Cooling water

Evaporation cooling is needed wherever process or machine cooling, or building services systems call for cooling water at more than 20°C. At temperatures below 20°C, chillers are usually employed.

To avoid problems, we take into account the specifications of the cooling tower manufacturer, general technology regulations, and the VDI 3803 and VDI 6022 codes of practice.

Exceeding the parameters defined in VDI 3803 can lead to corrosion, capacity-inhibiting incrustation and silting-up. Continuous oxygen transfer can promote corrosion.
Dirt particles and bacteria reach the circuit from the cooling tower and contaminate the system. The moist and warm conditions in the cooling tower area promote the formation of bacteria.

Water treatment objectives:

• To prevent deposits (to maintain efficiency rates)
• To avoid corrosion damage (reduction of salt load)
• Dosing of corrosion inhibitors
• To reduce silting-up (reducing the corrosive products and partial-stream filtration)
• To increase potential thickening (cost-effectiveness thanks to savings in water)

To enable efficient utilisation of the cooling water and to prevent damage and system failures, we offer water treatment solutions which are specifically tailored to your requirements and which comply with general technology regulations and manufacturer specifications.

Thanks to long years of experience, innovative technology, individual concepts and wall-to-wall solutions from a single source, Hager + Elsässer has the solution to all your water treatment problems.
We have a broad range of systems offering solutions for numerous applications relating to process and waste water.

Having our own production facility means that we’re able to offer flexible delivery times and the high quality standards generally associated with the “made in Germany” label.

Our round-the-clock customer service provides service and safety even long after purchase.

Our certified laboratory allows you to check the water treated by Hager + Elsässer at any time – or carry out a comprehensive analysis of the available raw water.

Tasks

With evaporation cooling, the water to be cooled is sprayed and trickled through a distribution system.

Trickling enables water to be retained in the cooling tower installations for a lengthy period. The ambient air is taken past the installations in a counter-current direction, causing some of the water to evaporate. The cooled water is then collected in the floor pan and re-routed to consumers.

Evaporation leads to a concentration of various water components (calcium, magnesium, sulphate, chloride). This process is called thickening and depends on the composition of the feedwater. When thickening is at a factor of around 3.5 or more, evaporation cooling can be regarded as cost-effective. When thickening exceeds the upper limit, blow-down is required and some of the water in the system has to be changed to remove the salt load.

The thresholds for the major parameters of recycling water are laid down in VDI 3803. Exceeding these parameters can lead to corrosion, capacity-reducing deposits and silting-up.

The required blow-down volumes and thickening factor are determined on the basis of the raw water analysis and the specifications in VDI 3803. Using a Hager + Elsässer water treatment plant enables you to achieve the highest possible thickening factors. Treatment plants enable blow-down volumes to be significantly reduced. This process can be automated by a blow-down system.

Contaminants such as pollen and dust which enter the system may lead to silting-up within the system. This can be reduced by appropriate partial-stream filtration, for instance.

Fouling and the formation of algae, which are fostered by conditions in the cooling tower, can be effectively controlled with the aid of Hager + Elsässer dosing agents. Also, bacteria and silt in the cooling, air scrubber and spray humidifier circuits can be removed by the use of ultrafiltration systems.