DEM-CFD SIMULATION OF THE GAS FLUIDIZATION OF A MIXTURE OF TWO SOLIDS

摘要

In this work a computational code based on a combined DEM-CFD approach is briefly described, together with a sensitivity analysis on the computational time to the system properties. The results of simulations carried out on a system representing the gas-fluidization of a mixture of two solids differing in density are discussed. In particular, the effect of three initial configurations on the fluidization patterns is analyzed. Stable-segregated, unstable-segregated and mixed initial configurations are reproduced, analyzing the process dynamics from fixed to fluidized bed state. The results demonstrate that the code is capable of reproducing theoretical as well as experimental results with very good accuracy. The atypical and not well understood overshoot in the fluidization curve at minimum fluidization for the unstable-segregated initial configuration is found and an interpretation of the wall effects is attempted with the aid of ad-hoc simulations under extreme conditions.