GB717679A - Improvements in or relating to fire precaution arrangements for aircraft gas turbineengines - Google Patents

Abstract

717,679. Gas turbine plant. BRISTOL AEROPLANE CO., Ltd. April 10, 1952 [April 19, 1951], No. 9220/51. Class 110(3) To lessen the risk of fire in an aircraft gas turbine engine, at least the fuel pump with associated accessories and the control apparatus and elements of the fuel system which operate at comparatively low temperature are enclosed by a casing carried by the engine. A comparatively low temperature is stated to be a temperature at which rapid evaporation of leaked fuel does not occur. The fuel pump 14, Fig. 4, fuel filter 30, and flow and air/fuel ratio controllers 31, 32, are bolted together and surrounded by a sheet metal casing 24. The casing is formed in two parts 24a, 24b which are held together by toggle clips 25. The top surface of the casing 24a is stiffened by two longitudinal angle members 26 which are pivoted at one end to lugs 27 carried by a ring 19 forming a seal between the casing 24 and the lubricating oil sump 15 and at the other end to resilient support arms 27 bolted to the compressor casing 11. This arrangement allows differential expansion between the pump and compressor casings. The casing 24 is suspended beneath the compressor casing 11 by a ring 19 and pivotal links 28. The filter 30 extends across the casing and has alternative fuel inlets at each side. The pilots throttle is connected to an operating arm 38. Fuel is sprayed into the combustion chamber 40 by a number of injectors 41 connected by pipes 42 to a distributor 43 which is connected by a pipe 44 to the controller 31. To minimize the fire risk due to the presence of the combustion chambers, the injectors 41 and their supply pipes are enclosed by a sheet metal shrouding ring 46 bolted to the flanges 47, 49. A tubular member 51 connects the casing 24 to the ring 46. The joints 52, 53 at each end of the member 51 allow a certain amount of universal movement and the joint 52 is also arranged to slide relative to the casing 46 so as to allow for differential expansion of the various parts. A member 54 is urged by a spring 55 against a facing 56 provided on the fuel pipe 44 to form a gas-tight joint between the casings. Provision is made for the supply of fire extinguishing or preventing medium such as methyl bromide into the ring 46 at 57 and into the casing 24. A modification in which the pump casing 24 is arranged to one side of the compressor casing is also described. Specification 703,645 is referred to.