Evaporative cooling towers

Monitoring the cooling water quality

Water cooling for industrial production

Most industries need the largest part (almost 90%) of their used water quantity for cooling. This immense water consumption clearly illustrates the essential role of water cooling for industrial production. Nowadays, hardly any branch of industry can manage without the cooling capacity of open evaporative cooling systems: the chemical industry, food industry, breweries, airports, data centres, etc.

In order to operate an evaporative cooling system as efficiently as possible, the consumption of cooling water should be reduced on the one hand and on the other hand the protection of the entire system against corrosion, deposits and biological growth should be increased. Therefore, a trouble-free, economical operation of an evaporative cooling plant requires an individually optimised water treatment for each system.

Requirements for the operation of cooling towers, evaporative cooling systems and wet separators

Since 2017, in Germany, the 42nd BImSchV – Federal Immission Control Ordinance – defines binding guidelines for the operation of cooling towers, evaporative cooling systems and wet scrubbers. The systems must be designed, constructed and operated according to the state of the art in such a way that contamination of the process water by microorganisms, especially legionella, is prevented.

Operators of these systems must meet the hygienic requirements as well as ensure an economic operation of the cooling towers. The treatment of the cooling water with different chemicals required for this purpose must be individually adapted to the respective system and the prevailing conditions. To ensure the desired effect of the chemicals used and at the same time keep their consumption as low as possible, continuous monitoring of the cooling water is essential.

Cooling Water Treatment with ProMinent

ProMinent offers all components required for automatic monitoring of relevant parameters of your cooling water circuit. Our portfolio includes measuring and control devices, sensors, pumps, disinfection systems, digital fluid management and pre-assembled complete solutions. These products, specifically optimised for cooling water treatment applications, are characterized by a long service life, low maintenance and high reliability.

Cooling water treatment in evaporative cooling systems - Our solutions: Measuring and control devices as well as pumps and sensors.

Our experts will be happy to advise you and create a solution tailored to your customer requirements.

Biology in cooling systems

The physical and chemical conditions in technical systems carrying water, such as evaporative cooling towers, provide ideal habitats for microorganisms due to their prevailing physical and chemical conditions. Most microorganisms live in biofilms, which can be an optimal environment for Legionella. For this reason, the formation of pronounced biofilms in evaporative cooling towers should be prevented by an appropriate mode of operation.

Corrosion in cooling towers

An excessive salt and mineral content in evaporative cooling towers can lead to calcification and corrosion in the cooling system and its pipes. Algae and biofilm formation as well as dust particles carried in from the ambient air also have a negative effect on the cooling capacity of the system and also damage the installed materials. The effects of corrosion damage are far-reaching. Continuous monitoring of corrosion enables early detection of incipient damage.

Water treatment in cooling towers

The concentrated process water resulting from evaporation must be regularly replaced with fresh make-up water. To ensure that the salt concentration does not have a negative effect on the efficiency and materials of the cooling system, the process water should be continuously monitored by means of conductivity measurement. Automatic blow down and an appropriate supply of fresh water minimise the risk of deposits and corrosion. In addition, a corrosion inhibitor and hardness stabiliser are added to protect the system.

Online measurement of oxidizing biocides

In order to fight microorganisms, either non-oxidizing or oxidizing biocides are added to the cooling water circuit. Non-oxidizing biocides have good material compatibility, but the bacteria present in the cooling water circuit can develop resistance. In contrast, oxidising biocides prevent the formation of resistance, and their effectiveness can be continuously monitored.

Online corrosion monitoring

The chemical and physical conditions prevailing in evaporative cooling systems have a favorable effect on the corrosion of metal surfaces. Therefore, in addition to the use of corrosion inhibitors, continuous monitoring of the cooling water parameters is recommended.