Thread Content
The corrosion and scaling of carbon steel coolers have always been difficult problems for petrochemical companies to solve. There are many methods to prevent corrosion, such as proper material selection, rational design, electrochemical protection, surface coatings, improving operating conditions, the use of corrosion inhibitors, and scientific management. Using stainless steel tube bundles is too costly, and the Cl‑ ions in the medium will damage the passivation film, resulting in poor performance. The application technology of electrochemical protection in heat exchange equipment in refineries is not yet mature. Considering both the comprehensive protection effects and economic benefits, the use of a non-metallic coating method is feasible. The corrosion prevention principle of non-metallic coatings is to isolate metal equipment from corrosive agents; it not only improves corrosion resistance but also helps to save a large amount of precious metals and alloys. Coatings should meet the following requirements: (1) The coating itself must be resistant to corrosion in the surrounding medium. (2) It has a tight structure, is completely pore-free, and cannot be penetrated by the medium. (3) It has a strong bonding force with the base metal. (4) It is evenly distributed over the entire protective surface and has a certain thickness. (5) For the heat exchanger core, it should also have little impact on the heat transfer efficiency and possess scale-inhibiting properties.