The primary characteristic of nozzle mix burner is separation of the fuel and oxidant until both exit the orifices of the burner and form a flame upon ignition in the throat of the burner. Usually the air and fuel are mixed in proportions such that the air exceeds the stoichiometric quantity needed to completely combust all of the fuel. With nozzle-mix burners, combustion air can be preheated, causing combustion to proceed even more rapidly and saving fuel. It is widely used for industrial furnace applications.