聚乙烯醇物料静电特性及其危害研究

Research on the electrostatic properties and hazards of polyvinyl alcohol

针对聚乙烯醇(PVA)在包装过程中存在静电放电引起着火的安全隐患问题,对两种型号PVA粉尘层电阻率、静电衰减时间及其包装过程中物料静电荷质比、料袋表面电位进行了测试与分析,并对PVA包装过程中下料口附近可燃挥发分浓度进行了采样分析。结果表明,颗粒大小、携带静电荷极性和环境温湿度参数影响PVA物料携带静电荷的消散速率;在潮湿环境下,包装过程中的PVA荷质比超过1μC/kg,料袋表面电位超过20kV;PVA下料包装口附近存在3种可燃挥发分且甲醇浓度高于爆炸下限,PVA包装过程存在静电放电引燃可燃挥发分风险,建议对PVA包装过程增加可燃气监控并强化静电防控措施。

In view of the potential safety hazards of ignition caused by electrostatic discharge of polyvinyl alcohol(PVA)during the packaging process, the resistivity, the the static decay time of two types of PVA dust layer, the static charge-mass ratio of the materials during the packaging process, and the surface potential of the packing bag were tested and analyzed,and the concentration of combustible volatile matter near the discharge port during the PVA packaging process was sampled and analyzed. The results showed that the particle size,polarity of the electrostatic charge carried and the environmental humidity all affected the electrostatic decay rate of PVA. In a humid environment, the charge-to-mass ratio of PVA during the packaging process and the the surface potential of the packing bag respectively exceeded 1 μC/kg and 20 kV. There are three types of flammable volatiles sampled and the methanol concentration was higher than the lower explosive limit. There’s a risk of igniting the flammable volatiles due to electrostatic discharge. Combustible gas monitoring should be added to the PVA packaging process and electrostatic prevention and control measures should be strengthened.