Abstract: The heating and mixing pot of coal tar enamel is the heating device used for coal tar enamel production and field application. The conventional heating method.mostly of direct heating, is hard to fit in with application requirements due to its low heat efficiency and heavy pollution. Indirect heating pot, with heat medium as carrier, also suffers from some disadvantages, such as defficient and insufficient mixing, high energy consumption, low overall coefficient of heat exchange between heat medium and coal tar enamel, long heating time, etc. In this connection, thermodynamically calculated are the Reynolds number, Re.Prandtl number, Pr, and Nusselt number, Nu for the heat exchange in the pot, and the overall coefficient of heat exchange between heat medium and coal tar enamel is obtained. The newly calculated results can be used as design basis for mixing pot, so as to improve heating efficiency, reduce heating time and promote economic performance.