Abstract:

Due to the accumulation of impurities and iron scale caused by under-deposit corrosion at the top of the atmospheric tower (ADT) in a petrochemical company, which blocked the downcomer and led to repeated issues such as increased pressure drop at the end of the operation cycle and difficulty in controlling the final boiling point of naphtha in the atmospheric and vacuum distillation unit. After the online desalination facility for the ADT circulation system was put into use, the operating parameters were consistent with the design values; the corrosion rate was 0.04mm/a, meeting the anti-corrosion requirements; the operation at the top was relatively stable, and the yield of kerosene products in the front line was maintained at a level higher than 9%; the water content in the circulating oil at the outlet of the desalination facility was less than 250μg/g, and the chlorine content was less than 0.2μg/g, both meeting the design requirements; the frequency of leaks in the top air cooler was reduced, the cost of replacing the air cooler was reduced by 2.4 million yuan per cycle, and the direct economic benefit increased by 600,000 yuan/year; it effectively avoided production fluctuations in downstream units caused by corrosion leaks at the top, ensuring smooth production in various units of the joint workshop, with indirect economic benefits far exceeding ten million yuan per year.

Key words:

color:#060607, font-family:-apple-system, blinkmacsystemfont, ", background-color:#FFFFFF, "> atmospheric distillation tower, tower top circulation system, online desalination facility, corrosion, chlorine content, water content, economic benefit

摘要：

某石化公司常压塔塔顶（常顶）垢下腐蚀产生的杂质及铁垢堆积并堵塞降液管，导致常减压蒸馏装置多次出现运行周期末期常顶压力降低、石脑油终馏点控制困难等问题。常顶循环系统在线除盐设施投用后，操作参数与设计值一致；腐蚀速率为0.04mm/a，满足防腐要求；常顶操作相对平稳，常一线煤油产品收率维持在高于9%的水平；除盐设施出口循环油中水质质量分数低于250μg/g，氯质量分数低于0.2μg/g，均满足设计要求；常顶空气冷却器泄漏频次降低，空气冷却器更换费用减少了240万元/周期，直接经济效益增加60万元/a；有效避免了因常顶腐蚀泄漏造成的下游装置生产波动，确保了联合车间各装置生产平稳，每年间接经济效益远超千万元。

关键词:

color:#060607, font-family:-apple-system, blinkmacsystemfont, ", background-color:#FFFFFF, "> 常压塔, 塔顶循环系统, 在线除盐设施, 腐蚀, 氯含量, 水含量, 经济效益