聚乙烯醇第二粉碎机“架桥”故障的机械改进

Mechanical improvement of the second PVA crusher against bridging accident

聚乙烯醇(PVA)的醇解生产就是将其固化、两次粉碎、压榨脱液最后再进行干燥的过程。其中进行第二次粉碎的设备称为第二粉碎机。它是一种单轴剪切式破碎机。在醇解生产中,经常出现第二粉碎机由于产能不足使进出物料不畅导致物料在进料口堆积的"架桥"现象,进而造成全线停车。本文从转子尺寸、动定间隙、动网间隙、主轴转速、滤网孔径、动刀数量以及定刀数量等多个方面分析了影响二粉机产能的机理,最终确定了少刀头、大径深刀盘匹配更小相关间隙的结构改进方案。实践证明效果很好。

The alcoholysis production of polyvinyl alcohol（PVA） is the process to make it solidified, crushed twice, squeezed the liquid out and dried finally. And the equipment to execute the second crush is called ＂the second crusher＂. It is a single-spindle shearing granulator. In the process of alcoholysis production, the flow of materiel is often jammed due to the lack of capacity of the second crusher. This causes the phenomenon called the ＂Bridging＂ that materiel accumulates in feed inlet of the second crusher. Even more, it always results in the suspension of the entire production line. This article analyzes the mechanism which impact the production capacity of the second crusher from the rotor size, the clearance between the fixed knives and the moving knives, the clearance between the moving knives and the screen, spindle speed, aperture of screen, the quantity of fixed knives and moving knives. Eventually the structure-improving plan including smaller related clearances and new cutting flywheel with less cutters and deeper groove is adopted. Practice has proven that the plan works well.