Su Lipeng, Du Qian, Wang Yide, Dong Heming, Gao Jianmin, Wang Min, Dong Peng
a School of Energy Science and Engineering , Harbin Institute of Technology , Harbin , People's Republic of China.
b College of Vehicles and Energy , Yanshan University , Qinhuangdao , People's Republic of China.
J Air Waste Manag Assoc. 2018 Jul;68(7):725-736. doi: 10.1080/10962247.2018.1460635. Epub 2018 May 14.
A self-flushing wet electrostatic precipitator was developed to investigate the removal performance for fine particles. Flexible material (polypropylene, 840A) and carbon steel in the form of a spiked band were adopted as the collection plate and discharge electrode, respectively. The particle concentration, morphology, and trace-element content were measured by electric low-pressure impactor, scanning electron microscope, and energy-dispersive x-ray spectroscopy, respectively, before and after the electrostatic precipitator. With increasing gas velocity, the collection efficiency of fine particles (up to 0.8 μm in diameter) increased, while it decreased for particles with diameters larger than 0.8 μm. Increasing the dust inlet concentration increased the collection efficiency up to a point, from which it then declined gradually with further increases in the inlet concentration. The particulate matter after the wet electrostatic precipitator showed different degrees of agglomeration. The collection efficiency of trace elements within PM was less than that of the PM itself. Notably, the water consumption in the current setup was significantly lower than for other treatment processes of comparable collection efficiencies.
Wet electrostatic precipitators, as fine filtration equipment, were generally applicable to coal-fired plants to reduce PM emissions in China. However, high energy consumption and unstable operation, such as water usage and spray washing directly in the electric field, seriously restricted the further development. The utilization of self-flushing wet electrostatic precipitator can solve these problems to some extent.
开发了一种自冲洗湿式静电除尘器，以研究其对细颗粒物的去除性能。分别采用柔性材料（聚丙烯，840A）和尖刺带形式的碳钢作为收集板和放电电极。在静电除尘器前后，分别用电低压冲击器、扫描电子显微镜和能量色散X射线光谱仪测量颗粒浓度、形态和微量元素含量。随着气体流速的增加，细颗粒（直径达0.8μm）的收集效率提高，而直径大于0.8μm的颗粒的收集效率降低。增加粉尘入口浓度会使收集效率在一定程度上提高，此后随着入口浓度的进一步增加，收集效率逐渐下降。湿式静电除尘器后的颗粒物呈现出不同程度的团聚。颗粒物中微量元素的收集效率低于颗粒物本身的收集效率。值得注意的是，当前装置的用水量明显低于其他具有可比收集效率的处理工艺。
湿式静电除尘器作为精细过滤设备，在中国普遍适用于燃煤电厂以减少颗粒物排放。然而，高能耗和不稳定运行，如在电场中直接用水和喷雾冲洗，严重限制了其进一步发展。自冲洗湿式静电除尘器的应用可在一定程度上解决这些问题。
