CFD simulation and experimental analysis of flow dynamics and grinding performance of opposed fluidized bed air jet mill

This paper presents a three dimensional Computational Fluid Dynamics (CFD) model to investigate the flow
dynamics of solid–gas phases during fine grinding in an air jet mill. Alpine 100AFG fluidized bed air jet mill is
considered for the study and the jet milling model is simulated using FLUENT 6.3.2 using a standard k-ε model.
The model is developed in GAMBIT 2.3.16 and meshed by tet/hybrid (T-Grid) and Triangular (Pave) meshes.
The effects of operating parameters such as solid feed rate, grinding air pressure and internal classifier speed
on the performance of the jet mill are analyzed. The CFD simulation results are presented in the forms of dual
phase vector plot, volume fraction of phases and particle trajectories during fine grinding process. Themass of
ground feed entering and leaving the cyclone (underflow) is also computed by simulation. The proposed
model gives realistic predictions of the flow dynamics within the jet mill. Experiments are conducted on the
Alpine 100AFG jet mill to study the particle size, morphology and mass of the ground product. The numerical
results are found in good agreement with the experimental results.