In a word, there are mainly six anti-corrosion methods: tubular graphite heat exchanger
1、 It is an additive. In order to reduce corrosion, corrosion inhibitor, scale inhibitor, bactericide, etc. can be added to the heat exchange fluid if conditions permit. For example, chromate is added to the cooling water of the heat exchanger to form a metal oxide protective film on the surface of the heat exchange metal, so as to control the corrosion reaction.
2、 It is electrochemical protection. DC power on the protected metal equipment to eliminate the potential difference causing corrosion. Protection is divided into shade protection and sun protection.
3、 Use corrosion resistant materials or coating (plating). It is made of corrosion-resistant metal or non-metallic material, or coated on the base material by some type of corrosion-resistant material. For example, the shell and tube heat exchanger is made of polypropylene with graphite; Apply metal coating on the heat transfer plate of plate heat exchanger.
4、 It is to improve the structural design. If impact corrosion (i.e. bubble corrosion) is likely to occur at the inlet end of the condenser cooling water pipe, a polyethylene sleeve can be added to the copper pipe in this part to cover the surface of the copper pipe. In order to avoid stress corrosion cracking, stress concentration should be avoided as much as possible in the structural design of the heat exchanger.
5、 Control operating conditions. Ensure that the heat exchanger operates under reasonable working conditions, and avoid increasing corrosion due to excessive deviation from the design working conditions resulting in excessive gradual temperature or flow rate.
6、 Pay attention to the temperature change of the cleaning heat exchanger. In order to prevent corrosion of the heat exchanger due to scaling, sludge blockage or microbial propagation, backwashing, chemical cleaning or mechanical cleaning shall be carried out according to the working environment of the heat exchanger
