Studying the particle size ratio effect on granular mixing in a vertically vibrated bed of two particle types--颗粒学报PARTICUOLOGY

Menbari, A., & Hashemnia, K. (2020). Studying the particle size ratio effect on granular mixing in a vertically vibrated bed of two particle types. Particuology, 53, 100-111. https://doi.org/10.1016/j.partic.2020.01.007

Studying the particle size ratio effect on granular mixing in a vertically vibrated bed of two particle types

Amir Menbari, Kamyar Hashemnia ^*

School of Mechanical Engineering, Shiraz University, Molla Sadra St., Shiraz, Iran

10.1016/j.partic.2020.01.007

Volume 53, December 2020, Pages 100-111

Received 23 July 2019, Revised 16 January 2020, Accepted 30 January 2020, Available online 19 April 2020, Version of Record 16 December 2020.

E-mail: khashmenia@shirazu.ac.ir

Highlights

• Particle size ratio affects granular mixing in vibrationally fluidized beds.

• As the particle size ratio increased, the particles were mixed faster.

• The particle mixture uniformity decreased with an increase in particle size ratio.

• Particle size had no significant effect on the convective mixing mechanism.

• Diffusive mixing mechanism strengthened for larger size ratios.

Abstract

The uniform mixing of solids is important in many industries, such as the pharmaceutical, food, petrochemical and chemical industries. We numerically investigated the effect of particle size ratio on the mixing of bisized particles in a quasi-two-dimensional vibrationally fluidized bed. The granular binary mixtures comprised spherical particles with different size ratios. Three-dimensional discrete-element simulations agreed with previous experimental results. Convective and diffusive mechanisms occurred within the vibrated bed. The particle size had no significant influence on convective mixing, whereas the diffusive mechanism strengthened for large size ratios. The average particle velocity was larger in a mixture of large size ratios. The stronger diffusive motion and larger average particle velocity caused the particles to mix faster for large size ratios. The final mixing index decreased with size ratio because of the difference between the size and number of small and large particles.

Graphical abstract

Keywords

Discrete-element modeling; Fluidization; Granular media; Mixing; Particle size ratio; Vibration

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