汽提塔底重沸器换热管腐蚀研究

The Study Involved in Corrosion of Heat Exchanger Tube at the Bottom of Stripper

汽提塔底换热器管束自首次开工,因腐蚀泄漏更换过一次管束。第一台管束运行时间为60个月,更换后的管束运行15个月后发生泄漏,运行时间大幅缩减75%,腐蚀速率加快。针对两台管束工艺操作条件对比,发现第二台管束运转周期短的原因是由于换热器壳程结垢严重,产生严重垢下腐蚀,导致管束大面积穿孔。主要原因是换热管材质为10号钢,材质等级较低。通过优化操作,增加表面防腐手段,提升换热器的运行周期,保证汽提单元长周期运行。

For the first time to start,the tube bundle of heat exchanger at the bottom of stripper which ran sixty months occurred corrosion leakage.But the new bundle which ran 15 months after replacement occurred leakage again.The operation time was reduced by 75%and the corrosion rate was accelerated.Comparing of operating conditions of two bundle process,we discovered the cause of short running period of the second tube bundles was due to the severe corrosion under the scale from shell side of the heat exchanger which led to the larger perforation of heat exchanger tube bundle.The main reason was that the material of heat exchanger tube is NO.10 steel which the grade is lower.We optimize operation and take measures to increase surface anticorrosion to improve heat exchanger operation cycle and ensure the stripping unit run for a long period of time.