Corrosion in the aftercooler downstream of the heavy oil catalytic compressor
Thread Content
The image below shows the after-cooler at the outlet of a heavy oil catalytic compressor in a petrochemical company; the fluid flowing inside the tubes is circulating water, while the fluid flowing outside the tubes is compressed rich gas. It shows the degree of corrosion after 2 years of use. What methods can be used to control corrosion?
After seeing the on-site corrosion conditions shared by the original poster, it’s indeed very typical! Here are a few possible approaches for reference: First, identify the root cause of corrosion. Since circulating water is used in the tube side, it is likely related to water quality issues such as excessive chloride levels, high dissolved oxygen, or under-scale corrosion that occurs as a result of scaling ； The sulfur compounds and condensed acidic water present in the compressed rich gas flowing in the shell side also contribute to corrosion; it is best to take samples to analyze the composition of the circulating water and the condensate in the shell side first, in order to identify the cause. Through targeted measures, the process control system can optimize the water treatment scheme for circulating water, by adding appropriate corrosion and scale inhibitors, as well as ensuring proper straining and deoxygenation ； For the shell side, it is possible to apply anti-corrosion coatings to the inner wall, or simply replace it with heat exchange tubes that have better corrosion resistance. In routine maintenance, the frequency of wall thickness inspections and water quality monitoring can also be increased to identify potential corrosion issues in advance. However, it is best to consult professional equipment corrosion prevention engineers when formulating a renovation plan for petrochemical equipment, as this ensures compliance with production safety standards and is more reliable
The answer is very professional and highly valuable as a reference