System for supplying fuel to and cooling a fuel injector of a dual head combustion chamber

Apparatus for supplying fuel to and cooling a fuel injector of a gas turbine engine comprising:

• a) a fuel injector assembly with a low power injector and a high power injector having fuel injection orifices, the high power injector being operable only during selected operational modes of the gas turbine engine;
• b) a fuel supply conduit connected to the high power injector to supply at least a portion of the total fuel flow supplied to the fuel injector assembly to the high power injector during all operational modes of the gas turbine engine;
• c) fuel control means to control the amount of fuel flowing through the fuel injection orifices;
• wherein the fuel control means comprises:
• i) a valve in the fuel supply conduit having a valve member movable between a low power position wherein fuel flow through the fuel injector orifices is prohibited and a high power position wherein fuel flow through the fuel injection orifices is at a maximum;
• and,
• ii) biasing means acting on the valve member so as to bias the valve member toward its low power position, whereby the valve member is moved toward the high power position when the fuel pressure in the fuel supply conduit reaches a predetermined threshold value;
• and
• d) a fuel evacuation conduit connected to the high power injector so as to evacuate unused fuel from the high power injector.