Factors on the Measurement of Effective Thermal Diffusivity of Molten Slag Using Double Hot Thermocouple Technique.

Abstract

The molten slags that are used not only in the continuous caster but also in every metal industry play an important role and affect the quality of products. The authors initially developed the double hot thermocouple technique (DHTT) for in situ observation of mold slag crystallization. In this study, the DHTT was further developed to allow the measurement of the overall thermal diffusivity of molten slag applying the principle of the laser flash method. The affecting factors (finite pulse time, shape of pulse and heat loss from sample surface) on the measurement of thermal diffusivity using the DHTT were discussed theoretically using both the analytical and the numerical methods. New relationship between the thermal diffusivity a and the time at half-maximum temperature to 5 was obtained as follows: α(×10 4 m 2 /s) = 0.000707(t 0.5 /t p ) -1.8946 The thermal diffusivity obtained from the experimental half-maximum time t 0.5 /t p (t p is the time of peak on the heat pulse) was in good agreement with the one from literature.