Patent GB-741325-A (GB)
Title: Improvements in or relating to vaporising combustion systems
Inventor: VICKERY JOHN
IPC: F23R3/32
Filed: 1953-04-22
Abstract: 741,325. Vapour burners. POWER JETS (RESEARCH & DEVELOPMENT), Ltd. April 21, 1954 [April 22, 1953], No. 11098/53. Class 75(1). [Also in Group XII] Combustion equipment for example of a gas turbine engine comprises a flame tube within an outer chamber and means for vaporising liquid fuel by the heat of combustion and for introducing such vaporized fuel into a primary combustion zone within the upstream end of the flame tube, a channel extending longitudinally from the upstream end for introducing coolant fluid such as air into the core of combustion products downstream of the combustion zone. In Figs. 1 and 2 a flame tube 21 is disposed in an outer casing 20 and combustion air is admitted to the flame tube through openings 22 at the upstream end. Some air also passes through the tube 24 and issues through openings 25, 26 to mix with the combustion gases. Fuel and air is introduced into the annulus 27 between the tubes 24 and 28, passes through the openings 30 and flows upstream through the spaces 31 formed by the corrugated tube disposed around the tube 28, the fuel becoming vaporised and issuing into the flame tube at 34. The annulus 27 is divided into sector-shaped ducts. In Fig. 3, the central air tube 24 is provided at its downstream end with a separate perforated end piece 35, the upstream end portion of which is crimped to provide passages 36 through which air flows to impinge on the upstream edges 37 of the slots 30 to prevent deposition at this point. In a similar embodiment, the tube 24 is formed with a perforated end portion and holes are provided for discharge of air near the slots 30 to prevent deposition. The upstream end of the tube 24 may be crimped as in Fig. 6 so that air supplied at the inlet 41 passes not only into the central passage but also through the spaces 42 to the annulus 27. Fuel is supplied to the annular manifold 45 and issues through apertures 46 into the annulus 27. In Figs. 8 and 9, the central tube 24 is provided with a convergent nozzle outlet 47 and swirl vanes 48. Disposed around the tube 24 are not only fuel and air passages 27 but also air passages 49, the latter having holes 50 through which combustion air flows radially outwards. Holes 51 are also provided adjacent the slots 30 to allow air to pass from the air passages 49 to the fuel and air passages 27 to prevent deposition. Fuel is introduced into the passages 27 from a distributer 53 through pipes 54. In Figs. 10 and 11, the central air tube 24 has a convergent-divergent nozzle 57 and a corrugated tube 55 is disposed around the tube 24 to provide fuel and air passages 27 between which the corrugated tube is in contact with the tube 24. Holes 56 are drilled through the tubes 24, 55 where they are in contact for discharge of primary combustion air. The passages 27 are covered with channel-section members 59 to provide vaporising channels for the fuel and air flowing in an upstream direction therethrough, the vaporised fuel and air issuing at 54 and also through holes 60. In Figs. 12 and 13 four fuel vaporising tubes of J-shape are provided being disposed around a central air tube 24 which has swirl vanes 62 at its outlet. An air channel 63 is disposed around the tube 24 and combustion air may be discharged therefrom through slots 64 adjacent the scoops 65. Air may also be discharged therefrom on to parts of the J-tubes which are prone to become hot spots. In Figs. 14 and 15 an annular combustion chamber is shown having an annular flame tube 21 in which an annular air channel 67 is provided. Annular fuel and air passages 71 are provided on the inner and outer surfaces of the channel 67 by means of annular sheets 69, 70. Fuel is introduced into the open ends of the passages 71 through ducts 77, 78. Fuel and air discharge from the passages 71 through slots 30 into the vaporising channels formed by the corrugations 79 and issues through the outlets 34. The channel 67 and sheets 69, 70 are supported within the flame tube by a plate 73. In Figs. 16 and 17 an annular channel 67 is provided within the annular flame tube 21, the upstream end of the channel being crimped at 80. Fuel and air passages 84 and air passages 83 are disposed alternately around the inner and outer walls of the channel 67, air issuing from the passages 83 through openings 86, while fuel and air pass through the slots 30 into the vaporising ducts formed by the corrugations.