催化裂化装置膨胀节失效原因分析与改造方案

针对大连石化公司催化裂化装置膨胀节的失效,利用能量色散X射线分析(EDX)、扫描电镜等手段对失效膨胀节进行检测分析,得出膨胀节失效的主要原因是膨胀节的工作温度正处于其敏化温度,在各种残余应力和硫酸、连多硫酸等特定腐蚀介质共同作用下发生的应力腐蚀开裂导致的失效;根据膨胀节的使用条件,提出采用填料函结构来补偿冷热变形的解决方案。

Failure analysis of expansion joint in catalytic cracking units and improving measures

Aiming at the failure of expansion joints in the catalytic cracking units of Dalian Petrochemical Corporation,the analysis was performed by means of various techniques including energy-dispersion X-ray analysis and scanning electronic microscopy (SEM).The results show that something like various residual stress and special erosive media in the expansion joints co-acted when the working temperature was at the sensitized temperature that resulted in cracks and failure in the expansion joints.Improving measures including the expansion joints were replaced by packed slip joints were provided according to the operating conditions.