Abstract:

Based on the electron transfer in flowing water film and ion directional migration in electrical field, the size distributions and dust layer morphology of collected particles on wet fabrics collector were studied and compared with the collected particles on dry metal collector. To study the deposition and exfoliation characteristics of collected particles on wet fabrics collector, a test bench was built. Besides, the key factors on the deposition and exfoliation process of collected particles on wet fabrics collector were also investigated. The results showed that the collected particles on wet fabrics collector (6.900 μm) were smaller than the dry metal one (9.018 μm) at same position (sample point 15). Wet fabrics collector exhibited a higher collection efficiency. Different from the collected particles on the dry metal electrode, the dust layer pattern on wet fabrics had no relation to the discharge current distribution. Charged particles preferentially deposited on the convex spots and became the depositional centre on the fabrics collector. Eventually, the aggregated particles formed a point or pod like packing structures. The electrostatic force between wet fabrics electrode and dust layer was decreased while the bond force between collected particles increased by the flowing water over fabric collector. Drag force, liquid bridge force, electrostatic force and dust layer gravity were the key factors on the exfoliation process of collected particles on wet fabrics collector.

Key words: particle size distribution, deposition, aggregation, exfoliation, fabrics collector, electrostatic field

摘要：

以极板表面荷电颗粒电子传递及离子定向迁移为基础，对纤维极板表面沉积颗粒粒径分布、粉尘层堆积形貌、颗粒沉积脱落过程及关键影响因素等进行了研究，并与金属极板进行对比。结果表明：静电场同一位置处（取样点15），纤维极板表面沉积颗粒物的粒度（6.900 μm）小于金属极板（9.018 μm），纤维水膜极板对颗粒物的捕集效率更高；与金属极板不同，纤维水膜极板表面粉尘层堆积形貌与电晕电流密度分布无明显关联性。荷电颗粒是以纤维束凸出处为沉积中心，沉积并聚集成球或链珠状，粉尘层厚薄随机且分布松散；纤维极板液体表面浸润和内部扩散，减小了纤维极板表面与粉尘层间静电力，增大了粉尘层内颗粒间黏结力；流动曳力、液桥力、静电力、重力是纤维极板控制粉尘层脱落的关键因素。

关键词: 粒度分布, 沉积物, 聚集, 脱落, 纤维极板, 静电场