GB723110A - Improvements in or relating to gas-turbine engines - Google Patents

Abstract

723,110. Gas turbine plant. ROLLSROYCE, Ltd. Sept. 17, 1952 [Sept. 17, 1951], No. 21832/51. Class 110 (3). [Also in Groups XI and XII] A fuel injection nozzle and fuel supply arrangement for a gas turbine engine comprises a plurality of fuel injectors and an annular manifold formed by a number of blocks, one for each fuel injector, each block having a main duct with socket ends arranged to receive circumferentially-extending pipes connecting it with adjacent blocks; the blocks and injectors being held together by releasable means and being located relative to one another by a spigot and socket joint through the spigot of which passes a branch duct body to the injector from the main duct. The gas turbine combustion equipment shown, Fig. 1, comprises inner and outer annular air casing walls 10, 11 surrounding a plurality of axially-extending flame tubes 12. Each flame tube is provided with a frustoconical duct member 14 which divides the air entering the air casing into two streams, one of which flows around the flame tubes as at 17, and the other of which flows into the flame tubes as at 15. Each flame tube 12 has a fuel injector comprising a nozzle 25 which engages the centre of the swirl vanes 18 and a strut 26 which extends through the air casing wall 11. A flange 27 on the strut partly fills an aperture 22 in the duct member 14 with the internal surface of which it forms a smooth surface. The strut is attached to the air casing 11 by a bolted flange 28. The nozzle 25 is of the type adapted to feed both pilot and main fuel into the flame tube 12 and this fuel is conveyed to it by ducts 30, 31 in the strut 26. The fuel is supplied to these ducts by a fitting 32 and a manifold comprising a plurality of blocks 32a connected by circumferentially-extending fuel pipes 38a, 38b. The fitting 32, Figs. 2 and 3, comprises a body portion formed with the outer ends of the ducts 30, 31 and with side ducts 33, 34 leading to a machined face 35. The duct 33 extends beyond this face in the form of a spigot 36. The bore of the duct 34 is enlarged adjacent the face and has an annular channel cut in the wall to receive a sealing ring 37. Each of the blocks 32a has a machined face 39 which abuts against the machined face 35, a spigot 40 which engages the enlarged bore of the duct 34 and a socket to receive the spigot 36. The socket is channelled to receive a sealing ring 43. The machined faces 35, 39 are held together by studs 41 engaged by nut members with hexagonal-heads 42a and threaded shanks 42b. The shanks are grooved to engage bifurcated lugs 44 extending from the fitting 32. The ducts 45, 47 in the block 32a are connected to circumferentiallyextending ducts 46, 48 which are provided with sealing rings 49 adapted to engage the ends of the arcuate tubes 38a, 38b. The manifold consisting of the blocks 32a and pipes 38a, 38b is attached to the air casing wall 11 by a number of straps 52 which engage a pair of clamping pieces 51 attached to the tubes 38a, 38b midway between the blocks 32a. Fuel may be fed to the manifold through one of these attachments. The flexibility of the tubes 38a, 38b allows the machined faces 35, 39 to be brought properly into abutment.