Erosive corrosion at the upper part of the heat exchange tubes in the two-stage evaporation heater
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In our urea production plant that uses the CO2 stripping method, the equipment involved is a two-stage evaporation heater with a DN400 diameter; its heat exchange area is 21 m2. It is installed in a vertical configuration, with steam flowing through the shell side, at a pressure of 8 KG and a temperature of 140 degrees； The pipeline carries urine, with a pressure of 0. 034KG (vacuum level), temperature 180 degrees. The shell side casing is made of Q345R, while the tube side tube sheet, heat exchange tubes, and tube box are made of 304L. It has been recently found that the nickel content in the system has consistently been above the limit (0. 45PPM). Tests confirmed that the upper part of the heat exchange tubes in the two-stage evaporation heater (about 200 MM in length) had suffered erosion corrosion. Are there any effective methods to prevent corrosion?
There is an article on the forum that specifically discusses the corrosion of this heat exchanger: http://bbs.hcbbs.com/viewthread.php?tid=395552. This post was last edited by jia717 on 2009-4-14 at 18:33
You can send me the dimensions of your pipes and information on their corrosion status to toyang123@163.com