Ceramic Materials Selection for A Glass Furnace Recuperator 790255

Procedures, materials and results are reported for the materials selection process performed in conjunction with efforts to develop, test, and evaluate High Temperature Range Recuperator designs for an industrial glass furnace. Potential materials were evaluated on material properties, fabrication capability, and relative performance in the flue environment of a day tank glass furnace. Polycrystalline alumina (Vistal), reaction sintered silicon carbide (KT and NC 430), chemically vapor deposited silicon carbide (CVD) and Sintered Alpha silicon carbide proved most satisfactory in the material temperature range of 2300°F to 2800°F. Relatively pure alumina (AD 998 and AD 94), mullite and cordierite were most satisfactory in the material temperature range of 1700°F to 2300°F. Thermo-mechanical stress for each material was calculated under expected operating conditions for the optimized design. Material strengths are shown to be greater than calculated stresses by factors ranging from 2.6 for KT silicon carbide to 16 for cordierite. Recuperator test sections were subjected to twice the expected thermal stress conditions with no evidence of failure. A test section was also subjected to the thermal shock of instant transfer between room temperature and a 2000°F furnace without damage.