US1855362A - Steam turbine and valves therefor - Google Patents

Description

April 26, 1932- c. A. PARSONS ET AL 1,855,362

STEAM TURBINE AIEYD VALVES THEREFQR Filed Mafi: 31,- 192%) 3 Sheets-Sheet l /Q/wi we ma April 26, 1932. c. A. PARSONS ET AL 1,855,362

STEAM TURBINE AND VALVES THEREFOR Filed May 31, 1929 I5 Sheets-Sheet 2 Pkg/5.

a W Q W K J izg d e jgg/dffug April 26, 1932. c. A. PARSONS ET AL A A 1,855,362

STEAM TURBINE AND VALVES THEREFOR Filed May 31, 1929 3 Sheets-Sheet 3 Patented Apr. 26, 1932 UNITED STATES PATENT 0F FIC E CHARLES ALGERNON PARSONS, STANLEY SMITH CODE, AND LOUIS MORTIMER DOUGLAS, 01'! HEATON WORK-S, NEWASTLE-ON-TYNE, ENGLAND; SAID 0002!! AND DOUGLAS ASSIGNORS TO SAID PARSONS; KATHARINE PARSONS, VINCENT THOMP- SON, AND FREDERICK GORDON i-LAY BEIDFORID LEGAL REPRESENTATIVES OF SAID CHARLES A 'LGERNON PARSQN-S, DECEASED STEAM TURBINE AND VALVESTHEBEFOB Application filed May' 31, 1929, Serial No. 367,191, and in-Great'Britain June 28, 1928.

The invention relates particularly-to valves for controlling the How of elastic fluid but,

while certain features'oifi the invention. are

of general applicability, our improved valve is especially designed for controlling'the flow of steam in marine turbine installations having ahead and asternfturbines and the invention'consi'sts inpartof combinations in'such an installation.

In'suc'hinstallations, it hasbeen found in practice that when running ahead, steam is liable to leak past .the relative controlling valve into the eastern turbine which is being rotated by the ahead turbine inn-a direction opposite to its working direction under which condition heat is generatedand in view of this fact and also of the fact that theleakage steam is initially at a temperature substantially -equal to the maximum temperature of the boiler or superheater a hightemperaturemay be reached and damage maybexcaused to "the astern turbine blades. g

The main object o'fthe present invention is -to avoid the above difficulty. This;result is secured by combining with the ast'ern turbine of such an installation our improved valve, which valve alsomay (be used in other combinations where it is important to prevent the passage of leakage elastic fluid.

With such an object, the invention consists in the combination of elements hereinafter described and particularly pointed out in the claims.

Referring to the accompanyin drawings, orm of the invention by way of example,

Figure 1 is a sectional elevation through the valve as a whole,

Figure 2 being as regards its upper halt a cross-section on the line A-A and as regards its lower half a cross-section on the line 13-13 of Figure 1;

Figure 3 shows a developed view of the I main steam ports;

Figures 4.- and 5 show in cross-sectional elevation modified forms of certain details of the leak-oil valve and adjuncts.

Figure 6 is a diagrammatic sectional elevation of a marine turbine installation with my improved valve.

In the particular example of the invention under description, it is assumed that the spindle is vertical and that the double-beat valves close in the upward direction.

When open, steam passes through the upper valve, a, direct and through the lower valve, '2'), by Way of the usual surrounding duct, h, to an additional valve chamber, .z', formed as an upward extension of the valve casing and gpr'e'ferably integral therewith. This additional chamber has the general form of a cylinder co-axial with the spindle (Lot the double beat valve and its lower part is surrounded by an annular duct, is, connected on the one hand "by way of theoutlet, m, to the condenser or elsewhere and'on the other hand by way ofa suitable iport ,-n, (or suitable {ports} to the interior of the chamber, the fun'ct ioniofthese parts being to lead ofi' any steam that may le'ak past the doublebeat valve;

The upperpart of-the chamber is surroundextension of the main valve spindle, d,

the additional valve chamber, 2".

The spacing of the ports, a andsythe dimensions ofthe piston valve, t, and-so forth areso chosen'that When the double-beat valve is closed the ports, 8, "to the main outlet, 9, are covered-bythe piston valve, t while the leakage-port a is open, .so that anysteam passingthe double beatxvalvejis led off direct to the condenser or elsewhere throu 'h the outlet, m. When, however,ithe "dou'b e beat valveisopenedfthe samemanipulativemovement causes the piston valve, t,to descend,

closing the leakage port, a, and at the same time by its continued movement opening the ports, 8, to the main outlet. I

In order to minimize leakage of steam dur ing the initial part of this opening movement before the leakage port is closed, the mitres on the two elements, a, b, of the double-beat valve may be provided with upwardly-projecting skirts, a 5 serving as pistons in re lation to their respective seatings, a 5

The piston valve, 25, may be either of a simple cylindrical form without packing (see Figure 1) working directly in contact with corresponding walls of the valve chamber, 2', or a liner, u, (see Figure 4) with ports, a and bridges, 14 may be fitted and the piston valve provided with ramsbottom rings, 25*; or al ternatively packing rings, a), (see Figure 5) preferably in conjunction with leaf or garter springs to press them against the piston valve, 2., may be arranged in the chamber wall.

Whatever the form of piston valve and packing adopted, if desired the upper edge of the piston valve, 25, maybe provided with anarrow cylindrical edge or lip, 6 (see Figure 5) adapted to come in contact with a fleXible annular disc, w, secured to the valve casing, 0, so that seating of the piston valve is effective notwithstanding difierential expansion due to temperature and so forth.

Suitable external indicating means, such as the indicator, w, (see Figure 1) pinned to the valve spindle, d, may be provided to show the position of the valve, such means preferably indicating the completely shut-off position and also the position when the valve first opens to the outlet branch.

In Figure 6, there is shown a marine turbine'installa-tion of the preferred form, embodying the'invention, in which A is a casing enclosing the ahead and astern turbines 10, 11, having the respective steam inlets 12, 13,

these ahead and astern turbines having the' common condenser passage 14 and condenser 15. Steam is admitted to the astern turbine inlet 13 through pipe 16 under the control of the valve above described, the leak-ofi port 1% of the valve being connected by pipe 17 to the condensing passage 14 of the condenser. It will be understood that the leak-off valve may be combined with other types of combined ahead and astern turbine installations.

Although the invention has been described by way ofexample with a valve of the doublebeat type, it will be understood that it is equally applicable with Valves of many other types whether hand or power operated. In addition the details of construction and rela tive arrangements of the component parts of the valve structure may take forms other than those described above without exceeding the scope of the invention. 7

What is claimed is:

1. An elastic fluid-controlling devicecomprising in combination, a valve casing having inlet and main and leak-off outlet ducts and disposed within said casing an inlet valve controlling said inlet duct and also disposed within said casing a common valve controlling said main and leak-ofi' ducts, said common valve being of the hollow piston type with imperforate walls and performing'its dual function by virtue of diiferent operative edges; positively-associated lengths of spindle on which said valves are mounted in such relation thereto and to said ducts that when said inlet and said outlet valves are both closed, said leak-off valve is open.

2. An elastic fluid-controlling device as claimed in claim 1, in which said Valves are mounted on a common spindle, said leakofi' duct being controlled by one operative edge of said piston valve and being disposed axially of said spindle between said inlet duct and said outlet duct controlled by the other operative edge of said piston valve.

3. An elastic fluid-controlling device as claimed in claim 1, in which said inlet valve is of the double-beat type, each beat to enspre tightness being provided with a piston s irt.

4. The combination with the ahead and astern turbines of a marine turbine installation,'of a valve device controlling the steam admission of the astern turbine and comprising a valve casing having inlet and main outlet and leak-off ducts. and interconnected valvescontrolling said ducts and arranged so that when the inlet is closed the main outlet duct is closed but the leak-01f duct is open, while when the inlet is open, the main outlet duct is open but the leak-ofl' outlet duct is closed, substantially as and for the purpose described. I

In testimony whereof we have signed our names to this specification.

CHARLES ALGERNON PARSONS. STANLEY SMITH COOK. LOUIS MORTIMER DOUGLAS.

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