Solids flow characteristics and circulation rate in an internally circulating fluidized bed--颗粒学报PARTICUOLOGY

Hu, J., Liu, D., Liang, C., Ma, J., Chen, X., & Zhang, T. (2021). Solids flow characteristics and circulation rate in an internally circulating fluidized bed. Particuology, 54, 69-77. https://doi.org/10.1016/j.partic.2020.02.009

Solids flow characteristics and circulation rate in an internally circulating fluidized bed

Jinding Hu ^a, Daoyin Liu ^a *, Cai Liang ^a, Jiliang Ma ^a, Xiaoping Chen ^a, Tao Zhang ^b

a Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, Jiangsu, China
b Guodian Science and Technology Research Institute, Nanjing 210031, Jiangsu, China

10.1016/j.partic.2020.02.009

Volume 54, February 2021, Pages 69-77

Received 21 September 2019, Revised 22 November 2019, Accepted 26 February 2020, Available online 25 May 2020, Version of Record 28 January 2021.

E-mail: dyliu@seu.edu.cn

Highlights

• Gas solid flow in an ICFBs studied by tracing a fluorescent particle.

• Particle flow behaviors in different regions analyzed systematically.

• Solid circulation rate obtained for a range of operating parameters.

• Most important parameters found to control solid circulation rate.

• Fitting solid circulation rate by correlation to yield particle flow coefficient 0.22.

Abstract

Internally circulating fluidized beds (ICFBs) enable effective control of the reactions and heat distribution in reactors. The ICFB contains two or more connected fluidized regions with different gas velocities to promote controlled solid circulation. The control of solid circulation rate (G₀) is a critical factor. We recorded single particle trajectories by tracing a fluorescent particle, based on which particle flow behaviors were analyzed in different regions. G₀ was obtained for a wide range of operating parameters. An increase in gas velocity in the down- and upflow beds shortened the particle circulation time in both beds and G₀ increased significantly. As the static bed height increased, the differential pressure on both sides of the circulation port increased, which resulted in an increase in the solid circulation rate. As the orifice area increased, the flow resistance through the orifice decreased and thus the solid circulation rate increased. G₀ increased with the decrease in particle size. The gas velocity in the upflowing bed and orifice area was the most important parameter to control the solid circulation rate. G₀ was compared with the experimental measurements in literature and predictions using the correlation based on Bernoulli’s equation, and they agreed well.

Graphical abstract

Keywords

Internally; Circulating; Fluidized bed; Particle tracing; Solid circulation rate

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