Patent ID: 7896646
Filing Date: 2011-03-01
Classification: F23C,F23D

Abstract:
1. A premixing burner for operating a combustion chamber by means of a liquid and/or gaseous fuel, comprising: a swirl generator for a combustion inflow air stream for forming a swirl flow; means for the injection of fuel into the swirl flow, the swirl generator being configured to be adjacent to the combustion chamber indirectly via a mixing zone or directly, in each case via a burner outlet; a cross-sectional widening at the burner outlet which is discontinuous in the flow direction of the swirl flow and through which the swirl flow bursts open so as to form a backflow zone, the swirl generator having at least two part-conical shells which complete one another to form a body and which jointly enclose a conically designed swirl space with a cone angle 2γ and air inlet slits tangential in the cone longitudinal extent; a mid-axis (M a contour locally narrowing a flow cross section of the swirl generator or of the mixing zone in the flow direction upstream of the burner outlet, which contour is arranged in a region of a foremost front of the backflow zone in the flow direction and has, in the flow direction, a first segment which continuously reduces the flow cross section, a second segment with a smallest flow cross section and a third segment adjoining the second segment in the flow direction and continuously increasing the flow cross section.