GB899913A - Improvements relating to monofuel reaction chamber apparatus - Google Patents

Abstract

899,913. Generating combustion products under pressure. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. April 19, 1961 [May 9, 1960], No. 16334/60. Class 51 (1). [Also in Group XXVI] The invention relates to apparatus for producing a flow of gaseous working fluid by the decomposition of monofuel within a reaction chamber, the gaseous fluid being utilized for example in a turbine starter for a gas turbine engine. The apparatus is shown in the Provisional Specification drawing and comprises a reaction chamber 1 which is supplied with monofuel from a tank 2 through ducting 3 which includes non-return valves 4, 5. Upon starting, air under pressure is supplied from a cartridge 9 through a non-return valve 8 to a shuttle valve 7. The valve is shown in Fig. 1 and comprises a body portion 20 containing a valve member 21 having an enlarged head 22 at its upper end and an enlarged head 23 secured at its lower end, the valve member having a longitudinal bore 24 and a transverse bore 25. The valve body portion 20 comprises a passage 26 which is connected to the air cartridge, a passage 29 which is connected to the reaction chamber 1, an outlet 28 connected to the low-pressure side of a pressure intensifier 9<SP>1</SP>, and a vent 30 open to atmosphere. The air supplied to the passage 26 at starting causes the shuttle valve 21 to rise until the head 23 abuts the shoulder 31 of the valve casing, and air then passes through passage 29 to the reaction chamber 1, also through outlet 28 to the pressure intensifier. The intensifier causes monofuel in the line 3 to pass into the reaction chamber through the atomizer 6, the monofuel mixing with the air supplied through the valve 7 and the mixture being ignited by a spark device. The pressure in the reaction chamber increases and so the shuttle valve 21 is caused to move downwardly, against the reducing pressure of air from the cartridge, to the position shown in Fig. 2 so cutting off the air supply which is vented to atmosphere. The pressure of gases within the reaction chamber is simultaneously applied to the low-pressure side of the pressure intensifier 9<SP>1</SP> through passage 29 and outlet 28 so maintaining the supply of monofuel through the line 3 and main fuel valve 10 to the reaction chamber, the valve 10 being opened by the pressure developed in the reaction chamber. An electrical control unit 11 is provided, operation of the unit causing air to be released from a cartridge 9, energizing the ignition device 14 and causing the by-pass valve 15 in the monofuel supply line to close. The high-pressure side of the pressure intensifier contains sufficient monofuel to enable a single starting operation to be performed. A stand-by cartridge 16 containing a deflagrant may be provided. Specifications 784,121, 787,572 and 816,752 are referred to.