GB861843A - Improvements in or relating to starting systems for gas turbine engines - Google Patents

Abstract

861,843. Gas-turbine plant. ROVER CO. Ltd. June 10, 1959, No. 19835/59. Class 110 (3). A starting system for a gas-turbine engine with a combustion chamber, the burner of which is supplied with air and fuel under pressure, comprises a motor 1 driving a pump 2 supplying air to the burner on starting the engine and until a predetermined compressor speed is reached, a rotary contact-breaker 4 with a condenser across the contacts also driven by the motor 1, an ignition coil 7 connected to a low-tension supply 6 and a sparking plug 10 connected to the secondary winding of the coil and positioned in a combustion chamber of the engine. Closing the ignition switch 8 closes a solenoid operated switch 25 which completes the ignition circuit through the lowtension supply 6 which also energizes a starter motor 24 which rotates the compressor 14 and turbine (not shown). Simultaneously energized are a solenoid 23, the air pump driving motor 1 and the contact-breaker 4. Air is supplied to the pump through a pipe 12. Air entering the pipe 12 is at a slightly higher pressure than the compressed air supplied by the compressor to the combustion chamber 11. The solenoid 23 operates a valve 22 thereby supplying fuel to the burner where the fuel-air mixture is ignited by the sparking plug 10. At a predetermined compressor speed a normally closed pressure-sensitive switch 27 opens and thereby de-energizes the solenoid of the switch 25. This cuts-out the ignition circuit and stops the motors 1 and 24, but the solenoid 23 remains energized until the switch 8 is opened when the fuel supply will be cut off. When the pump 2 is inoperative air is supplied to the burner through a by-pass pipe 18 having a non-return valve 19.