GB853706A - Valves for controlling re-heat fuel supply systems for an aircraft gas turbine engine - Google Patents

Abstract

853,706. Jet propulsion plant. LUCAS (INDUSTRIES) Ltd., J. Nov. 2, 1956 [Aug. 11, 1955], No. 23153/55. Class 110 (3). [Also in Group XXIX] Fuel supply control means for re-heat burners on aircraft gas turbines comprise a plurality of main fuel control valves d<SP>1</SP>, d<SP>2</SP> corresponding to the number of burners and each being opened by fuel or other fluid pressure in a common supply pipe a, an additional fuel or other fluid pressure actuated valve d<SP>x</SP> in association with each of the main valves except one, d<SP>1</SP>, the additional valves controlling fuel flow from a branch pipe a for preliminary filling of the associated burner supply pipe prior to the operation of the associated main valve, and a plurality of independently pilot-operable control-valves j<SP>1</SP>-j<SP>4</SP> for the fluid pressure operable valve. Fuel is supplied past a main valve 3 actuated by a piston 5 controlled by a hinged leak-off valve 12 having a spring follow-up connection with a piston at 8, in response to blower pressure acting on the bellows 13 modified by a pilot controlled cam 23 actuating a leak-off needle valve 18. A further valve 29 controlling the main fuel flow is actuated by a piston 31 under the control of a diaphragm valve 37 in response to the pressure drop across the main valve 3. When the pilot closes a first switch 27 to open a solenoid valve k<SP>1</SP>, fuel pressure is reduced within a bellows f<SP>1</SP> to open a valve d<SP>1</SP> and supply the first re-heat burner at b<SP>1</SP>. At the same time the valve 18 is slightly closed to increase the opening valve 3. To start the second re-heat burner b<SP>2</SP> a second switch 27 is closed together with the slight closure of the valve 18 whereby a solenoid valve j<SP>2</SP> reduces fuel pressure within a bellows f<SP>x</SP> to open a valve d<SP>x</SP> so that fuel at a<SP>x</SP> fills the pipe b<SP>2</SP> up to the second re-heat burner and fuel pressure adjacent to the re-heat burner contained in the duct for the hot propulsion gases acts via pipe z in a bellows u to move a hinged shuttle valve r to disconnect the solenoid valve from the bellows fx and allows it to reduce the pressure in a bellows f<SP>2</SP> whereby the valve d<SP>2</SP> opens and supplies fuel through the second reheat burner from the main conduit a. Further re-heat burners may similarly be brought into action by the pilot.