Bubble behaviors of geldart B particle in a pseudo two-dimensional pressurized fluidized bed--颗粒学报PARTICUOLOGY

Zhu, X., Liu, Y., Li, Y., Wang, H., & Wang, Z. (2023). Bubble behaviors of geldart B particle in a pseudo two-dimensional pressurized fluidized bed. Particuology, 79, 121-132. https://doi.org/10.1016/j.partic.2022.11.001

Bubble behaviors of geldart B particle in a pseudo two-dimensional pressurized fluidized bed

Xiaoli Zhu ^a *, Yibo Liu ^a, Yuehuan Li ^a, Haigang Wang ^b, Zhenbo Wang ^a *

a College of New Energy, China University of Petroleum (East China), Qingdao, 266580, China
b Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing, 100190, China

10.1016/j.partic.2022.11.001

Volume 79, August 2023, Pages 121-132

Received 21 August 2022, Revised 28 October 2022, Accepted 2 November 2022, Available online 10 November 2022, Version of Record 24 January 2023.

E-mail: zhuxiaoli@upc.edu.cn; wangzhb@upc.edu.cn

Highlights

Abstract

Pressurized fluidized beds have been developed in quite a few industrial applications because of intensified heat and mass transfer and chemical reaction. The bubble behaviors under elevated pressure, strongly influencing the fluidization and reaction conversion of the whole system, are of great research significance. In this work, the bubble behaviors of Geldart B particle in a pseudo two-dimensional (2D) pressurized fluidized bed were experimentally studied based on digital image analysis technique. The effects of pressure and fluidization gas velocity on the general bubble behaviors (i.e., size, shape and spatial distribution) and the dynamic characteristics, such as the time-evolution of voidage distribution and local flow regimes, were comprehensively investigated. Results show that increasing pressure reduces the stability of bubbles and facilitates gas passing through the emulsion phase, resulting in the “smoother” fluidization state with smaller bubbles and declined bubble fraction and standard deviation. The equivalent bubble diameter and bubble aspect ratio increase with the increasing gas velocity while decrease as pressure rises. The elevated pressure reduces bubbles extension in the vertical direction, prohibits the “short pass” of fluidization gas in large oblong bubbles/slugs and benefits the gas–solid interaction. The flow regimes variation with gas velocity is affected by the elevated pressure, and demonstrates different features in different local positions of the bed.

Graphical abstract

Keywords

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