Cooling Water

Process description

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.

Gas application

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 solution

Messer provides the process design as well as technology for adjusting cooling water pH with CO₂.