Patent ID: 8113824

Claim:
A burner with low emissions and low unburned fuel losses, comprising: a fuel nozzle means with an axis and an outlet; at least one inner air zone with an outlet end concentrically surrounding said fuel nozzle means; an outer air zone with an outlet end having a wall concentrically surrounding said inner air zone; first means for imparting swirl positioned in said inner air zone; second means for imparting swirl positioned in said outer air zone; and an air separation cone for splitting secondary air flow in said outer air zone into two separate streams and deflecting a portion of said secondary air flow radially outward, wherein said imparted swirl produces internal recirculation zones, said air separation cone having a horizontal axis; wherein said air separation cone includes a cylindrical leading edge that fits in said outer air zone, said cylindrical leading edge being completely parallel to said horizontal axis of said air separation cone, and wherein a diverging angle of said air separation cone with respect to said axis of said fuel nozzle means ranges from 25 to 45 degrees; wherein said at least one inner air zone comprises: a first annular transition zone concentrically surrounding said fuel nozzle means, said first annular transition zone being constructed to provide air for near-burner mixing and stability; and wherein said fuel nozzle means includes a center passage for secondary air and a surrounding outer passage for primary fuel with primary air for combustion in a primary zone; wherein said at least one inner air zone is an annular transition zone concentrically surrounding said fuel nozzle means, said annular transition zone being constructed to provide air for near-burner mixing and stability; wherein said air separation cone is supported by standoffs inside said outer air zone; and wherein said air separation cone divides said outlet end of said outer air zone into two outlets.