常压塔顶部N08367不锈钢的腐蚀与对策

Corrosion of N08367 stainless steel on the top of atmospheric tower and its countermeasures

介绍了在常减压蒸馏装置常压塔顶部五层塔盘、塔壁等低温部位,尤其是冷回流返塔区域等采用N08367不锈钢材质后的腐蚀情况,其腐蚀主要原因为冷回流返塔流量过大,而且返塔温度偏低(仅为40℃),造成冷回流返塔区域形成局部过冷区域、铵盐结晶吸潮和HCl溶解,造成塔盘局部严重腐蚀,并提出优化操作、降低冷回流量和常顶循脱盐技术改造等防护措施。

The fifth layer of tray, walls and other low-temperature sections on the top of atmospheric tower in atmospheric and vacuum distillation unit were introduced. An overview of the corrosion situation of N08367 stainless steel applied in cold reflux area was especially provided. It was concluded that the large flow and low return temperature(40 ℃) of cold reflux accelerate the formation of local supercooling area within cold reflux scope, ammonium salt crystal and HCl dissolution, which end up with serious local corrosion of the tray. Solutions were proposed such as optimizing operation, adjusting cold reflux flow and developing desalination technology of atmospheric tower.