GB739076A - Liquid fuel control valve assembly - Google Patents

Abstract

739,076. Gas turbine plant. LUCAS (INDUSTRIES), Ltd., J. Oct. 23, 1953 [Oct. 27, 1952], No. 26885/52. Class 110 (3). [Also in Group XXIX] A control valve assembly for controlling the supply of liquid fuel to the atomizer of an enginestarting turbine comprises a spring-closed closure member d controlling communication between a fuel supply passage b and a return passage f, a spring-closed closure member h controlling communication between the passage b and a cylindrical chamber having an outlet o to the atomizer and a drain outlet q, a spring- loaded valve piston m slidable in the chamber j to control the inlet i to the chamber and also the drainage outlet q, and a pair of solenoids or electromagnets t, u for imparting opening movements to the closure members d, h respectively. After both solenoids have been energized and the supply pump started, a restricted flow of fuel passes through the valve seat c to the return passage f but the piston m maintains the inlet i closed after a predetermined time, the solenoid t is de-energized due to the operation of a time switch and the closure member c engages its seat c. The sudden rise of pressure thus caused in the passage b is sufficient to open the passage i so that fuel then passes to the atomizer. At the same time the piston m engages a seat r to cut off the drainage outlet q. Once the passage i is open, the fuel pressure acting on the full area of the piston m keeps it open. To interrupt the fuel supply to the atomizer the solenoid u is de-energized by opening a further switch. If sufficient clearance is provided between the piston m and the wall of the chamber j, the passage p between the outlet o and the drainage outlet q may be dispensed with.