US Patent 7370466 Extended flashback annulus in a gas turbine combustor

An extended flashback annulus (520) is formed between an exterior surface (506) of a shroud or casing (508) associated with a main swirler assembly inner body (500) or other fuel/air mixing device and the inner surface (514) of an annulus casting (510) which are in operational relationship with one another in a gas turbine combustor assembly. The extended flashback annulus (520) is capable of forming an extended protective cylindrical air barrier (550) that extends farther into the combustion zone, this barrier being more robust and providing for the reduction or prevention of flashback to the baseplate and other heat-susceptible upstream components.