Fall Season Impact on Cooling Towers

Have you Cleaned your Cooling Towers yet?

Especially after a high duty cycle summer months, dirt and debris collect and attach to various components of the cooling tower. If not physically cleaned on a schedule, this dirt and debris may facilitate the accumulation of sediment and create corrosion which may impact the whole system. The additional debris and sediment will eventually reduce the heat transfer efficiency, increase the approach temperatures and eventually increase energy costs.

The Impact

More importantly, system physical cleanliness has a significant effect on microbial control. Debris, sediment, and deposits shield bacteria from biocides, and bacteria may flourish in that environment. Deposits become sites for under-deposit corrosion and react with biocides of all types, creating a large biocide demand while reducing its effectiveness. The installation of a side stream filtration to remove suspended solids can significantly improve the effectiveness of microbial control measures and reduce cleaning requirements and biocide dosages.

Preparedness

Depending on your side-stream filtration set-up at your cooling tower, it is recommended that all cooling towers be cleaned and disinfected once per year. Twice per year cleanings are preferred. and more often may be necessary to achieve good bacteria counts. Cleaning and disinfection are also recommended on the start-up of new and stagnant systems and anytime amoebae or protozoa are detected in the system water. The Legionella guidelines issued by the Cooling Technology Institute (CTI) specify online disinfection before and after tower cleaning. Good control of the overall microbial population is key to minimizing the risks associated with Legionella bacteria and Legionnaires’ disease.