Steel project fact sheet: Steel reheating for further processing

摘要

Steel reheating is an energy-intensive process requiring uniform temperature distribution within reheating furnaces. Historically, recuperators have ben used to preheat combustion air, thereby conserving energy. More recent innovations include oxygen enrichment and the use of regenerative burners, which provide higher preheat air temperatures than recuperators. These processes have limitations such as equipment deterioration, decreasing energy efficiency over time, high maintenance costs, and increased NO(sub x) emissions with increased air preheat temperature, unless special equipment is used. Praxair, Inc., supplier of oxygen and other industrial gases to the steel industry, proposes to introduce an innovative oxy-fuel burner technology (using 100% oxygen) to the steel reheating industry. Oxy-fuel combustion reduces or eliminates nitrogen in combustion air and substantially reduces waste heat carried out with flue gas. Based on technology currently used in the glass, hazardous waste, and aluminum industries, Praxair has developed and patented low temperature, oxy-fuel burners that can be used in high temperature industrial furnaces where temperature uniformity is critical and extremely low NO(sub x) emissions are desired. The technical goal of the project is to demonstrate the use of oxy-fuel burners in a slab reheat furnace while reducing energy consumption by 45% and NO(sub x) emissions by 90% within the converted furnace zones. Successful implementation of this technology also will eliminate the need to periodically replace recuperators and install NO(sub x) removal equipment.