From Water Treatment
Cooling Towers: Open evaporative cooling towers use water to dissipate heat from a process, usually via a heat exchanger. Unfortunately damage to these systems can arise and therefore proper monitoring and maintenance is required to prevent damage and also to comply with Health and Safety Commission Approved Code of Practice for the prevention of legionnaires disease.
In the case of Evaporative Condensers cooling water is contained within and is used to cool tubes containing a primary coolant or refrigerant. Whilst these types of systems are generally easier to maintain, they still require the same level of water treatment control and monitoring as a cooling tower.
Another option is to use Adiabatic and Wet/Dry systems to reduce or eliminate completely the need for water in the cooling process.
Such systems may be low maintenance, however they should be considered during the legionella risk assessment to establish the need for further control measures.
Many cooling plant failures can be attributed to microbiological fouling. Rapid growth can block filters and other sensitive equipment and reduce heat transfer. Methods of control are divided into two camps, “non-oxidising biocides”and “oxidising biocides.”
Scale and Corrosion
Poor water quality can lead to scale deposition on heat exchange surfaces. This may reduce flow through pipes and equipment, or cause complete blockages.
Corrosion can destroy metallic components and pipes surprisingly rapidly, forming rust that is a nutrient for bacterial growth. A proactive approach to water treatment can maintain maximum efficiency and reduce costly down time.