ESP电场粉尘高质量浓度区气流强制收集技术

A forced dust collection technology for high-dust-concentration air flow in ESP electric field

针对电除尘器靠近收尘极板存在高质量浓度粉尘气流的事实,采用电除尘器末端加装吸风口,将靠近极板的气流强制等速吸入并进行高效净化,可以显著提高电除尘的收尘效率。为了准确描述电除尘器出口断面粉尘质量浓度分布的规律,从而得到吸风口吸入风量与除尘器除尘效率提高量之间的数量关系,采用有限差分法对电场粒子二维输运方程进行数值计算。得到电场各断面粉尘的分布结果,通过与实验模型实际测试得到断面浓度分布结果进行比较二者吻合较好,证明建立的输运方程正确,采用的数值计算方法可行。依据对实际电除尘器出口断面粉尘浓度数值模拟结果,并结合在电除尘器末端极板处加装强制等速吸风口流动规律的理论描述,得到吸风口高度与除尘效率提高量二者之间的数量关系,据此关系可以提出实现保障电除尘器达标排放所必须强制吸入的流量。

Dust concentration is normally very high around the dust arresting plate of electrostatic precipitation. An air catcher can be installed at the end of ESP in order to suck in dusty air at a constant velocity and purify air efficiently. The method can increase the efficiency in dust collection. In order to accurately describe the characteristics of sectional concentration distribution at the exit of electrostatic precipitation, and obtain the relationship between air quantities sucked in and dust collection efficiency, the finite difference method （FDM） is used to solve the two-dimensional particle transport equations of electric field particles. Comparing the equation results with the experimental results, both results are very close. It proves that the transport equation is valid and the computing method is practical. According to the simulation on sectional concentration distribution at the exit and the characteristics of constant velocity air catcher at the end of electrostatic precipitation, a relationship between the height of air catcher and the efficiency of dust removal can be obtained. The relationship can be used to calculate the compulsory air quantity for meeting discharge limits.