Fertilizer plant cold exhaust anti-corrosion solution
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I would like to ask everyone, what kind of coating is used to prevent corrosion of water-cooled radiators in fertilizer plants? The radiator in our unit has corroded after more than half a year. What kind of coating should we use to prevent corrosion? The cold radiator is in direct contact with circulating water and the atmosphere, and the wall temperature is below 180 degrees.
Water contains electrolytes, and the air contains large amounts of oxygen and other acidic gases. Corrosion is easily caused by contact with both. 1. Polish and planer the anti-corrosion parts. 2. Use various anti-corrosion coatings. Generally speaking, the pH of circulating water is 8~9 and should contain corrosion inhibitors. Just use general anti-corrosion coatings. The key is pre-treatment and post-maintenance. for example: Paint preservative TF-469 2.1 Main components of TF-459: CMIT/MIT solid mixture 2-5% Preservative B 1-5% Preservative C 0.5-1.5% Additive A A small amount of Additive B A small amount of Additive C A small amount of water + pH adjuster balance
The cold radiator area is indeed difficult to deal with, but this difficulty is caused by the owner's lack of adequate construction supervision measures.； Personally, I think it is best to allow enough construction time before using the cold radiator. In addition, anti-corrosion needs to be done on both the inner and outer walls. ； The substrate must be polished ； Regarding the choice of anti-corrosion coating, you can choose the national standard inorganic zinc-rich primer/epoxy zinc-rich primer, 80-100 microns ； Epoxy mica gray intermediate coat, 120 micron ； Phenolic epoxy anticorrosive topcoat, 120-150 microns ； After construction, sufficient time should be allowed to maintain the coating (generally subject to the requirements of the paint manufacturer) ； After installation, any damage to the coating such as welding must be repaired in a timely manner.
The cold radiator is similar to a tube-and-tube heat exchanger. The cooling medium flows through the tube side, and water generally flows through the shell side. The outer wall of the casing inside and the outer wall of the cold radiator need to be anti-corrosion maintenance. When the casing inside the cold radiator is inspected, the casing inside the cold radiator must be sand-blasted and flaw-detected before being anti-corrosion. The coating anti-corrosion measures used by our unit are to compare the original epoxy coal pitch paint with two coats of primer and topcoat. The outer wall of the cold radiator is in direct contact with the atmosphere, so a wide range of coatings can be used. . .