What material offers the best corrosion resistance for the heat exchanger tubes in acidic water stripping units?

In acidic water stripping units, the best way to select a material with the highest corrosion resistance is to determine it based on the type and concentration of acid used. Different acids have varying corrosion properties; therefore, it is necessary to select the appropriate material based on the actual conditions. The following are several commonly used corrosion-resistant materials: 1. Teflon: It exhibits excellent corrosion resistance against inorganic substances such as strong acids and weak acids, but it is not suitable for high-temperature or high-pressure environments. 2. Carbon steel lined with PTFE/silicone/rubber: A lining is added on top of Teflon, which improves its corrosion resistance and also enables it to function in environments with high temperatures and pressures. 3. Titanium alloys: Titanium alloys are metal materials with high strength, light weight, and excellent corrosion resistance; they can be used in various corrosive environments, but they are relatively expensive. 4. Stainless steel: Stainless steel is suitable for many moderate corrosion conditions, such as low-concentration hydrochloric acid and nitric acid, but it is not suitable for acidic steam stripping units with strong acids and high chloride ion contents. In summary, determining which material offers the best corrosion resistance requires analysis based on specific circumstances, taking economic factors into account as well. .

In the acidic water stripping unit, it is the ammonia condenser located on the side line of the stripping tower that is used to cool the ammonia gas; the temperature of this ammonia gas drops from 85°C to 33°C! This heat exchanger basically needs to be replaced every two years!

Some ordinary coatings can solve the problem, but they will affect heat exchange efficiency