How to maintain and prevent corrosion of titanium heat exchanger in application
How to maintain and prevent corrosion of titanium heat exchanger in application? Know the causes of different corrosion of titanium heat exchanger, reasonable selection of anti-corrosion measures, in order to achieve the purpose of good use of equipment. In view of the corrosion situation, the following anti-corrosion methods are proposed: Here is mainly introduced corrosion inhibitor, electrochemical protection.
1. Corrosion inhibitor.
The corrosion inhibitor with chromate as the main component is commonly used in cooling water system. Chromate ion is an anode inhibitor. When it is combined with a suitable cathode inhibitor, satisfactory and economical corrosion prevention effect can be obtained.
Chromate - zinc - polyphosphate: the use of polyphosphate is because it has the effect of cleaning the metal surface, has the ability to resist corrosion, polyphosphate can be partially converted into orthophosphate, they can also generate large colloidal cations with calcium, inhibit the cathode process.
Chromate - zinc - phosphonate: This method replaces polyphosphate with sodium phosphonate, which is similar to the previous method in that aminomethylphosphonate can also be used in situations where the pH value is higher than that specified for polyphosphates. Aminomethylidene phosphonates prevent scale and control calcium salt precipitation even at a pH of 9.
Chromate - zinc - hydrolyzed polyacrylamide: Due to the dispersion of polyacrylamide hydrolyzed by cationic copolymers, it can prevent or inhibit the generation of scale into dirt.
2. Electrochemical protection.
Cathodic protection and anode protection are adopted. Cathodic protection is the use of external DC power supply to make the metal surface into a cathode to achieve protection, this method consumes a lot of power, high cost. Anode protection is to connect the protected titanium heat exchanger to the anode of the external power supply, so that the metal surface can generate passivation film, so as to be protected.