How should the plate heat exchanger be maintained and protected in application?
Knowing the reasons for the corrosion of the heat exchanger, reasonable selection of anti-corrosion measures can achieve the purpose of using the equipment. Aiming at the corrosion situation, the following anti-corrosion methods are proposed: Here, corrosion inhibitors and electrochemical protection are mainly introduced.
The corrosion inhibitor with chromate as the main component is commonly used in cooling water systems. Chromate ion is an anode inhibitor. When it is combined with a cathode inhibitor, it can have a satisfactory and economical anticorrosive effect.
Chromate-zinc-polyphosphate: The use of polyphosphate is because it has the effect of cleaning the metal surface and has the ability to inhibit corrosion. Polyphosphate can be partially converted into orthophosphate. They can also generate large amounts of calcium with calcium. Colloid cation.
Chromate-Zinc-Phosphonate: This method uses sodium phosphonate instead of polyphosphate. Similar to the previous method, carbamate phosphate can also be used at a pH higher than that specified for polyphosphate. High occasion. Methanephosphonates can be scale-free and control the precipitation of calcium salts even at pH 9.
Chromate-zinc-hydrolyzed polyacrylamide: Due to the dispersive effect of the hydrolyzed polyacrylamide of the cationic copolymer, it is possible to prevent scale from becoming a scale.
Cathodic protection and anodic protection. Cathodic protection is the use of an external DC power supply to make the metal surface into a cathode for protection. This method consumes large power and costs a lot. Anode protection is to connect the protected heat exchanger to the anode of an external power source, so that a passivation film is formed on the metal surface to obtain protection.
The above content is the electrochemical protection method of the plate heat exchanger. It helps a lot to understand the maintenance and anticorrosion of the plate heat exchanger.
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