Problems and suggestions regarding the anti-corrosion coating of heat exchanger tube bundles

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1. The anti-corrosion coating for carbon steel water coolers in the TH-847 series has been used in China for many years, and it has proven effective for preventing corrosion and scale formation in water coolers used in industries such as petrochemicals, steel manufacturing, and power generation. This coating offers reliable quality, feasible application techniques, satisfactory product performance, and significant economic benefits. Currently, these industries have over 50,000 large-scale cooling units in total, and the effectiveness of coating treatments for corrosion prevention is less than 20% at present; there is still great potential for further widespread adoption. 2. During the coating application process, technical specifications must be strictly followed, and quality inspection and supervision should be strengthened; improving the quality of the coating is key to the widespread use of coated heat exchangers. It has been proven that without high-quality coatings and strict construction techniques as well as a competent workforce, the product quality will not be satisfactory. The promotion of coating anti-corrosion technologies should follow scientific procedures. 3. Developing horizontal cooperation to drive the advancement of construction equipment technology toward higher levels of sophistication is necessary for further and sustained progress. By working together, research and development enterprises are gradually enabling the application of different anti-corrosion coatings on equipment before it leaves the factory, in accordance with the various requirements of users. Mechanical manufacturing plants should establish a one-stop service for anti-corrosion manufacturing. 4. Provide research services related to repainting, in order to enhance the advantages of coated heat exchangers. The emergence of these coated heat exchangers makes it advantageous to use carbon steel instead of stainless steel for heat exchanger applications. By replacing the equipment regularly based on its safe operating life, it is possible to ensure long-term leak-free operation. For users, it would be even more beneficial to remove the old coating from coated heat exchangers that have been in use for 8–10 years, apply a new coating, and then use them for another 8–10 years. 5. Efforts should be made to address the problem of scaling in power plant condensers. In China, most condensers in power plants are manufactured using Navy copper tubes; although these tubes have a long service life, scaling is a serious issue that prevents the turbines from operating at their full efficiency. Due to the large size of these devices and the thin walls of the tubes, it is difficult to solve this problem using existing construction techniques or types of coatings. Further development of new coating types and application techniques is needed to advance this field. 6. Coatings do not provide universal corrosion protection; the coating used in TH series water coolers solves the corrosion problem associated with the cooling of internal medium circulating water at 150°C. However, when used as a coating for heat exchangers, its effectiveness is insufficient due to the relatively low temperature, and the results are not very satisfactory.