电除尘器粉尘层反电晕击穿厚度理论与试验

Charged Dust Layer Thickness at Back Corona Breakdown Point in Electrostatic Precipitation

为了合理地确定静电除尘器清灰振打周期,通过理论与试验方法确定静电除尘器粉尘层反电晕击穿厚度很有必要的。首先基于静电学理论导出带电粉尘层内的电量分布和电场分布数学模型,然后根据粉尘层反电晕发生条件,得出粉尘层反电晕击穿厚度的计算式,结果表明,反电晕击穿厚度是粉尘比电阻、电晕电流密度及极配的函数。通过对高比电阻不同厚度的粉尘层的反电晕击穿试验研究,结果表明,各击穿点的连线呈较连续光滑的弧线,提出了利用伏安特性曲线确定粉尘层反电晕击穿厚度的简易图解法。

It is necessary to determine charged dust layer thickness at back corona breakdown point in electrostatic precipitation in order to select rapping periodicity reasonably. A mathematical model of charges and additional electric field in dust layer were developed by electrostatics and a formula for calculating charged dust layer thickness at back corona breakdown point was obtained in accordance with condition equation of back corona breakdown field strength. Results indicated that dust layer thickness is the function of corona current density, dust resistivity, and arrangement of electrodes of electrostatic precipitator. It was found that since the connection line of back corona breakdown points at different thickness became a very smooth and continuous curve, a simple graphical method was proposed to determine dust layer thickness at back corona breakdown point with the help of curves of voltage-current characteristics.