Patent ID: 6383462
Filing Date: 2002-05-07
Classification: F23C,F23L

Abstract:
A method of reducing the content of nitrogen oxides in flue gases produced by the combustion of an at least substantially stoichiometric mixture of fuel gas and combustion air introduced into a burner connected to a furnace comprising the steps of:(a) conducting said combustion air to said burner; (b) providing a first mixing chamber outside of said burner and furnace for mixing flue gases from said furnace and a flow motivating gas with said fuel gas, said mixing chamber including a fuel gas jet-forming nozzle, at least one flow motivating gas jet-forming deflector and a venturi and mixing compartment therein; (c) discharging said fuel gas in the form of a fuel gas jet into said first mixing chamber by way of said fuel gas jet-forming nozzle so that flue gases from said furnace are drawn into said mixing chamber and mix with and dilute said fuel gas in said venturi and mixing compartment therein; (d) discharging a flow motivating gas in the form of at least one flow motivating gas jet into said first mixing chamber by way of said flow motivating gas jet-forming deflector so that additional flue gases from said furnace and additional fuel gas, if needed, are drawn into said mixing chamber and mix with each other and with said flow motivating gas in said venturi and mixing compartment therein; and (e) conducting the mixture of flue gases, flow motivating gas and fuel gas formed in steps (c) and (d) to said burner wherein said mixture is combined with said combustion air and burned therein and in said furnace.