Impact of friction coefficient on particles circulation velocity calculated by euler-lagrange model in spouted bed apparatus for dry coating

This paper is a continuation of research concerning gas-solid flow modelling using the Euler-Lagrange approach in a spout-fluid bed apparatus. The major challenge in this case was to determine the friction coefficient for particles hitting against the walls of the apparatus. On the basis of the properties of similar materials the value of this quantity was estimated at 0.2. Therefore, it proved useful to check the model’s sensitivity to the value of this parameter. The study investigated the effect of friction coefficient on calculated values of particles velocity in the draft tube and the annular zone of the device for various volumes of the circulating bed. In the course of calculations, a relatively small influence of friction coefficient on particles velocity was observed in the tested zones of the apparatus. The changes were most visible for large volumes of the bed, which was connected with an increase in the number of collisions of particles with the walls.