Hydrodynamics of a bubble-induced inverse fluidized bed reactor with a nanobubble tray--颗粒学报PARTICUOLOGY

Deng, Y., Ma, K., Shao, Y., & Zhu, J. (2023). Hydrodynamics of a bubble-induced inverse fluidized bed reactor with a nanobubble tray. Particuology, 73, 8-16. https://doi.org/10.1016/j.partic.2022.03.006

Hydrodynamics of a bubble-induced inverse fluidized bed reactor with a nanobubble tray

Yicheng Deng ^a, Keying Ma ^{b c}, Yuanyuan Shao^{a c *}, Jesse Zhu ^{b a *}

a School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
b Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Ontario, N6A 3K7, Canada
c Institute of Shaoxing, Tianjin University, Zhejiang, 312300, China

10.1016/j.partic.2022.03.006

Volume 73, February 2023, Pages 8-16

Received 9 November 2021, Revised 17 March 2022, Accepted 24 March 2022, Available online 4 May 2022, Version of Record 16 May 2022.

E-mail: yshao@tju.edu.cn; jzhu@uwo.ca

Highlights

• Hydrodynamics of bubble-induced inverse fluidized bed was studied with a nanobubble tray.

• Flow regimes and the transition gas velocities were identified.

• Three empirical formulas for the transition gas velocities were proposed.

Abstract

This paper reports on the hydrodynamics of a bubble-induced inverse fluidized bed reactor, using a nanobubble tray gas distributor, where solid particles are fluidized only by an upward gas flow. Increasing the gas velocity, the fixed layer of particles initially packed at the top of the liquid starts to move downwards, due to the rise of bubbles in this system, and then gradually expands downwards until fully suspended. The axial local pressure drops and standard deviation were examined to delineate the flow regime comprehensively under different superficial gas velocities. Four flow regimes (fixed bed regime, initial fluidization regime, expanded regime, and post-homogeneous regime) were observed and three transitional gas velocities (the initial fluidization velocity, minimum fluidization velocity, and homogeneous fluidization velocity) were identified to demarcate the flow regime. Three correlations were developed for the three transitional velocities. As the fine bubbles generated from the nanobubble tray gas distributor are well distributed in the entire column, the bed expansion process of the particles is relatively steady.

Graphical abstract

Keywords

Bubble-induced; Inverse fluidized bed; Pressure drop; Flow regime; Bed expansion ratio; Standard deviation

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