Electrochemical anticorrosion method for plate heat exchanger

The plate heat exchanger is likely to be corroded after a period of use, so it is very important to select an appropriate anti-corrosion method. Next, let's briefly understand the electrochemical anti-corrosion method of the equipment.

1. Corrosion inhibitor

The corrosion inhibitor with chromate as the main component is commonly used in cooling water system. Chromate ion is an anode agent. When it is combined with a suitable cathode agent, a better anti-corrosion effect can be obtained.

Chromate zinc polyphosphate: polyphosphate is used because it can clean the metal surface and has corrosion inhibition ability. Polyphosphate can be partially converted into orthophosphate. They can also form large colloidal cation cathode process with calcium.

Chromate zinc phosphonate: this method uses sodium phosphonate instead of polyphosphate. Similar to the previous method, carbamate can also be used in occasions with higher pH than that specified for polyphosphate. Dimethylaminophosphonate can prevent scale and control the precipitation of calcium salt even if the pH value is 9.

Chromate zinc hydrolyzed polyacrylamide: due to the dispersion of cationic copolymer hydrolyzed polyacrylamide, it can prevent or prevent the generation of scale.

2. Electrochemical protection

Cathodic protection and anodic protection are adopted. Cathodic protection uses an external DC power supply to turn the metal surface into a cathode to achieve protection. This method consumes a lot of power and costs a lot.