常减压塔顶腐蚀与防护

CORROSION AND PROTECTION OF DISTILLATION TOWER OVERHEAD

主要论述了某石化公司1 000万t/a蒸馏装置运行周期2年,装置在停工检修期间,发现在初顶、常顶冷凝冷却系统和减预部位发生不同程度结垢与腐蚀现象。文章根据蒸馏"三顶"的腐蚀环境以及腐蚀机理,研究在生产运行周期內,对产生设备腐蚀和结垢原因进行了分析。同时调查了当时低温部位装置防护措施应用效果,如原油电脱盐的脱盐效果和塔顶注水的性质等。最后根据装置加工原油性质,重新评定合适"三顶"使用的缓蚀剂,得出合理的结论,并提出适合本公司生产装置的建议。

This paper mainly discusses scaling and corrosion phenomena of different degrees found in the primary tower overhead system,atmospheric tower overhead condensing cooling system and vacuum tower overhead system of the 10 million tons/year distillation unit in some Petrochemical Company during the shut-down maintenance after the unit has run for two years.According to the corrosion environment and corrosion mechanism of the three overhead systems,this paper makes an analysis on the causes for the scaling and corrosion of the unit during the production cycle.Meanwhile,it investigates the application effect of protective measures for the low temperature part of the device such as the desalting effect of the electric desalting of crude oil and the properties of the tower water injection and so on.Finally,the paper re-assesses the corrosion inhibitor suitable for the three overhead systems which are the primary tower overhead system,atmospheric tower overhead system and vacuum tower overhead system,and arrives at reasonable conclusions.It also puts forward some suggestions suitable for the Company's production plant.