Flame retention head assembly

A three-stage flame retention head assembly for use in the air tube of a fuel burner having a fuel nozzle mounted coaxially within the air tube, said assembly comprising:

• (a) a tubular member concentrically mounted within said air tube just in front of the fuel nozzle, said tubular member comprising a conical section, a cylindrical section joined at one end thereof to the larger end of said conical section, and an outwardly flaring flage section joined at the smaller end thereof to the other end of said cylindrical section, said outwardly flaring flange section being dished to provide a convex outer surface;
• (b) a spinner plate mounted in the smaller end of said conical section of said tubular member and adapted to mix and swirl air and fuel, said spinner plate having a central opening therein defined by a continuous annulus, and having vanes in its outer periphery extending outwardly from said continuous annulus;
• (c) said cylindrical section of said tubular member having circumferentially spaced openings therein;
• and
• (d) said outwardly flaring flange section having a row of circumferentially spaced, elongated slots therein, said openings and said elongated slots passing air into the tubular member when the assembly is in operation, said conical section providing a first mixing and heating chamber wherein primary combustion takes place, said cylindrical section providing a second mixing chamber, and said flange section providing a third mixing chamber.