Burner

In a vortex burner having a burner block with a generally longitudinally extending opening, said block having a cup therein at the outer end of said opening, a cylindrical sleeve positioned in said opening for feeding combustion supporting air therethrough, said sleeve containing a fuel supply means for conveying fuel to a position within the sleeve and whirling the fuel against the inner wall of the sleeve, the improvement comprising the combination of:

• (a) said cup having an outwardly convex curvature forming a surface along which the combustion products flow in a radially outward direction from said opening, the surface causing the radially flowing combustion products to form a negative pressure in the cup;
• (b) the length of said sleeve being substantially less than said burner block opening, the outer dimension of the sleeve being smaller than the inner dimension of the burner block opening thereby providing an annular passageway between them;
• (c) means forming an air passage in communication with the inner end of the opening in said burner block;
• and
• (d) said sleeve having a central opening in communication with said air passage and having a thin beveled edge on its outer portion extending slightly beyond the outer end of the opening in said burner block so that a low pressure region is formed by said thin edge.