HF烷基化装置塔顶空冷器腐蚀及防护

Overhead Air Cooler Corrosion of HF Acid Alkylation unit and proteetion

某化工厂HF酸再生及提馏塔顶混合物空冷器在使用过程中因介质及温度变化,造成管束内腐蚀和严重结垢,装置被迫多次非计划停车对泄漏点进行处理,严重影响到装置的平稳运行。从HF酸对碳钢材料的腐蚀机理着手,结合工艺流程、运行参数等进行分析,发现空冷器入口两股物料参数不一致,特别是温度、含水量的变化是造成HF酸腐蚀剧烈的主因。通过合理的流程优化方案,将两股不同物料分开进行冷却,对高品位的热源进行能量回收,并利用装置停工检修的机会实施了改造。运行2 a来,有效地解决了空冷器管束腐蚀,同时还达到了节能降耗的目的。

The tubes of overhead air coolers in HF acid regeneration stripper in a chemical plant suffered trom serious corrosion and fouling in operation because of changes of temperature and media. The unscheduled shutdown of the unit had to be made many times to trouble shoot the leakages, which had seriously affected the normal stable operation of the unit. On the basis of analysis of corrosion mechanisms of HF acid on carbon steel materials, the main causes of serious corrosion were concluded to be the variations of parameters of two effluents at the inlet of air cooler, especially the changes of temperature and water content. After process flow optimization, separated cooling of two effluents, recovery of high - level heat and revamping during the unit shutdown, the problems of frequent corrosion failures of air cooler tubes and unscheduled shutdowns of the unit have been solved, and energy consumption has been reduced.