Using the discrete element method to assess the mixing of polydisperse solid particles in a rotary drum--颗粒学报PARTICUOLOGY

Alchikh-Sulaiman, B., Alian, M., Ein-Mozaffari, F., Lohi, A., & Upreti, S. R. (2016). Using the discrete element method to assess the mixing of polydisperse solid particles in a rotary drum. Particuology, 25, 133-142. https://doi.org/10.1016/j.partic.2015.05.006

Using the discrete element method to assess the mixing of polydisperse solid particles in a rotary drum

Basel Alchikh-Sulaiman, Meysam Alian, Farhad Ein-Mozaffari ^*, Ali Lohi, Simant R. Upreti

Department of Chemical Engineering, Ryerson University, 350 Victoria Street, Toronto, Canada M5B 2K3

10.1016/j.partic.2015.05.006

Volume 25, April 2016, Pages 133-142

Received 3 November 2014, Revised 20 March 2015, Accepted 22 May 2015, Available online 26 September 2015, Version of Record 18 February 2016.

E-mail: fmozaffa@ryerson.ca

Highlights

• Mixing of polydisperse particles in a rotary drum was evaluated using DEM method.

• Effects of drum rotational speed, particle size, and initial loading method were investigated.

• Good mixing could not be achieved for polydisperse particles as for monodisperse particles.

• Best mixing quality for polydisperse particles was achieved for the top–bottom initial loading.

• Addition of particles with sizes in between of the small and large particles reduced segregation.

Abstract

Despite the wide applications of powder and solid mixing in industry, knowledge on the mixing of polydisperse solid particles in rotary drum blenders is lacking. This study investigates the mixing of monodisperse, bidisperse, tridisperse, and polydisperse solid particles in a rotary drum using the discrete element method. To validate the model developed in this study, experimental and simulation results were compared. The validated model was then employed to investigate the effects of the drum rotational speed, particle size, and initial loading method on the mixing quality. The degree of mixing of polydisperse particles was smaller than that for monodisperse particles owing to the segregation phenomenon. The mixing index increased from an initial value to a maximum and decreased slightly before reaching a plateau for bidisperse, tridisperse, and polydisperse particles as a direct result of the segregation of particles of different sizes. Final mixing indices were higher for polydisperse particles than for tridisperse and bidisperse particles. Additionally, segregation was weakened by introducing additional particles of intermediate size. The best mixing of bidisperse and tridisperse particles was achieved for top–bottom smaller-to-larger initial loading, while that of polydisperse systems was achieved using top–bottom smaller-to-larger and top–bottom larger-to-smaller initial loading methods.

Graphical abstract

Keywords

Rotary drum mixer; Discrete element method; Mixing index; Polydisperse particles; Loading methods

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