Patent GB-714338-A (GB)
Title: Improvements in or relating to gas-turbine engines
Inventor: DAVIES DAVID OMRI
IPC: F02K1/16
Filed: 1951-06-18
Abstract: 714,338. Jet propulsion plant. ROLLS-ROYCE, Ltd. June 6, 1952 [June 18, 1951], No. 14454/51. Class 110(3) A gas turbine jet propulsion engine with a variable area propulsion nozzle and means for burning fuel in the exhaust pipe has a control system comprising means to initiate the fuel supply to the exhaust pipe, means to ignite this fuel supply, means to initiate opening of the variable area properly nozzle simultaneously with. the initiation of the fuel supply to the exhaust pipe and time operated means to cut off the fuel supply on failure of the nozzle to open to a selected area within a selected time from the moment of the initiation of the main fuel supply. The gas turbine jet propulsion engine shown has a variable area propelling nozzle 13b and means 20 for injecting fuel in to the jet pipe 13a. The fuel injecting means 20 is as described in Specification 667,394 and comprises an atomiser 21 located on the downstream side of a baffle 22 associated with an igniter 23, a pilot burner 26 and main fuel injectors 27. The atomiser 21 is fed with fuel from the supply to the main combustion chambers through a pipe 31 and solenoid operated valve 32. The pilot burner 26 and main fuel injectors 27 are supplied with fuel by a pump 38 driven by an air turbine 43, as described in Specification 608,963.The supply of fuel is controlled by a solenoid operated shut-off valve 40 and the supply of air to the turbine is controlled by a valve 45 controlled by mechanism 46 as described in Specification 694,322. A valve 47 actuated by a solenoid 48 permits control of the valve 45 by the mechanism 46. The variable area nozzle is controlled by a reversing valve 53 which is also solenoid operated. When the pilot requires the reheat system in operation he closes the switch 60. This causes the igniter 23 to be energized directly and the solenoids 48, 41, 56 and 33 to be energized through the time switch 66. Air is then supplied to the turbine 43, fuel to the atomiser 21 and pilot and main burners 26, 27, and compressed air to the right hand end of the cylinder 50 to cause the variable area nozzle 13b to open to its maximum extent. After a given period, say three seconds, the time switch 66 opens and if before that time the contacts 62 have not been closed by the opening of the variable area nozzle, the solenoids 48, 41, 56 and 33 are de-energized. This causes the air supply to the turbine 43 and the fuel supplies to the atomizer 21 and the pilot and mam burners 26. 27 to be shut off and compressed air to be supplied to the left hand end of the cylinder 50 to cause the variable area nozzle 13b to close When the variable area nozzle 13b is fully open, contacts 62 are closed, relay 64 energized and contactor 65 thereby closed. Since contactor 65 is arranged in.parallel with the time switch 66, operation of this switch will not deenergize the solenoids 48. 41, 56 and 33 when the contacts 62 have been closed by opening of the variable area nozzle. The burner 20 will then remain in operation until the switch 60 is reopened. Specification 598,183 also is referred to.