Frustoconical burner can assembly

Claim 1

In a gun type burner having a fuel injector for discharging a conical spray pattern centrally of a surrounding blast tube and means for supplying pressurized air to said tube, the improvement comprising; a perforated, frustoconical burner can surrounding, and concentric with, the downstream end of said injector spray pattern; said burner can comprising the downstream wall of a preheating plenum chamber surrounding said injector for defining, with said conical spray pattern, a rotationally static frustoconical fuel/air mixing zone; said plenum chamber including a plurality of upstream inlet passages for admitting substantially the entire air flow through said blast tube to said plenum chamber and whose aggregate cross-section exceeds that of the burner can perforations; means for directing substantially the entire flow of air in said blast tube through said upstream passages; said burner can perforations being symmetrically disposed about the burner can axis; and said frustoconical burner can exhibiting a perforated to non-perforated surface area ratio decreasing from a maximal adjacent the smaller upstream end thereof to a minimal adjacent the downstream end thereof and then increasing, at the extreme downstream end thereof, to a value intermediate said maximal and minimal ratios.

Claim 11

A method of increasing the fuel/air mixing efficiency in a gun-type oil burner having a fuel injector for discharging a conical fuel spray pattern centrally of a central blast tube and having means for supplying pressurized air to said blast tube, comprising the steps of: (1) directing substantially the entire flow of air in the blast tube through upstream inlet passages of a plenum chamber; (2) preheating the air in the plenum chamber; and (3) generating rotationally static air curtains in the vicinity of the conical fuel spray pattern by forcing the air from the plenum chamber through a perforated frustoconical burner can surrounding, and concentric with, the downstream end of the injector fuel spray pattern, and forming the downstream wall of the plenum chamber, the perforations in the burner can being symmetrically disposed about the burner can axis and the perforated to non-perforated surface area ratio of the burner can decreasing from a maximal adjacent to the smaller upstream end thereof to a minimal adjacent to the downstream end thereof and then increasing, at the extreme downstream end thereof, to a value intermediate said maximal and minimal ratios.

Claim 12

A method of increasing the fuel/air mixing efficiency in a gun-type oil burner having a fuel injector for discharging a conical fuel spray pattern centrally of a central blast tube and having means for supplying pressurized air to said blast tube, comprising the steps of: (1) directing substantially the entire flow of air in the blast tube through upstream inlet passages of a plenum chamber; (2) preheating the air in the plenum chamber; and (3) generating rotationally static air curtains in the vicinity of the conical fuel spray pattern by forcing the air from the plenum chamber through a perforated frustoconical burner can surrounding, and concentric with, the downstream end of the injector fuel spray pattern, and forming the downstream wall of the plenum chamber, the perforations in the burner can being symmetrically disposed about the burner can axis and the perforated to non-perforated surface area ratio of the burner can decreasing from a maximal adjacent to the smaller upstream end thereof to a minimal adjacent to the downstream end thereof and then increasing, at the extreme downstream end thereof, to a value intermediate said maximal and minimal ratios.