The flow of rod-like particles in a spout-fluid bed was simulated by computational fluid dynamics/discrete element method (CFD-DEM), with rod-like particles being modeled by super-ellipsoids. The impacts of fluidization gas velocity, spout gas velocity and particle shape on the flow and mixing of rod-like particles were analyzed. The simulation results showed that the flow behaviors of rod-like particles in a spout-fluid bed basically accorded with the typical spout characteristics. Increasing fluidization gas velocity and spout gas velocity both can improve particle mixing, and the fluidization gas velocity has more effect on the particle mixing than the spout gas velocity does. The impact of particle shape on the particle mixing is mainly realized through the factors of consistency of particle orientation that is quantified by the proposed method and interlock between rod-like particles, so that the mixing degree decreases firstly and then increases with the particle aspect ratio.
Hua-qing MA,Yong-zhi ZHAO. CFD-DEM investigation on mixing of rod-like particles in spout-fluid bed. Journal of ZheJiang University (Engineering Science), 2020, 54(7): 1347-1354.
Fig.3Comparisons of flow patterns between simulations and experiments
us/(m·s?1)
H/m
实验值
模拟值
0.7
0.309±0.020
0.291±0.028
1.0
0.346±0.039
0.358±0.057
Tab.4Comparisons of bed heights between CFD-DEM simulations and corresponding experiments
Fig.4Snapshots of flow patterns for Rod 2 and Rod 4 at different gas velocities
Fig.5Variation of mixing index with time for Rod 3 at different gas velocities
Fig.6Time-averaged particle velocity during 2-10 s
Fig.7Variation of mixing index with respect to time at B-gas velocity for particles with different shapes
Fig.8Schematic diagram of divided subcells in spout-fluid bed
Fig.9Quantification of consistency of particle orientation
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