GB862528A - Improvements in combustion devices for continuous-flow internal combustion engines - Google Patents

Abstract

862,528. Generating combustion products under pressure. SOC. NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION. Nov. 19, 1957 [Nov. 27, 1956], No. 35987/57. Class 51 (1). A combined fuel injector and flame stabilizing device for use in a combustion chamber through which passes a flow of combustion-supporting gas such as air at high speed, comprises a body the cross-section of which diverges in the direction of flow, being formed by walls or a wall which diverge or diverges from the upstream end, the upstream end of the body being provided with an opening or openings for flow of air into the space between the divergent walls or wall, and with means which project inwardly so as to create a turbulent zone downstream thereof, fuel injection devices being disposed adjacent the opening or openings and so directed that jets of fuel inclined downstream with respect to the direction of air flow through the body, impinge on the divergent walls or wall. The device in Figs. 1 and 2 comprises a pair of flat plates 1, 2 which are disposed. so that they diverge in the direction of flow F of the combustion air stream. Two fuel distributers 4, 4a and 5. 5a are disposed within the open upstream end 10 of the device, the distributers having fuel discharge orifices 6, 7, which are disposed so that jets of fuel 8, 9 issuing therefrom impinge on the walls 1, 2. To increase the turbulence created by the walls 1, 2 external fins 3 may be provided. The device shown in Figs. 4 and 5 comprises a wall 11 of frusto-conical form diverging downstream and having an inwardly-curved lip 16 at its upstream end. The fuel injection device comprises a ring manifold 17 having discharge orifices 18, 20 through which fuel is ejected so as to impinge on the wall 11. A further set of fuel discharge orifices 22 is provided in the manifold through which fuel is injected in a direction parallel to the axis. A fuel distributer of cylindrical form may be provided in place of the ring manifold 17, the discharge orifices being formed in a frusto-conical wall thereof. A device in accordance with the invention is utilized in the apparatus shown in Fig. 6 which also comprises a fuel distributer 24 and a pilot burner device 25 which comprises a fuel injector 28 and an air intake, not shown, the pilot flame issuing through opening 27. The combined fuel injector and flame stabilizing device is similar to that of Figures 1 and 2 except that fuel is also ejected through orifices 33, 34 to flow along the outer surfaces of the plates 1, 2, and an auxiliary screen 35 mounted on a plate 36 is also provided. In Fig. 8, the device comprises a pair of divergent annular walls 50, 51 having ring manifolds 40, 41 respectively at their upstream ends, an end-plate 52 having air inlet openings 53 being disposed between the upstream ends of the walls. The downstream ends of the walls 50, 51 are provided with longitudinally-extending slots 54. Supplementary fuel injectors may be disposed around and within the annular device 50, 51. A perforated grid may be disposed downstream of the annular device 50, 51 and supplementary fuel injectors so as to produce a homogeneous flame. A series of annular devices similar to that of Fig. 8 may be combined in one unit, the devices being of increasing diameters and spaced axially along the length of the combustion chamber, the device of least diameter being the most upstream. In Fig. 12 a pre-combustion chamber 63 is provided having a flame-holder device 64, the combustion gases and further air passing through conduits 66 to an annular collector 67 and thence into an annular device 50, 51 similar to that of Fig. 8, supplementary fuel injectors 55 being disposed around and within the device 50, 51.. The device is stated to be suitable for combustion chambers of gas turbine jet engines, ram-jet units and for reheat combustion chambers, the walls of the device in the latter case being made so that they may be retracted when reheat is not in use.