Causes of corrosion in flue gas desulfurization and dust removal equipment for boilers

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1. Chemical corrosion: This occurs when corrosive substances present in flues react chemically with steel at certain temperatures, resulting in the formation of soluble iron salts that gradually damage the metal equipment. 2. Electrochemical corrosion: This occurs when there is water and an electrolyte on the metal surface, forming a galvanic cell that generates electricity and causes the metal to rust gradually; it occurs more easily at weld joints. 3. Crystal corrosion: When an alkaline liquid absorbs SO2, soluble sulfates or sulfites are formed. The liquid phase penetrates into the capillaries of the surface anti-corrosion coating. When the boiler is not in use and dries naturally, crystalline salts are formed; the resulting volume expansion generates internal stresses within the anti-corrosion material, causing it to peel, flake, become loose, or develop cracks. Idle desulfurization equipment is more prone to corrosion than that that is in regular use. 4. Wear and corrosion: This refers to the turbulent friction between solid particles in the flue gas and the surface of the equipment, which continuously alters the surface texture and accelerates the corrosion process, causing it to thin out over time. The only way to extend the service life of desulfurization equipment and enhance its corrosion resistance is to enclose the metal components tightly to provide effective protection and prevent all forms of corrosion. How to apply a protective coating is an issue that our anti-corrosion engineers need to pay attention to.