Patent ID: 8327643

Claim:
A staging fuel nozzle having, in the center thereof, a pilot fuel injection portion and a main fuel injection portion of a pre-mixing type that has a main swirler and a liquid film forming body around the pilot fuel injection portion, wherein the main swirler comprises a plurality of swirlers, the plurality of swirlers comprises an innermost swirler that is arranged closest to a central axis of the fuel nozzle, an intermediate swirler, and an outermost swirler, a fuel injection port of the main fuel injection portion is provided in an inner wall surface of a main fuel injection portion air flow channel located downstream of the plurality of swirlers, a wall surface in the vicinity of the fuel injection port includes a convex wall surface that protrudes radially outward from an innermost surface of the innermost swirler, the convex surface is formed at least as far as a downstream end of the liquid film forming body, and the liquid film forming body extends downstream between the innermost swirler and the intermediate swirler, the innermost swirler and the intermediate swirler swirl in an opposite direction to each other, the innermost swirler and the outermost swirler swirl in the same direction, the plurality of swirlers are combined to obtain swirling of an intensity that enables the formation of a stable recirculation flow in the entire configuration, and the main swirler is a triple annular swirler.