Tall Crown Furnace Technology for Oxy-Fuel Firing Lowers Costs and Maintains Heat Transfer

Praxair has developed an advanced oxy-fuel glass melting technology to reduce silica refractory corrosion, NOx formation, and SOx and particulate emissions while maintaining the high heat transfer and energy efficiency of oxy-fuel glass melting. The Praxair technologies incorporate several important furnace design features to reduce the concentration of alkali vapors that can corrode silica refractory. Since over 80% of particulate emissions are caused by volatilization of the alkali vapors, the tall crown design also reduces particulate emissions.
A tall crown reduces the bulk concentration of alkali vapors by 50% over a conventional oxy-fuel furnace, and improves temperature uniformity on the glass melt and refractory surfaces. In addition, the furnace design allows for deep oxygen staging which reduces the formation of NOx emissions. In spite of a small increase in the wall heat loss due to the increased side wall height, the overall furnace heat transfer and energy efficiencies remain the same by better radiative heat transfer in the Tall Crown Furnace.