GB874502A - Improvements in fuel distribution system for jet propulsion engine afterburners - Google Patents

Abstract

874,502. Jet propulsion plant. GENERAL ELECTRIC CO. May 27, 1958, No. 16947/58. Class 110 (3). In a fuel distribution system for jet propulsion afterburners having a series of radially extending spray bars arranged substantially in a plane at right angles to the longitudinal axis of the afterburner combustion zone, and manifolds connecting selected groups of spray bars, fuel control means responsive to engine operating conditions control the quantity of fuel passing to the manifolds and a fuel selector valve positioned in accordance with the engine throttle setting is associated with at least one manifold to control the fuel distribution to that manifold after distribution to the manifolds has been initiated by the fuel control means. The groups of spray bars are brought into operation sequentially and remain in operation until finally all are in operation and complete fuel distribution over the whole combustion zone area is achieved. The fuel spray bars of an afterburner, Fig. 2, are arranged in a number of groups 17, 18, 20, 21, which are connected in pairs to separate fuel supply manifolds 19, 22. It is not essential that the groups 17, 18, 20, 21 overlap as shown. The groups of fuel injectors 17, 18, 20, 21 are represented by triangles 23, 24, in Fig. 3. Fuel supplied by a pump 25 is metered by a control 26 in response to engine operating conditions which, as shown, are compressor discharge pressure and the throttle lever position. In operation, fuel is first supplied by the fuel control through sectors 24 to provide fuel injection in sector patterns and when a predetermined throttle position is reached a fuel selector valve 32 is actuated, and fuel is injected through the additional sectors 23 to provide for uniform distribution throughout the tail-pipe combustion area. In a modification, Fig. 4 (not shown), a flow dividing valve is provided, to divide the fuel flow proportionally between the manifolds 19, 22. To avoid over-rich mixtures at increased fuel flows, the flow-dividing valve may be arranged to vary the proportions supplied to the manifolds as the total fuel flow increases. In another modification, Fig. 5 (not shown), the flow divider valve is used to divide the flow between two fuel injector systems of the kind shown in Fig. 3.