Plate heat exchanger how to prevent corrosion

Want to do a good job of plate heat exchanger corrosion should be the right medicine, first understand why corrosion causes, and then according to the reasons to prevent in order to do the real corrosion. Then there are mainly the following two methods of anti-corrosion.

1. Corrosion inhibitor

Chromate as the main component of the corrosion inhibitor is commonly used in cooling water systems, chromate ion is an anode (process) inhibitor, when it is combined with the appropriate cathodic inhibitor, can get satisfactory and economic anti-corrosion effect.

Chromate-zinc-polyphosphate:Polyphosphate is used because it is the role of cleaning the metal surface, corrosion inhibition ability, polyphosphate can be partially converted to orthophosphate, they can also be with the calcium to generate large colloidal cations, inhibit the cathodic process.

Chromate-zinc-phosphonate: This method uses sodium phosphonate instead of polyphosphate outside similar to the previous method, aminomethylphosphonate can also be used for higher pH than that specified for polyphosphates. The aminomethylphosphonate prevents scaling and controls the precipitation of calcium salts even at pH 9.

Chromate-zinc-hydrolyzed polyacrylamide: Due to the dispersing effect of the cationic copolymer hydrolyzed polyacrylamide, it can prevent or inhibit the production of scale into dirt.

2. Electrochemical protection

The use of cathodic protection and anodic protection. Cathodic protection is the use of external DC power supply, so that the metal surface into a cathode and achieve protection, this method of power consumption, high cost. Anodic protection is to protect the heat exchanger connected to an external power supply anode, so that the metal surface to generate a passivation film, so as to get protection.

I hope that from the above two aspects can be for you to solve the problem of anti-corrosion plate heat exchanger.