Increased production capacity in heating furnaces through flameless oxy-fuel combustion

摘要

This paper presents the latest development and practical results from the use of ultra low NO_x combustion technology for highly efficient heating furnaces in the steel industry. Achieving low NO_x levels demands control of the nitrogen in the combustion process, the oxygen content in the furnace and low peak flame temperatures. Flameless oxy-fuel combustion has shown to produce ultra low NO_x values, below 25 mg/MJ, both in pilot scale tests made by the Royal Institute of Technology, Sweden and at three industrial installations in reheating and annealing furnaces, converted to all oxy-fuel. A secondary effect with flameless oxy-fuel is the more even heat distribution in the heated material, resulting in improved rolling, annealing and forging processes. The flameless oxy-fuel technology results in improved efficiency; more heating capacity in existing furnaces, reduced specific fuel and CO_2 emissions, improved processing and ultra low levels of NO_x.