Burner for Particulate Fuel

Abstract

Disclosed is a burner for particulate fuel, in particular made of biomass, with a primary tube and a core tube arranged in the primary tube. The primary tube and the core tube form a primary tube gap and the primary tube gap is configured to guide a flow of particulate fuel and gaseous combustion means from an inlet-side end to an outlet-side opening of the primary tube. In order to prevent the drawbacks occurring when using coarse-grain particles, preferably biomass, as a fuel for dust firing, or at least to reduce them without having to accept an increased outlay for equipment and/or additional energy losses, at least one device is provided for centring the flow within the primary tube in the region of the outlet-side end of the primary tube.

1 . A burner for particulate fuel, in particular made of biomass, comprising a primary tube and a core tube arranged in the primary tube, wherein the primary tube and the core tube form a primary tube gap, wherein the primary tube gap is configured to guide a flow of particulate fuel and gaseous combustion means from an inlet-side end to an outlet-side opening of the primary tube, and wherein at least one device is provided for centring the flow within the primary tube in the region of the outlet-side end of the primary tube. 
     
     
         2 . The burner according to  claim 1 , wherein the core tube, viewed in the longitudinal direction of the burner, ends before the primary tube and wherein the axial spacing between the outlet-side ends of the core tube and primary tube in the longitudinal direction of the primary tube is at least 50%, preferably at least 75%, in particular at least 100%, of the mean width of the primary tube gap. 
     
     
         3 . The burner according to  claim 1 , wherein the core tube is configured tapering toward its outlet-side end. 
     
     
         4 . The burner according to  claim 3 , wherein the core tube tapers continuously toward its outlet-side end. 
     
     
         5 . The burner according to  claim 4 , wherein the core tube tapers conically toward its outlet-side end, preferably at an angle of inclination α of less than 20°, in particular less than 10°, if necessary approximately 7°. 
     
     
         6 . The burner according to  claim 1 , wherein a deflection device is provided at the outlet-side end of the core tube in the primary tube gap to deflect the part of the flow guided in the primary tube gap close to the core tube inwardly. 
     
     
         7 . The burner according to  claim 6 , wherein the deflection device is configured to deflect about 30% by volume to 70% by volume, preferably 40% by volume to 60% by volume, of the flow guided in the primary tube gap. 
     
     
         8 . The burner according to  claim 6 , wherein a flow channel is provided between the core tube and the deflection device and wherein the free flow cross section of the flow channel remains substantially constant in the flow direction. 
     
     
         9 . The burner according to  claim 1 , wherein at least one flow director is provided in the primary tube gap to influence the swirl of a part of the flow guided in the primary tube gap close to the core tube. 
     
     
         10 . The burner according to  claim 9 , wherein the at least one flow director is oriented in the longitudinal direction of the primary tube and, preferably, is configured to be much wider in the longitudinal direction than in the peripheral direction. 
     
     
         11 . The burner according to  claim 9 , wherein the at least one flow director is inclined transverse to the longitudinal direction of the primary tube. 
     
     
         12 . The burner according to  claim 9 , wherein the at least one flow director is provided within the inner 80%, preferably 70%, in particular 60%, of the width of the primary tube gap. 
     
     
         13 . The burner according to  claim 9 , wherein the at least one flow director is provided downstream in the flow direction of a swirling device preferably arranged in the primary tube gap, and wherein the swirling device is provided to impress a swirl on the flow guided in the primary tube gap. 
     
     
         14 . The burner according to  claim 7 , wherein the at least one flow director is provided in the flow direction, preferably directly in front of the deflection device. 
     
     
         15 . The burner according to  claim 7 , wherein a flame-holder projecting inwardly into the flow of the primary tube is provided on the outlet-side end of the primary tube.