Patent ID: 6438963
Filing Date: 2002-08-27
Classification: F23K,F23R

Abstract:
A gas turbine comprising:a main compressor, a combustor and a turbine; a liquid fuel supply coupled to provide liquid fuel to the combustor; a gaseous fuel supply coupled to provide gaseous fuel to the combustor; a liquid fuel purge system further comprising: a purge manifold; a coupling to a compressor air discharge port of the main compressor to draw compressor air into the purge system; a conduit between the discharge port and the purge manifold through which passes compressor air to the purge manifold, and a valve alternatively coupling the manifold and liquid fuel supply to the combustor, said valve including an actuator coupled to said fuel supply, and said valve having a purge setting in which purge air passes through the valve to the combustor and a liquid fuel setting in which liquid fuel passes through the valve to the combustor, wherein said valve has a passive switch mode in which said valve is switched to said fuel setting by liquid fuel pressure applied to said actuator and an active switch mode in which said valve is maintained in said fuel setting, during a high fuel flow condition, by an external force applied to the actuator.