1980 Volume 66 Issue 12 Pages 1640-1649
Temperature distribution in slag bath and heat transfer rate to cooling water at various interfaces were investigated on 80 mmφ ESR furnace. Effective thermal conductivity of slag crust was also measured. CaO-Al2O3-CaF2 slags were used in these experiments. Effects of heat transfer characteristics on melting rate and the shape of metal bath are discussed.
The results obtained are as follows:
(1) Overall heat transfer coefficient of the interface region between slag bath and cooling water in ESR and effective thermal conductivity of CaO-Al2O3 are 0.014 cal/cm2·s·deg and 2.2×10-3 cal/cm·s·deg, respectively, and they both increase with the increase in CaF2 content.
(2) In case of oxide-base slag, temperature in slag bath gradually decreases in radical directions, but in fluoride-base one, it doesn't change so much to the vicinity of slag crust.
(3) The temperature gradient in slag crust of CaO-Al2O3 slag is very steep. However, it becomes gentle and the temperature gap at the slag crust-mold wall interface increases with the increase in CaF2 content.
(4) The shape of metal bath differs according to slag composition. Its depth depends on the temperature of slag bath. On the other hand, the height of the cylindrical part of metal bath is related to the heat transfer rate across the slag bath-metal bath interface.