US879748A

US879748A - Elastic-fluid turbine.

Info

Publication number: US879748A
Application number: US22100804A
Authority: US
Inventors: Charles G Curtis
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1904-08-17
Filing date: 1904-08-17
Publication date: 1908-02-18
Anticipated expiration: 1925-02-18

Description

No. 879,748. PATBN'I'ED FEB. 18, 1908. C. G. CURTIS. ELASTIG FLUID TURBINB. A PPLIoATIoN FILED AUG. 17. 1904.

2 SHEETS-SHEET 1.

Witnesses Attorneys.

4PATENTE)122:13.1s, 150s. o. G. CURTIS. 1

v EL'ASTIG FLUID TURBINE. APPLIUATION FILED AUG. 1'7, -19o 4.

2 sums-SHEET 2.

Witnsses; n i n Inven or UNITE fg .arras retratar ernten OHARLES'G. CURTIS, OF 1TEW YORK, Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO GENERAL ELECTRIC COMPANY, A CORPORATIOhv OF NEW YORK. i

ELASTIC-E`LUID TRBINE.

Specicatpn of Letters Patent.

rammed ret. is, reos.

Application filed August l'li 1904. Serial No. 221.008.

State of New York, have invented a certainneW and useful Improvement in Elastic- Fluid Turbines, of which the Jfollowing is a specification.

The object I have in view is to produce an 'elastic fluid turbine'especially designed as a marine engine of high power, but oapableof use for other purposes, to be as simple as possible in construction and occupy as little space as ossible, and at the same time have a high e ciency and a relatively louT speed. Another object is to .reduce the number of diaphragms separating the stages. Owing to the fact that" the high pressure stages use nozzles andv iixed intermediates which eX-v and intermediates can be multiplied greatly exceeding those in the high pressure stages,

provided the expansion of the steam is properly taken care of. t. e., provided the nozzle end pressurr` be suiiiciently high. and suit-` able expansion be provided passing through the buckets.

Another object of the invention is to redum` or partially relieve the end pressure on the turbine Wheels `which necessarily results Wheels in such'shell.

from the conditions existing in. the turbine 5 of the annular and pressure character.

In carrying out my invention I construct a turbine having a number of erqhiansion'l stages in accordance with the principle set forth in my Patent No. 565,969, and I employ for the high pressure stages a .iet turbine, preferably compounded in each stage While for the low pressure stages, I employ the annular form of turbine constructed in one or more stages and highly conipounfgled in each stage.

The high pressure stages are constructed in accordance with the principle of my jet 1 l i l i l l accordance with the turbine which has been made familiar by my patents. There. may be two or more of these high pressure stages, preferably as many as four, each provided with a sectional nozzle made in accordance with my Patent No. 700,744. The nozzle of the first stage is preferably an expansion nozzle, While the nozzles of the succeeding high pressure stages are preferably Without expansion. The iirst stage nozzle is not necessarily an expansion nozzle, as the difference in velocity between the nozzles is relative, therefore all of the high pressure stage nozzles can be non-expansion nozzles, 'the succeeding high pressure stage nozzles beyond the nrst passing less than their capacity. Each of these high pressure stages has preferably two or more sets of moving buckets, preferably four sets of moving buckets and three sets of intermediate buckets being used for each stage. The circumferential area occupied by the nozzles and intermediates is progressively greater throughout these high pressure stages and the Working passage through the moving aml'statimiary buckets of each stage is ere panded in the direction of How ol' the elastic liuid. T he several high pressure stages are inclosed in a common shell, which is divided into separate compartments, in which progressively lower pressures are muintaiiwd, by diaphragms which carry the sectional nozzles. The high pressure jet stages will be utilized to reduce the pressure of the elastic fluid 4down to a definite point which 1u ay be, for illustration, atmospheric pressure.

The Wheels of the high pressure stages are mounted upon a common shaft, end this shaft also 'extends through the shell of the low pressure stage or stages and carries the The shaft is preferably supportedby end bearings-as Well as by an intermediate bearing between the shells of the high and low pressure stages. The low pressure stages, which may be two or more in number, lare mounted in a common shell, and consist of Wheels carrying each a relatively large number of annular rows of mov ing buckets, there preferably as many eight of these rows in each stage, which co iezate with intermediate buclkets carried by'the shell and extending completely around the circumference. Each of the low pressure is provided with a complete annular sect le in stationary lli) N o. 700,744, but without expansion between the throats of the nozzle sections and their delivery ends. The moving and stationary buckets are made progressively.-(5f-greater height so as to give the proper' expansion of the Working passage through them. The shell containing the low pressure stages is divided into-separate compartments corre- Y v1e s onding with the number of stages, preferably by means of partitions or diaphragme 'which extendinwardly from the shell only part way to the shaft. These relatively vnarrow annular diaphragms carry at their inner openings, rings which make a close fit with drums carried bythe wheels of the adjoining stages. i x V 'v The movingbuckets f the low pressure stages may be made without bands or coverings on their outer ends and move in close contact with finished surfaces upon the shell, I

and the rows of' stationary intermediate buckets may also be madewithout covers on their inner ends, these bucketsworking close to finished annular surfaces on the wheels between the rows of 'moving buckets. Both the moving and stationary buckets of these lowpressurestages may, however, be provided with bands or covers.

To revent as far as possible the escape of the e astic fluid at the clearance between the nozzle end of the first low pressurestage and the first set o fl moving buckets iny that stage inwardly into the space around'the shaft and between the head of the shell and the first Wheel, I

provide'lateral projections, lips or ring segments in accordance with the construction disclosed in my Patent No. 726,032, which project laterally from the nozzle end over the inner surface of the wheel'so as to transfer the clearances from the radial to the cylin-I drical surfaces. These lips extend entirely aroundv the circumferencenand are preferably made .adjustable lradially so as to reduce to the mmimum the clearance betweenthe lips and the wheel rim, the latter being finished with a .true circular surface over which the lipsJproject. These laterally projecting lips or ring segments not only serve to reduce thev leakage inwardly from the'clearance between the nozzle and the first set of moving buckets, and tend to'restrict the leakage to. that Which takes lace around the outer ends of the moving uckets Where the elastic fluid .successive sets buckets.

A.sures at .the nozzle ends of the low; pressure annularl stages.

elastic fluid is delivered to the nozzleof the vthe second low pressure As for illustration, if thek .buckets of each stage will be sufiiciently expanded to cause the desired gradual decline 1n pressure and theresultant roduction of velocity. The elect at full oads will be therefore to cause the elastic fiuid to act by 8'0- 'im ulse and reaction in the low'pressure annu ar stages. .At less than full loads, the pressure difference between. the nozzle end and the stage lin any given stage will be less than at full loads, and the fluid will therefore .8 5 operate more by impulse than by reaction, vthe reactive effect decreasing as the load de-` creases, but not necessarily in the same proportion. The inward leakage atthe end of the nozzle for the first low pressure stage will on account of the relativelyhigh pressure at the nezzle end, produce considerable pressure upon. the-wheel o 'the first low pressure stage exerting a thrust towards the exhaust end of the machine. I propose to relieve this pressure by providing a channel for the flow of the elastic fluid from the space be tween the head of the shell and the `wheel of the first low pressure stage into the exhaust space of the first -low pressurel stage. This channel may be a pipe connecting 4the head of the'shell and extending outwardly around the shell to a connection through its side with l the exhaust chamber of the first low pressure stage and in this pipe may be located a relief valve set for al definite pressure so thatthe pressurev upon the Wheel of the rst low pressure stage may be-relieved tovany desired extent; or, if desired, openings of suitable size` to give the proper relief ofpressure may ex- 1-'10 tend directly'through the webs of the Wheel vconnecting the space between theshell head and the Wheel with the exhaust chamber of the first low pressure stage. The elastic fluid which is thus deliveredto the exhaust chamberof thefirst stage without' passing lthrough the moving and stationary buckets of that stage mingles With-'the elastic uid'" delivered bythe buckets of the first low resj sure stage and is delivered by the nozz e of stage to the buckets` i of thatstager' The pressure which is produced on the wheel of the Second-low pressure stage by the inward'leaka' e at the noz zle end of that `stage' is not s to make necessary the relief of the pressure' at that point, although, if desired, this canl be done, in a similar way.

.In the drawings', Figure 1 isl a lo itudinal sectie illustrating aturbine embo ying my. 139'V ciently high. I 4

ISU

The high and low pressure stages are individed by diaphragme l into separate coni- V rl`he elastic il uid delivered by the secoi'nl low arenas present invention. Fig'. 2 is a section on a larger scale through 4one side of the first low l pressure stage. iFig. 3 is an elevation and half section. of the low pressure stages showing modification of the manner' of relieving the pressure on the wheel ot' the first lori'v pressure stage; and Fig. 4 is a section through the moving' and stationary buckets ol one of l the low pressure stages illustrating the enr ployinent of covers. for the ends of such buckets- A, B, C, D, are the high pressurestages, and E and l?, are the low pressure stages.

closed in shells G, and ll. The shaft l, eX- tends through both shells, and vcarries the Wheels ol the several stages'. yThis shaft is. supported by outside bearings J, K, and by an intermediate bearing L. The shell G is partrnents. These diaphragins and 'the head ol' the shell carry the nozzles 2. The Wheel-s '3 of the high pressure stages carry two or more annular set-s, preferably tour, of moving' buckets el between which in the line ot' flow opposite vthe nozzles arethe segmental sets of stationary intermediate buckets 5,. supported by the shell. rl`he nozzles 2 and the stationarly buckets 5 occupy progressively an increasing portion of tee circui'nle'rence as illus trated. T he shell H- of the low pressure stages is d-ividedinto two'conipartinents by a 'narrow diaphragm 6 extending from the shell-to a druin 7 carried by the 'Wheels 8 of tne adjoining stages. The diaphragm 6 carries rings l) on its inner annular edge so as to give an extended surface which is brought as close as possible to the drum 7 to reducev leakage-f.; The Wheels 8 of the low pressure stages carry annular sets of moving buckets .l which cooperate with intermediate ts of stationary buckets ll carried by the shell'.v These moving and stationary buckets are. ireferably without covers on their ends as illustrated in F 2. Escl-rot' the low res sure stagesis provided with a relatively arge number of moving buckets preferably as many as eight rows of such buckets being employedl in each stage. The nozzles 12 of the low pressure stages are sectional nozzles which extend around the entire circunilier ence and deliver the elastic fluid to the entire set ol' moving buckets opposite thein. The nozzle for thesecond low pressure is carried by the diaphragm 6 while the nozzle for the iirst louv pressure stage is carried by the head of the shell il. The exhaust ol' the last high pressure stage l) is connected with tl' nozzle ol the firstlow pressure stage by a channel M, which widens out into a coniplete en'nulus. where it joins the nozzle pressure stage. l passes ont al. the er; 'ianst ll. The end oll the Anozzle l2 ol' the in t low pressure stage carries the plate le which is held 'Fig 3.

the moving and stationary buckets of the 85 by bolts ll and made adjustable by a cani 16 as illustrated in my Patent No. 726,032. A nuinber of plates 1 4 will be employed to permit of `ad}ustn1ent. These plates overlap the clearance between the nozzle end and the l wheel so als to reduce the lexika ze inwardly at the clearance between the nozzle end and the l'lrst set of inov-ing buckets. The pipe 17 provided with a relief valve 1S connects the .head of the shell H with-the chamber into 75 which the elastic fluid is delivered by the lirst low pressure rstage E and from which it is taken by the nozzle l2 of the second low pressure stage l?. instead of employing the pipe l? extending'around the shell, for the 5,)

reliel' of the pressure on the Wheel of the iirst loW pressure stage E, channels lll may be formed directly in the Wheel as illustrated in `While I `prefer to leave the ends of low pressure stages uncovered,these bucketsinay be provided with coversas illusv tratedlullig; 4.

What l claini is l. Iii a stage expansion elastic iiuid turbine, the combination of' high pressure jet stages and low pressure annular stages, opv erating at lour velocityand high pressure at the nozzle end, substantially as set forth.

2. In a stage expansion elastic lluid tur-` bine, the combination ofv two or'inore high pressure stages having moving buckets and lprovided with nozzles and stationary intermediate bucketsoccupying a part only` of the circumference, with two or more louY pressure annular stageseach having a greater number of annular buckets than the high pressure stages, and provided with nozzles and stationary intermediate buckets occupying the entire circumference, substantially as set forth. l

3. ln a stage expansion elastic fluid turbine, the combination of tWo or more high pressure jet'stages having each two or vmore sets of moving buckets and provided' with 110 nozzles and stationary intermediate buckets occupying a part only of the circumference, with two or more low pressure 'annular stages each having a greater number of annular' buckets than the high pressure stages and 1,15

provided with nozzles and stationary intermediate buckets 'occupying the entire circumference, substantially as set forth.

4. In an elastic 'liuid turbine, the combina tion `with an annular nozzle and an annulango set of moving bucketsto which the nozzle delivers the elastic fluid, of a lateral projecd tion extending across the inner clearance between the nozzle end and the inoving buck-r ets and ,traiislerring the clearance from rav 1235 dial to cylindrical surfaces, substantially as set forth..

5. An elastic fluid-turbine comprising a plurality .of stage compartments Working at.

different pressures, a nozzle for a high pressure stage which converts the available pressure thereof into velocity, and whose end pressure is substantially the saine asthat of the exhaust from the stage compartment, lwheel buckets coperating therewith to abstract the velocity, an annular nozzle fora low pressure stage which partially converts` the available pressure of the stage into velocity and has an endpressure considerablyin excess of that of the exhaust from the stage compartment, a wheel having rows of buckets, all of which are active, and a complete annular row of intermediate buckets, the said rows of intermediate and wheel buckets alternately converting the pressure of locity of theiluid received from'the nozzle,I

- a wheel for the buckets' which is balanced as y to Huid pressures, an annular low pressure finto velocity,

nozzle which converts only a certain percentage dffthe available stage ressure into velocity, wheel and interme iate vbuckets arranged in rows, all of which are active and cooperate with the nozzle to abstract the velocity from the fluid,` due to the nozzle and also to alternatel create velocity and abstract it'as the fliiid'flows toward the exvhaust.-

7. An elastic fluidl turbine comprising a plurality of vstages workinor at successively decreaslng pressures, nozzlesA 'for `the'` high pressure stages that convert theavailable pressure ofveachof the high pressure stages fluid withoutl imparting velocity thereto, annular -nozzles' for the. low pressure" stages whichvconyert only alimitedl portion of the available ressure of each stage into velocity, n

bination with two annular stages each provided with a nunlberof sets of movingbuckwheel an 'intermediate buckets arranged to abstract the velocity of the fluid as received from the annular nozzles and also to create` velocity and abstract it by successive steps -asthe fluid flows through the stage, wheels for the buckets, and supports for the'low pressure intermediate' buckets, the wheels and supports 4cooperating to prevent the fiuid from "flowing from a .point of high to `a .point of low pressure without passing .throu h the bucket spaces.

5,5. n elastic fluid turbine comprisinga chsing, high and lowpressure diaphragrns for dlvidin the casing linto stage compartments, buc ret Wheels for the high pressure stagevcompartments, bucket wheels for the low pressure stage compartments having a Wheel .buckets cooperating 'therewith which abstract' the energyl offthe .greater number of rows of buckets than those sure stages which convert a portion on y of the 4available stage pressure into velocity, and intermediate low pressure buckets, the

wheel and intermediate buckets of the low' pressure stages being constructed and arranged to work by impact of the motive fluid under certain load conditions and t`o work by impact -and reaction under other load conditions. v

9. An elasticA fluid turbine comprising a plurality of high pressure stages working on l the partial flow plan, low pressure stages working on the total How plan, nozzles for the high pressure stages, rows of wheel buckets therefor, nozzles for the low pressure stages, and rows of wheel buckets therefor which alternately convert the pressure of the fluid into velocity and extract it, the number of rows of wheel buokets'being greater in the low pressure stages than in the high.

10.A In an elastic fluid turbine, the c'orn-4 bination with a turbine wheel 'and a ,nozzle delivering the elastic Huid to the wheel throughout its entire circumference, of a channel connecting the wheel chamber o n\ opposite sides of the wheel so as to relieve the pressure produced upon the Wheel bythe inward leakage at the nozzle end, 4andarelief valve in said .channel to maintain adefinite difference in pressure between the opposite sidesgof the wheel, substantially as set forth.

11. In an elastic fluid turbine, the combination with an inclosed shell, of a turbine lwheel therein and a nozzlev delivering the' 'elastic Huid tothe entire circumference of the wheel, of a lateral projection on the shelll across the inner clearance between t'he nozzle end and the wheel, and a channel connect- `ing the chambers on opposite sides of' the wheel, substantially as set forth. v

12. In an elastic fluid turbine',` the comets and with a nozzle delivering the elastic fluid throughout the entire circumferencaof means for reducing tlie inward leakage at the nozzle end of the first stage, `and means for discharging the pressure on the first wheel produced by vinward leakage at the nozzle 'end into the nozzle lchamber ofthe second stage, substantially as set forth.

This specification signed 'and witnessed this tenth day of August, 1904.

CHARLES G. CURTIS.

Witnesses:

` JNo.vRoBT TAYLOR,

LEONARD H. DYER.,