Causes of corrosion in the amine-based desulfurization and decarburization reboiler
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This post was last edited by adsl121 on 2012-12-12 09:40. As the title suggests: What are the causes of tube bundle corrosion in horizontal thermal siphon reboilers used for amine-based desulfurization and decarbonization? The regeneration of the reboiler in a certain unit uses saturated steam; the areas where corrosion occurs in the tube bundle are mainly located in the upper part. The reboiler has one inlet at the middle of the bottom, while the outlets are arranged at each of the two ends. Could everyone please analyze the possible causes, especially from the perspectives of equipment and manufacturing processes? Thank you!
This post was last edited by adsl121 on 2012-12-12 09:41. A similar situation occurred in our plant as well; the corrosion was mainly found in the tube bundle near the reboiler outlet. The main cause of corrosion is that the upper part consists of a vapor-liquid mixture, resulting in high linear velocity that causes erosion of the tube bundle, especially at the outlet where the linear velocity is even higher. Recommended measures: 1. If the baffle plates in your tube bundle are arranged vertically, it is recommended to arrange them horizontally; this requirement is also specified in GB151. 2. Cut off about 50 mm from the upper part of the baffle at the outlet to reduce the exit linear velocity. 3. Adjust the liquid level at the bottom of the tower to keep the evaporation space of the reboiler at an appropriate level. Give it a try.
Would using a tank-type reboiler improve the corrosion situation? The solvent regeneration unit we have newly built uses a tank-type reboiler, which can in principle replace one set of trays; by allowing the gas and liquid phases to return to the tower separately, this facilitates the operation of the reboiler.