A model for predicting the segregation directions of binary Geldart B particle mixtures in bubbling fluidized beds--颗粒学报PARTICUOLOGY

Liu, C., Zhao, Y., Li, Y., Feng, Y., Duan, C., Zhou, C., & Dong, L. (2024). A model for predicting the segregation directions of binary Geldart B particle mixtures in bubbling fluidized beds. Particuology, 90, 340-349. https://doi.org/10.1016/j.partic.2024.01.006

A model for predicting the segregation directions of binary Geldart B particle mixtures in bubbling fluidized beds

Chenmin Liu ^{a b}, Yuemin Zhao ^{a b}, Yanjiao Li ^{a b}, Yuqing Feng ^{b c}, Chenlong Duan ^{a b}, Chenyang Zhou ^{a b *}, Liang Dong^{a b *}

a Key Laboratory of Coal Processing and Efficient Utilization, Ministry of Education, China University of Mining and Technology, Xuzhou, 221116, China
b School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, 221116, China
c Mineral Resources Business Unit, CSIRO, Clayton, VIC 3169, Australia

10.1016/j.partic.2024.01.006

Volume 90, July 2024, Pages 340-349

Received 25 June 2023, Revised 22 December 2023, Accepted 10 January 2024, Available online 19 January 2024, Version of Record 7 February 2024.

E-mail: zhoucy@cumt.edu.cn; dongl@cumt.edu.cn

Highlights

• Comprehensive analysis of mixing and segregation factors in binary fluidized beds.

• The development of a predictive model for bubbling fluidized bed segregation directions.

• Segregation reversal induced by variations in gas velocity or bed composition.

• Demonstration of good validity under gas velocities less than 3.2 times minimum fluidization velocity.

Abstract

In gas fluidization processes involving different types of particles, the mixing or segregation behavior of the solid mixture is crucial to the overall outcome of the process. This study develops a model to predict the segregation directions of binary mixtures of Geldart B particles with density and size differences in bubbling fluidized beds. The proposed model was established by combining the particle segregation model, a previous particle segregation model, with a derived bed voidage equation of the bubbling fluidization based on the two-phase theory. The model was then analyzed with different function graphs of the model equations under various conditions. The results indicated that an increase in gas velocity or volume fraction of larger particles would strengthen size segregation, causing the larger and less dense components to descend. To validate the model, 42 sets of data collected from 6 independent literature sources were compared with the predictions of the model. When the gas velocities were below 3.2 times the minimum gas velocity, the predictions were consistent with experimental results. This study has shed new light on the mechanisms of particle segregation in binary fluidized systems and provides a theoretical foundation for designing and manipulating gas-solid fluidized reactors.

Graphical abstract

Keywords

Particle segregation; Binary mixture; Bubbling fluidization; Geldart B particles; Two-phase theory

文章导读