Industrial cooling towers may seem pretty straightforward and harmless, serving the helpful purpose of cooling the fluid that results from industrial processes. And for the most part, this is the case. But without proper maintenance, industrial cooling towers do have the potential to cause harm, as we’ve seen recently in the news.
This month, Portugal has fallen victim to one of the largest outbreaks of Legionnaire’s Disease in history, with eight dead and over 200 infected. It has since been discovered that the source of this outbreak was industrial cooling towers at a local fertilizer plant. Adubos de Portugal, a unit of Spanish company Fertiberia, in the affected area of Vila Franca de Xira, has shut down their cooling towers in hopes of bringing the situation under control.
But how did a cooling tower manage to create such chaos? The answer lies in the method in which Legionnaire’s disease is spread. The disease is contracted by breathing in a mist or vapor contaminated with the Legionella bacteria, which can grow in water cooling towers, showers, hot tubs and other water sources. It is not transmitted directly from person to person. People who are already in poor health are the most vulnerable.
Part of the process of evaporative cooling towers is the drift, or water droplets that are allowed to escape from the cooling tower through its discharge. These droplets are what can contain the dangerous bacteria, if it already existed within the tower.
There are, however, precautions in place at most cooling towers to avoid too much drift escaping during the cooling process. Items called drift eliminators are fit over the top of the cooling tower, and capture the moisture droplets before they can leave, returning them to the tower.There are also drift eliminators that change the direction of airflow to keep the droplets from escaping.
There have also been actions taken and guidelines created to help prevent the growth of Legionella bacteria in cooling towers. These guidelines are pretty basic, and boil down to regular cleaning and upkeep.
Hopefully we will be able to avoid future problems like the dangerous situation in Portugal.
