Patent GB-717669-A (GB)
Title: Liquid fuel supply systems for prime movers
Inventor: JONES WILLIAM EDWARD
IPC: F02C7/22
Filed: 1950-11-08
Abstract: 717,669. Gas turbine plant. LUCAS, Ltd., J. Nov. 2, 1951 [Nov. 8, 1950], No. 27270/50. Class 110(3) [Also in Group XXIX] In a liquid fuel supply system for jet propulsion engines and gas turbines in which fuel is supplied to a burner f by the joint action of two pumps a, a<SP>1</SP> and is regulated by a pair of automatically controlled servo-operated means, the servomechanism of one of the regulating means is controlled by one of a pair of automatic control means 1, 2 and the servo-mechanism of the other regulating means is controlled by the other automatic control means and a normally open isolating valve k is arranged in a connection between the two servo-mechanisms so that on failure of either servo-mechanism or its automatic control means, the fuel supply may be maintained by the unaffected pump on closure of the isolating valve. Manually operated means 3, 4 are provided to modify the action of the respective control means 2, 1 to enable the effective pump to maintain an adequate supply of fuel. The pumps shown are of the variable delivery swash-plate type described in Specification 577,016, [Group XXIX], the obliquity of the swash-plates being regulated by spring-loaded servo-pistons b under the control of the respective vent valves h, i which form part of the automatic control means 1, 2. Liquid fuel from the pumps a, a<SP>1</SP> passes in succession through the control means 1, 2 to the burner f. The control means 1 is responsive to the flow of fuel and to the atmospheric pressure and the control means 2 is responsive to the flow of fuel and to the pressure of air supplied by a blower to the prime mover. The vent pipes e of the servo-mechanisms are connected by a pipe j containing the isolating valve k. The latter may be operated manually or automatically in response to an abnormal fuel pressure in any part of the system. The vent valve h is operated by a capsule o subject to the pressure drop across two throttles in, p arranged in series in the fuel supply line. The throttle m is operated manually by the lever 4 and the throttle p is operated by a,servo-piston r under the control of a vent valve v. The valve v is actuated by a lever w subject to the action of opposed springs x and opposed capsules 5, 6. The capsule 6 is open to the atmosphere and the capsule 5 is evacuated. One of the springs acts on the piston r through a push rod y. The other vent valve i is operated by a spring-loaded lever 23 actuated by a diaphragm (or piston) 26 subject to the pressure drop across a fuel throttle 7 actuated by a servopiston 8. The piston 8 is controlled by a vent valve 10 carried on a lever 11 loaded by opposed springs 12, one of which is connected to the piston 8, and actuated by an evacuated capsule 14 in a chamber 15. The latter is connected through a conduit 16 with a restriction 17 with the blower delivery. The manually-operated means 3 comprises a throttle 19 by which the pipe 16 may be connected to atmosphere to modify the effect of the blower air pressure on the control means 2. The manually-operated means 3, 4 may be operated by a common linkage. Instead of controlling the pump regulating means. the servomechanisms may control spill or by-pass valves, or throttles in the fuel supply lines. Specification 612,624, [Group XXIX], also is referred to.