CFD-DEM Simulation Study on Heat and Mass Transfer of Wheat Particles in Gas–Solid Fluidized Bed

Abstract

Understanding the physical phenomena during fluidized bed drying is crucial. In this study, the dispersion and drying behavior of wheat particles under different fitting models were studied based on Computational Fluid Dynamics–Discrete Element Method. The impact of air parameters on heat and moisture transfer was revealed. The results indicate that the particle dispersion coefficient ranges from 10⁻³ to 10⁻¹ m² s⁻¹. The drying non-uniformity in the fluidized bed increases with time, while the heating rate gradually decreases. The accumulation of particles in the bottom region is identified as the primary cause of drying non-uniformity. For the 5S and 7S models, the standard deviation of particle moisture distribution and bed heating rate during drying differs by ~1%. Air temperature emerges as the key factor affecting drying rate, and variations in air velocity can mitigate the non-uniformity of drying in the fluidized bed. These findings contribute to optimizing fluidized bed drying systems.