Abstract: A fuel vaporizer for a gas turbine engine combustion chamber comprises a hollow cylindrical stem open at one end and branching into two radial branch ducts at the other end which terminate in outlets facing towards the inlet end. In order to ensure more even cooling of the vaporizer stem, the fuel injector which lies inside the stem has two outlets which direct fuel onto those parts of the interior wall of the stem which lie between the branch passages, and a baffle divides the interior of the stem to ensure that each branch passage is fed with fuel from only one fuel injector, and each fuel injector supplies only one branch passage.

Abstract: A gas turbine engine comprises an annular combustion chamber (13) intended for low nitrogen oxide emission. The chamber has a pre-mixing section (20) in which an air-fuel mixture is brought to a significant degree of vaporization before issuing through a grill (22) at the end of the pre-mixing section into a main section (21) of the chamber. Pilot sections (18,19) at opposite sides of the pre-mixing section have outlets (28,29) through which burning mixture from the pilot sections is discharged into main section (21). The grill (22) defines openings (35) through which the fresh mixture from the pre-mixing section (20) is discharged across the outlets (28,29) of the pilot sections (18,19) to mix with and become ignited by the burning mixture.The pre-mixing section (20) is an annular duct (33) having walls (15,16) which extend in the direction of the axis of the chamber and are straight in that direction though slightly convergent. The arrangement favors vaporization in the duct without auto-ignition.

Abstract: The invention relates to a fuel system for a gas turbine engine wherein an annular combustion chamber 10 has an annular series of pairs of first and second nozzles 15,16. In one mode of operation fuel is supplied only to the first nozzles 15. In another mode, fuel is supplied also to the second nozzles. The change has to be made during operation of the engine. If the first and second nozzles had separate supply manifolds, the manifold pertaining to the second nozzles would have to be primed and purged respectively when initiating and terminating the use of the second nozzles. To avoid this difficulty the first and second nozzles are supplied by a single manifold 12 and the second nozzles are controlled by individual valves 21 situated close to the latter nozzles and operated collectively by a fluid pressure supply 26,27.

Abstract: A gas turbine engine comprises an annular combustion chamber (13) intended for low nitrogen oxide emission. The chamber has a pre-mixing section (20) in which an air-fuel mixture is brought to a significant degree of vaporization before issuing through a grill (22) at the end of the pre-mixing section into a main section (21) of the chamber. Pilot sections (18,19) at opposite sides of the pre-mixing section have outlets (28,29) through which burning mixture from the pilot sections is discharged into main section (21). The grill (22) defines openings (35) through which the fresh mixture from the pre-mixing section (20) is discharged across the outlets (28,29) of the pilot sections (18,19) to mix with and become ignited by the burning mixture.The pre-mixing section (20) is an annular duct (33) having walls (15,16) which extend in the direction of the axis of the chamber and are straight in that direction though slightly convergent. The arrangement favors vaporization in the duct without auto-ignition.