GB753219A - Means for controlling the supply of liquid fuel to gas turbines - Google Patents

Abstract

753,219. Gas turbine plant. LUCAS (INDUSTRIES), Ltd., J. Jan. 26, 1954 [Jan. 28, 1953], No. 2416/53. Class 110(3) [Also in Group XXIX] To prevent excess liquid fuel being supplied to a jet propulsion or other gas turbine engine during acceleration a valve 15 adapted to control a fuel by-pass is provided, this valve being operated through a lever 14 responsive to the opposed actions of a liquid pressure responsive to engine speed and the fuel pressure difference across a restricted orifice f in the fuel supply duct e and operating to open the bypass temporarily when the means for controlling the fuel supply is moved in a direction to increase that supply. As shown, the lever 14 is acted on at opposite ends by two flexible diaphragms 5, 9 loaded by springs 6, 10. The diaphragm 5 separates a compartment 4 in which the pressure is related to the turbine speed from a compartment 3 connected through a further compartment i with the suction side of a fuel pump c. The pump c which may be driven by the engine supplies the burner nozzle a through a pipe e containing an adjustable restriction f the pressure drop across which is applied to the diaphragm 9 so as to oppose the pressure in the compartment 4. The fuel by-pass comprises a passage q branching into a pipe 16 controlled by the valve 15 and a passage p controlled by a further valve o in the compartment i. The valve o is carried by a lever n and operated by a diaphragm k subject to the opposed actions of a tension spring r adjustable by a driver's pedal t and the pressure in a compartment j related to engine speed. The compartments 4 and j are supplied from the pipe e through a restriction w and the pressure in them is controlled by a centrifugally operated leak-off valve 22 carried on a rotor 19 driven by the turbine and divided by a partition 20 one side of which is connected to the outlet of the restriction w through ports 23 and a pipe u and the other side of which is connected to the inlet of the pump c through a passage 24 and the compartment i. In a modification in which spill type burners are used, the restriction f is adjusted by an evacuated capsule in response to atmospheric pressure and the burner spill pipe is provided with a re-circulating and a relief valve. Any of the flexible diaphragms described may be replaced by equivalent pistons.