Sound attenuators for cooling towers

Why do cooling towers need sound attenuators?

For those that aren’t familiar, a cooling tower is a structure within processing facilities such as power plants and oil refineries that uses water to remove the massive amounts of heat generated and release it into the atmosphere.

There are several different types and designs of these structures, however they all make noise that can exceed maximum limits and need to be controlled using measures such as sound attenuators (or silencers as they can also be known). 

How much noise do cooling towers make?

There are a few major sources of cooling tower noise:

• Mechanical noise – The sound generated by mechanical components in the cooling towers, such as fans, motors and gear boxes.
• Water noise – The sound generated by the movement of water in the cooling towers, typically through either spraying and falling within the tower.
• Air noise – The sound generated by the turbulent movement of air as it enters and exits cooling towers.

These can be over maximum limits in some zones, especially near residential areas, and the companies that operate these facilities often need to take noise reduction measures to comply.

Thankfully, there are a number of things that can be done in this department. Options to limit the noise generated exist in the form of high-efficiency cooling fans and variable frequency drives on motors, as well as simple noise reduction mats for water droplets as they hit the ground. 

In addition to targeting the source, noise emissions can be reduced externally through the installation of sound attenuators for cooling towers, and that’s what we’ll take a closer look at now.

How does a sound attenuator for cooling towers work?

While there’s once again several different types, perhaps the most common sound attenuator for cooling towers come in the form of rectangular attenuators made from galvanised steel, aluminium, or stainless steel.

These can be installed on either the top or side of the cooling tower and consist of a series of panels containing sound-absorbing media (e.g. inorganic minerals, glass fibre) that allows the air to flow through and the noise levels to be reduced.

The level of noise reduction delivered by sound attenuators for cooling towers varies with factors like the size and construction of the units, however sound levels can be reduced by up to 30dBA in some cases.