驻极体磁纤维捕集荷电Fe基细颗粒数值模拟

Numerical simulation of electret magnetic fiber in trapping charged Fe based fine particles

为了进一步实现超低排放,针对钢铁冶金以及铸造行业生产过程中产生的Fe基细颗粒,提出驻极体磁纤维提高对微细颗粒捕集的方法.本文基于计算流体力学-离散相模型(CFD-DPM)分别研究了纤维荷电量、颗粒预荷电电场强度、纤维磁感应强度以及颗粒磁化率对驻极体磁纤维捕集性能的影响.结果表明:在驻极体磁纤维周围颗粒所受到的磁场力相对于库仑力受距离影响更加明显,磁场力只在纤维附近极短距离内作用明显.捕集效率与纤维荷电量以及预荷电电场强度呈线性关系,对于0.5μm颗粒,捕集效率随纤维荷电量以及预荷电电场强度的增长速率低于2.5μm的颗粒.当颗粒粒径为0.5~1.0μm时,增大驻极体磁纤维的磁感应强度以及提高颗粒磁化率对于捕集效率的提高作用较小.当颗粒粒径为1.5~2.5μm时,增大驻极体磁纤维的磁感应强度以及提高颗粒磁化率能够明显提高纤维的捕集效率.

In order to achieve ultra-low emission of Fe based fine particles in the production process of ferrous metallurgy and casting industry,this study proposed a method to improve sub-particle capturing by electret magnetic fibers.Based on CFD-DPM(Discrete Phase Model),the influence of charge distribution on fibers,particle pre-charge electric field intensity,fiber magnetic flux density and particle magnetic susceptibility on electret magnetic fiber capturing property was investigated.The results showed that:around the electret magnetic fiber,the magnetic force was more significantly affected by the distance than did the Coulomb force.The effect of magnetic force was limited within an extremely short distance around the fiber,and there was a linear relationship between the capturing efficiency and charge distribution on fibers and pre-charge electric field intensity.As for 0.5μm particle,the growth rate at which fiber carrying capacity and pre-charge electric field intensity increased the capturing efficiency was lower than that of 2.5μm article.When the particle size was between 0.5 and 1.0μm,enhancing the magnetic flux intensity of electret magnetic fiber and improving particle magnetic susceptibility were less effective in improving the capturing efficiency.When the particle size was between 1.5 and 2.5μm,enhancing the magnetic flux intensity of electret magnetic fiber and improving particle magnetic susceptibility could significantly improve the fiber capturing efficiency.