Eliminators and Louvers

Eliminators and louvers are common cooling tower components. Most often they consist of thin PVC plastic sheets stacked against one another leaving openings for air flow. Alternate materials can be steel, fiberglass or even wood. While eliminators and louvers can look alike, each has a specific purpose.

Eliminators fit in the path of air flow just after the water interacts with the heat transfer surface. Their purpose is to separate the water droplets from the air stream so the exiting air doesn't contain large water drops that can damage buildings, leave stains or simply waste water. Eliminators accomplish this by changing the direction of air flow several times forcing the entrained water droplets to slam into the eliminator and drop back into the tower. A totally efficient eliminator would cause an appreciable impediment to air flow so some small droplets are generally allowed to escape. Typical allowable 'carry over' would be around .2 percent of the total recirculated flow. For projects requiring minimal 'carry over', the preferred approach is to oversize the tower and reduce the fan speed.

Louvers cover the air inlet face of 'draw thru' towers to prevent falling water from splashing out onto the ground. 'Splash out' is generally not a big problem when the tower fan operates at full speed but it gets worse as fan speed is reduced. Large industrial towers can get by with no louvers at all when the water collection basin has a plan area big enough to collect all the falling water. Some crossflow towers have the louvers grafted onto the wet deck while others use large, horizontal, corrugated steel or fiberglass louvers. All serve the same purpose of keeping water from splashing out of the tower.

Don Davis

Expert Cooling Tower Repair, LLC