Multi-fluid modeling of density segregation in a dense binary fluidized bed--颗粒学报PARTICUOLOGY

Chao, Z., Wang, Y., Jakobsen, J. P., Fernandino, M., & Jakobsen, H. A. (2012). Multi-fluid modeling of density segregation in a dense binary fluidized bed. Particuology, 10(1), 62–71. https://doi.org/10.1016/j.partic.2011.10.001

Multi-fluid modeling of density segregation in a dense binary fluidized bed

Zhongxi Chao ^a *, Yuefa Wang ^a, Jana P. Jakobsen ^b, Maria Fernandino ^c, Hugo A. Jakobsen ^a

a Department of Chemical Engineering, NTNU, Trondheim 7491, Norway
b SINTEF Energy, Trondheim 7491, Norway
c Department of Energy and Process Engineering, NTNU, Trondheim 7491, Norway

10.1016/j.partic.2011.10.001

Volume 10, Issue 1, February 2012, Pages 62-71

Received 9 July 2011, Revised 7 September 2011, Accepted 2 October 2011, Available online 9 January 2012.

E-mail: chao@chemeng.ntnu.no; realizedream@hotmail.com

Highlights

► Density segregation in dense fluidized beds is modeled.

► Binary velocities are closely coupled though segregation exists.

► Particle flow profiles are superficial gas velocity dependent.

► Particles may segregate both axially and radially.

Abstract

This paper presents simulation results of the density segregation in a dense binary gas fluidized bed using a multi-fluid model from Chao et al. (2011). The segregation behavior of two types of particles with approximately same particle diameters and different particle densities was studied and validated using the experimental data from Formisani et al. (2008). Some detailed information regarding the gas, particle velocity profiles, the distributions of the particle volume fractions and the flotsam-to-total particle volume fraction ratios is presented. The simulation results show that the simulated axial average flotsam-to-total particle volume fraction ratio distribution agrees reasonably with the experimental data of Formisani et al. (2008). The binary particle velocities are closely coupled though the segregation exists. The segregation behavior and the particle velocity profiles are superficial gas velocity dependent. The number and distribution of particle velocity vortices change dramatically with superficial gas velocity: at a comparatively low superficial gas velocity, the particles mainly segregate axially, and at a comparatively high superficial gas velocity, the particles segregate both axially and radially.

Graphical abstract

Keywords

Fluidized bed; Binary flow; Density segregation; Multi-fluid model; Granular flow

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