GB826408A - Combustion apparatus - Google Patents

Abstract

826,408. Vapour burners: igniting burners. POWER JETS (RESEARCH & DEVELOPMENT) Ltd. Feb. 1, 1957 [Feb. 2, 1956], No. 3296/56. Classes 75(1) and 75(3) [Also in Group XII] Combustion apparatus for operation on diesel or other heavy distillate fuel oil and for use, e.g. in gas turbine plant comprises a casing 1 having an inlet e.g. at the left hand end for air and an outlet at the right hand end for the combustion gases, a porous block 19 supported in the path of air from the inlet and fed with liquid fuel from a supply pipe 23 to saturate the block with fuel, an electrical igniter 24 for igniting fuel vapour emitted from the block, a combustion zone within the casing 1 on the outlet side of the block 19, a vaporizing tube 11 arranged in the path of ignited vapour from the block 19 to be heated by the ignited vapour and extending within the combustion zone and a fuel injector 16 to inject fuel into the vaporizing tube and thence to pass into the combustion zone. As shown, the combustion apparatus is mounted within an elongated air casing 1 arranged to receive air at its inlet 18 from a compressor through a heat exchanger, a turbine driving the compressor and receiving combustion gases from the combustion chamber and discharging into the heat exchanger. At the upstream end a tubular casing 8 is supported by flexible struts 10, and at its downstream end is supported in the upstream end of a flame tube 4 by frusto-conical part 8a and a crimped spacer 9 to define an annular gap between members 8a and 4, the flame tube 4 being in turn supported in the casing 1 at its upstream end by three radial pins 6 secured to the casing 1 and slidably engaging in bushes 7 let into the flame tube 4 and at the down stream end by a Z-section ring 5. The member 8 has apertures 8c to admit air from the inlet end to carry the ignited fuel vapour into the flame tube 4 through the vaporizing tube 11 and around this tube via holes 12a in the plate 12 supporting the tube 11 in the casing 8. A cap 13 fits around the end of the tube 11 within the combustion zone and forms with the tube 11 an annular passage for leading fuel/air mixture in an upstream direction into the combustion zone at the entrance to the flame tube 4. The outlet end of this passage is divergent and an annular baffle 14 is provided within the passage. Secondary air enters the flame tube through the gap 9 and apertures 4a, 4b in the wall of the flame tube. The pipe 15 is enclosed by a jacket 17 fed with cooling air tapped from the outlet of the compressor upstream of the heat exchanger finally escaping through holes 17a, the air serving to protect the fuel in pipe 15 against overheating by the heated inlet air of the combustion chamber. The porous block 19 is made of two sleeves 19a, 19b of porous ceramic material nested one within the other with an electric heating element 20 in the space between them.