Patent ID: 7430851

Claim:
In a fuel injector assembly, for dispensing fuel in the combustion chamber of a gas turbine engine, having a fuel nozzle tip within a fuel insulating cavity that is only partially sealed so as to permit an emergency fuel leakage path, said nozzle tip comprising in combination: a. a generally cylindrical fuel body; b. a generally cylindrical shroud juxtaposed around said fuel body; c. a peripheral emergency fuel venting gap, of a predetermined radial extent, between said fuel body and said shroud, near the inner ends thereof; d. said emergency fuel venting gap merging into a peripheral emergency first fuel/air venting gap, said shroud including a plurality of peripherally spaced air inlets, for providing tertiary air for a positive air wash into said first fuel/air venting gap; e. a peripheral restrictor, within said first fuel/air venting gap, downstream of said plurality of air inlets, for temporarily narrowing the radial extent of said first fuel/air venting gap; f. said first fuel/air venting gap merging into a peripheral emergency second fuel/air venting gap, downstream of said first fuel/air venting gap, said second fuel/air venting gap, near the outer ends of said fuel body and said shroud, being adapted to channel a fuel/air mixture to a vent exit of said nozzle tip downstream of a combustion liner that radially adjoins said shroud; and g. a generally cylindrical air transfer sleeve, intermediate said fuel body and said shroud, of a radial inner dimension so as to maintain said first and second fuel/air venting gaps, said air transfer sleeve having a peripheral outer recessed cavity, the inner end thereof encompassing said plurality of air inlets in said shroud, and an outer end thereof being provided with a plurality of air openings, said air openings connecting said recessed cavity with said first fuel/air venting gap in the area downstream of said restrictor.