GB2211285A

GB2211285A - Combustion equipment

Info

Publication number: GB2211285A
Application number: GB8724534A
Authority: GB
Inventors: Robert George Ward
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 1987-10-20
Filing date: 1987-10-20
Publication date: 1989-06-28
Also published as: GB8724534D0

Abstract

Combustion equipment (10), which is particularly suited for use with a low power industrial gas turbine engine, comprises a metallic cylindrical liner (11) having a plurality of circumferentially abutting ceramic tiles (25, 26) provided on its radially inward surface. The tiles (25, 26) may be of generally pentagonal or trapezoidal cross section and have circumferentially abutting surfaces which lie in radial planes relative to the longitudinal axis of the liner (11) so that radially inward movement of the tiles (25, 26) is inhibited. A fuel supply nozzle (22) and swirler vanes (20, 21) control fuel and air supply for combustion. <IMAGE>

Description

COMBUSTION EQUIPMENT This invention relates to combustion equipment and particularly, although not exclusively, to combustion equipment suitable for use with a gas turbine engine.

Gas turbine engine combustion equipment is required to withstand, over long time periods, the extremely high temperatures which are conventionally generated during the combustion process necessary to sustain such engines. In order that such equipment is fully capable of withstanding these high temperatures, it is usual to manufacture it from high temperature resistant alloys, for instance nickel-based alloys, and additionally provide some degree of cooling of the equipment. While such measures are, in the main, successful in providing combustion equipment which is capable of prolonged, efficient operation, they do result in the equipment being very expensive to manufacture. Such expense can be cost effective in the case of combustion equipment for gas turbine engines which are destined for use in aircraft propulsion.However if the gas turbine engines are intended for lower grade use, for instance in an industrial enviro,nment, such expense can be more difficult to justify.

One way in which combustion equipment can be made more cost effective is to manufacture it from a ceramic which is capable of withstanding high temperatures and which requires little or no cooling. However the drawback with such materials is that when they are exposed to rapidly changing temperatures, as is often the case with gas turbine combustion equipment, the stress induced thereby almost inevitably results in the cracking of the material.

It is an object of the present invention to provide combustion equipment which is at least çartially formed from a ceramic material and which is capable of operation with at least a substantial reduction in the cracking problems usually associated with ceramic-based combustion equipment.

According to the present invention, combustion equipment comprises a cylindrical liner member having its radially inward surface covered by a wall of ceramic material, said wall of ceramic material comprising a plurality of discrete abutting ceramic tile members, each tile member being so configured as to cooperate with circumferentially adjacent tile members in such a manner that radially inward movement of said tile member is inhibited.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a sectioned side view of combustion equipment in accordance with the present invention.

Figure 2 is a part view on section line A-A of Figure 1.

Figure 3 is a partially broken away perspective view of a portion of the combustion equipment shown in Figure 1.

With reference to Figure 1, combustion equipment generally indicated at 10 comprises a cylindrical metallic liner 11, which is provided with a flange 12 at its upstream end. The flange 12 engages a corresponding flange 13 provided on the downstream end of a first sleeve 14 which communicates with a generally part spherical casing 15. The casing 15 is adapted to receive compressed air from a suitable source (not shown) through a second sleeve 16, the axis 17 of which is generally normal to that 18 of the liner ll.

Interposed between and supported by the first sleeve 14 and the liner 11 there is provided a flanged ring 19 which supports two concentric annular arrays of swirler vanes 20 and 21. The innermost 21 of the annular arrays of swirler vanes 20 and 21 in turn supports the downstream end of a fuel supply nozzle 22 so that the nozzle 22 is so positioned as to be capable of directing fuel for combustion into an appropriate region of the interior of the combustion equipment 10. The remainder of the fuel nozzle 22 extends through the interior of the spherical casing 15 to an appropriate source of fuel (not shown).

In operation, compressed air supplied to the interior of the spherical casing 15 through the second sleeve 16 is directed through the swirlers 20 and 21 to mix with fuel ejected from the fuel supply nozzle 22. The resultant -fuel/air mixture is then combusted and the combustion products are exhausted from the downstream end 23 of the combustion equipment 10 to, for instance, drive a suitable turbine (not shown).

In order to protect the inner surface of the metallic liner 11 from the high temperature of the combustion process, a wall 24 of ceramic material is provided on that inner surface. The wall 24, which can be seen more easily if reference is made to Figures 2 and 3, is made up of an annular array of ceramic tiles 25 which abut the liner 11 and a further annular array of ceramic tiles 26 which is located radially inwardly of and abut the ceramic tiles 25.

The ceramic tiles 25 are of pentagonal cross-section shape and extend axially with respect to the axis 18. The face 27 of each tile 25 which is adjacent the radially inner surface of the liner 11 is provided with an axially extending ridge 28 at its mid-portion. Each ridge 2 serves to radially space apart the majority of its respective tile 25 from the liner 11.

each side face 29 of each ceramic tile 25 abuts the corresponding side face 29 of the ceramic tile 25 which is circumferentially adjacent to it. The side faces 29 of the tiles 25 lie in radial planes with respect to the axis 18. It will be seen therefore that each tile 25 is constrained against movement in a radially inward direction by its engagement with the tiles 25 which are circumferentially adjacent to it.

The remaining two faces 31 and 32 of each tile 25 converge in a radially inward direction to provide abutment surfaces for corresponding surfaces 33 and 34 which are convergent in a radially outward direction provided on circumferentially adjacent tiles 26 defining the radially inward tile array.

As in the case of the tiles 25, each of the side faces 35 of the tiles 26 abuts the corresponding side face of the tile 26 which is circumferentially adjacent to it and the side faces 35 lie in radial planes with respect to the axis 18. This being so, each of the tiles 26, like the tiles 25 is constrained against movement in a radially inward direction by its engagement with the tiles 26 which are circumferentially adjacent to it.

All of the tiles 25 and 26 are provided with concavely radiused edges 36 adjacent their radially convergent faces 31-34 so that axial passages 37 are defined which accommodate the apices 38 of the radially divergent faces 31-34, thereby avoiding problems of fit.

A further feature of the tiles 25 and 26 which can be seen both in Figure 1 and Figure 3 is that each tile 25 and 26 is axially staggered with respect to the tiles 25 and 26 which are adjacent ther-eto.

It will be seen therefore that the shapes and interrelationships of the tiles 25 and 26 ensure that they are constrained against movement in a radially inward direction. There is however, no axial constraint of the tiles 25 and 26 except as is provided by the flanged ring 19 and whatever structure the downstream end 23 abuts when the combustion equipment 10 is operationally installed in a suitable device such as a gas turbine engine. This being so, either removal of the flanged ring 19 or the removal of the combustion equipment from the device in which it is installed facilitates the easy removal of the tiles 25 and 26 by their axial sliding out of the liner 11.

By providing a wall 24 of ceramic material which is made up of a plurality of comparatively small ceramic tiles 25 and 26, the wall 24 are far less prone to cracking as a result of thermal stress then would be the case if a monolithic ceramic structure were to be employed. Moreover the tiles 25 and 26, since they are each of simple configuration, are substantially easier and cheaper to manufacture than would be the case with a monolithic structure.

Although the present invention has been described with reference to combustion equipment 10 provided with two rows of tiles 25 and 26, it will be appreciated that other numbers of rows could be used if so desired. Thus, for instance, if reference is made to Figure 2 there is shown on a portion of the liner 11 a single row of tiles 39 which are generally of the same configuration as the tiles 25 and 26. However since there is only one row, the tiles 39 are of trapezoidal cross-sectional shape rather then the pentagonal cross-sectional shape of the tiles 25 and 26.

The combustion equipment 10 is primarily intended for use with a gas turbine engine and in particular to a low power output engine intended for industrial use. However, it will be appreciated that it could be used in other suitable equipment.

Claims

Claims:

1. Combustion equipment comprising a cylindrical liner member having its radially inward surface covered by a wall of ceramic material, said wall of ceramic material comprising a plurality of discrete abutting ceramic tile members, each tile member being so configured as to cooperate with circumferentially adjacent tile members in such a manner that radially inward movement of said tile members is inhibited.

2. Combustion equipment as claimed in claim 1 wherein said tile members have circumferentially abutting surfaces which lie in radial planes relative to the longitudinal axis of said cylindrical liner so as to provide said inhibition of radially inward movement of said tiles.

3. Combustion apparatus as claimed in claim 1 or claim 2 wherein said tile members are axially elongate.

4. Combustion apparatus as claimed in claim 3 wherein each of said tile members is axially staggered with respect to the tiles adjacent thereto.

5. Combustion apparatus as claimed in any one preceding claim wherein said tile members ae arranged in two concentric annular arrays.

6. Combustion apparatus as claimed in claim 5 wherein each of said tile members is of pentagonal cross-sectional shape.

7. Combustion apparatus as claimed in any one preceding claim wherein said tile members adjacent said radially inwa-rd surface of said cylindrical liner member are radially spaced apart from said radially inward surface by spacer means provided on one or both of said tile members and radially inward surface.

8. Combustion apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.