Patent ID: 7878001

Claim:
A premixed combustion burner of a gas turbine, the premixed combustion burner comprising: a fuel nozzle; a burner tube disposed to encircle the fuel nozzle for forming an air passage between the burner tube and the fuel nozzle; and swirl vanes which are arranged at a plurality of locations along a circumferential direction of an outer peripheral surface of the fuel nozzle in such a state as to extend along an axial direction of the fuel nozzle, and which progressively curve from an upstream side toward a downstream side for swirling air flowing through the air passage from the upstream side toward the downstream side, characterized in that an angle formed by a tangent to an average camber line of the swirl vane at a rear edge of the swirl vane and an axis line extending along the axial direction of the fuel nozzle is 0 to 10 degrees on an inner peripheral side of the rear edge of the swirl vane, and the angle is larger on an outer peripheral side of the rear edge of the swirl vane than the angle on the inner peripheral side of the rear edge of the swirl vane, and a clearance is provided between an outer peripheral side end surface of the swirl vane and an inner peripheral surface of the burner tube, wherein in order to render said clearance between said outer peripheral side end surface of the swirl vane and said inner peripheral surface of the burner tube constant, a clearance setting rib, which makes intimate contact with the inner peripheral surface of the burner tube, is provided at a portion of the outer peripheral side end surface of the swirl vane.