Patent ID: 9534788
Date: 2017-01-03
CPC Classifications: F23R

Claim:
1. A system for premixing fuel and air prior to combustion in a gas turbine engine, comprising: a mixing duct having a circular cross-section defined by a wall; a centerbody fuel injector located along a central axis of the mixing duct and extending substantially the full length of said mixing duct, an outer annular swirler located adjacent an upstream end of the mixing duct and including a plurality of circumferentially spaced vanes oriented so as to swirl air flowing therethrough in a first swirl direction; an inner annular swirler located adjacent of the mixing duct upstream end and including a plurality of circumferentially spaced vanes oriented so as to swirl air flowing therethrough in a second swirl direction opposite of the first swirl direction; a hub separating said inner and outer annular swirlers to permit independent rotation of an air stream therethrough; and a plurality of hollow paths located radially outward around the centerbody fuel injector and at a radially inward side of the inner annular swirler; wherein the plurality of hollow paths are configured to allow a flow of sweeping air over a surface of the centerbody fuel injector, wherein the plurality of hollow paths comprise a plurality of holes disposed in the vanes of the inner annular swirler.