GB1058083A - Engine fuel supply systems - Google Patents

Abstract

1,058,083. Gas turbine engine fuel systems. BRISTOL SIDDELEY ENGINES Ltd. Sept. 24, 1963 (Sept. 24, 1962], No.36234/62. Heading F1G. [Also in Division G3] A liquid fuel supply system for a jet propulsion engine comprises a metering valve 12a, Fig. 4 controlling the flow of fuel to burners 20a. The valve 12a is positioned by the fluid pressure in a chamber 14a which pressure is controlled by a valve 22c. The valve 22a comprises a valve closure 24a rotated by a diaphragm which is subjected to a reference pressure and a pressure responsive to an engine condition. The closure 24a controls the opening of conduits 28a, 29a connected to the fuel passage 11 and a drain passage respectively. Two conduits (28), (29), Fig.3 (not shown) are provided on opposite sides of the closure (24) which is thus pressure balanced and rotation of the closure in response to an engine error signal connects chamber 14a to high pressure or low pressure to adjust the metering valve 12a. An override valve 59 may be provided to by-pass the valve port 28a and throttle a restrictor 34a in conduit 29a to supply pressure to chamber 14a causing rapid closure of valve 12a. A rich limiting valve may be provided comprising a valve 41 actuated by a piston 42 controlled by a valve 49. The valve 49 is positioned by ram pressure Pc in chamber 55, fuel pressure P 1 upstream of valve 12a which is fed to a bellows 54 and pressure P 3 at the burners fed to a bellows 53. The valve 59 controls leakage from ports 47, 48 connected to the opposite sides of the piston. In a modification a valve similar to 41 maintains a constant pressure drop across the metering valve 12a and the pressure in conduit 28a is modified in accordance with the pressures P 1 and Pc.