A Study on the Fluidization of the Granular Materials and the Pressuer Drop in Vertical Type Mill

To improve the pressure drop characteristics of vertical type mill, the fundamental relationship between the fluidization of raw materials in the mill and some parameters such as initial bed hight, gas velocity, particle diameter, blade configuration, and mixing ratio was studied experimentally in the case of miscellaneouse kind of granules. The results showed that both minimum fluidization velocity and minimum fluidization pressure drop increased as bed height and particle diameter increased, and that the fluidization characteristics were influenced considerably by blade configuration when the blade opening ratio was less than 0.25. Experiments indicated that the effective energy consumed for fluidization decreased as the mean diameter of granular particle increased. To estimate the minimum fluidization velocity for multicomponent particles, correlation of minimum fluidization velocity with the mixing ratio was given. Furthermore, control algorithm for driving the system at minimum fluidization velocity was investigated, and test runs showed a remarkable control characteristics.