聚丙烯挤压造粒机螺杆芯轴断裂失效分析

Fracture Failure Analysis of Screw Core Spindle in a Polypropylene Squeezing Granulator

针对某石化公司聚丙烯挤压造粒机螺杆芯轴的断裂失效,进行了材质核查、断口分析、受力分析,结果表明:该螺杆芯轴属于疲劳断裂,断裂位置发生在芯轴的固体输送区和熔融区交界处,由于此处扭矩的施加位置、大小和方向的不连续变化,以及芯轴与混炼元件的对中和配合间隙存在问题而造成,提出改进该螺杆芯轴工作区段的设计,以及校核和调整芯轴与混炼元件的装配同心度和间隙的建议。

In this paper,the fracture reason of screw core spindle in an polypropylene squeezing granulator of a petrochemical enterprise is analyzed,and the fracture analysis,material analysis and stress analysis are done. The results show that the fracture of spline screw core spindle is fatigue fracture,and that the fracture location is between the intersection of solid conveying zone and melting zone in the core spindle,and that the fracture reasons are because the applied location,size and direction of the torque discontinuous change,and the assembly concentricity and fit clearance between the spindle and mixing elements are unreasonable. So the work section of core spindle need to redesign and the assembly concentricity and fit clearance need to check and adjust.