Burner for heat generator

A burner for operating a heat generator, the burner comprising:

• a swirl generator comprising swirl vanes that receives a combustion air flow and that includes means for injecting at least one fuel into the combustion air flow, wherein the swirl generator is integrated into an inlet flow duct into which the combustion air flow flows, said inlet flow duct having a rectangular inlet flow cross section that merges into an approximately square or round cross section over the length of the swirl generator and completely surrounds the swirl generator in the radial direction, with the swirl generator being subjected to the combustion air flow only in the longitudinal direction;
• a mixing section arranged downstream of the swirl generator, the mixing section having a first section part in a flow direction of the combustion air flow, and a number of ducts in a transition piece for the transfer of a flow formed in the swirl generator into a mixing tube connected downstream of the transition piece;
• and
• a combustion space formed by a cross-sectional expansion being arranged downstream of the mixing section.