ESP电场粉尘浓度分布及高浓度区粉尘强制收集技术的研究

Particle concentration distribution and forced collection technique for particles in the high-concentration region of an electrostatic precipitator

为了进一步提高电除尘器收尘效率以满足日益严格的国家排放标准,提出了电除尘器高浓度区粉尘强制收集技术.通过建立电场粉尘传输数学模型和对实测断面粉尘浓度分布曲线进行回归,分别得到了理论和实际电场粉尘浓度分布公式.结果表明,电场中粉尘浓度分布与断面位置有关.电场中每个断面上从电晕线到收尘极板质量浓度逐渐提高,极板附近存在高质量浓度粉尘区.在极板末端收尘板两侧加装等速吸风口,将极板附近的粉尘气流加以强制收集并采用袋式除尘器进行净化或循环至入口进行二级处理,可以显著提高电除尘器的收尘效率,降低极板振打引起的粉尘飞扬造成的粉尘流失.利用流函数对吸风口流场分析并根据实测的断面粉尘浓度分布可得到吸风口宽度与收尘效率的数值关系.粉尘强制收集技术是电除尘技术领域中的一项创新.采用该项技术既可以对运行中的电除尘器加以改造,又可以在电除尘器的设计中加以实施.

To improve the performance of electrostatic precipitation （ESP） to meet the increasingly stringent emission standards, a new technique of forced collection for particles in the high concentration region is proposed in this paper. Theoretical and experimental equations of the dust concentration distribution were acquired through analysis of the theoretical transfer model of particles and curvilinear regression to the measured dust concentration in the collection field. The results demonstrate that a mass concentration gradient exists within the electric field and the concentration of the particles near the collection plate is higher than in the corona wire area. Gas containing a high-concentration of particles near the collection plate is sucked through an opening installed at the end of the plate and then introduced to a high-efficiency baghouse for treatment or（ discharged again into the inlet of the ESP for loop treatment. This new technique will reduce the chance of re-entrainment of particles in the high concentration region and of collected particles which should drop into the hop because of rapping the collection plates, thus improving the collection efficiency of ESPs. A theoretical relationship between suction width of the opening and dust collection efficiency was also achieved through analysis of the flow function of gas flow and measurement of the particle concentration field. The technique of the forced collection proposed in this paper is an original innovation in the field of ESP and can be applied to new ESP designs and reconfiguration of old ESPs.