Mixing and segregation of solid particles in a conical spouted bed: Effect of particle size and density--颗粒学报PARTICUOLOGY

Kiani, M., Rahimi, M. R., Hosseini, S. H., & Ahmadi, G. (2017). Mixing and segregation of solid particles in a conical spouted bed: Effect of particle size and density. Particuology, 32, 132-140. https://doi.org/10.1016/j.partic.2016.06.006

Mixing and segregation of solid particles in a conical spouted bed: Effect of particle size and density

M. Kiani ^a, M.R. Rahimi ^a^*, S.H. Hosseini ^b^*, G. Ahmadi ^c

a Department of Chemical Engineering, Faculty of Engineering, Yasouj University, Yasouj, Iran
b Department of Chemical Engineering, Faculty of Engineering, Ilam University, Ilam 69315-516, Iran
c Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY 13699-5725, USA

10.1016/j.partic.2016.06.006

Volume 32, June 2017, Pages 132-140

Received 26 December 2015, Revised 25 March 2016, Accepted 28 June 2016, Available online 28 February 2017, Version of Record 20 April 2017.

E-mail: mrrahimi@yu.ac.ir; s.h.hosseini@ilam.ac.ir; hosseini49@gmail.com

Highlights

• Mixing and segregation of binary particle mixtures were studied experimentally in 2D spouted bed.

• An image-processing technique was used to obtain particle concentration profiles.

• Axial and lateral segregation and particle flow patterns were studied.

• Equilibrium time and bed pressure drop at different air velocities were measured and discussed.

Abstract

In this work, the mixing and segregation of binary mixtures of particles with different sizes and densities in a pseudo-2D spouted bed were studied experimentally. A binary mixture of solid particles including sand, gypsum, and polyurethane was used. To determine the particles mass fraction, and their mixing and segregation in the bed, an image-processing technique was developed and used. Important hydrodynamic parameters, such as the axial and radial segregation profiles of the solid particles, were measured. The effects of air velocity, particle size, and particle mass fraction were also evaluated. The flow regime in the spouted bed and the time required for reaching the equilibrium state of the solid particles were discussed. The results showed that the segregation of solid particles and the time to equilibrium both decreased when the air velocity increased to much larger than the minimum spouting velocity. The axial segregation increased with the diameter ratio of the particles. Upon completion of the test, coarse particles were concentrated mainly in the spout region, while fine particles were aggregated in the annulus region. Examination of the flow pattern in the spouted bed showed that the particles near the wall had longer flow paths, while those near the spout region had shorter flow paths.

Graphical abstract

Keywords

Experimental; Segregation; Binary particles; 2D spouted bed

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