Development of an oxygen-enhanced combustor for scrap preheating in an electric arc furnace

The performance of a pilot-scale oxygen-enhanced furnace for scrap preheating with a multi-nozzle inverse diffusion combustor was studied. Natural gas and oxygen diluted in air were supplied to the oxygen-enhanced combustor with a range of 120–300 Mcal/h. The internal flow field of the furnace was simulated with a computational fluid dynamics program before any experiments were carried out. Meanwhile, the characteristic time for furnace heat-up and the level of pollutant emission were experimentally measured. Results showed that the temperature rise in the furnace increased steeply with an increase in the oxygen mole fraction in an oxidant. In addition, the characteristic time for furnace heat-up decreased exponentially as the thermal input power increased.