Abstract
An experimental investigation of the effect of the distance between the fuel and air nozzles on NO_x emission at different temperatures and oxygen concentrations of the oxidizer in high air temperature combustion cylindrical furnace was conducted. Highly preheated oxidizer (air and nitrogen) was injected in the furnace through an oxidizer nozzle positioned at the center of the base of the cylindrical furnace. Propane was injected through three different sets of fuel nozzles, one set working at a time. As a result, the emission of NO_x decreased as the distance between the fuel nozzles and the oxidizer nozzle increased. At lower preheating temperatures and lower O2 concentrations of the oxidizer, the emission of NO_x tends to become lower.