Maintenance method for plate type heat exchanger
To do good work must first sharpen his tools. How to maintain the heat exchanger corrosion in the daily application? The following is a summary of the following:
Know the causes of various corrosion of the heat exchanger, reasonable choice of anti-corrosion measures, in order to achieve the purpose of efficient use of equipment. In view of the situation of corrosion, this paper puts forward the following anti-corrosion methods: the main introduction of corrosion inhibitor, electrochemical protection.
1 corrosion inhibitor
As the main component of the corrosion inhibitor is used in cooling water system with chromate, chromium is an anodic inhibitor (process), when it and the appropriate cathodic inhibitor combination, can get satisfactory effect of corrosion protection and economic.
Chromate zinc - phosphate: polyphosphate is because it has a clean metal surface, corrosion inhibition ability, polyphosphate can turn into a part of orthophosphate, they can also produce calcium colloidal cations, inhibit the cathodic process.
Zinc chromate - phosphonic acid salt: this method with risedronate sodium polyphosphate instead of similar outside a method of amino methylene phosphate can be used as stipulated in the ratio of polyphosphate to high pH value. Amino methylene phosphonic acid salt can prevent scale, even if the pH value is 9 to control calcium salt precipitation.
Zinc chromate - hydrolyzed polyacrylamide: the dispersion effect of cationic copolymer hydrolysis polyacrylamide, can prevent or inhibit the production scale into the dirt.
2 electrochemical protection
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, this method consumes a large amount of electricity, high cost. Anode protection is the protection of the heat exchanger to the external power supply of the anode, so that the surface of the metal passivation film, resulting in protection