Abstract: A gas-turbine engine combustion system has a combustor with a burner head having both pilot gas and pilot liquid-fuel injection arrangements, the pilot gas arrangement comprising an annular gallery communicating with a downstream face of the head and a deflecting arrangement adjacent the gallery for directing the pilot gas-fuel towards a longitudinal axis of the combustor and over a central part of the downstream face. The combustion system is designed so that, during both gas- and liquid-fuel operations, the flame front face is located close to the burner head and, during liquid-fuel operation, air is forced across the downstream face to cool the head. Advantageously, the cooling air is made to replace the pilot gas-fuel in the annular gallery, so that it is deflected, like the gas-fuel, and contacts the central part of the downstream face. The burner head also features main gas and liquid-fuel injection arrangements, these communicating with one or more passageways in a radial swirler attached to the head.

Abstract: A combustor for a gas turbine engine comprises an annular combustion chamber having radially outer and inner rows of fuel injectors disposed concentrically in the combustor head wall. Injectors in one of the rows are in angular registration with spaces between injectors in the other row. Each fuel injector produces a fuel/air mixture having a swirling motion, and has a downstream mixing duct. Each mixing duct opens into the combustion chamber through the combustor head wall and has a length sufficient to allow at least partial mixing of the fuel/air mixture before entry to the combustion chamber as a divergent swirling stream. Mixing ducts in the first and second rows of injectors have longitudinal centerlines oriented to coincide with generating rays of respective first and second imaginary conical surfaces.

Abstract: A gas-turbine engine combustion system comprises a plurality of combustors interconnected by crossfire tube assemblies adapted to pass an ignition flame from an ignited combustor to another combustor on start-up of the engine. Each crossfire tube assembly comprises a cooling air inlet for introducing air into the assembly to film-cool its inner, ignition flame-facing surface, and a cooling sleeve surrounding the crossfire tube assembly in the region in which it opens into the combustor. The cooling sleeve directs the cooling air so as to cool the outer surface of the assembly, the inside of the sleeve and the inside surface of the combustor wall adjacent the cooling sleeve.