Abstract: An improved burner assembly and process for operating same using a burner design that produces very low levels of undesirable nitrogen oxides is provided. The burner assembly premixes primary fuel and air in a venturi system and recirculates combustion gases back to the burner through a plurality of recirculation conduits where it is mixed with the premix of fuel and air and secondary air prior to combustion in a primary combustion zone. Rapid premixing of the primary fuel and air in the venturi system and the dispersion of the recirculated furnace gases is believed to result in lower peak flame temperatures and therefore minimizing the formation of the pollutants, such as nitrogen oxides.

Abstract: An improved process for heating furnaces using a burner design that produces very low level of undesirable nitrogen oxides is provided. The process recirculates a large volume of furnaces gases back to the burner where it is mixed with fuel gas in a plurality of recirculation ports prior to combusting with air in a primary combustion zone. Dispersion of the fuel gas in the recirculated furnace gases is believed to result in lower peak flame temperatures and therefore minimizing the formation of the pollutants, such as nitrogen oxides.

Abstract: Improved methods and burner apparatus are provided for discharging mixtures of fuel and air into furnace spaces wherein said mixtures are burned and flue gases having low NO.sub.x content are formed therefrom. The methods basically comprise discharging a first fuel mixture containing a portion of the fuel and flue gases from the furnace space into the furnace space whereby the mixture is burned in a primary reaction zone therein and flue gases having low NO.sub.x content are formed therefrom, and then discharging the remaining portion of the fuel into a secondary reaction zone wherein the remaining portion of fuel mixes with air and flue gases to form a second fuel mixture which is burned in the secondary reaction zone and additional flue gases having low NO.sub.x content are formed therefrom.

Abstract: Improved methods and burner apparatus are provided for discharging mixtures of fuel and air into furnace spaces wherein said mixtures are burned and flue gases having low NO.sub.x content are formed therefrom. The methods basically comprise discharging a first fuel mixture containing a portion of the fuel and flue gases from the furnace space into the furnace space whereby the mixture is burned in a primary reaction zone therein and flue gases having low NO.sub.x content are formed therefrom, and then discharging the remaining portion of the fuel into a secondary reaction zone wherein the remaining portion of fuel mixes with air and flue gases to form a second fuel mixture which is burned in the secondary reaction zone and additional flue gases having low NO.sub.x content are formed therefrom.

Abstract: Improved methods and burner apparatus are provided for discharging mixtures f fuel and air into furnace spaces wherein said mixtures are burned and flue gases having low NO.sub.x content are formed therefrom. The methods basically comprise discharging a first fuel mixture containing a portion of the fuel and flue gases from the furnace space into the furnace space whereby the mixture is burned in a primary reaction zone therein and flue gases having low NO.sub.x content are formed therefrom, and then discharging the remaining portion of the fuel into a secondary reaction zone wherein the remaining portion of fuel mixes with air and flue gases to form a second fuel mixture which is burned in the secondary reaction zone and additional flue gases having low NO.sub.x contents are formed therefrom.

Abstract: Improved methods and burner apparatus are provided for discharging mixtures of fuel and air into furnace spaces wherein said mixtures are burned and flue gases having low NO.sub.x content are formed therefrom. The methods basically comprise discharging a first fuel mixture containing a portion of the fuel and flue gases from the furnace space into the furnace space whereby the mixture is burned in a primary reaction zone therein and flue gases having low NO.sub.x content are formed therefrom, and then discharging the remaining portion of the fuel into a secondary reaction zone wherein the remaining portion of fuel mixes with air and flue gases to form a second fuel mixture which is burned in the secondary reaction zone and additional flue gases having low NO.sub.x content are formed therefrom.

Abstract: A burner assembly for process heaters or the like comprising a burner block, primary gas jets, secondary gas jets, a flame holder, and an air register for installation in a furnace wall or furnace floor is described. The burners are characterized in that primary fuel is introduced into the primary combustion zone of the burner at an angle horizontal to the flame holder whereby the fuel induces furnace gases from the furnace into the primary combustion zone. Similarly, the secondary fuel jets introduce a secondary fuel through the burner block for consumption in a combustion zone at the surface of the burner block. The secondary fuel also draws furnace gases into the combustion zone for consumption. The design provides for intense mixing of combustion air with the fuel and furnace gases, resulting in low NO.sub.x levels.