The methods for preventing corrosion of Air to Air Heat Exchanger generally include the following:
Corrosion resistant material
Use corrosion-resistant materials such as binocular stainless steel, Hastelloy, titanium, titanium alloy, copper, etc. These materials have high corrosion resistance and can improve the service life of heat exchangers. However, these high corrosion-resistant materials are expensive, high in manufacturing cost, and the cost of one-time investment is too large, and AC Air Conditioner Factory are generally difficult to accept and difficult to promote.
2. Electrochemical protection method
(1) Cathodic protection method
The use of an external DC power source to protect the anode on the metal surface from the cathode is protected. This method consumes a large amount of electricity, is expensive, and is rarely used.
(2) Anode protection method
The protected device is connected to the anode of the power supply to produce a passivation film on the metal surface to achieve protection. Carbon steel heat exchangers are low in cost but poor in corrosion resistance.
The service life of the heat exchanger can be improved by using sacrificial anode protection technology, but the protection of this technology is limited to a limited length at the inlet of the tube, and it is difficult to achieve cathodic protection in the depth of the tube.
3. Add corrosion inhibitor method:
On the metal surface, a layer of corrosion-resistant paint protection layer is covered by a certain coating method to avoid direct contact between the metal surface and the corrosive medium. This method is the most cost-effective and is initially used to prevent corrosion of gaseous media. Most of the coatings used are organic polymer mixture solutions.