汽油分馏塔塔釜封头开裂原因分析及处理措施

CAUSE ANALYSIS OF THE BOTTOM HEAD CRACK IN GASOLINE FRACTIONATOR AND THE COUNTERMEASURES

针对汽油分馏塔塔釜封头开裂渗漏事故,分别从设备制造、硫化氢应力腐蚀、氢氧化钠应力腐蚀方面进行了研究分析,最终确定根本原因是废碱聚结器制造缺陷导致废汽油夹带废碱液进入汽油分馏塔系统,造成塔釜湿环境氢氧化钠应力腐蚀。通过修复釜封头碳纤维、检修废碱聚结器消除腐蚀介质、调整工艺操作及采取相应的安全措施,保证了汽油分馏塔的稳定、安全、长周期运行,避免了长时间停车。

This paper analyzes the reasons Inr the cracking and leakage accident in the bottom head of gasoline fraetionator from the aspects of equipment manufactures H_2S stress corrosion and NaOH stress corrosion.It is found that the manufacturing defect of spent eaustic coalescer is the root cause,Spent caustic is entrained into the gas fractionator by spent gasoline,resulting in the NaOH stress corrosion of fower keltle in wet environment.By repuiring the end sockpt with carbon fiber,removing corrosive medium from the spent mustie coalescer,adjusting process operation and carrying out corresponding safely precaulions,the stable,safe and long-term operation of gasoline fractionator can be ensured,and the shuldnwn of gasnline fractionator for a long time can he avoided.