Determination of void boundary in a packed bed by laser attenuation measurement--颗粒学报PARTICUOLOGY

Lu, Y., Jiang, Z., Zhang, X., Liu, S., Wang, J., & Zhang, X. (2020). Determination of void boundary in a packed bed by laser attenuation measurement. Particuology, 51, 72-79. https://doi.org/10.1016/j.partic.2019.09.004

Determination of void boundary in a packed bed by laser attenuation measurement

Yuanxiang Lu ^a, Zeyi Jiang ^{a b *}, Xinru Zhang ^a^c, Sihan Liu ^a, Jingsong Wang ^d, Xinxin Zhang ^{a b}

a School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
b Beijing Key Laboratory of Energy Saving and Emission Reduction for Metallurgical Industry, Beijing 100083, China
c Beijing Engineering Research Center of Energy Saving and Environmental Protection, Beijing 100083, China
d State Key Laboratory of Advanced Metallurgy, Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China

10.1016/j.partic.2019.09.004

Volume 51, August 2020, Pages 72-79

Received 29 April 2019, Revised 26 June 2019, Accepted 23 September 2019, Available online 3 January 2020, Version of Record 11 April 2020.

E-mail: zyjiang@ustb.edu.cn

Highlights

• Void boundaries in 3D packed beds are determined via a novel optical method.

• The voids are ellipsoid and their shapes and locations are relatively stable.

• The effects of the blast and the geometric parameters on the void are analyzed.

• Laser attenuation measurements can determine void boundaries in small cold models.

Abstract

Voids are important regions in some industrial processes, particularly in the iron-making process, because a void is a zone in which gas–solid heat transfer and reactions occur. This paper presents a 3D experimental study of void formation measurement with 2D projection in a packed bed using an optical method. By developing an experimental laser-attenuation scanning method, invisible voids that form in a packed bed can be detected and identified as relatively stable ellipsoids. The effects of various operational parameters on void formation are analyzed in terms of the resulting void sizes and shapes. The results show that the void shape that forms in the packed bed is close to an ellipsoid and is relatively stable. The void size is positively correlated with the blast volume rate and is negatively correlated with the blowpipe diameter. The blowpipe depth has no significant effect on either the void formation or size. The blast angle affects the void location strongly; when this angle is increased, the void moves upward. The information and methods obtained in this experiment are significant in aiding understanding of the mechanism of void formation in gas–solid reactors.

Graphical abstract

Keywords

Gas–solid reactor; Void formation; 3D experiment; Optical method; Laser attenuation

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