Enhancing mixing of particles by baffles in a rotating drum mixer--颗粒学报PARTICUOLOGY

Jiang, M., Zhao, Y., Liu, G., & Zheng, J. (2011). Enhancing mixing of particles by baffles in a rotating drum mixer. Particuology, 9(3), 270–278. https://doi.org/10.1016/j.partic.2010.06.008

Enhancing mixing of particles by baffles in a rotating drum mixer

Maoqiang Jiang, Yongzhi Zhao^*, Gesi Liu, Jinyang Zheng

State Key Laboratory of Chemical Engineering, Institute of Chemical Process Equipment, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, China

10.1016/j.partic.2010.06.008

June 2011, June 2011, Pages 270-278

Received 14 January 2010, Accepted 1 June 2010, Available online 7 April 2011.

E-mail: yzzhao@zju.edu.cn

Highlights

Abstract

Baffles with shape of “–” (single baffle), “+” (cross-baffles with four arms) and “*” (baffles with 6 arms) are used to enhance the mixing of particles in a rotating drum mixer. A micro-dynamics study of mixing and segregation of a bi-disperse system of two particle sizes in the rotating drum with these three kinds of baffles is carried out using the discrete element method (DEM). The effect of the baffles on mixing, and the mechanisms of mixing enhancement by the baffles are discussed and analyzed. Simulation results show that in an unbaffled drum mixer, particle convection, particle diffusion, and size segregation of bi-disperse particles, all play important roles in the mixing process; whereas size segregation will be largely restrained when the drum mixer has a baffle, regardless of its shape, and the degree of mixing is higher than that in an unbaffled drum mixer. The different mixing characteristics for “–” shaped baffle, “+” baffle, and “*” baffle are revealed by the simulation results. For “+” or “*” style baffles, there is an optimal size of baffles for the mixing of particles, and the optimal mixing efficiency is higher than that for “–” baffle.

Graphical abstract

Keywords

Particle mixing; Size segregation; Baffle; Drum mixer; Discrete element method (DEM)

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