Thermal analysis of walls in a new-type billet caster tundish with a vacuum shell

To reduce thermal loss from molten steel in a tundish during continuous casting production,a new tundish fabricated by welding radiation-proof steel plates onto the steel plates of the exterior walls of a billet caster tundish was proposed. This new tundish was used to investigate the effect of pressures inside the vacuum chamber on the uniformity of the temperature of molten steel and the thermal conditions of the vacuum layer. The results show that the conversion radiation coefficient is not sensitive to pressure and its value at high temperatures is merely 1. 5times greater than that at low temperatures. Pressure is the key factor affecting additional factor of conversion convection. This factor is more than 100 times greater at 10~5 Pa than at 10~2 Pa,and the temperature at inner points at 10~2 Pa is,on average,4 K higher than that at 10~5 Pa. Meanwhile,the local temperature difference of the inlet at 10~2 Pa is 1 K higher than that at 10~5 Pa. Thus,the proposed vacuum billet caster tundish can achieve low superheat teeming of steel because of the thermal preservation capability of the vacuum,which helps to reduce the tapping temperature and improve the uniformity of the temperature of steel.