Combustion gas corrosion resistance of heat exchange materials and refractories for glass furnaces at high temperatures; Part 1: Silicon carbide and molybdenum silicide

The materials for gas-fired indirect radiant burners are now being developed, which will allow independence of the atmosphere over the glass from gaseous combustion products. As immersed tubes, they will display higher heat transfer efficiency to the glass, as heat radiates, conducts, and convects in all directions from the tube surface to the glass. Over-the-glass radiant tubes will heat the glass from a high-emittance source. Since combustion product temperature will be rapidly quenched to the temperature of the radiant tube, NO[sub x] emissions will be greatly reduced. Such tubes will be most useful for temperature stabilization in the fore-hearths, as well as immersed to form localized hot spots to achieve desired molten glass convective flow patterns. This work focuses on the combustion gas corrosion of candidate materials, categorized into two groups: silicon-based materials and oxides. The work on silicon-based materials is described herein; oxide materials and composites will be in the March Ceramic Bulletin. The results in these two articles are useful in the evaluation of the corrosion resistance of glass tank breastwall and crown refractories as well as evaluation of candidate materials for indirect radiant burner tubes.