CFD-DEM Evaluation of Rod-like Particles Size Effect on the Mixing of Fluidized BED Containing Spheres and Rod-like Particles

Fuidization of particles can be used for a variety of purposes, including biomass gasification, drying applications, food processing, and pharmaceutics production. In practice, spherical particles are usually added to the bed to improve the fluidization quality of non-spherical particles. Understanding the particles mixing behavior in fluidized bed is essential in this case due to its role in process design improvement. Coupling of computational fluid dynamic-discrete element method (CFD-DEM) is used to investigate particles mixing in this study. Non-spherical particles are modeled by the multi sphere method. This work aims to investigate the effect of rod sizes on binary fluidization of spheres and rods. Also, the influence of the rod volume fraction and gas velocity on binary mixing are studied. The results illustrate that increasing the rod volume fraction and rods size increase the minimum fluidization velocity. Fluidized bed mixing becomes faster by reducing the rod-like particle size. Similar trend was observed by decreasing the fraction of rod-like particles. As a result, the addition of spherical particles and approaching particle shape to spherical leads to improvement of the fluidization quality and particle mixing. Furthermore, particle mixing improves by increasing the gas velocity in all investigated cases.