Regenerative blast furnace gas blastoflame ultra low NOx burner

Worldwide tightening of energy supplies combined with the high costs of this energy represents a constraint on the operations of integrated steel production. The efficient utilization of lower quality by-product fuels in the reheat furnaces represents a source of savings in this part of the plant. Specifically, these types of fuels include blast furnace gas, coke oven gas, and BOF converter gas as well as their mixtures. While these fuels have been commonly in use since the early years of steel production, recent environmental concerns regarding NOx and CO2 emissions and increased cost of high calorific fuels such as natural gas represent a new technological challenge in this application. This paper will introduce a combustion system based on the regenerative preheating of the blast furnace gas and recuperative preheating of the air to achieve efficient heating at the temperatures required for reheating of steel. Through extensive Lab tasting combined with CFD modelling and advanced control systems we were able to develop and design a burner with excellent flame stability and heat transfer capability. Flame shape is optimized to furnace chamber and product being heated. Through controlled mixing of the fuel and air we are able to avoid excessive oxidizing and/or reducing atmosphere conditions at the product surface. The possibility for the use of back up fuels is also a consideration.