Abstract: A gas turbine fuel injector has a fuel mixing barrel, including an air swirler incorporating a fuel flow outlet, suspended in the combustor air stream by a cantilevered injector body. The cantilevered body is mounted in the combustor wall and includes a fuel flow control valve in a valve chamber located in a part of the body in a relatively cool air surrounding the combustor. The fuel outlet is located towards the downstream end of the swirler barrel. A purge passage is provided from a location towards the upstream end of the barrel extending into the outlet side of the valve chamber. When fuel flow is shut-off a pressure differential between the upstream and downstream ends of the swirler barrel causes an air flow up the purge passage into the valve chamber and down the main fuel passage to purge residual fuel.

Abstract: A staged fuel system for a gas turbine engine in which the main burners are supplied with fuel through fluid pressure actuated, servo-controlled valves. All pilot and main burners are supplied from a single manifold. However, fuel flow to the main burners is controlled by the servo-valves which are controlled by pressure in a servo-manifold fed with fuel tapped from a high pressure region of the fuel system. Thus, a simple variable control valve on the outlet of the servo-manifold is able to control fuel staging.