EFFECTS OF MEASURING METHOD ON THE EFFECTIVE THERMAL DIFFUSIVITY OF PACKED COAL COLUMN DURING CARBONIZATION.

The effective thermal diffusivity ( kappa //e//f//f) of pulverized coal was measured by the continuous heating method and the modified periodic heating method in which continuous heating is overlaid with periodic heating. Results are similar at a temperature lower than about 750K. Above 750K, the temperature dependency on kappa //e//f//f is different. kappa //e//f//f is characterized by three temperature regions between 400 and 1100K; in the first kappa //e//f//f is constant, in the second, kappa //e//f//f increases with temperature and in the third, kappa //e//f//f increases.