CFD-DEM investigation of fine charged particle coating in fluidized beds

Particle coating is widely employed across various industries, including chemical, pharmaceutical, and food sectors. Different types of equipment, such as fluidized beds, are commonly used for coating both wet and dry particles. Among these methods, dry particle coating utilizes electrostatic forces, where fine particles adhere to the surface of oppositely charged carrier particles. This study focuses on modeling the coating process of fine particles on carrier particles in a quasi-2D fluidized bed using CFD-DEM. The modified van der Waals and modified electrostatic forces were identified as key factors influencing particle cohesion and the successful coating of fine particles on carriers. Additionally, the study examines the effects of inlet gas velocity, carrier particle diameter, charge, and quantity on the coating process. Modeling results showed that as the charge of carrier particles increases, both coating thickness and the number of long-time remained particles on the carrier particles increases. Also, lower fluidization velocities were more suitable for the coating process in fluidized beds, as cohesive forces outweighed the drag force.