNE,ENGLAND,

- AssICNoR ToALLIs- CHALMEES COMPANY., ,oF JEEsEiT CITY, NEWY uERsEY, A CoRPoRA'rroN CE NEW JERsEY.- f.

specification of Lettersratent. ,Patentedumareh 13,1906. f Applifgtion-meitgust 18,1995.' senti No.:2 21.254.

Be it-pknown that' I, HUGH FRANCIS'FUL- fILAGAR, a `subject of the Kin of 'GreatfBriti ain and Ireland, residing at ewcastle-uponstepped shaft or drum y.(hc'ereinaftercalled the Tyne, in thecounty ofNorthumberlan'd, Engr land, have invented Improvements inl'Turbines, of-Whi'ch the followin is a specification.

In axial-flow turbines W ich have several vWhichthge-rotary'blades are mounted upon a spindle )I increasing in diameter from the in-` let to the exhaust it is usual, in order to balance the end thrust of the steamer other Working fluid (hereinafter referredl to as vf steam upon the rotary rings'. lof .blades and 'annular- 'sur- H faces ofthe stepsv of tliespindle, to/provide the spindle atitsinlet fen with similar but yreversely arranged steps the'diameters-of which.' correspond to those'- of the in ain" ory blades.

" Workin's'teps" carrying the lrotary rings' of radial'. ength offthefbla es in the rings 4of lengthare used on 'eachfstep;` the reverselyarranged steps being.:- 4'rovldedin vlieu of bladesWi-thfrotary labyrrnth-packin devices,

thus forming :What -aref-'usualy vcal ed balance-pistons so that the end pressure: of the stearnupon the annular surfaces'offthese balancinig 'steps or 'plstons iseq'ual'to'and' couneqalduring-flthe. Workin 'fof the turbine ,'t e parts of 'corresponding signed to 'counterbalanceor..upon the 'mean us.' an' amount e' ual usuallyto .the

ances the steam-press'u'reupon the iirst-A finentionfe'd r-steps; and the 'rotat1n, l rings of' 1 blades'ffcarried thereby,l 'ln-order tof ,iri'suwre-y 'Qthatjthe pressure -fofl steam-` u on the. corre-- spondin .f vvorkingandzbalanemg steps shall f be-,exact 4o ainetel,` ofthetwo sets jof steps-'are connected bypas- 1 sa' esorports,jtheouter' vside;of-the largest. Fuse o'ia'hngerA and strongerspindle.- Moreith thisarrangement, 'ho 'Wev'eij'A as fthefbalance-pistonshave to be made-of *dif-- :ferentdiameters that v 'are "dependent *uponv fand approximate 1to1-the vdifferent diameters- .f the' rotaryv rings" vfof-Ablades in the 'correfoliage thelturbine-izasing' has to be made `eta stepped shape 'to accommodatethe balancepistonsr and when there arefa number of such pistons'fthe casing at 'the' corresponding end ssl ofthe turbine has to be made of considerable diameter" .toaccomrnodate :the o utmost and largest-balancepiston," which is objectionable inifpractice. To', obviate this; I have heretofore removed the largest' balance-piston from the spindle at the inlet end of the A* turbine' andv attached ixt thereto at the ex,- haust end at a 'part' thereof adjacent to and .`nside the outer end Wall vof the exhaustchamber located at' the outlet end of the last vand largest set `o f rings of blades, such balance-piston being arrangedfin achamber. the rear or pressure end ofwhich/is connected vto Athe steam-space between the Alast two bladedV -steps lof the .spindle, the usual labyrinthpacking being provided betweenthe piston land thejwallot the chamber toretard the 7.5.

lowlofsteam from the piston-chamber to the eXhaust-chamber.' The front or exhaust end of the 'chamber containin' the balance-pis"-` ton of next smallersize an located atthe inlet end of the turbine was connected, vas usual: to the) stearnspace between the, t'Wolast 8vol I bladedstepsvof'the spindle. -This arrange- "ment, althou h it' enablesthe diameter of the l inletiendof t eturbine-casingto be reduced,

requires tha-t the .balance-piston for 'the last 'bladedj ortion of the spindle shouldstill be iglarge diameter.. Fllithermore, such an arrangement necessitates the 'placing` of theglands at the' two ends of the turbine-cas-l ing and the twobearings for the turbine-spinmade o die at la. greaterdistance a art than isl neces sayf inthe case 'of a -tur mejac'cording to the first-described arrangement and having the saine I iumberiand,diameters of rin is. of

b1a'des,' 'and has' consequentlynecessitate the .over,' balancepistons ofl large ldiameter re- .quire to berna e `in one vpiece With thespindle or; .to 'be very firmly vattached to the same,

thus" addingV to *the -cost of manufacture. Furthermore, it is impossible to employ such 'fine clearances upon large balanceistons as canvbe used. with smal-ler ones, oot because.

he 1retienend -alsosbeeause such pi heralfvelo'city l loo liable to cause serious damage if they should come accidentally into hard contact with -tlze part of the casing or cylinder that surrounds them. Also, owing to this high peripheral velocity, the unavoidable presence of water in the packing-grooves causes very considerable friction and loss of power.

Now thisy invention has for object to obi `viate the disadvantages above described attending the use of balance-pistons of large diameters. For this purpose in' order to counterbalance the end thrust upon the largest step of the turbine-spindle or drum and theblades carried thereon a separate piston is employed, situated, preferably, in a space vor chamber at the exhaust end of thev turbine and having an effective end or transverse area substantially less than the annular varea of the large-piston heretofore usually employed for the purpose. This separate piston is therefore of much smaller diameter than the one it replaces. In fact, it is usually, smaller than the large end of the s indle, and consequently can be formed at t e exhaust end of the spindle adjacent to a portion thereof of reduced diameter without interfering,

with the passage of steam from the blades to the exhaust-chamber, which in'one arrangement surrounds the space or chamber containing the ysaid separate balance-piston,

Steam is admitted to the back of this piston between it and the outer end wall of its space or chamber by means of a'passage preferably provided within the spindle itself and extending from the steam-space between the last two sets of rotary blades, the free escape of such steam to the exhaust being prevented by a lab'rinthpacking device of the kind hereinbe ore referred to located between the periphery of the balance-piston and the walll of the adjacent portion of the exhaust-chamber when this chamber surrounds that containing the se arate balance-piston. The outer end of t e last balance-piston at the lnlet end of the turbine is connected with the exhaust, and the labyrinth-packing device therefor may be made of such additional lengthl as is necessar to reduce the leakage at this point to the esired extent.

' is illustrated by the accompanying drawings,

wherein-Q y Figures 1 and 2 represent, partly'in longitudinal section and partly in velevation with the rings of blades removed, two exam )les of turbines constructed according to this invention.

In the example shown in Fi 1 thc turbinespindle comprises three blade steps (1 b, and

0. To two of'these-namely, a and b-there correspond balance-pistons d and e, provided with labyrinth-packing devices d and e of the ordinary type, the pistons d and e being arranged on the opposite side of the steam-inlet f of the turbine-casing g to the bladedsteps a and?) and the adjacent end surfaces of the bladed step a and the piston d bein in direct communication, while Vthe end sur ace of the bladed step b, facing the effective side of pistone, is in communication through a pipe or passage e2 with vthis effl ctive sidne of piston e. To balance the end thruston the inlet end of the bladed step @instead of a balance-piston arranged as an annular step of larger diameter than the piston e and at the farther side thereof from the bladed steps'a, b, and c, there is employed a piston 7L, separate from the piston e and placed in the ex-` ample now being described in a space or chamber t at the exhaust `end of the bladed step c, that part of the space or chamber 't that is farthest from the step c being in communication with the steam-space between f the spinthe last two bladed steps b and c o dle through symmetrically-arranged assages.

7c, extending through the spindle an the piston, so that the rear end surface of the latter, which is thev effective side, is subject to the pressure of the steam in the said space Also the front end of the space or chamber m, containing thebalanceiston e at the op osite side of the steam-i et f, instead of being in communication with the steam-space y' between the two last bladed steps of the spindle, as heretofore, is in direct communication by a pipe n with the exhaust-chamber o. The ineffective side of the piston e therefore conimunicates .with theexhaust. The space or chamber L containin the balanceiston h is separated by an ordinary labyrint i-packing device 7L between the piston h and the inwardly-projecting or rentrant Wall o of the exhaust-'chamber o, which surrounds the said s ace or chamber i. By this arrangement.

t e end thrust due to a iven difference of pressure at the two ends o one bladed stepnamely, c'-.of the spindle is balanced by adding this difference of pressure to that' acting upon the balanee-piston-namely, e-which tween the balances the difference of pressure l name y,

two ends of the previous b adedf'ste b-and by applying the same pressuregto a separate or additional pistonnamely, 7L. In this way the `lialance-pistoih c balances. notl only the end thrust on its own fference of' 'roo bladed step-b of the spindle, but also p'art of theendthrust on the bladed step c, sothat theseiparate piston t'has only tobalancethe i.

i remaining portion ofsuchen'd thrust. As a result of this arran h forthe 4largest b adedstep c can be made'i with an effective area substantially.less-than the effectiveannular area of thebalance-.pis-

" ton that Wouldin the ordinary yWa be prof vided at the o made Vso much smaller .infdiameterthan the step c'thatit will not .interfere with the pas.-

sage vo 'steam-from 4the blades of that' step.

need not be. eater power,

` such pistonv -is made of greater'len th thanV therequired retar ation of' l `vbination of a bladed lcasingfa bladed spindle.

bladed. steps b and c' of thespindle.' *The-rear side-'of the .chamberm'of the-piston. e' in the exhaust end of the turbine may 'ranged at the inlet end ther'eor",'asv sho/Wn in To compensate for the absence ofa bal'- anc'e-piston at theouter end of the balance-v piston ,the l'abyrinthepacking device e for usual tosecure `The piston h instead of rbeing arraned at F 2. In this' case', ythe balance-piston 7l for the larger step of the s indle is arranged in :a

space or chambent', t at'is .separated from; t'

e space or chamber m' containing .the balance-'piston d. by a xed Wall .s with labyrinthe: packing device t. The rear side ofthe piston is'in communicationl througlifa pipek. with the steam-'space j `between .the last' two commnication'th'rough the assagee With the steam-space --betweenf t V'e two fbladed steps a and 'b ofthe spindle. The front ends of the tWo chambers t and m arefin"communi-y cationwith the exhaustecharnber o through a pipe ncommon to them., This arr ngement .acts in the same Way as thatshown 1n Fig. 41

the end-thrust on the largest bladedfste'p vc'oi" the spindle being' balanced partly by the pis' ton e andpartly'by theipiston h,1which is se.

cured upon the reducedforward end p' ofthe turbine-spindle and is for a'given size of tur- .pluralitypfsteps a ance-pistonsthereforr,a separate chamber in'4 a., separate exhaust# communicationjfor said separate chamber, and aco'mmunication for i said separatey chambeifito the workinggpasf,

sage of the turbineintermediate theinlet and bine made of much smaller diameter than the casing, abladed-s therein comprisingl a qual.- plurality of bale the casing for one ofs'aid balancepistons,

lexhaust thereof.

ement the'balance-piston'- Y2. y ln av longitudinal-dmv'turbine, 'abladlcdl equal plurality of balance-pistons therefor, a chamberfor one of the pistons,'a separate stepped chamber. for the remaining pistons,

spindle. comprising a plurality of steps, an i and ducts connecting the chambers to vari-A bination of av laded casing, a' bladed spindle therein, separatechambers in the casing, bal'- ance-pistons in lthe chambers, andducts for i connecting the vchambers to various points valong the workin passage of the turbine.

4. Inalon itu inaleiloW turbine.,the combination of a laded casing', 'a bladedspindle cluding immediately separateducts connecting the chambers to the exhaust. .L

fao

therein, separate'charnbers in thecasing, bal-1 ance-pistons in' the .chambers-.separate ducts for connecting the chambers to vvarious points ialong. the Working' passage ofthe turbine i.n-v 8 5 5.-- im longitudinalflow turbine, weidse-14:1'

to different pressures for balancing endvvise pistons having the-inner'fxnargin'of its 'eiiectl' 1ve surface ofless diameter than theouter bination of. aj bladed casin a bladed spindle plurality `.of pistonsfor ba ancing endwisethrust, vone of the pistons having itseifective surface nearer tliej axis "than its c01.1 .esp0nd ing step-surface'.

7. In-a lo'ngitudinal-lovxT turbine, the com bination of a bladed casing, abladed spindle therein comprising xa' plurality of steps, an

equal plurality of balance-pistons',therefor, a'.

chamber forone of the'pisto'ns', a separate' stepped chamber for the remainingfpistons,

ducts connecting thechan'ibe'rs to various oints along the Working. passage Vof. thejturine, and the-solitary piston having the inner 'margin Iof its-effective 'surface'of less' diamevter than .the outer'margin ofthe electivesurface of the largest of the remainingpistons. ordinary balance-piston, which' itA replaces. The detailsof'constructionrnaybe altered`N Without. depart-ing'frm the' essential-'features 1,8. In ir longitudinal-'flow turbine, the com bination of abladed casing', a bladed spindle,- thereiricomprising a plurality of ste' s, a 'b alizo i a balance-piston having vthe inner margmof its effective surface oflessdiameter than the' outer marginfof the egective^,surface ofthe` i former balance-piston and subject onone face' to admission-pressure'ior theblades of a" larger step.

therein, a'chainber in :the casing and. removed vbi'natio'n of. 'a bladed casing, fa 4bladed spindle ton therein, a chamber in the exhaust end of the casing, 'a secondbalance-piston therein, and means for subjecting the second piston to a pressure of steam equal to that at a point intermediate the inlet and exhaust of the turbine.

10. In a longitudinal-flow turbine, the comi bination of a bladed casing, a bladed spindle therein comprising a plurality of steps, an equal j lurality of corresponding balance-pistons t erefor, a chamber in the exhaustend of the casing for one of the pistons, means for subjecting said piston to admission-pressure for the blades of the largest step, a composite chamber in the head end of thecasing for the remaining pistons, and means for subjecting said pistons to admission-pressures respectively for the blades of the remaining steps.

11. Ina longitudinal-flow turbine, the combination of a bladed casing, a bladed spindle therein comprising a plurality of steps, an

' equal plurality of corresponding balance-pis- ,Sov

tons therefor, a chamber in the exhaust end 'of the casing for one of the pistons, ducts in the spindle connecting said chamber and the inlet of the largest step, a composite chamber in the head end of the casinglfor the remaining pistons, and means for subjecting said istons to admission-pressures respectively o r the blades of the remaining steps.

12. In a longitudinal-How turbine, the combination of a bladed casing, a bladed spindle therein comprising Aa plurality of" steps, lan -equal plurality of corresponding balance-pistons t erefor, a chamber in the exhaust end of the casing for one of the pis-tons, said cham-, ber surrounded by the exhaust-space -of the turbine, means for subjecting said piston to admission-pressurev for the blades of the largest step, a composite chamber in the head en of the casing for the remaining pistons,

and means for subjecting said pistons to admission-pressuresy respectively for the blades ofthe remaining steps.

13. In alongitudinal-flow,turbine, the combination of a bladed casing, a bladed spindle therein comprising Aa plurality of steps, an-

equal lurahty of ,corresponding balance-pistons t erefor, a chamber in the exhaust end ofthe casing for one of' the istons, means for subjecting said/piston to a mission-pressure i vfor the blades of the'largest step,l a composite lchamber in the headend ofthe casing for Ithjremaining pistons, means for subjecting said pistons to admission-pressures respectively or the blades ofthe remaining steps, and means for .subjecting the unbalanced opposite sides of the pistons to exhaust-pres- 14. Inalon bination ofa laded casing, a bladed spindle therein comprising a `plurality of steps, an

' equal lurality of corresponding balance-pistons t erefor, a chamber'inA the exhaust end of the casing vfor one of the pistons, said 4 itudinaI-low turbine the comof the turbine, ducts in the spindle connecting said chamber and the inlet of the largest step, a com losite chamber in the head end of the casing or the remaining pistons, means for ,subjecting said pistons to admission' pressures respectively for the blades of the remainln steps, an means for subjecting the unba anced opposite. sides ofthe pistonsvl to Aexhaust-pressure.

16. In a longitudinal-flow turbine, the combination of a bladed casing, a bladed spindle -therein comprising a plurality of steps, an equal lurality of corresponding balance-piston t erefor, a chamber inthe exhaust end of t e casing for one of the pistons, said chamber surrounded by theexhaust space of the turbine, ducts in the spindle connecting said chamber and the inlet of the largeststep, a composite chamber in the head end of the casing for the remaining istons, and means for subjecting the unba anced opposite sides ofthe pistons to exhaust-pressure.

, `17. Ina lon itudinal-flow turbine, the combination of aladed casing,a bladed spindle therein comprising a plurality of steps, a balance-piston subject on 'one face to admission-pressure for the blades of a smaller step, and a balanceiston at the exhaust end of a larger step an having the inner margin of its efectivesurface of.,less diameter than the outer margin of the effective surface of the former balance-piston and subject on one face to admission-pressure for the blades of said larger step.

y18. A longitudinal-flow turbine, alcasing therefor having chambers, and pressure balance-pistons in said chambers, the turbineexhaust havin communication with the ineective side o a lurality of pistons.

19. A rotor, baiance-piston thereon, a stator, and separate chambers vin the stator for the pistons, a plurality of the chambers having communication with the exhaust.'

IOO

IIS

20, A turbine spindle, a casing therefor having. huid-chambers, a pressure lbalancepiston in one of the chambers, and means of communication leadin through the spindle vfrom one of the other iambers to the effective side of the piston.

21. A turbine having an exhaust-chamber lwith staltiohary rentrant inner Wallsand 'a pressure balance-piston peri herally coacting With the rentrant inner Wa s;

i 22 A. stepped turbine,- spindley havin "aw pressure balance-piston of less diameter t an the-lovwpressure portioncf the spindle,- an.

' exhausig-chamber with stationary rentrant A inner .W'al'ls said iston' coacting'with 'they re1- balance-pist0ns onthe rotorlocated in separate chambers, means for placing the eiectof a piston being opento'exhaust. 1 l

*124. In a turbine, a-easing, a-rotor coacting with the casing to Aforni a Working'passa e,

.balance-pistons-on the rotorA nearits en s,

means for .placing the effective sides ofthe pistons 'in communlcatlonwith I the Working passage vat different points;Y and -means Vfor placing the lneiecti've .side ofa piston in coinmunication With the exhaust."

25 Ina turbine, acasing, airotoroacting with the ca slng .to form, a- Working passage,

ive sides of the pistons in communication"- 'With the Working passage at different points, and vmeans.forplacing the ineffective side of a 'piston in 'communication With the exhaust. '26, In a turbine, the combination of a bladedcasing having an inlet formotive Huid and an'outlet forfexhaust, a spindle located Within said casing and comprising bladeg1 an- 'lnular steps increasing in dlameter from said inlet toward saidoutlet, and a balance-pisltonffor each-step', the balance-piston for the step of largest diameter being located in a chamber-that is `separatefrom that contain- 4 ing the other balancepist'on' and has a separate exhaust-and is in communication W1tl1 Signed at Newcastle u on- Tyne, in the county of Northumbrlan Ju1y, 1904.

HUGH FULLAGAR. I

y Witnesses:

CHARLES' EDGAR. GRoUNsELL, JAMES .Roemenen this Z 1st day of Athe interior of the Casing at a part thereof between its saidin'let -and outlet;

Images