Patent ID: 8752388

Claim:
A premix burner of a combustion chamber of a gas turbine, comprising: at least one annular duct for supplying air and fuel; a radially outer and a radially inner combustion chamber wall relative to a burner central axis; at least one swirler arranged in the duct, said swirler including a plurality of flow-guiding elements distributed around a circumference of the duct cross-section; at least one radially inner duct wall provided in an area of the flow-guiding elements; an inner concave recess positioned in the radially inner duct wall and shaped as an annular groove, a concavity of the inner concave recess positioned toward the flow-guiding elements, each flow-guiding element having flow profile that is provided between an inflow-side leading edge and an outflow-side trailing edge, with the inflow-side leading edge and the outflow side trailing edge each being arranged on a cross-sectional plane perpendicular to the burner central axis, a depth of the concavity of the inner concave recess being greater at a first position intermediate the plane of the leading edge to the plane of the trailing edge than at both of the plane of the leading edge and the plane of the trailing edge.