Ultra low NOx side burners for preheating furnaces in the steel mills

Low NOx and CO2 emission from preheating furnace becomes a very important subject to a modernization and building of new reheating furnaces in the steel mills. The rising emission trading makes this issue a real production cost factor which has to be minimized. The emission of nitrogen oxides from fuel flames is subject to a number of different factors mainly comprising the flame temperature, oxygen supply and dwell time. This paper will describe some proven techniques to reduce NOx emissions in preheating furnaces by altering the combustion process in burners for side or front wall installation. A brief overview of the interactive variables that affect the NOx generation will be presented to understand how changing the combustion process reduces emissions. An Ultra-LOW-NOx burner application on pusher furnaces in a heavy steel mill is introduced and discussed.