Influence of the particle size ratio on mixing in a vertically vibrated bed containing spherical particles

The uniform mixing of solids is an important process in many industries such as pharmaceutical, food, petrochemical and agriculture. The present work numerically investigated the effect of particle size ratio on mixing of bi-sized particles in a vibrationally fluidized bed.The granular binary mixtures were made up of spherical particles with different size ratios. It was found that the 3D discrete element simulations were in agreement with previous experimental results. It was observed that the convective and diffusive mechanisms occurred within the vibrated bed. The particle size had no significant influence on convective mixing, while the diffusive mechanismbecame stronger in large size ratios. It was indicated that the average velocity of particles was larger in the mixtures of large size ratios. It was also found that the stronger diffusive motion and larger average velocity of particles caused the particles to mix faster in large size ratios. However, the final mixing index decreased by size ratio due to the difference between the size and number of smalland large particles.

کلیدواژه ها:

Discrete element modeling ، Fluidization ، Granular media ، Mixing ، Vibration