GB859805A - Improvements relating to gas turbine engine combustion systems - Google Patents

Abstract

859,805. Generating combustion products under pressure. GENERAL MOTORS CORPORATION. July 15, 1959 [July 21, 1958], No. 24270/59. Class 51 (1). In gas turbine engine combustion equipment of the kind comprising a series of flame tubes disposed within an annular casing, each flame tube has at its upstream end a boss having an aperture to receive an actual or a dummy igniter plug, the plug and the boss having inter-engageable parts so arranged that the plug can be inserted through the aperture and may then be rotated to a position in which the parts can engage so that the flame tube can then be supported on the plug and the plug cannot be withdrawn. The object of the invention is to support the flame tubes temporarily pending the insertion of the fuel injector nozzles. The flame tube 22 is disposed within an annular casing, the outer wall of which is shown at 12, being normally supported at its upstream end by means of the fuel injector nozzle 42 engaging a central opening 38 in the flame tube end wall 28, and at its downstream end by means of the transition section 29 which engages within an annular sleeve 27 secured to the flame tube, the transition section being secured at its upstream end to the outer casing 20 by means of supports 31. A hollow boss member 50 is secured at the upstream end of the flame tube by means of a sheet metal plate 48, the radially inner end of the boss being formed with a transverse slot 54 which provides two ledge portions 55. The igniter plug 56 is provided with a flange 64 on its stem portion 62, the flange being of circular form with two side pieces cut away to provide a pair of parallel straight edges 66, the flange being so dimensioned that it may pass through the boss 50 when the edges 66 are disposed parallel to the sides of the slot 54. To support the flame tube therefore before the fuel injector nozzle 42 is fitted, the igniter plug 56 is entered through the opening 58 in the outer casing 12, through the aperture in the boss 50 and then through the opening 60 in the flame tube end wall 28, the plug being disposed so that the flats 66 on the flange 64 are parallel to the sides of the slot 54 in the boss 50 to permit this. The igniter plug is then turned through 90 degrees so that openings in the plug mounting plate 70 align with openings in the plate 76 fixed to the outer casing 12, the plug being secured in position by means of bolts 78. In this position the ledges 55 of the boss 50 rest on the curved end portions 68 of the flange 64 whereby the flame tube is temporarily supported on the igniter plug. Upon insertion of the injector nozzle 42, the flame tube will be displaced slightly so that the boss 50 is lifted off the flange 64, as shown in Fig. 1.