The present invention relates to a fuel burner apparatus and method for burning a fuel in an oxidant. More particularly, the present invention relates to such a fuel burner apparatus and method in which the oxidant is oxygen or oxygen enriched air. The present invention also relates to a nozzle that is capable of producing a flat, divergent uniform flow of a fluid that is particularly suited for forming oxidant nozzles used in a fuel burner apparatus and method in accordance with the present invention.
Fuel burners are used in many industrial applications in which a material to be processed is melted, for example, glass, copper, aluminum, iron, and steel. In order to maximize the heat available from the fuel, oxy-fuel burners have evolved in which the fuel is burned in oxygen or oxygen enriched air. These burners generally produce flames having a highly concentrated power output which can in turn produce hot spots in the melt. Typically, such burners utilize high velocity oxidant and high mass flow rates of fuel to produce the high power outputs. Taken together, the concentrated heating tends to evolve volatiles within the melt and the high velocities tend to entrain feed material to the exhaust of the furnace. The entrained feed material and evolved volatiles can thereby be lost and pollute the atmosphere or can form a deposit which accumulates within the furnace or exhaust heat recovery systems used in conjunction with furnaces.
A still further problem in oxy-fuel burners is that the high temperature combustion of the fuel in oxygen or oxygen enriched air can produce polluting NO.sub.x.
As will be discussed, the present invention provides a burner apparatus and method that is less susceptible than prior art apparatus and methodology to forming hot spots and entraining feed particles within the flow of oxidant and fuel and further, is readily adaptable to employ a NO.sub.x limiting form of combustion.