GB781923A - Improvements in or relating to combustion equipment of gas-turbine engines - Google Patents

Abstract

781,923. Generating combustion products under pressure. ROLLS-ROYCE, Ltd. Aug. 31, 1955 [Sept. 8, 1954], No. 26072/54. Class 51 (1). Combustion equipment for a gas turbine engine comprises a flame tube having a wall part 14c formed with large apertures 26 for the flow of air to within the flame tube, and a plurality of angularly-spaced beam members 30 which lie on the side of the wall part remote from the combustion space, extend from upstream to downstream of the apertures, are relatively thin in the circumferential direction, are secured at axially-spaced spaced points to annularly-extending structure, and are secured at an intermediate point thereon to the flame tube wall part adjacent the apertures to support the wall part. The combustion equipment shown comprises an annular flame tube disposed within an annular air casing formed by inner and outer walls 11, 12. The flame tube inner wall 13 comprises parts 13a, 13b, 13c, 13d, 13e and the outer wall 14 comprises parts 14a, 14b, 14c, 14d, 14e, and corrugated or tangential spacer elements 18 are disposed between the wall parts 13a, 13b; 13d, 13e; 14a, 14b; 14d, 14e so as to permit air to flow over the inner surfaces of the flame tube to cool them. The inner wall part 13c is formed with corrugations 20, 22, with apertures 25 and with an upstream extension 13f. The corrugations are secured to the adjacent wall parts 13b, 13d. The outer wall part 14c is also formed with corrugations 21, 23, with large apertures 26 and with an upstream extension 14f. The corrugations are secured to the adjacent wall parts 14b, 14d. Beam members 30 are disposed around the wall parts 14b, 14c and are formed of sheet metal, the outer edges being folded over at 31 to provide stiffness. The upstream end of each beam is of L-section and the flange 32 thereof is secured to the extension 14f. A Z-section ring 33 having apertures 34 is secured between the extension 14f and the wall part 14b in the region of the flanges 32. The intermediate portion of each beam 30 is also of L-section, the flange 37 thereof being secured by welding to the corrugations of the wall part 14c so as to support the outer wall 14. The downstream ends of the beams 30 are secured to a Z- section ring 35 the central flange of which is apertured at 36. Hook-shaped parts 42 of short circumferential dimension are secured at the downstream side of the ring 35. Z-shaped brackets 43a, 43b, 43c, 44a, 44b, 44c are secured to the flame tube outer wall 14, the brackets 43a, 43b, 44a, 44b being secured to the wall part 14d, and the other two brackets 43c, 44c being secured to the wall part 14e. Upon assembly of the combustion equipment, only one set of brackets, say 43a, 43b, 43c, is secured in position and a bar 40 of H-section is moved circumferentially so as to engage under the three brackets. At the same time a hook-shaped extension 41 on the bar engages with the bracket 42 on the Z-section ring 35. The other set of brackets 44a, 44b, 44c is then welded in position on the flame tube wall parts. The outer air casing wall 12 is then placed in position and setscrews 46 are passed through the outer wall and engaged with tapped holes in the bar 40. An annular sealing member 51 is welded to the part 14e and co-operates with the outer air casing wall 12. Specifications 744,657 and 776,366 are referred to.