Oil premix burner

Abstract

An oil premix burner, having a burning element, a burner surface on the outer lateral surface, a distribution chamber below the burner surface, a central oil injection device, a combustion air duct connected to a fan situated upstream, and an air heat exchanger for preheating the combustion air in the area of the burner surface. The combustion quality and the robustness are optimized in an oil premix burner, in particular with respect to the modulation capability. It is provided that the air heat exchanger is composed of at least one double tube element including an inner tube, having inline throughflow, and an outer tube concentric to the inner tube. The air heat exchanger is situated above the burner surface and is composed of multiple parallel throughflow double tube elements symmetrically distributed over the circumference and which extend axis-parallel to the burning element at least over a portion of its length.

1 - 11 . (canceled) 
     
     
         12 . An oil premix burner, comprising:
 a burning element, a burner surface on the outer lateral surface, a distribution chamber below the burner surface;   a central oil injection device;   a combustion air duct connected to a fan situated upstream; and   an air heat exchanger for preheating the combustion air in the area of the burner surface, wherein the air heat exchanger includes at least one double tube element including an inner tube, having an inline throughflow, and an outer tube concentric thereto.   
     
     
         13 . The oil premix burner of claim  11 , wherein the air heat exchanger is situated above the burner surface and includes multiple parallel throughflow double tube elements symmetrically distributed over the circumference and extending axis-parallel to the burning element at least over a portion of its length. 
     
     
         14 . The oil premix burner of claim  11 , wherein each double tube element has a deflection zone on the front side of the free end as a connection between the inner tube and an annular space formed between the inner tube and the outer tube. 
     
     
         15 . The oil premix burner of claim  11 , wherein each double tube element is connected with the entry side of the inner tube to the combustion air duct, wherein the combustion air, after leaving the inner tube, arrives in a deflection zone on the front side of the free end and flows into the annular space formed between the inner tube and the outer tube and flows back in the direction of the front side near the oil injection device and there enters the distribution chamber in the area around the oil injection device as preheated combustion air. 
     
     
         16 . The oil premix burner of claim  11 , wherein in a double tube element, the inner tube projects at the end near the oil injection device beyond the outer tube in the longitudinal direction so that it passes through the outlet area of the annular space connected to the distribution chamber and reaches through a boundary wall up into the combustion air duct. 
     
     
         17 . The oil premix burner of claim  11 , wherein the inner tube and/or the outer tube has/have turbulence generating surfaces, a profiling and/or surface enlarging elements. 
     
     
         18 . The oil premix burner of claim  11 , wherein the inner tube and/or the outer tube are provided with profilings and/or beads for turbulence generation, which run spirally on the tube surface. 
     
     
         19 . The oil premix burner of claim  11 , wherein at least the inner tube on its outer side has an arrangement for influencing the flow in the surrounding annular space. 
     
     
         20 . The oil premix burner of claim  11 , wherein the diameters of the inner tube and the outer tube are dimensioned so that the free cross section in the course of the flow path of the combustion air remains at least the same or increases. 
     
     
         21 . The oil premix burner of claim  11 , wherein the inner tube has multiple openings in its housing which permit a direct flow into the surrounding annular space and generate local turbulences and cooling effects in the annular space and, in cross section, are at least ten times smaller than the internal diameter of the inner tube. 
     
     
         22 . The oil premix burner of claim  11 , wherein the inner tube and the outer tube are mutually supported at least at selected points, this taking place in particular in the deflection zone on the front side of the free end and/or via fittings and/or a special design of the tube wall.