GB902511A - Improvements in or relating to combustion chambers - Google Patents

Abstract

902,511. Generating combustion products under pressure. BRISTOL SIDDELEY ENGINES Ltd. March 27, 1961 [April 19, 1960], No. 13597/60. Class 51 (1). The invention relates to combustion equipment for a gas turbine engine of the kind comprising an outer casing, at least one flame tube disposed within the outer easing, means for supplying fuel to the or each flame tube, a diffusing inlet for delivering air under pressure into the outer casing, means to divide and to guide the air flow into an annular diffusing passage or passages between the outer casing and the flame tube and into a diffusing region immediately upstream of the flame tube, and inlet means for admitting air into the flame tube from the diffusing region. According to the invention, the dividing and guiding means comprises at least one ring, disposed immediately upstream of the flame tube, which is shaped and arranged to direct part of the air flow from a compressor of the engine into the annular diffusing passage or passages between the outer casing and the flame tube and to direct the remaining air flow into the diffusing region, the downstream end of the ring being spaced axially from the upstream end of the flame tube by a short distance so as to allow flow in either direction between the diffusing region and the annular diffusing passage or passages whereby variations of static pressure across a transverse plane just upstream of the upstream end of the flame tube can be substantially equalized. The invention is shown applied in the case of combustion equipment comprising an annular flame tube 1 disposed within an annular air casing formed by walls 9, 10, the upstream end of the flame tube being shaped so as to form a pair of annular troughs 4 within the flame tube and an annular trough 2, 5 outside the flame tube. Fuel vaporizing tubes 3 of J-shape are disposed within the flame tube being secured to the wall 2. Two ring members 14, 15 are disposed in the diffuser passage 11 upstream of the flame tube, the leading edge of the ring 14 being disposed upstream of that of the ring 15. The trailing edges of the two rings are spaced upstream of the upstream end of the flame tube so as to afford annular gaps 16, 17. The rings 14, 15 provide with the upstream end walls 2, 5 of the flame tube an annular diffusing region 8. The rings 14, 15 are mounted on struts 13. Air enters the flame tube through the J-tubes 3, also through inlet openings 7 and 19. Specification 902,510 is referred to.