Fuel Systems Textron Inc.

Theodore R Koblish

Jerome R Bradley

Leonard D Bell

Fei P Lee

Robert M Halvorsen

Fenton L Angell

Alfred A Mancini

James W Sager

A self-purging fuel injector for a combustor of a gas turbine engine wherein the fuel injector comprises an injector body having first and second air discharge orifices for discharging air to the combustor and first and second fuel passage means having respective first and second fuel discharge orifices for discharging fuel to the combustor. The first and second fuel passages are in communication upstream of the fuel discharge orifices. The first air and fuel discharge orifices have a relationship to establish a pneumatic pressure at the first fuel discharge orifice and the second air and fuel discharge orifices have a relationship to establish a different pneumatic pressure at the second fuel discharge orifice such that, in the event the supply of fuel to the first and second fuel discharge orifices is interrupted, the fuel residing in the fuel passages between the first and second fuel discharge orifices is subjected to a pressure differential effective to purge the resident fuel into the combustor.

Fuel purging fuel injector

A fuel-injector system for a combustor of a gas turbine engine includes first and second fuel injectors rendered operative to discharge fuel to the combustor during a high power regime of engine operation and rendered non-operative during a lower power regime of engine operation. The first and second fuel injectors include respective first and second fuel discharge passages in fuel flow communication to one another and to the combustor via associated fuel discharge lips to sustain a flame region. The first and second fuel injectors are operatively associated with respective first and second air discharge means having air discharge lips for discharging air to the combustor for sustaining the flame region therein.

Self-sustaining fuel purging fuel injection system

A fuel injector system for a combustor of a gas turbine engine includes first and second fuel injectors rendered operative to discharge fuel to the combustor during a high power regime of engine operation and rendered non-operative during a lower power regime of engine operation. The first and second fuel injectors include respective first and second fuel discharge passages in fuel flow communication to one another and to the combustor via associated fuel discharge lips to sustain a flame region. The first and second fuel injectors are operatively associated with respective first and second air discharge means having air discharge lips for discharging air to the combustor for sustaining the flame region therein. When the fuel injectors are rendered non-operative, different pneumatic pressures are established at the fuel discharge lips to purge fuel from the fuel injectors to the combustor.

The gas turbine combustor air swirler includes a spring temper swirler member having a plurality of air control doors or vanes so cut therein about the longitudinal axis of the combustor inlet as to be integrally and resiliently pivotally connected to the swirler member. The air control doors are progressively canted open to provide predetermined air flow rate and air swirl angle to the combustor inlet in response to increases in air pressure differential thereacross resulting from progressive increases in fuel flow through the nozzle during various regimes of engine operation. The swirler is free of linkages and sliding or other contacting components that are susceptible to binding and other malfunctions in service in the engine.

Variable area combustor air swirler

The small airblast fuel nozzle improves cold ignition of small gas turbine engines of the type having a stagnation air pressure of only 1-11/2 inches of water available from the compressor for cold ignition. The fuel nozzle includes an inner air swirling system comprising a longitudinal cylindrical inner air swirl chamber and multiple air inlet slots spaced circumferentially on the nozzle body to supply air to the chamber. The air inlet slots each include an inner tapered section converging toward and into intersection with the chamber and an outer tapered section converging from the exterior of the nozzle body toward and into intersection with the inner section. The inner section and outer section are canted with respect to one another and in the same direction from one slot to the next so that the inner air slots collectively form a hooked cross type pattern when viewed in plan. The inner air swirl system is effective to provide much enhanced air swirling in the inner chamber with a high efficiency or use of the small available stagnation air pressure available at the nozzle exterior for improved cold ignition.

Small airblast fuel nozzle with high efficiency inner air swirler

The small airblast fuel nozzle improves cold ignition of small gas turbine engines of the type having a stagnation air pressure of only 1-1-1/2 inches of water available from the compressor for cold ignition. The fuel nozzle includes an inner air swirling system comprising a longitudinal cylindrical inner air swirl chamber and multiple air inlet slots spaced circumferentially on the nozzle body to supply air to the chamber. The air inlet slots each include an inner tapered section converging toward and into intersection with the chamber and an outer tapered section converging from the exterior of the nozzle body toward and into intersection with the inner section. The inner section and outer section are canted with respect to one another and in the same direction from one slot to the next so that the inner air slots collectively form a hooked cross type pattern when viewed in plan. The inner air swirl system is effective to provide much enhanced air swirling in the inner chamber with a high efficiency or use of the small available stagnation air pressure available at the nozzle exterior for improved cold ignition.

An elongate igniter is disposed in the inner air chamber of an air blast nozzle coaxial with the longitudinal axis thereof such that the discharge tip of the igniter discharges a spark generally longitudinally downstream of the tip out of the path of swirling inner air flow and in the path of a reverse flow field of atomized fuel established downstream of the tip by relatively controlled inner and outer air swirl strengths.

Fuel nozzle and igniter assembly

Coking of the hot external face of fuel nozzles operating in the combustor of a gas turbine engine is reduced by controlling air discharging from the nozzle face in a manner to provide a recirculation zone spaced away from the nozzle face a distance effective to substantially reduce coking and yet maintain a stable flame front in the combustor.

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Birmingham, MI, United States of America

Theodore R Koblish