US1349878A - Extraction and mixed-pressure turbine - Google Patents

Description

J. H. DURAN. EXTHACTION AND MIXED PRESSURE TURBNE. APmlcAuoNFILEDJUNE14,191S.

lrwvearwtor: JOHN FLDcfraw,

His ofttorneg.

' chests.

"UNITED STATES PATENT OFFICE.

JOHN H. DORAN, OF SOHENEOTADY, NEW YORK, `AssIcTNOR 'ro GENERAL ELECTRIC `COMPANY, A CORPORATION or NEWKYORK.

EXTRAOTION n AND MIXEDLPRESSURE TURLBINE.

To all whom it may concern: v

lBe it known that I, JOHN H. DORAN, a citizen of the United States, residing .at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements lin .Extraction and Mixed-Pressure Turbines, of which the following is a specification.

The present 'invention relates generally to elastic fluid turbines of the type having,

a radial llow blade system comprising two bladesv carrying elements or rotors 'arranged to rotate vin opposite directions, each ele ment delivering power to a'shaft which, for example, may be connected tothe rotor of an electric generator or other power consuming agent,

' The object .of my invention is to provide an improved arrangement of partswhereby steam atan intermediate pressure can -be extracted from the' blade system 'after it has performed workl lin the turbine or whereby .intermediate or low pressure steam can be admitted tothe turbine to perform work therein in the lowpressure stages or portion. d

For -a consideration of what I believe to be novel and my. invention, attention is -directed to' the accompanying description and claims vappended thereto.

I n the drawing, Figure 1 isa partial sec- -tional view. of a. turbine having oppositely,

rotatin bla'de systems; Fig. 2"is a detail vie'wo a part ofthe steam chest taken on line 2--2of Fig. 1; Fig. 3 is a. detail view of a portion of the auxiliary steam chest, and Fig. LLis a sectional view of the steam 5 indicates the innerportion of one' of the rotors which is'mounted on a stubv shaft, A6, the latter in turn being connected to one of the main shafts (not shown).l To the said inner-portion is 'connected an interme;

diate rotor portion 7, by an expansion ring 8.A 9 indicates the outer rotor portion which is connected to the intermediate portion by the expansion ring'10. The right hand side of the machine is 'a duplicate of the left and for that reason can be readily understood .without further illustration.

,.,To the inner, intermediateand outer portions `of the rotor are connected concentric rir'lgsy or blades 11, each of Awhich is secured Specification of Letters Patent. Patented Alig'. 17,1920. Application mea June 14,

isi-s. serial No. 239,942.

to the rotor by an expansion ring 12 which is similar to but of smaller size than the eX pansion rings which conne'ctithe parts of the rotor. As will be seen these expansion rings are provided with enlarged rounded rings carried thereby. The purpose of theseeXpansion rings is to divide the partsinto regions or Zones of different temperatures,

the transfer of heat through saldrings being relatively slow and restricted.r Further more, these rings permit the-parts to ex# pand and contract at different rates without causing the stresses in one part being transmitted to the other parts. They also serve as means to prevent the escape of steam between dilerent parts .as will be evident upon inspection.

Located between the 44.blade ringsA 11., are other and concentric blade yrings 14: whichy are supported in the same manner bythe right hand rotor portions. The `outer portion i; ofthe rotor is also'provided 'with radially extending blades or buckets '15: through which low pressure steam flows in anaxial direction. 16 indicates stationary vnozzles or fluid discharging deyices which receive steam from the radial flow blade system ol3 the machine, c'. e.,-the rings of blades 1l and '14, and deliver it to the axialtlow portion,

only one of which is illustratedl Thenozl zles are supported by rings 17 and 18 which in turn are supported by an annular member 19 and diagonal braces 20. The member is supported by an annular rib 21 on the inside of the inclosing casing22 and also by one or more pins 23 which hold-it against` i 24 and 25, of which the disk 24, rotates while the disk 25- is stationary. Tov reduce the leakage between .th'evpdisks'the opposed faces thereof are provided with:fa-labyrinthpacking 26 of any suitable `constructiomdn this casealt'ernate projectionsb andfjgrooves.

Through this packing'Y live steam flows f radi,v

ally rom the center toward'. the outside and as the pressure therein from point to point. ,substantially corresponds to that' ofthe the inside of the casing of the turbine in any suitable manner. Between "the plate and chest is an expansion ring 32 acting as the lvother expansion ringsdo to compensate for unequal stresses due to .temperature changes. The thrust' and balancing disk A25 is carried by the stationary steam chest,

said parts being unitedby two concen-v trica'lly arranged expansion .rings 33 which rings in addition to forming a supporting means also forni steam tight joints to prevent leakage' of steamfrom the chest.

vSteam from theunainI supplyv chamber 28 flows to the inner blades nearv the axis of the machine in the manner-indicated by the arrows 34.' Steam from the overload chamber 30 flows through a 'series ot' uniformly spaced'axia'lly extending holes or passages. 35,36, and 37 in the thrust and balancing disks and inner "portion 5 vCif-the rotor to an intermediate pressure region of the blade system.

Referring n ow to the arrangement of parts whereby steam may beextracted from the turbine for heating purposes, r whereby low pressure rsteam may be admitted to perform work inthe turbine, 40 'indicates an auxiliary steam chest lwhich may be supported in any suitable manner, preferably by the/main chest. -It may be made integraltherewith or it maybe bolted thereto, as shown in the drawing. The arrangement will be determined principally by. the construction of the main steam chest. If the latter' is a forging the auxiliary chest will beA made separate; if a casting, the vtwo chests maybe made in one piece. yMounted or formed on the main chest is apshoulder 4'1 to which the auxiliary c hest is secured b ybolts 42, and in said shoulder are holes or passages V43 registering with similar holes or passages in the auxiliary chest and through which steam may enter or leave the turbine. 'To' the shoulder 41 is `attached by an expansion ring 44 an annulus 45 forming part of an axial packing. rounding this .annulus and forming the other part of the packing is a second annulus 46 which is secured to theintermediate part of the rotor, by Aan expansion ring 47. The opposed faces of the two parts are provided with 'alternate grooves Surand projections or yother means-.tored'uce .and from the space between the thrust and balancing disks 24 and 25.* Steam'vfrom an intermediatepressure region in the rotor flows laterally through the axial holes or passages 49 in the yintermediate portion 7 ot the rotor as indicated by the small 'arrows. The passages 49 which open laterally from the main steam path should be numerous so as to equalize the flow ofsteam from the region' ot intermediate pressure' between the parts of the blade-system, The passages are shown 'extending .axially since this is the simplest construction but they may be formed otherwise il desired. 'lf flow pressure steam is supplied from an external source the iiow of steam is'of course in th'e opposite direction but through the same passages In order to convey steam from or to the turbine the auxiliary steam chest is provided with an extension lon its upper side in'vvhichvis seated the pipe' 50, the latter extendingthrough the wall of the turbine casing in any appropriate manner. As shown, two auxiliary steam chests are provided for each side of the machine, there being in all four pipes 50, of which two are shown.

Then operating as an extraction machine under normal' load conditions, vsteam will issue from the numerous passages 49 at about 15 lbs. gage, pressure, for example,

.into the annular equalizing chamber 5l from -which it flows over the periphery 'of thethrust and balancing disks into the annular chamber 52 and thence through Athe passages 43 into the auxiliary chests'40 and outlet 'pipes 50. The pressure ofthe steam leaving the packing space between the disks would under the conditions described also be about 15 lbs. gage, and steam from both in all-cases, howevergsteam admitted to or.

yis not limited tri-having oppositely r or admitting it to both sides of the rotor in the same region, the axial balance of the rotor is not disturbed, a feature of the utmost importance in a turbine of this type where the parts of tlieblade system revolve ances are small. l

As previously stated there are two packings, one a radial. iow packing and the other an axialjflow packing, lThis arrangement is made necessarybythe `fact thatsufiicient balancing pressure cannot be had if the steam isA allowed to expand to the eX- haust pressure of the turbine at the outside diameter of the balancing .'disks. Siiliicient balancing pressure could bev obtained if the diameter ef -the radial packing could be made greater but this is impossible because they bore of the surrounding wheel cannot be enlarged on account of the high stresses in its hub. The provision of the axialflow packing, however, inseries with the radial flow packing permits of the necessarv iiicrease of` pressure at the outside diameter .of the balancing disksand radial pfiickiiig. ,I take advantage of the fact that two packings are required by providing a steam passage between them, and by utilizingthis passagealong with passages49 in the roto'r and also chambers 5l and 52 and auxiliary steam. chests 40 it 'is apparent that'steam can be ei'itracted from or admitted to the turbine 'without essentially modifying the structure of the turbine itself.

'I'n the broader aspects of my invention it blades since one set of! bladesv can while .the others are held stationary. ever, the' double-ro ion system ableL because of s superior e iency. Neither is limited in its broader aspects to having an axial flow packing in series with the radial flow pack: forun some instances it is possibleto provide two radial' flow packings and. obtain the desired result,

flowing from' the auxiliary chest will flow through the space between theV two packings.

'In accordance' with thefprovisionsof the patent statutes, I have described the principle of operation of my invention,'together with the apparatus which I now consider to representthe best embodiment thereof; but I desire to have'it understood that the apparatus shown is only illustrative and that the invention'can becarried outbygother means.

What I claim as new and`desire to secure by Letters Patent of the United States, is 1.' Inan elastic fluidturbine, the combination of relatively rotating parts, two separate sets vof packings for reducing leakage,

ysaid sets ofpackings being spaced to form an annular passage between them, fluid conveying means Which connects a region of 1ntermediate pressure 1n said rotating parts rotatingvpart andthe turbinecasing, fluid passages in one of said parts, .a chamber adapted top receive fluid vfrom or admit it to saidpassages, a chest having a chamber in communication 4with the' first mentioned 'chambei-,and a conduit opening into the chest and also to the outside of the casing.

8. In an elastic Yfluid turbine, the combination of rotors having blades which rotate in opposite 'direci';ions,` said rotors having passages opening inte region of intermediate pressure, sets of pacllzings on opposite sides of the rotating structure. the parkings on each side being separated by a steam passage which is in communication with certain of the iii'st named passages, steam chests on oppositesides of said rotors which communicate with said steam passages, and conduits for conveying steam between the chests and the outside of the 'turbine casing.

el. In an elastic fluid turlfne, the coinlfination oi a rotor having a i il liow blade system and also passages which open into a region of intermediate pressure in the blade system, apair of thrust and balancing disks,

-a labyrinth packing between the disks, a

second packing through which exhaust from the labyrinth packing flows, the two packings being separated by'a passage through y which steam flows to orfroin said passages in the rotor, a steam chest which communicates with and a coinA conveying steam to or nu the chest.

5. In an elastic fluid t "bine, the combination of arotor which has a radial flow blade system, a pair of thrust and balancing disks, one of which is connected to the rotor, a labyrinth packing between the disks, passages in the rotor through which steam may flow into or from the rotor and over the periphery olf'the disks, a second packing which maintains a pressure at the end of the labyrinth packing above the purbine exhaust pressure,- a main steam chest' supported by the casing which carries one of the thi disks, an auxiliary chest which commun cates with the region between the two packiiigs, and a conduit through which steam flows into or from the auxiliary chest. i

6. In an elastic fluid turbine, the combination of a rotor having a radial-'flow blade annular body of the packing, and a conduit communicating with the chamber in the chest.

7. In an elastic Huid turbine, the combination of a rotor having a radialliow blade system and also lateral. passages, a pair of thrust and balancing disks, one ofv Which is connected to ltherotor, a packing between the disks tol reduce leakage, a steam chest which is supported bythe turbine casing, supplies steam to .the blade system 4and also-supports one of the disks, va second packing which receives steam from the first and comprises two concentric annular bodies, one of Which is supported by the rotor, and the' other by the steam chest, an auxiliary chest which is in communication .with the lateral passages in the rotor and the'space between the packings, and -a conduit opening into the auxiliary chest. v

8. In an elastic-duid turbine, the combination of a rotor having radial and axial-How blade systems, a ,pair of thrust and balancing disks, one ofwhich'is carried by the rotor, a packing between the disks, a stationary annnlar .steam chest located between a Wall of the turbine casing and the rotor Whichsupports one of the disks, a second packing which receives exhausty from the 4first and comprises two concentric annular bodies, said bodies being located Within that portion of' the rotor Which carries an axial flow blade system, means for attaching one of the bodies to that portion of the roto'r which carries a radial fiow'blade system, and means-for at- 'Lamers taching the other .body vto the stationary steam chest. l

9. In an elasticuid turbine, the combination of rotors having oppositely rotating blades, a pair of thrust and balancingdisks for each.v set of blades, one of Which iscarried bya rotor, a stationary steam chest which lateralspassages, one set supplying steam'for overload purposes, thesecond'setbein'g arranged to .discharge steam for extraction lpurposes and toV receive steam for mixed pressure operation, thrust and 4balai'icing disks, leakage reducing packing means between the edges of the disks and the nal exhaust, means foriadmitting steam to the first set of lateral passages, and'means for conveying steamover the edges of the disks to or Jfrom the second set of lateral passages.

In witness whereof, I have hereunto set my 4hand this 12th day of June,vl9l8.

JOHN n. Dorian.

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