Wherever cooling water is used in open, recirculating cooling systems, treatment of the cooling water is necessary. Reliable adjustment of the cooling water pH value is part of the treatment programme to prevent corrosion and scale formation. Conventionally, an acid such as sulphuric acid is used for pH-control.
Instead of sulphuric acid, CO2 is used to adjust the pH value in the cooling water. PH control with CO2 has many advantages. CO2 is non-corrosive and inert. Compared to mineral acids, the handling of CO2 is therefore easy and safe. In water, CO2 is a weak acid and therefore there is no risk of over-acidification of the cooling water. The use of CO2 prevents enrichment of sulphate in the water, which is helpful for the discharge permit of the blow down water. At the same time it preserves the buffering alkalinity from make-up water. Both aspects contribute to prevention of corrosion in the cooling system. The consumption of CO2 is calculated for each application from the operating parameters, such as the pH set-point, number of cycles of condensation and the quality of the added water.
Advantages of using carbon dioxide at a glance:
- Easy and safe adjustment pH value without hyper-acidification
- Safe to use, no handling of dangerous, aggressive acids
- Reduces corrosiveness of cooling water
- Lower salt content in blow down water
Messer provides the process design as well as technology for adjusting cooling water pH with CO2.