Anti-corrosion maintenance methods for plate heat exchanger units.
Due to the limited factory environment conditions, the plate heat exchanger unit will inevitably have corrosion problems after a period of use. In order to improve the utilization rate of the equipment, anti-corrosion is also one of the essential tasks.
The intelligent heat exchanger is a heat exchange system composed of multiple plate heat exchangers that transfer heat from one fluid to another. It consists of a series of plate heat exchangers, each of which is composed of a series of aluminum plates and spiral tubes. There are certain gaps between these aluminum plates and spiral tubes, allowing the two different fluids to contact each other in the gap, thus achieving heat transfer.The advantage of the plate heat exchanger unit is that it can provide high-efficiency heat exchange, and various heat exchanger combinations can be designed according to customer requirements to meet different needs.
The corrosion inhibitor used in the cooling water system is mainly composed of chromate, because the chromate ion itself is an inhibitor of the anodic process. When there is a suitable cathodic inhibitor, they react and combine together to achieve our anti-corrosion purpose.
Chromate-zinc-polyphosphate is used for corrosion prevention. Polyphosphate itself has the ability to inhibit corrosion and clean the metal surface. Because polyphosphate can be converted into orthophosphate in water, orthophosphate can form large colloidal cations with calcium ions in water, which inhibits the cathode and thus achieves the purpose of corrosion prevention.
Chromate-zinc-phosphate is used for corrosion protection. The principle of using sodium phosphate and polyphosphate is similar. The pH value of the phosphate application environment can be higher than that of polyphosphate. Phosphate mainly prevents the formation of scale and can cause calcium salts to precipitate even in a medium with a pH value as high as 9.
Chromate-zinc-hydrolyzed polyacrylamide is used for corrosion protection. Hydrolyzed polyacrylamide is a cationic copolymer that has a divergent effect in water and can inhibit scale from turning into dirt.
Cathodic protection and anodic protection are used for corrosion prevention. Cathodic protection involves adding a DC power source to the plate heat exchanger's metal surface, turning it into a cathode, thereby providing protection. However, this method consumes a large amount of power and is expensive. Anodic protection involves adding a powered anode to the heat exchanger, which creates a passivation film on the metal surface, achieving corrosion protection.
What are the anti-corrosion measures?
Anti-corrosion paint or anti-corrosion coating should be used on the surface of pipelines and boxes to prevent corrosion.
Use anti-corrosion valves and other anti-corrosion equipment to prevent corrosion.
Use corrosion-resistant materials to manufacture pipes and boxes to prevent corrosion.
Install temperature sensors to monitor the temperature of the heat exchanger unit to prevent corrosion.
Install an automatic sewage discharge device to remove dirt inside the heat exchanger unit to prevent corrosion.
Regularly inspect the heat exchanger unit to check whether the anti-corrosion measures are effective to prevent corrosion.