Experimental and computational studies on flow behavior of gas–solid fluidized bed with disparately sized binary particles--颗粒学报PARTICUOLOGY

Gao, J., Chang, J., Lu, C., & Xu, C. (2008). Experimental and computational studies on flow behavior of gas–solid fluidized bed with disparately sized binary particles. Particuology, 6(2), 59–71. https://doi.org/10.1016/j.partic.2007.11.003

Experimental and computational studies on flow behavior of gas–solid fluidized bed with disparately sized binary particles

Jinsen Gao, Jian Chang, Chunxi Lu, Chunming Xu ^*

State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Changping, Beijing 102249, China

10.1016/j.partic.2007.11.003

Volume 6, Issue 2, April 2008, Pages 59-71

Received 6 August 2007, Accepted 18 November 2007, Available online 9 April 2008.

E-mail: xcm@cup.edu.cn

Highlights

Abstract

This paper presents experimental and computational studies on the flow behavior of a gas–solid fluidized bed with disparately sized binary particle mixtures. The mixing/segregation behavior and segregation efficiency of the small and large particles are investigated experimentally. Particle composition and operating conditions that influence the fluidization behavior of mixing/segregation are examined. Based on the granular kinetics theory, a multi-fluid CFD model has been developed and verified against the experimental results. The simulation results are in reasonable agreement with experimental data. The results showed that the smaller particles are found near the bed surface while the larger particles tend to settle down to the bed bottom in turbulent fluidized bed. However, complete segregation of the binary particles does not occur in the gas velocity range of 0.695–0.904 m/s. Segregation efficiency increases with increasing gas velocity and mean residence time of the binary particles, but decreases with increasing the small particle concentration. The calculated results also show that the small particles move downward in the wall region and upward in the core. Due to the effect of large particles on the movement of small particles, the small particles present a more turbulent velocity profile in the dense phase than that in the dilute phase.

Graphical abstract

Keywords

Binary particles; Distinct size difference; Mixing; Segregation; Fluidized bed; CFD

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