GB773148A - Improvements relating to fuel systems for gas turbine engine installations - Google Patents

Abstract

773,148. Gas turbine plant; centrifugal pumps. ROLLS-ROYCE, Ltd. March 25, 1955 [March 25, 1954], No. 8816/54. Classes 110 (1) and 110 (3). [Also in Group XXIX] In a fuel supply system for a series of jet propulsion gas turbine engines 10, see Fig. 2 and also Fig. 1 (not shown), each engine is supplied from a branch line 20 connected to a common supply line 12 fed by two pumping units. Each pump unit comprises a non- return valve 16, relief valves 17, 18 and a centrifugal pump 22 driven by an air turbine 23. Each branch pipe 20 is provided with a regulating valve 21 and a control valve 11 whilst the pipe 12 is provided with a control valve 13. If desired, the fuel injectors of the engine may be of the spring- loaded variable-area orifice type in which case the valve 21 is omitted. Each relief valve comprises a lever 28 loaded by an evacuated capsule 26, a spring 31 and a piston 32 which is subjected to the delivery pressure of the pump. The lever 28 controls the leakage of fuel from a chamber 35 to a drainage connection 37, the chamber 35 communicating through a restrictor 39 with the delivery side of the pump and having a spring-loaded valve 40, 41 controlling communication between the delivery side of the pump and a by-pass connection 44 leading to the tank or the inlet of the pump. In a modification, see Fig. 3, each pump is of the swashplate type and connected to a piston 51 acting in a cylinder 52. One end of the cylinder is directly connected to the delivery pipe 54 of the pump whilst the other end is connected to the pipe 54 through a restrictor 56 and has connected to it a pair of valve-controlled vents 58. Each vent valve 59 is mounted on a lever 60 which is loaded by a spring 61, apiston 62 subjected to the pressure in the pipe 54, and a capsule 64 subjected to atmospheric pressure.