CFD-DEM investigation into flow characteristics in mixed pulsed fluidized bed under electrostatic effects--颗粒学报PARTICUOLOGY

Li, H., Wang, L., Du, C., & Hong, W. (2022). CFD-DEM investigation into flow characteristics in mixed pulsed fluidized bed under electrostatic effects. Particuology, 66, 100-112. https://doi.org/10.1016/j.partic.2021.08.005

CFD-DEM investigation into flow characteristics in mixed pulsed fluidized bed under electrostatic effects

Hongwei Li ^*, Lei Wang, Changhe Du, Wenpeng Hong

School of Energy and Power Engineering, Northeast Electric Power University, Jilin 132012, China

10.1016/j.partic.2021.08.005

Volume 66, July 2022, Pages 100-112

Received 28 June 2021, Revised 4 August 2021, Accepted 13 August 2021, Available online 10 September 2021, Version of Record 29 November 2021.

E-mail: lihongweihw@163.com

Highlights

• Electrostatic effects and mixed pulsed fluidized bed are combined.

• Flow characteristics are studied by using the coupled CFD-DEM model.

• Differences between particle flow in fluidized bed with/without charge are compared.

• Law of particle motion at different pulse frequencies is researched.

• Effect of different gas flow ratios on particle mixing is analyzed.

Abstract

Static electricity has an important effect on gas–solid fluidized bed reactor fluidization performance. In the process of fluidization, electrostatic interaction between particles will obviously accelerate particle agglomerate formation, which consequently reduces the fluidization performance. Pulsed gas flow injection is an efficient method to enhance particle mixing, thereby weakening the occurrence of particle agglomerate. In this study, the two-dimensional hybrid pulsed fluidized bed is established. The flow characteristics are studied by using the coupled CFD-DEM numerical simulation model considering electrostatic effects. Influences of different pulsed frequencies and gas flow ratios on fluidized bed fluidization performance are investigated to obtain the optimal pulsed gas flow condition. Results show that in the presence of static electricity, the bubble generation position is lower, which is conducive to the particle flow. Pulsed gas flow can increase the particle velocity and improve the diffusion ability. The bubble generation time is different at different frequencies, and the frequency of 2.5 Hz has the most obvious effect on the flow characteristics. Different gas flow ratios have significant impacts on the particle movement amplitude. When the pulse gas flow accounts for a large ratio, the particle agglomerate tends to be larger. Therefore, in order to improve the fluidization effect, the ratio of pulsed gas flow to stable gas flow should be appropriately reduced to 0.5 or less.

Graphical abstract

Keywords

Mixed pulsed fluidized bed; CFD-DEM; Electrostatic effects; Flow characteristics

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