Gas-fired burner, in particular for a drying drum of an asphalt mixing plant

Abstract

A gas-fired burner for a drying drum of an asphalt mixing plant, such that the burner preferably has a central primary air duct (6), which opens into a combustion zone (4) via a swirl body (2). The burner has gas supply openings (9) in the area of the circumferential boundaries of the swirl body (2) for supplying fuel gas to the primary air for firing the burner. It has been shown that a stable and well-developed flame can be produced over a very large load range with such burners according to the disclosure.

What is claimed is: 
     
         1 . A gas-fired burner, in particular for a drying drum of an asphalt mixing plant, having a primary air duct, in particular a central primary air duct, which flows via a swirl body into a combustion zone, the burner having gas supply openings in the region of the circumferential boundaries of the swirl body for supplying fuel gas into the primary air for firing the burner. 
     
     
         2 . The burner according to  claim 1 , wherein the swirl body has gas supply openings in its circumferential boundaries for supplying fuel gas into the primary air for firing the burner. 
     
     
         3 . The burner according to  claim 2 , wherein the gas supply openings are formed as radial bores in the circumferential boundaries of the swirl body, in particular with regular spacings in the circumferential direction. 
     
     
         4 . The burner according to  claim 1 , wherein the gas supply openings are arranged between the vanes of the swirler, in particular between all the vanes. 
     
     
         5 . The burner according to  claim 4 , wherein the gas supply openings are each arranged in the region of the lower pressure sides of the swirl body vanes. 
     
     
         6 . The burner according to  claim 4 , wherein the gas supply openings are each arranged in the region of the outlet edges of the swirl body vanes. 
     
     
         7 . The burner according to  claim 1 , wherein the swirl body is surrounded on its outlet side by a plurality of gas supply openings for supplying fuel gas for firing the burner into the primary air. 
     
     
         8 . The burner according to  claim 1 , wherein the circumferential boundaries of the swirl body are designed as a cone widening towards the combustion zone. 
     
     
         9 . The burner according to  claim 1 , further comprising a secondary air duct arranged concentrically around the primary air duct, which opens into the combustion zone. 
     
     
         10 . The burner according to  claim 7 , wherein in the region in which the secondary air duct opens into the combustion zone, an edge projecting radially outwards into the secondary air flow from an inner boundary wall of the secondary air duct is arranged. 
     
     
         11 . The burner according to  claim 7 , wherein the burner is designed in such a way that the ratio of primary air and secondary air is adjustable, in particular individually and differently for variable load stages. 
     
     
         12 . The burner according to  claim 1 , comprising a fuel gas supply which is arranged concentrically around the primary air guide and opens into the gas supply openings. 
     
     
         13 . The burner according to  claim 10 , wherein the combustion gas supply is arranged concentrically between the primary air duct and the secondary air duct. 
     
     
         14 . The burner according to  claim 1 , further comprising a supply for liquid fuel, which is arranged in the center of the primary air duct and opens into the combustion zone via a nozzle, for supplying atomized liquid fuel into the primary air emerging from the swirl body. 
     
     
         15 . The burner according to  claim 1 , wherein the combustion zone is surrounded by a conical flame tube 
     
     
         16 . The burner according to  claim 1 , wherein the burner is designed such that the entire quantity of fuel gas used for firing the burner can be supplied in particular exclusively via the gas supply openings. 
     
     
         17 . Use of the burner according to  claim 1  for heating a drying drum of an asphalt mixing plant.