CFD–DEM–CVD multi-physical field coupling model for simulating particle coating process in spout bed--颗粒学报PARTICUOLOGY

Liu, M., Chen, M., Li, T., Tang, Y., Liu, R., Shao, Y., . . . Chang, J. (2019). CFD–DEM–CVD multi-physical field coupling model for simulating particle coating process in spout bed. Particuology, 42, 67-78. https://doi.org/10.1016/j.partic.2018.03.011

CFD–DEM–CVD multi-physical field coupling model for simulating particle coating process in spout bed

Malin Liu ^*, Meng Chen, Tianjin Li, Yaping Tang, Rongzheng Liu, Youlin Shao, Bing Liu, Jiaxing Chang

Institute of Nuclear and New Energy Technology, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Tsinghua University, Beijing 100084, China

10.1016/j.partic.2018.03.011

Volume 42, February 2019, Pages 67-78

Received 30 November 2017, Revised 19 March 2018, Accepted 19 March 2018, Available online 29 August 2018, Version of Record 21 January 2019.

E-mail: liumalin@tsinghua.edu.cn

Highlights

• A coupled CFD–DEM–CVD multi-physical field model for particle-coating simulations was proposed.

• The velocity field, temperature field, concentration field and deposition behavior was simulated.

• Deposition rate and coating efficiency showed opposite tendency with increasing inlet gas velocity.

• The model can provide some guidance for operating conditions and parameters design of spouted bed.

Abstract

Particle coating is a very important step in many industrial production processes as the particle coating layers may fix surfaces with unique advantages. Given the limitation and disadvantages of the existing simulation methods, a coupled CFD–DEM–CVD multi-physical field model for particle-coating simulations has been established taking into account the velocity field, temperature field, concentration field, and deposition model. In this model, gas behavior and chemical reactions are simulated in the CFD frame based on the conservation laws of mass, momentum, and energy. The particle behavior is simulated in the DEM frame based on the gas–solid interphase force model and contact force model. The deposition behavior is simulated in the CVD frame based on the particle movement–adhesion–deposition model. The coupled model can be implemented in Fluent-EDEM software with their user definition function and application programming interface. The particle coating process involving the pyrolysis of acetylene was investigated, and the effect of bed temperature and inlet gas velocity on deposition rate and coating efficiency were investigated based on the proposed model with adjustable deposition coefficients. Both the average deposition layer mass and the average deposition layer thickness were found to be proportional to the elapsed time and increased at the rate of about 1.05 × 10⁻² mg/s and 3.45 × 10⁻⁴ mm/s, respectively, setting the inlet gas velocity to 11 m/s and bed temperature to 1680 K. A higher temperature and larger inlet gas velocity lead to a larger deposition rate, but the coating efficiency decreases because of limits imposed by the chemical reaction. At a bed temperature of 1280 K, the average deposition rate is 7.40 × 10⁻³ mg/s when the inlet gas velocity is set to 11 m/s, which is about double the deposition rate when the inlet gas velocity is set as 5 m/s. The proposed model can provide some guidance for the operating conditions and parameters design of the spouted bed in actual coating settings and can also be further developed as a basic model of mechanisms to integrate detailed information across multiple scales.

Graphical abstract

Keywords

Particle coating process; CFD–DEM–CVD; Multi-physical field; Chemical vapor deposition model; Multiscale simulation

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