GB738006A - Improvements in or relating to gas turbine engines - Google Patents

Abstract

738,006. Gas turbine plant. ROLLSROYCE, Ltd. Oct. 21, 1953 [July 12, 1952], No. 18428/52. Class 110 (3). [Also in Groups XII and XXXIII] In gas turbine engine combustion equipment of the kind comprising a flame tube or tubes enclosed in an air casing, means are provided for bleeding-off boundary layer air from a wall of the diffuser ducting which connects the compressor discharge to the combustion equipment, the air bled-off being led into the flame tube. The diffuser ducting comprises inner and outer walls 18, 17 which are interconnected at spaced intervals by hollow streamlined struts 19. A tubular flame tube 15 is disposed between the inner and outer walls 13, 14 of the air casing and comprises a flare member 26 with air inlets 25 and swirl vanes 27. The downstream end of each strut is formed with a frusto-conical duct part 20 which extends both upstream and downstream of the trailing edge of the strut and supports, at its downstream end the inlet end 22 of the flame tube. The downstream end of the strut 19 is also formed with a hollow boss 34 and also a radial web 35 which is formed with an axially-projecting boss 36 to carry a fuel injector 37, to which fuel is supplied through the bore 38. Boundary layer air is tapped off the walls 17, 18 of the diffuser duct through circumferential slots 28 into annular manifolds 29, 30 and thence passes through ports 31, 32 into the hollow interior of the strut 19. The bled-off air passes through the hollow boss 34 and swirl vanes 27 into the flame tube. Further combustion air flows through the duct 20 and openings 25 in the flare 26 to the flame tube. The invention is applicable to combustion equipment for gas turbine engines having either axialflow or centrifugal-flow compressors.