Experimental and CFD Analysis of Heat Transfer in a Two-Dimensional Fluidized Bed Coater

This work presents an integrated experimental and numerical investigation of heat transfer behavior in a two-dimensional fluidized bed coater. A CFD model based on an Eulerian–Eulerian two-fluid formulation coupled with the kinetic theory of granular flow was developed to describe the gas–solid motion of air and urea particles. Simulations were performed under an inlet air temperature of 353 K, and four drag models Gidaspow, Huilin–Gidaspow, Syamlal–O’Brien, and Wen–Yu were evaluated to examine their influence on the predicted flow structure and thermal behavior. After establishing the hydrodynamic characteristics of the system, the model was extended to include heat and mass transfer, enabling prediction of particle heating and droplet evaporation. The numerical results were assessed using experimental temperature measurements. Among the tested drag laws, the Gidaspow model showed the closest agreement with the experimental data, predicting an average outlet temperature of 333.9 K with a deviation of 2% from the measured value. The results show that drag law selection strongly affects both the hydrodynamic and thermal response of the fluidized bed coater. The resulting simulations capture the spatial distribution of solids and their velocity patterns, along with the internal temperature fields of the coating unit.