Low NOx burner
AssigneeSelas Corporation of America
InventorsJohn J. Van Eerden, Chad F. Gottschlich, Wayne C. Gensler
Life of this patent
Estimating the term…
Abstract
A gaseous fuel burner provides substantial reduction of nitrogen oxide content in the combustion gases by creating a screen of premix combustion products, by introducing secondary gaseous fuel for admixture with the screen, and by exposing secondary air to the mixture for reaction with the secondary gaseous fuel.
Claims19
A gaseous fuel burner comprising a burner body having a burner tip installed in a wall of a furnace or the like for combustion of gaseous fuel therein,
- a primary supply means for introducing a primary gaseous fuel and primary air forwardly along said burner body and said burner including means at said tip for discharging a mixture of said fuel and air in a direction to form a combustion gas screen extending substantially parallel with and along an inner surface of said furnace wall;
- secondary air supply means forming a secondary air passage extending along said burner body and having a secondary air outlet opening which is at a location spaced from said means for discharging said fuel and air, and
- secondary gaseous fuel supply means forming a secondary gaseous fuel passageway extending along said burner body and having an outlet opening means at said burner tip for discharging said secondary fuel in a direction extending substantially concurrently with said mixture of fuel and air and along an inner surface of said furnace wall,
- whereby at least some mixing occurs at the burner tip between said combustion gas screen and the incoming secondary air before said secondary air undergoes combustion with said secondary gaseous fuel, whereby said burner produces combustion gases of reduced nitrogen oxide content.
In a furnace for burning a gaseous fuel, said furnace having a wall with inner and outer wall surfaces and a burner extending through said wall into such furnace for burning gaseous fuel with reduced production of nitrogen oxides in the resulting combustion flue gas, the combination which comprises:
- (a) a burner block extending through said furnace wall surrounding said burner with intervening space between said burner block and said burner for flow of secondary air;
- (b) said burner block having a hot face which extends into said furnace beyond said inner wall of said furnace;
- (c) said burner having a tip which extends into said furnace beyond said hot face of said burner block;
- (d) means at said burner tip for providing a combustion gas screen directed generally along said hot face of said burner block;
- and
- (e) means at said burner tip for introducing a separate flow of secondary gaseous fuel for flow generally along said hot face of said burner block, whereby said secondary gaseous fuel is mixed with both said combustion gas screen and the incoming secondary air from said intervening space.
In a method of heating a furnace with a gas burner located adjacent to a furnace wall, to provide a reduced percentage of nitrogen oxide components in the furnace flue gas, the steps which comprise:
- (a) burning a mixture of primary gaseous fuel and primary air in said furnace;
- (b) guiding the products of combustion of step (a) to form a combustion gas screen directed generally along a portion of said furnace wall adjacent to said burner;
- (c) introducing a separate flow of secondary gaseous fuel in a path also directed toward the area along said portion of said furnace wall;
- and
- (d) introducing secondary air along said burner, whereby said secondary air is contacted by and at least partially mixed with said combustion gas stream as said secondary air moves into position to react with said secondary gaseous fuel.
Dependencies are inferred from the claim text.