GB900765A - Improvements in or relating to combustion equipment - Google Patents

Abstract

900,765. Generating combustion products under pressure. ROLLS-ROYCE Ltd. Nov. 7, 1958 [Nov. 15, 1957], No. 35734/57. Class 51 (1). A combustion stabilizing device for use with combustion apparatus in which combustion supporting gas flows at high velocity such as in the main or reheat combustion equipment of gas-turbine or jet-propulsion engines comprises a V-section member having sides diverging in the direction of gas flow through the combustion space defining between them a channel open in the downstream direction, and a foraminate combustion-promoting catalytic element of platinum or platinum containing alloy extending across the channel between the sides of the member. The reheat combustion equipment in Fig. 2 comprises three hollow struts 17 carrying a easing 17a within which is supported a conical baffle 18. A pipe 20 supplies fuel to a pilot injector 21, which directs fuel past a baffle 18 to an igniting device 22. A second fuel supply pipe 23 leads to a number of tubular ring manifolds 24 having apertures 25. The combustion stabilizing device 27, Fig. 3 comprises an annular V-section member 28 supported by struts 26 from the casing 17a. Fixed at the downstream end of the member 28 is a series of ceramic elements which have roots 29a and flanges 29b and alternate circumferentially around the member 28 with a series of catalytic combustion promoting elements 30. Each combustion promoting element 30 is in the form of gauze or perforated sheet of platinum or platinum alloy. In a modified form (not shown), the stabilizing device comprises two layers of platinum or platinum alloy, one layer is flat and attached to the edges of the V-section member and a second layer is bent to arcuate form which extends between and is attached to the sides of the V-section member and is spaced from the first layer by an internal wall of gauze, also of platinum alloy. In a further embodiment (not shown), flanges 29b of each ceramic element have circumferentially extentions projecting over the edges of elements 30 which assist to reduce heat loss from the elements 30. In two further modifications, ceramic elements are not employed and the catalytic elements are set upstream from the downstream edges of the V-section member. The embodiment shown in Fig. 8 comprises alternate ceramic blocks 129 and catalytic elements 130 housed within the annular V-section member so that the sides of the member project downstream of the blocks and elements which are retained in position by grooves in their surfaces engaging edges 128a formed in the sides of the gutter.