Cooling Tower
Cooling towers are a prime environment for the proliferation of micro-organisms due to the elevated temperatures
and continual scrubbing of nutrients and dirt from the air. This continues to build as the tower operates and can
cause serious problems both in the tower itself and in the system through which the cooling water circulates.
Among these problems are:
and continual scrubbing of nutrients and dirt from the air. This continues to build as the tower operates and can
cause serious problems both in the tower itself and in the system through which the cooling water circulates.
Among these problems are:
- Increase in demand for biocide and a favourable environment for pathogens such as Legionella
- Loss of heat transfer, due to the low thermal conductivity of the biofilm and inorganic deposition. Increased pumping energy required to circulate the cooling water in the presence of a biofilm which has a high friction factor and the reduction in cross sectional area of the pipework and heat exchangers where the water flows.
- Build-up of odours and slime, caused by an increased micro-organism population.
- Increased corrosion rates, due to electrochemical cell formation in the biofilm and blocking of the contact of any corrosion inhibitor with the metal.
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How ClO2 can solves the problems
- Control of micro-organism build-up in the tower is essential for efficient operation of the cooling loop. The need is for a biocide that is measurable, effective at all pH levels and demonstrates broad spectrum activity. One of the most efficient biocides for micro-organism control in cooling towers is chlorine dioxide. This is especially true now that cooling water treatment has been shifted into the alkaline pH range. In the alkaline range chlorine is not a particularly effective biocide because of the poor dissociation to HOCI.
Benefits:- Chlorine dioxide has 2.5 times the oxidizing power of chlorine.
- It will kill blue-green algae where chlorine cannot.
- It does not chlorinate organic molecules (no chlorophenols or trihalomethanes), meaning no toxic pollutants, nor does it form chloramines with NH3, resulting in a much lower demand for chlorine dioxide.
- Its excellent biocidal activity is constant over a wide pH range.
- The organisms cannot find metabolic pathways around its biocidal activity.
- It is a wide spectrum biocide, killing bacteria, fungi and viruses.
- Effectively control Legionella
- Chlorine dioxide is much less corrosive to cooling tower equipment than other oxidants