Airblast fuel injector tip with integral cantilever spring fuel metering valve and method for reducing vapor lock from high temperature

摘要

The airblast fuel injector capable of accommodating high fuel temperature at the injector tip without deleterious fuel vaporization problems and resultant combustion instability in a gas turbine engine includes an annular spring valve mounted on an annular shoulder of an inner injector body forming an inner air chamber with the valve having a cantilever valve head for controlling fuel flow from a fuel swirling orifice in the shoulder near the injector tip. The spring bias of the cantilever valve head is adjusted by lapping the valve head prior to fastening the spring valve to the inner injector body and before the inner injector body is assembled within an outer injector body having means forming an outer annual fuel chamber and air chamber. The method involves valving the fuel flow in the injector tip near to the fuel discharge orifice in a valve closed manner below a selected minimum fuel pressure and in a valve metering manner above the selected fuel pressure with valving located sufficiently upstream therefrom that the airblast operational characteristics of the injector are not adversely affected.