Simple low cost fuel nozzle support

A fuel nozzle support stem for delivering a primary liquid fuel and a secondary liquid fuel to be mixed with compressed air in the combustor of a gas turbine engine, the stem having:

• a longitudinal axis;
• an elongate substantially cylindrical body symmetric about the axis and having an outer diameter D0 and length L;
• an inlet end with primary and secondary liquid fuel inlet ports;
• and an outlet end with primary and secondary liquid fuel outlet ports, the support stem having a concentric longitudinal secondary liquid fuel bore having an inner diameter DI and communicating between the secondary inlet port and the secondary outlet port, and a concentric primary liquid fuel tube disposed within the bore, sealed to the inlet and outlet ends of the support stem and communicating between the primary inlet port and the primary outlet port;
• wherein D0 is greater than 2DI, and L is less than 10(D0−DI′);
• an outer cylindrical insulating sleeve disposed outwardly a distance from the cylindrical body of the stem thus defining an elongate annular insulating air gap between the sleeve and body, the inlet and outlet ends of the stem body each including a cylindrical shoulder extending radially outward from the stem body and disposed within the sleeve;
• the inlet end including a liquid fuel adapter having primary and secondary fuel system sealing connectors, and having a stem body mounting socket within which an outer end of the stem body is mounted;
• and
• the outlet end including a dual liquid fuel spray nozzle assembly with a nozzle axis disposed at an obtuse angle relative to the longitudinal axis of the stem.