Anti-corrosion of air separation cold boxes
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I would like to ask everyone: what kind of paint is used on the cold boxes in your units? The paint on the cold boxes in my unit starts to rust within less than a year – is it a problem with the paint or with the insulation quality of the cold boxes?
It depends on the local climate conditions; in areas with heavy rainfall and high humidity, anti-corrosion and insulation measures need to be renewed every 3–5 years. The main cooling tank, in accordance with anti-corrosion requirements, should be painted three times. In cases where the primer, epoxy anti-corrosion paint, and topcoat cause rusting within just one year, it is likely due to severe water damage; check whether the area is frequently exposed to water or has standing water. If it’s no longer viable, just paint the affected area to provide appropriate protection
Here, we applied 3 layers of paint: primer, epoxy anti-corrosion paint, and topcoat. Due to our location in the north, there has been no significant peeling or corrosion after 3 years. It’s possible that the rust on the cold storage steel plates wasn’t thoroughly removed before painting, or that the high humidity in the area has caused localized peeling; anti-corrosion treatment should be applied in those areas to prevent further spread.
Corrosion prevention painting requires thorough rust removal; usually, silver powder paint is sufficient. Painting can be done conditionally; epoxy zinc-rich paint (white) is the best choice. Once it’s set up, it will work fine for 3 years.