GB718105A - Liquid fuel supply systems for internal combustion prime movers - Google Patents

Abstract

718,105. Jet propulsion engines; gas turbines. LUCAS (INDUSTRIES), Ltd., J. Aug. 19, 1952 [Aug. 27, 1951), No. 20114/51. Class 110(3) [Also in Groups XI and XXIX] A gas turbine or jet propulsion engine fuel system comprising a pump supplying fuel to a number of nozzles arranged in parallel each with a spill duct for returning excess fuel to the pump, has a throttle valve associated with each nozzle for controlling the spill flow and a by-pass valve, actuated by a pressure difference across a restricted orifice in a duct leading to one of the nozzles, to divert fuel from between the pump and the nozzles. The burner nozzles a are supplied with fuel from an electrically driven fuel pump f through ducts e restricted orifices c and ducts b. Each nozzle has a spill duct d connected to a main spill duct h. The supply ducts b each have an isolating valve i and the spill ducts d, a throttle valve j. The valves i, j are interconnected by a link k and all the throttle or isolating valves are interconnected by a link m. By the provision of lost motion in the interconnecting means between the throttle and isolating valves, the nozzle can be brought into or put out of action successively. The link in is manually controlled by a lever n. The by-pass valve comprises a closure member o attached to a spring loaded piston r. One end of the cylinder t is connected to the fuel supply duct e and the other end to a passage u which terminates in a valve seating v. The flow through the valve seating v from the duct e and thus the pressure on the right hand side of the piston r is controlled by a spring loaded flexible diaphragm x the movements of which are controlled by the pressure drop across one of the restrictions c. Increase of this pressure drop will cause the pressure on the right hand side of the piston r to increase and the valve member o to open and reduce the flow to the nozzles a. Each isolating valve i is arranged to be fully opened by a small movement of the valve i and to remain open during further movement of the valve j. There may be provided with some of the isolating or throttle valves or their connecting means, switches 12 for controlling the speed of the motor g so that when some of the nozzles are cut out the speed of the motor is reduced. An alternative method of controlling the pressure on the righthand side of the piston r by the diaphragm x is also described. In this arrangement, a pivoted lever actuated by the diaphragm x diverts fuel from the chamber on the left hand side of the diaphragm x either to the right-hand side of the piston r or to the suction of the pump.