GB880488A - Improved reheat combustion equipment of gas-turbine engines - Google Patents

Abstract

880,488. Generating combustion products under pressure. ROLLS-ROYCE Ltd. Jan. 15, 1960 [Jan. 22, 1959], No. 2377/59. Class 51 (1). [Also in Group XXVI] Reheat combustion equipment of a gasturbine engine comprises two or more injector means for injecting fuel into the gases exhausted from the turbine or from a stage thereof and at least two open-ended flame tubes or tubular shields are provided downstream of the fuel injection means, the flame tubes being disposed one within the other and their upstream and downstream ends being substantially co-terminous. Fuel is supplied to the spaces afforded by the flame tubes and means are provided for variably selecting the number of injector means to which reheat fuel is supplied. The invention is shown applied in the case of exhaust reheat equipment of a gas-turbine jet engine, a spider member 15 disposed within the jet pipe 13 supporting annular reheat fuel manifolds 16, 17, 18 which have orifices for injection of fuel into the gas stream. The spider member 15 also supports a pilot ignition chamber 28 to which fuel is supplied by means of injector 29, ignition being effected by means of an igniter 29a. Two tubular flame tubes or shields 34, 35 are disposed downstream of the fuel manifolds 16, 17, 18 and a V-section flame stabilizing ring 31 is supported within the flame tube 34 by means of three radially-extending V-section flame stabilizers 33; a flame stabilizing ring 32 is similarly supported within the flame tube 35. The flame tube 35 is spaced from the wall of the jet pipe 13 by means of corrugated spacers 37, 38 so that relatively cool gases flow adjacent the wall of the jet pipe. Fuel is supplied from a tank 19 by means of a pump 20 to a cylinder 21, the outlets to the ducts 23, 24, 25 which are connected to the manifolds 16, 17, 18 respectively being controlled by an axially-movable piston 26. The pilot fuel injector 29 is connected by a duct 30 direct to the outlet duct from pump 20. Reheat fuel is first supplied to manifold 18 and then additionally to manifold 17, fuel from these manifolds passing into the space within flame tube 34, combustion occurring at approximately the stoichiometric ratio. With maximum reheat, fuel is also supplied to the manifold 16, this fuel passing into the combustion space between flame tubes 34, 35, combustion again taking place at approximately stoichiometric ratio.