延迟焦化高压水除焦泵叶轮开裂原因分析及改进措施

Cracking Analysis and Improvements for Water Pump Impeller ofDelayed Coking Unit

某炼油厂延迟焦化装置高压水除焦泵投产3年后,发生了多次叶轮开裂故障。采用宏观检查、扫描电镜分析及金相分析等方法对损坏的叶轮进行了分析,结果表明,叶轮开裂的根本原因是不锈钢叶轮在含氯化物介质中产生了应力腐蚀和疲劳开裂。提出了控制介质氯化物含量、升级叶轮材质等有针对性的改进措施。应用实践表明,改进措施的实施从根本上解决了叶轮频繁开裂的问题,保证了装置安全平稳运行。

Water pump impeller cracked repeatedly after three years operation of delayed coking unit in a refinery.Damaged impeller was analyzed by means of macro examination,SEM and metallographic analysis.It was found that the root causes are stress corrosion and fatigue cracking which result from stainless steel impeller in chloride media.Improvements were put forward such as controlling chloride content and upgrading impeller material.Practice proved that the method is reliable and ensure stable operation of the unit.