US2801821A

US2801821A - Cooled turbine casing

Info

Publication number: US2801821A
Application number: US406527A
Authority: US
Inventors: Burger Willi
Original assignee: BBC Brown Boveri France SA
Current assignee: BBC Brown Boveri AG Germany; BBC Brown Boveri France SA
Priority date: 1953-02-05
Filing date: 1954-01-27
Publication date: 1957-08-06
Anticipated expiration: 1974-08-06

Description

g- 1957 w. BURGER COOLED TURBINE CASING Filed Jan. 27, 1954 I N VENTOR W/LL/ 510F653 ATTORNEYS gesellschaft Brown, Bore-2i a Elie, a joinbstoe ir company Appiication .iannary 27, 1954, No. 495,532?

iratinn Switzerland 5, 1955.2 2 tllaims. (Cl. 23--39.1)

This invention relates to a cooled turbine casing and more particularly to externally cooled casings for steam and/or gas turbines.

With the increase in the temperature of the propellant it became necessary to cool the turbine casing at least in the region of the first expansion stage. It is known to employ a double-walled construction and to pass a coolant through the space between the walls, but this requires a complicated and correspondingly expen sive construction which, moreover, is open to the disadvantage that it is not well adapted to resist high heat stresses.

Objects of this invention are to provide readily manufactured and inexpensive external cooling devices for the casings of superheated steam and combustion gas turbines. More specifically, an object is to provide tor-- bine casings with external cooling devices which have a high resistance to heat stresses and which take the form of corrugated channels of sheet metal welded to the exterior of the casing parts to be cooled.

These and other objects and the advantages of the invention will be apparent from the following specification when taken with the accompanying drawing, in which:

Fig. 1 is an elevation, with parts in section of a part of the entrance portion of a turbine provided with cooling devices embodying the invention; and

Fig. 2 is a fragmentary vertical section of the same on line 11-11 of Fig. 1.

In the drawing, the reference numeral 1 identifies the inlet passage by which the expandible propellant, super heated steam or a combustion gas, is introduced into the turbine inlet ring 2. The turbine casing includes an upper portion 3a and a lower portion 3b of conventional design and construction housing the rotor 4 carrying rows of rotor blades 5 which are interleaved with rows of guide blades 6 which are supported by the casing portions, 3a, 3b.

In accordance with the invention, external and parallel cooling ducts are formed on the casing portions by a plurality of channels 7 of corrugated sheet metal of open, and preferably of semicircular cross-section with the corrugation transverse to their lateral edges which are secured to the casing portions by weld metal W. The channels 7 are connected by inlet manifolds 8 and atent O M 2,801,821 Patented Aug. 6, 1957 exhaust manifolds 8' which are also transversely corrugated for greater flexibility to resist stresses due to differential expansion, secured to the casing portions by weld metal W, and provided with inlet pipes 9 and exhaust pipes 10, respectively, for the circulation of a coolant such as saturated steam or air through the cooling system.

The cooling system is economical to construct, of high efiiciency and, in view of the flexibility of the corrugated sheet metal channels, is not damaged by the expansion differences which of necessity arise between the heated inner portions in contact with the turbine casing and the colder exterior portions of the ducts.

I claim:

1. A turbine casing comprising two complementary casing portions, a plurality of parallel cooling ducts on the external surface of each casing portion, said ducts comprising transversely corrugated metal channels having their lateral edges welded to the respective casing portions, inlet and exhaust manifolds on each casing portion communicating with the cooling ducts of that casing portion, and inlet and exhaust pipes connected to the inlet and exhaust manifolds respectively; said manifolds comprising transversely corrugated open channels with their lateral edges welded to the external surfaces of the casing portions.

2. An externally cooled casing for a superheated steam or combustion gas turbine comprising a casing housing a rotor, rows of blades on said rotor and interleaved with rows of guide blades supported by said casing, said casing consisting of two complementary portions, a plurality of parallel cooling ducts on each of said casing portions, said cooling ducts consisting of corrugated sheet metal channels of open section with the corrugations transverse to the lateral edges of said channels, the edges of said channels being welded to the external surfaces of said casing portions, a corrugated sheet metal inlet manifold and a corrugated sheet metal exhaust manifold for each of said casing portions in communication with the cooling ducts thereon, said manifolds comprising channels of open section Welded to the external surfaces of the casing portions, and inlet and exhaust pipes connected to the inlet and exhaust manifolds respectively.

References Cited in the file of this patent UNITED STATES PATENTS 635,919 Curtis Oct. 31, 1899 1,730,748 Schmidt Oct. 8, 1929 2,186,706 Martinka Jan. 9, 1940 2,241,782 Jendrassik May 13, 1941 2,288,734 Noack July 7, 1942 2,432,359 Streid Dec. 9, 1947 2,474,404 Richeson June 28, 1949 2,618,461 Frankel Nov. 18, 1952 2,621,027 Tatsch Dec. 9, 1952 FOREIGN PATENTS 825,698 France Dec. 16, 1937