Electrochemical Antiseptic Maintenance of Plate Heat Exchanger



Hofmann Plate Heat Exchanger

How does plate heat exchanger in the application maintain anti-corrosion?
After knowing the reasons for a variety of corrosion of the heat exchanger, it is necessary to choose reasonable anti-corrosion measures in order to achieve the purpose of efficient use of equipment. To the corrosion of the situation, there is an anti-corrosion method. Here mainly introduced corrosion inhibitor, electrochemical protection.
1. Corrosion inhibitor
Corrosion inhibitors with chromate as the main ingredient are commonly used in cooling systems. Chromic acid is an anodic (process) inhibitor, which, when combined with a suitable cathodic inhibitor, has satisfactory and economical anti-corrosion effect.
Chromate – Zinc - Polyphosphate:
Polyphosphates is used because it has the effect of cleaning metal, has the ability to inhibit corrosion. They can be partially converted to orthophosphate; can also produce large colloidal cations with calcium to inhibit the cathode process.
Chromate - zinc – phosphonate:
This method uses sodium phosphonate instead of polyphosphate. Similar to the previous method, amino-methylene-phosphate can also be used in applications where the pH is higher than that specified for polyphosphates. Amino-methylene-phosphate can prevent scale. Even if the pH value is 9, it can control the precipitation of calcium salt.
Chromate - zinc –hydrolyzed polyacrylamide
Due to the dispersion of the polyacrylamide hydrolyzed by the cationic copolymer, it is possible to prevent or inhibit the generation of scale.
2 Electrochemical protection
It is using cathodic protection and anode protection. Cathodic protection is the use of external DC power supply, so that the metal surface into the cathode to achieve protection. But this method need high power consumption, high cost. Anode protection is the protection of the heat exchanger connected to the external power supply anode, so that the metal surface to generate passivation film to protect.

The above is the electrochemical protection of plate heat exchanger. Through the understanding of the plate heat exchanger maintenance and corrosion, it is a great help for our use.

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