Patent ID: 8863524

Claim:
A burner for a gas turbine engine, comprising: a burner housing in which the burner is enclosed, the burner having axially opposed upstream and downstream end portions; a pilot combustor disposed at the upstream end of the burner; a plurality of quarl sections surrounding an exit of the pilot combustor and extend from the exit in a downstream direction; a main combustion room is defined downstream from the pilot combustor by end portions of the plurality of quarls; and a first channel defined as a substantially annular space between an upstream quarl section, first quarl section, and the closest downstream quarl section, second quarl section, providing air and fuel to a main flame in the main combustion room, wherein the pilot combustor is provided with fuel and air for burning the fuel and is sized to effect creation of a first flow of an unquenched concentration of radicals at non-equilibrium and heat from a pilot combustion zone directed downstream along a centre line of the pilot combustor through a throat at the exit of the pilot combustor, wherein less fuel is supplied to the pilot combustor than to the main combustion room, wherein an outer quarl section, second quarl section, includes a greater first diameter than an second diameter of an inner quarl section, first quarl section, wherein the outer quarl section, second quarl section, extends a greater distance downstream than the inner quarl, first quarl section, and wherein the main combustion room is arranged to house the main flame and a recirculation zone for directing a second flow of free radicals back to a forward stagnation point at the exit of the pilot combustor.