US1885512A

US1885512A - Turbine

Info

Publication number: US1885512A
Application number: US570118A
Authority: US
Inventors: Cook Stanley Smith; Bennett Andrew Philp
Original assignee: EXECUTORS
Current assignee: EXECUTORS
Priority date: 1930-10-13
Filing date: 1931-10-21
Publication date: 1932-11-01
Anticipated expiration: 1949-11-01

Description

Nov. 1, 1932. s COCK ET AL 1,885,512 Y TURBINE I Filed Oct. 21, 1931 INVENTORS BY THEIR ATTORNEYS I I Patented Nov. 1, 1932 UNITED STATES PATENT OFFICE STANLEY SMITH COOK AND ANDREW PHILIP BENNETT, OF NEWCASTLE-ON-TYNE, .AND

CHARLES ALGERNON PARSONS, DECEASED, LATE OF NEWCASTLE-ON-TYNE, ENG- LAND, BY KATHERINE PARSONS, OF KIRKWHELPINGTON, VINCENT THOMPSON, OF NEWCASTLE-ON-T'YNE, AND FREDERICK GORDON HAY BEDFORD, OF WYLAM-ON- TYNE, ENGLAND, EXECUTORS; SAID COOK D SAID BENNETT ASSIGNORS TO SAID EXECUTOBS Application filed October 21, 1931, Serial No. 570,118, and in Great Britain October 18, 1930.

The invention relates to turbine units having ahead and astern sections within a common casing.

A main object of the invention is to improve the lay-out of such a turbine unit with a view to securing advantages of the kind set forth below.

\Vith such an object, the present invention consists in a turbine unit comprising the combinations of elements hereinafter described and particularly pointed out in the claims.

The accompanying diagrammatic drawing shows an elevation partly in section through an ahead and astern turbine according to one form of the invention.

In carrying the invention into effect ac-. cording to the form shown applied to a steam turbine unit, the high-pressure ahead turbine, A, is of the reaction type, steam being admitted at one end, 2, of the rotor and exhausted at the other end, 3.

The astern turbine, B,- of the impulse type is mounted on the same rotor, 4, as the ahead turbine and is disposed within the same casing, 5, at the inlet end of the ahead turbine, the astern steam admission being shown at 6, and the exhaust at 7, adjacent the inlet end, 2, of said vahead turbine. A conical diaphragm, 8, preferably integral with the easing, 5, is provided with packing, 9, in relation to the rotor shaft, 4a, interposed between the ahead and astern turbines, A and B, and between this diaphragm, 8, and the highpressure blades, 10, a second seal or packing is provided taking the form of a hollow cylinder, 11, having an internally-projecting flange, 12, bolted to the rotor, 4, and rotatable within a corresponding cylinder, 13, with an externally-projecting flange, 14, bolted to 0 a cylindrical wall, 15, projecting from the diaphragm, 8, and preferably integral therewith.

An annular leak-off space, C, more or less triangular in cross section is thus formed between the cylinder, 13, and the conical diaphragm, 8, and on the inner side .of the lat ter, this space being connected to the condenser, F, by the outlet, 16, and pipe, 16a,

while a corresponding space, G, on the outside of the diaphragm receives the exhaust from the astern turbine, B. I

In order to minimize leakage from the ahead turbine to the space, C,-and so to the condenser and consequent loss of power, steam may be tapped-off through the duct, 17 from an intermediate point of the length of the said second packing and led to chamber, D, formed by the added wall, 18, and wall, 15, and thence by way of the outlet, 19, and pipe, 19a, to the exhaust end of the ahead turbine, A.

It will be understood that the rotor, 4, is supported in the usual manner in suitable bearmgs, E, E, outside the casing, through the ends walls of which it passes fluid-tight by help of suitable gland packing, 20.

If desired, reaction blading may be used for the astern turbine also.

By virtue of the present invention the following advantages are obtained When going ahead or astern, owing to the fact that the non-operative turbine in accord-- ance with usual practice runs in a vacuum, there is no leakage of steam into the idle turbine, since the pressure on both sides of the diaphragm gland, 9, when going ahead and of the second packing, 11, when going astern is the same, namely the pressure of the condenser. Any steam leaking into the space, C, between the second packing, 11, and the diaphragm, 8, when going ahead and across the diaphragm gland, 9, when going astern passes direct to the condenser. Frictional losses and excessive heating and damage to the idle turbine are thus avoided.

In addition, the astern turbine, B, arranged at the hotter end, i. e., the inlet end, of the high-pressure ahead turbine, A, is maintained at a fairly high temperature by conducted heat, with the result that when steam is admitted to the astern turbine, the latter is not so liable to suffer from unequal expansions as in the ordinary construction.

Further, the large-diameter exhaust pipes connected to branches, 3 and 7, are at opposite ends of the'unit and are thus more easily arranged and connected to succeeding turbines, if any. Crowding and difficult pipe work are in this way avoided.

Finally, it will be seen that with the ahead ing and by a wall projecting inwardly from turbine, A, in operation andthe astern tursaid casing.

bine, B, running in a vacuum, the exhaust In testimony whereof we have signed our pressure acting on the. left-hand end of the names to this specification.

ahead turbine is in excess of the condenser pressure in the space, C, so that there is an. excess of pressure to the right balancing the PIFSSIIIG of the steam on the blades to the le t.

When, however, the ahead turbine, B, is in operation and the astern turbine, A, runs in a vacuum, there is no unbalanced pressure axially on either the ahead or astern turbines.

In both cases, therefore, the ahead and astern turbines considered as a single rotating unit are balanced in the longitudinal direction.

Departures may be made from the precise constructional forms described without exceeding the scope of the invention.

Having now described the invention what is claimed as new and desired to secure by Letters Patent is 1. An elastic-fluid parallel-flow turbine unit comprising an ahead turbine and an astern turbine having a common rotor body and a common casin g, at least one of said turbines bein of the reaction type, the exhaust end of sai astern turbine being arranged adjacent the inlet end of said ahead turbine,

easing diaphragm means between said ahead. and said astern turbines, said dia hragm means having walls spaced apart axially of said turbines with a chamber therebetween, each wall being in substantially fluid-tight relation to said common rotor body, a condenser and means for connecting said chamber to said condenser.

2. An elastic-fluid parallelsflow turbine unit, com rising an ahead turbine and an astern tur ine having a common rotor body and a common casing, at least one of said turbines bein of the reaction type, the exhaust end of sai astern turbine being arranged adjacent the inlet end of said ahead turbine, casing diaphragm means between said ahead and said astern turbines, said diaphragm means'having walls spaced apart axially of said turbines with a chamber therebetween, each wall being in substantially fluid-tight relation to said common rotor body, a condenser and means for connecting said chamber to said condenser, an annular duct within said casing and surrounding said chamber, a connection between said annular duct and a lower-pressure point of said ahead turbine and means for leading leakage to said an nular duct from an intermediate point of the fluid-tight path between said common rotor body and that wall of said diaphragm means adjacent said ahead turbine.

An elastic-fluid turbine unit as claimed in claim 2, in which said annular duct is bounded by said dia hragm means, by a wall projecting from sai diaphragm, by said cas- STANLEY SMITH COOK, ANDREW PHILP BENNETT, KATHERINE PARSONS. VINCENT THOMPSON, v FREDERICK GORDON HAY BEDFORD, Emccutors of Charles Algernon Parsons, Deceased.