A cooling tower is built to cool the cooling water by using the ambient air. The cooling tower equipment is designed to increase the surface area of the tower water relative to the air. For the actual cooling, the phenomenon of so-called evaporative cooling is used.
An open cooling tower is part of an open cooling water system. The warm cooling water comes back from the consuming devices. This can be heat exchangers, chillers, tank jackets, molds or motors, or other types of systems to be cooled.
The tower water is pumped into the upper part of the tower. As seen on the photo to the left. The water flows through the cooling tower to the bottom in the sump. Form there again back into the loop of the cooling system.
During this process, part of the water evaporates, so the water cools down. The mechanism behind this, water needs energy to change from liquid to gas. This energy is extracted from the water, ergo it becomes cooler.
To improve the efficiency of a cooling tower, all kinds of tools and methods are used, such as fans in induced draft cooling towers, baffles or baffle plates inside the cooling tower. All these equipments are used to improve the heat transfer between air and water.
Nowadays, it is common practice to treat cooling tower water. This treatment applies not only to the cooling tower, but also to the cooling circuit and connected equipment that consume the water.
Chemical water treatment is the classic way to treat tower water. Typical are biocides to fight algae, biofilm, legionella and bacteria, corrosion inhibitors to prevent or fight corrosion or scale inhibitors against lime deposits.
In many water systems, lime scale, rust, algae or Legionella are found in the cooling water despite all classical chemical water treatment.
Cooling tower water treatment using Merus Ring
In addition to the water treatment of industrial heat exchangers, the treatment of cooling tower water and the associated circuits is our most important application. The success of the system is independent of the size or number of cooling towers. We achieve excellent results in small, medium and large cooling systems. Even in complex water treatment systems with several large cooling towers and their connected circuits, our technology works safely and reliably.
In the classic chemical tower treatment in the industry, biocides are used against biofilm and bacteria, corrosion inhibitor against rust and corrosion, scale inhibitor against lime deposits. In contrast, we as Merus are able to store all these functions in only one Merus Ring.
We install instead only one Merus Ring Bio to prevent algae growth, formation of legionella, corrosion and scaling. Especially in warmer areas of the world you have to react fast to prevent biofouling in the whole system – starting with algae in one spot in the cooling tower.
Often the Merus Rings are the only industrial water treatment used, by our customers. Good for larger, complex cooling systems and the connected heat exchangers. One large Merus Ring at the beginning of the cooling tower water treatment, treating all the cooling tower water might be not enough. Merus has to install rings at several strategic right positions in such a system. And yet the Merus Rings are a very cost effective way to treat the cooling tower water.
Saving water in the cooling tower
The consumption of cooling water is affected by three major factors: the actual evaporation and wind drift, the quality of the feeding water and the frequency of blowdown. With the chemical free Merus Ring we have influence on the third factor. As the solubility of salts (also limescale) in the water is increased, more salt is solved in the water, instead of settling in pipes amd machines.
Therefore the cooling system can work with a higher concentration of salt in the water. There are less blow-downs necessary and water is saved. Up to 25% less feed water is needed, depending on the quality of the feed water.
To describe this more technical we can increase the COC in the cooling system using Merus Ring.