粒子の種類を変えた充填層における高温気体から粒子への伝熱特性

抄録

High temperature gas was blown to several kinds of solid particle packed bed. Heated air at 55-100°C was blown to the packed bed under conditions with a blowing flow rate of 70-160L/min and a blower pressure of 0.1-0.3MPa(G). Alumina spheres with a particle size of 10 mm and sintered ore and coke with a particle size of 9-11 mm were charged into the packed bed. Since it is unsteady-state experiment, the time to reach equilibrium was calculated, and the ratio of heat transfer from gas to particles and the average heat transfer coefficient were calculated. From the results of experiments using alumina spheres, it was found that the heat transfer coefficient increases as the flow rate increases.Moreover, when the blast temperature was changed, the effect on the heat transfer coefficient was small. In addition, assuming that the Ranz-Marshall equation for the heat transfer of a single particle could be applied to the filling layer of this experiment, the coefficients in the equation were calculated as parameters. Ranz's equation shows that the average Nu number of the filling layer is larger than that of a single particle sphere, but the heat transfer in the filling layer in this experiment shows that the average Nu number is smaller than that of the single particle sphere heating.