液滴荷电雾化湿式电除尘器颗粒捕集特性研究

为研究液滴荷电雾化作用下静电场中粉尘颗粒的捕集特性，设计并搭建了线板式湿式电除尘装置，通过实验获得了电场强度、停留时间、粉尘浓度和液滴流量等参数对捕集效率的影响规律.结果表明，施加雾化荷电液滴后各粒径段颗粒的分级穿透率均低于干式电除尘器，随着电场强度增加至3.5kV/cm，分级穿透率降幅逐渐增大，出口浓度降幅达到最大值，PM_0.5、PM₁和PM_2.5分别降低了28.7%、28.0%和27.1%，高于3.5kV/cm后降幅逐渐减小.相同电场强度下，捕集效率随停留时间的增加而增大，电场强度为4kV/cm时，停留时间由2.14s增大至4.04s，PM_0.5、PM₁和PM_2.5的分级穿透率分别降低了50.2%、49.3%和48.5%.随着粉尘浓度的增加，颗粒碰撞和凝并作用提高，捕集效率逐渐增大，当空间电荷密度难以满足颗粒充分荷电后，继续增大粉尘浓度将导致捕集效率降低.液滴流量的增大能够促进颗粒荷电与凝并，有利于提高捕集效率.与传统湿式电除尘器相比，采用液滴荷电雾化能够明显降低耗水量，且保持较高的颗粒捕集效率.

Particle collection characteristic in wet electrostatic precipitator under charged water drop atomization

A plate-type wet electrostatic precipitator was designed and built to research the particle capture characteristic under atomization of charged water drop. The effects of electric field intensity, residence time, dust concentration, and liquid flow rate on removal efficiency were acquired. Results showed that particle grade penetration ratio with charged droplets was higher than the dry ESP. As the electric field intensity increased, reduction of penetration ratio and outlet concentration firstly increased and then decreased with the division of 3.5kV/cm, at which the outlet PM_0.5, PM₁ and PM_2.5 decreased by 28.7%, 28.0% and 27.1% respectively. Longer residence time resulted in higher removal efficiency under the same applied voltage, the penetration ratio for PM_0.5, PM₁ and PM_2.5 reduced by 50.2%, 49.3% and 48.5% when the residence time increased from 2.14s to 4.04s at 4kV/cm. Particle collision and agglomeration could be reinforced as the increase of dust concentration, thus the removal efficiency increased correspondingly. While the electron density was insufficient for particle charge, further enhancement of dust density led to decrease of removal efficiency. Improving the water flow rate was benefit for particle charge, agglomeration, and increase of removal efficiency. Compared with the traditional wet electrostatic precipitator (WESP), adoption of charged dropletscould largely reduce the water consumption and keepthe collection efficiency at relatively high level.