US2330730A

US2330730A - Turbine gland apparatus

Info

Publication number: US2330730A
Application number: US433154A
Authority: US
Inventors: Donald J Mosshart
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1942-05-03
Filing date: 1942-05-03
Publication date: 1943-09-28
Anticipated expiration: 1960-09-28

Description

Sept. 28, 1943. D. J. MOSSHART TURBINE GLAND APPARATUS Filed March 5. 1942 INVENTOR DONHLD J. MOSSHHRT- WITNESSES:

(XI-d5 ATTORNEY xwmw Patented Sept 28, 1943 a, Westinghouse, Electric & Manpiacturing Qom can, East Pittsburgh, Ra a corporation, 01; l

Pennsylvania" Application May a, 1942; sena-1'iya rea ist 1 aolaims. c1; an- 9);

318i innention relates; to glands. for L sealing a turbine, casing with: respect. to a spindle. andit {on an objectzto: provide an apparatus! 015 this character utilizingsteam to. form. condensate" in thecleatancespace ot'the glandland'l whereinone or more; helical threads; are employedi' to utilize rotary: movement iot the spindle tolexertia pumpingreff-ectn onnthe condensateropposedto pressure exentedithereon by, steamz-insthe casing; whereby theibodyi of condensateiacoumnlatingsin thegland cleapance: spaceendi acted on by these". opposed forces:iseffectiveifioaconstittute the seals; i l

A. more:v particular objection the: invention is to provide a.. gland fori aa substantially "vertica-litum cine spindle wheneina steam fromi the turbine casz ing ise used; to: foam"; condensate and". threadsiare. provideda to exert 2,1 pumping; efiect on: the condensate, opposed; to. thepnessunee exertedither'eorr by thessteami ml the i tiurbin'e casing togethenwith' packing meansiarrarrged' therebelow. ior-restnicw invention comprises an improved gland, at M,

carried by the casing and cooperating with the spindle to minimize leakage.

Preferably, as shown, the spindle extends substantially vertically and the gland, at M, is carried by the lower side of the casing.

The gland, at M, comprises a, housing l6 having an inner cylindrical portion l1 cooperating with the cylindrical portion 18 of the spindle to provide a suitably small running clearance space The housing construction 16 has a jacket space 2| encompassing its cylindrical portion H and the jacket space is provided with inlet and outlet connections 22 and 23 providing for the circulatlon of cooling medium through the jacket space, the cooling medium serving to abstract heat from steam entering the clearance space to produce condensation of the latter.

One or both of the cylindrical portions I1 and I8 are threaded with the thread or threads so exten ing that, for the 'clirection of rotation o'fthe' spindledil; a pumping efiec't' is" exertedentire condensate in the running 'cl'eararic'e'space N1 in posit'io'n to" pressure exerted tlieno'ii bysteam in the cas ng. the annular" body of can; densat'e iii the runni irg-clearancespace constitutes an effective-semi and iany'leahage' the can densat'ej body so formed is made up by further condensatibn of fsiieam. 7 r I ss-saowm both the c'ylir'rd'rical po'rti o'ns l' 'l and [8 are threaded to increase the pumping effect, the

cylindrical portion I1 havin'g a'rrinternal thread 7 25' and the-- cylindrical portion 18 having an exremap thread 26; Further-more, byhaving threads on both= cylindrical portions, not only is the pumping efiectlindreased'i 'but tiirbulence'due thereto contributes to tliis and makes possible more effectivetransfer'ofheaiitb' the cooling mediuni in' the jackett Also; heattransfer is iinproved because- (if? the? eife'ot' of the internal thread? 2'5 providihg' increased heat transfer surface. l

' nischargegqr condensate from tne outer or lower end of thecleara-n'oe space zll'is' iinpeded by any suitable pa'ckiri'g 2 arranged betWe'eii'. the housing and the spindle; the packingcooperating with the: spindle' and the housing to provide" a sp ce- 28 rentne secumuiation or condensate; A l'oak ofi' connection ra provides for discharge of drainage from the space 23. Condensate supplied from the space 28 saturates the packing 21 and thereby renders the sealing relation of the latter with respect to the spindle more effective.

Preferably, as shown, the housing structure is comprised by inner and outer tubular members 3| and 32 providing a jacket space and the inner member having the cylindrical portion l1 and there is connected to the lower end of the tubular member 3! a tubular member 33 spaced from the spindle to provide for accommodation of the packing 21. Also, a sleeve 34 is preferably carried by the spindle, the sleeve having the cylindrical portion i8 at its upper end and having its lower portion cooperating with the sleeve member 33 to define the space for the packing 21. A leak-off ring 36 cooperates with the packing at the lower side thereof.

In order to guard against the leakage of condensate along the spindle below the gland, pas sages are formed to provide for the leak-oft of any water between the. sleeve 34 and the spindle as well as water from the space at the lower side of the packing 21. Accordingly, the sleeve 34 is shown as being provided with an internal annular groove 31 connected by radial passages 38 to the inner groove 39 formed in the ring 35, such inner groove being connected by radial passages 40 to the outer annular groove 4| formed therein. The outer annular groove cooperates with the interior surface of the sleeve member 33 to form an annular chamberconnected by ports 42 with the annular space 43 in communication with the leakoff connection 29.

Thus, it will be seen that the packing 21 resists the escape of condensate from the lower or outer end of the clearance space, that is, due to the packing, the pressure difierence between the interior of the turbine casing and the space 28 is substantially reduced, thereby reducing the pressure effective to produce flow outwardly through the clearance space and making it easier for the threads effectively to exert the necessary opposing pumping action. Any leakage from the gland construction occurs through the leak-off.

connection 29, the grooves and passages formed in the sleeve.34, the ring 36 and in thesleeve member 33 providing for drainage of all-spaces to the leak-off connection 29. a r 1 1 While the invention has been shown 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 changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall .be placed thereupon as are specifically set forth in theappended claims. I What is claimed is: j

1. In a gland for sealing a substantially vertical turbine spindle with respect to the casing, a ho using carried by the casing at thelower side thereof and encompassing the spindle; a sleeve carried by the shaft and arranged within the housing; said housing and sleeve'having closely spaced cylindrical portions defining small running clearance communicating at, its upper. end with the interior of the turbine casing; said housing having an annular jacket space encompassing its cylindrical portion; means providing for the circulation of cooling medium, through the jacket space to effect condensation of steam entering the running clearance space'from the casing; internal and external threads carried by thecylindrical portions, bounding'the running clearance space, and extendingv so that, for the direction of rotation of the rotor, they exert a pumping action on the condensate in the clearance space opposed to pressure exerted thereon by steam in the casing; means opposing the dis- 5 charge of condensate from the outer end of the running clearance space comprising packing cooperating with the housing and with the sleeve; a ring cooperating with the packing at the lower end thereof; and means including passages formed in the lower end portion of the sleeve, in the ring, and in the housing and providing for the leak-01f of condensate from the space I between the sleeve and the spindle and from the packing.

2. In a gland for sealing a turbine spindle with respect to its casing, a sleeve construction carried by the casing and encompassing the spindle; said sleeve construction including a first member having one end exposed to the interior of the casing and a second member extending outwardly fromthe first member; said first member and the spindle having closely spaced cylindrical portions defining an annular condensing clearance space communicating at one end with the interior of the casing; means cooperating with the first member to provide an annular jacket space encompassing said cylindrical portion thereof; meansproviding for the circulation of cooling medium through the jacket space to effect condensation of steam entering the clearance space from the interior of the casing; a thread on at least one of said cylindrical portions and extending so that, for the direction of rotation .of' the rotor, it exerts a pumping action on the condensate in the clearance space to oppose the pressure exerted thereon by steam in the casing; said second membercooperating with the spindle to provide an annular packing spacein' communication with the other end of 40 said clearance space; .packing in said annular space and having sealing relation with respect to the spindle, the sleeve construction, the spindle, and the casing being constructed and arranged to provide a leak-01f space for con- 0 densate escaping from the packing; and a leakoff connection carried 'by the casing and communicating with the leak-0E space.

DONALD MOSSHART.