Burners in prior art exhibit combustion instabilities in certain ranges. The operating range of burners is restricted by said instabilities. In an inventive burner, the combustible has a concentration distribution, whereby the concentration of the combustible reduces in a radial direction from the interior to the exterior.
1. A burner, comprising:
a means for providing a flow of compressed air and/or oxygen in a flow direction through a channel;
a means for creating a mixture in the channel, the mixture comprising the flow of compressed air and/or oxygen and a fuel, the means for creating a mixture comprising fuel discharge openings arranged to create a concentration distribution of fuel within the mixture that is not constant across a distance defined along a length of a first axis which is oriented perpendicular to the flow direction in order to avoid combustion instabilities during operation of the burner; and
a means for imparting a swirl to the mixture in the channel about the flow direction, the means for imparting swirl comprising a redirecting surface for redirecting the flow, wherein an outflow angle of the swirled mixture at a redirecting surface downstream end varies in magnitude in a single direction along a length of a second axis perpendicular to the flow direction.
2. The burner according to claim 1 , wherein the burner has a burner longitudinal axis, and wherein the first axis intersects the burner longitudinal axis.
3. The burner according to claim 2 , wherein the burner longitudinal axis represents an interior area of the burner, and the concentration distribution of the fuel decreases from the interior to an exterior portion of the burner located a distance away radially from the interior area.
4. The burner according to claim 1 , wherein the channel is embodied annularly around a burner longitudinal axis.
5. The burner according to claim 4 , wherein a fuel-gas mixture flows in the channel.
6. The burner according to claim 1 , further comprising a diffusion or pilot burner arranged centrally along a burner longitudinal axis.
7. The burner according to claim 1 , wherein the redirecting surface is a swirl blade.
8. The burner according to claim 7 , wherein the fuel is supplied to the channel via a fuel nozzle in the swirl blade.
9. The burner according to claim 8 , wherein the swirl blade has fuel nozzles with diameters that vary and produce the non-constant concentration distribution of the fuel.
10. The burner according to claim 9 , wherein the burner has a burner longitudinal axis that represents an interior area of the burner and the burner has a radial direction disposed perpendicularly to the burner longitudinal axis, and the diameter of the fuel nozzles of an installed swirl blade decreases in the radial direction from the interior to an exterior portion of the burner located a distance away radially from the interior area.