Numerical and experimental study of radial segregation of bi-disperse particles in a quasi-two-dimensional horizontal rotating drum--颗粒学报PARTICUOLOGY

Hou, Z., & Zhao, Y. (2020). Numerical and experimental study of radial segregation of bi-disperse particles in a quasi-two-dimensional horizontal rotating drum. Particuology, 51, 109-119. https://doi.org/10.1016/j.partic.2019.09.006

Numerical and experimental study of radial segregation of bi-disperse particles in a quasi-two-dimensional horizontal rotating drum

Zhichao Hou, Yongzhi Zhao ^*

Institute of Process Equipment, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China

10.1016/j.partic.2019.09.006

Volume 51, August 2020, Pages 109-119

Received 6 December 2018, Revised 11 February 2019, Accepted 23 September 2019, Available online 12 December 2019, Version of Record 11 April 2020.

E-mail: yzzhao@zju.edu.cn

Highlights

• DEM simulation and experiment are combined to study particle segregation in a drum.

• An effective image analysis was conducted for particle segregation.

• Effects of rotational speed and volume ratio on radial segregation are reported.

• Mechanism of reverse segregation of particles in the rotating drum is clarified.

Abstract

Radial segregation easily occurs in a horizontal rotating drum partially filled with particles of different properties under various operational conditions. DEM (discrete element method) simulations and experiments were combined together to investigate the segregation of bi-disperse particles of the same density but unequal sizes in a quasi-two-dimensional horizontal rotating drum. A linear spring-dashpot model was adopted in simulations. An easy and effective image analysis was conducted for the segregation/mixing of particles of different sizes. By comparing the repose angles, degrees of segregation, and particular phenomenon ("sun pattern" and reverse segregation) in simulations under different operating conditions with those in experiments, the discrete-element model is verified. The effects of rotational speed and volume ratio on radial segregation are also considered systematically. From an analysis of the results of experiments and simulations, the degree of segregation generally decreases with increasing rotational speed, whereas the volume ratio shows different influences on segregation in different flow regimes. Moreover, the mechanism underlying the reverse segregation in the cataracting regime has been clarified as well.

Graphical abstract

Keywords

Discrete element method; Radial segregation; Granular flow; Rotating drum; Reverse segregation

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