钢铁行业磁性纤维捕集非球形粉尘动力学研究

为研究非球形颗粒在磁场中被磁性纤维捕集的动力学行为，以钢铁行业炼钢过程中转炉和精炼炉中排放的转炉灰和精炼灰等两种粉尘为基础，利用形状系数计算公式得出的φ=0.21，0.78，0.81，1.00分别表示圆片形（厚度H=底面圆直径d/40），椭球形（x轴赤道半径：y轴赤道半径：z轴极半径=a：b：c=1：1：4），正方体形，球形颗粒，并对其进行研究.模拟结果表明，相同工况参数下，当形状系数接近时，捕集效率和运动轨迹与粉尘颗粒具体表现的形状特征无关.在传统单纤维捕集过程中，当入口风速v=0.1m/s，d_p>2.0μm时，形状系数相差越大，捕集效率差距越大.形状系数对颗粒被捕集影响程度大小与单纤维捕集效率增减呈正相关；在磁性纤维产生的磁场中v=0.1m/s，d_p>0.5μm时，形状系数相差越大，捕集效率差距越大.φ≥0.4时，捕集效率随形状系数的增加趋于稳定，形状系数对颗粒被捕集影响程度大小与单纤维捕集效率增减无关；在高梯度磁场中v=0.1m/s，d_p=1.0μm时，形状系数相差越大导致捕集效率之间差距越大的规律越明显.当v=0.1m/s，0.5μm≤d_p≤2.5μm时，形状系数对颗粒被捕集影响程度的大小与单纤维捕集效率增减呈正相关.

Study on the dynamic of non-spherical particles captured by magnetic fibers in steel industry

In order to study the dynamic behavior of non-spherical particles captured by magnetic fibers in the magnetic field, and based on the two kinds of dust, converter ash and refined ash, discharged from the converter and the refining furnace in the steel-making process in the iron and steel industry. The shape factor is calculated by formula, φ=0.21, 0.78, 0.81 and 1.00, respectively expressing the circular shape (thickness H=diameter of the bottom circle d/40), ellipsoid shape (radius of the equator of the x-axis:equator of the y-axis:z-axis polar radius=a:b:c=1:1:4), square shape and spherical particles. Under the same working conditions, the simulation results show that when the shape factor is close, the capture efficiency and moving track has nothing to do with the specific shape characteristics shown by dust particles. During the traditional single fiber capture process, while the inlet velocity v=0.1m/s and d_p>2.0μm, the larger the difference of shape factor is, the larger the difference of capture efficiency will be. The influence of shape factor on particles captured is positively correlated with the increase or decrease of single fiber capture efficiency. In the magnetic field produced by magnetic fiber, while v=0.1m/s and d_p>0.5μm, the larger the difference of shape factor is, the larger the difference of capture efficiency will be. When φ ≥ 0.4, the capture efficiency tends to be stable with the increase of shape factor, and the influence of shape factor on particles captured is not related to the increase or decrease of single fiber capture efficiency. In the high gradient magnetic field, when v=0.1m/s and d_p=1.0μm, a larger difference of shape factor leads to more obvious of a rule in which the difference between capture efficiency is larger. When v=0.1m/s and 0.5μm ≤ d_p ≤ 2.5μm, the influence of shape factor on particles captured is positively related to the increase or decrease of single fiber capture efficiency.