The cooling tower is a large-scale reinforced concrete structure, which is mainly composed of a cast-in-place reinforced concrete reservoir, a tower and a water spraying facility. It is most used in the chemical, petroleum, textile, and medicine industry.
The corrosion of cooling towers includes reinforced concrete corrosion and steel components corrosion. During the long-term use of natural cooling towers, due to medium erosion, plus corrosion of CO2 and chloride ions in the air, the corrosion effects of microorganisms and freeze-thaw cycles, various concrete components, including cooling tower air ducts, water-spraying structure beams and pillars, and water reservoir, will get loose, powdered, and peeled off, then causes corrosion of the steel bars inside. The anti-corrosion treatment measures taken for conventional cooling towers generally apply anti-corrosion paint on the surface of the concrete. Conventional cooling tower anticorrosive coatings include chlorinated rubber anticorrosive coatings, high chlorinated polyethylene anticorrosive coatings, chlorosulfonated polyethylene anticorrosive coatings, polyurethane anticorrosive coatings, modified acrylic anticorrosive coatings, alkyd resin anticorrosive coatings, epoxy anticorrosive coatings, etc.
There are many factors that affect the anticorrosion serving life of reinforced concrete structures, but the main factors are adhesion and corrosion resistance property. In the cooling tower, the temperature in the high-temperature zone is 30-80°C. The anti-corrosion coating can be used for a long time at this temperature, and the circulating water will not cause obvious damage to the anti-corrosion layer.
Epoxy coal tar paint has strong adhesion, tough paint film, strong moisture, and water resistance. Pure epoxy resin paint and modified epoxy glass flake coatings are also the most frequently used heavy-duty anticorrosive coatings for cooling towers, especially seawater cooling towers.