GB856437A - Combustion system for a gas turbine engine - Google Patents

Abstract

856,437. Generating combustion products under pressure. ARMSTRONG SIDDELEY MOTORS Ltd. Sept. 23, 1958 [Oct. 19, 1957], No. 32718/57. Class 51 (1). In a combustion system for a gas turbine engine, an annular manifold is provided having an open upstream end to receive a proportion of the output from an air compressor of the engine and a main supply of fuel, this air and fuel being for main combustion. Either the inner wall or the outer wall of the manifold forms an upstream wall portion of the flame tube and is provided with ports through which the mixture of main combustion air and fuel enters the flame tube. Means are also provided for delivering a pilot supply of fuel and air from the compressor in an upstream direction to the closed upstream end of the flame tube so as to provide a pilot combustion flame into which the 'main combustion air and fuel are discharged. In the annular type of combustion apparatus shown, the annular flame tube comprises an outer wall 12, 20 and an inner wall 13, the two walls being closed at the upstream end. The flame tube is mounted within an annular air space formed by outer and inner walls 11, 15. The upstream portion 12 of the outer wall of the flame tube is surrounded by a wall 17 so as to form an annular manifold space open at its upstream end and closed at its downstream end where the walls 12, 17 are secured together. An annular sealing ring 19 is disposed at the downstream end of the space. The inner wall 12 of the manifold is formed with three rows of openings 28, 29, 30 through which air from the engine compressor and main fuel from the ring manifold 26 discharge from the manifold 12, 17 into the flame tube. The wall 17 is formed with openings 22 from which V-shaped pipes 21 extend into the flame tube, the discharge ends 21a of the pipes being directed towards the closed upstream end of the flame tube. Fairing members 23 are disposed between the walls 11, 17 being open at their upstream ends for inflow of air from the compressor. The fairings each surround an inlet to a V-shaped pipe 21, and pilot fuel is supplied to each pipe 21 through a pipe 27 so that pilot fuel and air discharge from the pipe outlets 21a and produce pilot combustion which causes ignition of the main fuel and air mixture supplied through openings 28, 29, 30. Further air enters the flame tube through openings 25 in the outer wall 20. Air supplied to the space between the inner wall 13 of the flame tube and the casing wall 15 enters the flame tube through spaces formed between overlapping sections of the wall, thereby cooling the inner surface thereof.