GB746055A - Means for controlling the rate of supply of liquid fuel to combustion apparatus - Google Patents

Abstract

746,055. Gas turbine plant; jet propulsion plant. LUCAS (INDUSTRIES), Ltd., J. June 4, 1954 [June 22, 1953], No. 17181/53. Class 110(3) [Also in Group XXIX] Apparatus for controlling the supply of liquid fuel to a prime mover such as a jet propulsion engine or a gas turbine comprises a spill valve i controlling a pipe d branching off a conduit between a constant displacement pump e and burner f, a liquidoperated servo-mechanism for operating the spill valve including a spring-loaded stepped or like differential piston c working in a corresponding cylinder a, b, means responsive to a variable working condition for controlling communication between the smaller end b of the cylinder and a region of low pressure and means connecting the larger end a of the cylinder remote from the spill valve also to a region of low pressure, the servo-mechanism being responsive also to the pressure at which fuel is delivered to the burner. The servo-control means comprises a vent valve p movable in response to variations in a working condition such as the speed of the prime mover, the atmospheric air pressure, the pressure of the air supplied to the combustion chamber by a blower, or the temperature of such chamber. The valve p controls the leakage of high pressure fuel from the. smaller diameter part b of the servo-cylinder and in the event of failure of the servo-control means, the latter may be isolated by a manually operable emergency valve q. The servo-piston c then opens the spill valve when the fuel delivery pressure is such that the difference in the total pressures on the ends of the piston overcomes the spring j. The spill valve may be constituted by the larger end of the piston c or by a conical or like plug formed on or secured to the piston. The spill valve may be separate from but operatively secured to the piston. The ends of the piston c are connected by a passage n containing a restricted orifice m. The passage may be formed in the cylinder wall.