减少聚乙烯产品中细粉含量的对策

摘要

Since polyethylene unit was put into operation, the phenomenon of fines entrainment in products had become increasingly obvious, which resulted in the users' frequent feedback on fine content problems. The reasons were finally found out in combination with the practical situation of the system flow and the observation of polyethylene particle appearance changes in the whole process. Fines were generated because burr which formed on the particle surface due to external force such as friction and impact during the process of blending and storage came off in the air conveying system. The problems of large content of fines were resolved successfully through optimizing dust removal effect of the elutriation device, adding air supply in the elutriator, regularly purging the fines gathered in the stock bin, reducing the particles' resistance of air conveying system, implementing the plan of not blending in the products tank, etc.%聚乙烯装置自投产以来，产品中夹带细粉现象日趋明显，用户反映细粉含量问题的频次也有增加。结合系统流程实际情况，观察生产全过程聚乙烯颗粒外表面的变化，找出产生细粉的原因，如聚乙烯产品经过掺混、转贮等工序时，颗粒表面受到摩擦、撞击等外力作用后产生毛刺，在风送过程中毛刺脱落形成细粉。通过优化淘析器除尘效果、增加淘析器空气补充量、定期清除料仓积聚细粉、减少风送系统粒子阻力、实施成品罐不掺混方案等，使细粉含量多的问题得到解决。