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US 2006/0230996 A1Published application
Method of operating furnace to reduce emissions
AssigneePraxair Technology, Inc.
InventorsEdward Kaczenski, Lawrence Bool, Hisashi Kobayashi
Life of this patent
Estimating the term…
Abstract
Emissions of NOx and CO are reduced from combustion devices such as coal-fired furnaces by increasing the stoichiometric ratio of burner(s) having a lower average temperature and increasing the stoichiometric ratio of burner(s) having a higher average temperature.
Claims18
A method for combusting hydrocarbonaceous fuel containing bound nitrogen in a furnace comprising
- (A) providing a furnace which comprises a plurality of burners, means for supplying combustion air to each of said plurality of burners including a common source for the combustion air fed to said plurality of burners, overfire air means for supplying overfire air into said furnace, and means for supplying hydrocarbonaceous fuel containing bound nitrogen to each of said plurality of burners,
- (B) feeding said fuel and combustion air to said burners, feeding air through said overfire means into said furnace, and combusting said fuel and combustion air in said burners to generate from each burner a flame within said furnace, wherein a first group of two or more contiguous burners produce a first group of flames and a second group of contiguous burners produce a second group of flames whose average temperature is higher than the average temperature of the first group of flames, and wherein said combustion produces flue gas containing NOx and CO, and
- (C) decreasing the NOx content and the CO content of said flue gas by increasing the stoichiometric ratio of said first group of burners and decreasing the stoichiometric ratio of said second group of burners,
- wherein the total amount of oxygen fed into said furnace is at least 100% of the amount needed to completely combust the total amount of fuel fed into said furnace.
1 more element
A method for combusting hydrocarbonaceous fuel containing bound nitrogen in a furnace comprising
- providing a furnace which comprises a plurality of burners including first and second groups of burners wherein the burners in said first group are closer to a side wall or to the bottom of said furnace than the burners in said second group, means for supplying combustion air to each of said plurality of burners including a common source for the combustion air fed to said plurality of burners, means for supplying hydrocarbonaceous fuel containing bound nitrogen to each of said plurality of burners and means for supplying overfire air to said furnace, feeding said fuel and combustion air to said burners and combusting said fuel and combustion air in said burners,
- wherein the stoichiometric ratio of said first group of burners is 0.9 to 1.5 and the stoichiometric ratio of said second group of burners is 0.2 to 0.7, and wherein the total amount of oxygen fed into said furnace is at least 100% of the amount needed to completely combust the total amount of fuel fed into said furnace.
Dependencies are inferred from the claim text.