Abstract：To reveal the mechanism of the entrapment of fine particles generated from the iron and steel industry by magnetic fibers, numerical simulation based on the Computational Fluid Dynamics-Discrete Phase Model (CFD-DPM) was used to simulate the capture of Fe-based magnetic fine particles by magnetic single fibers in high gradient magnetic fields when the deflection angles between the dust flow direction and the background magnetic field direction was set at 0°, 15°, 30°, 45°, 60°, 75° and 90°. The effects of particle size, inlet wind speed and magnetic field intensity on the particle trajectory and the trapping efficiency were studied in high gradient magnetic field. The results proved that the deflection angle controlled the region of the fine particle entrapment by magnetic fibers. When the deflection angle was set at 0°, a particle trapping region was formed in front of the fibers facing the wind incoming direction, and a large cavity was generated on the leeward side. As the deflection angle was shifted to 90°, the particle trapping regions were formed on both sides of fibers along the dust flow direction. The deflection angle exerted less effects on the entrapment of smaller particles. The capture efficiency of particles around 0.5μm was 4.1% at a deflection angle of 0°, while the efficiency only shifted to 3.9% when the deflection angle was changed to 90°. With the increase of the particle size, the entrapment efficiency decreased first and then raised. For all the particles with different sizes, the trapping efficiency was the highest when the deflection angle was at 0°. Along with the rise of the deflection angle from 0° to 90°, in the wind speed range from 0.02 to 0.04m/s, the trapping efficiency reduced first to achieve a minimum value at around 45° and then increased. The enhancement in magnetic field intensity could promote the trapping efficiency, but the elevation rate varied at different deflection angles. When the deflection angle was set at 0° and 60°, the elevation rates of the trapping efficiency were higher in the range of magnetic field intensity from 0.1 to 0.3 T compared to the values in range from 0.3 to 0.9 T. As the deflection angle was changed to 30° and 90°, the elevation rates in the range from 0.1 to 0.5 T were higher than the rates in the range from 0.5 to 0.9 T.
贾中坚, 刁永发, 张俪安, 庄加玮, 沈恒根. 偏转角影响磁纤维捕集Fe基细颗粒的数值模拟[J]. 中国环境科学, 2021, 41(2): 643-649.
JIA Zhong-jian, DIAO Yong-fa, ZHANG Li-an, ZHUANG Jia-wei, SHEN Heng-gen. Numerical simulation of the entrapment of Fe-based fine particles by magnetic fibers with different deflection angles. CHINA ENVIRONMENTAL SCIENCECE, 2021, 41(2): 643-649.
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