Water treatment is asset management

Prevent corrosion, deposits, and pipe fractures in your district heating system with the right water treatment. Correct water quality is essential for asset management.

Remove the oxygen

Oxygen is a prerequisite for corrosion to proceed. By removing the oxygen from the water before it enters the district heating network, the risk of corrosion is eliminated. Also, the need for oxygen binder is reduced, and in some cases it can be left out completely.

Desalinate the feed water

Salts increase the conductivity of water and thus the risk of electrochemical corrosion. At the same time, salts provide good conditions for bacterial growth and microbial corrosion. Desalinated feed water removes the basis for corrosion to proceed. 

Adjust the pH

Circulating district heating water should have a pH-value of 9.8 (± 0.2), as this ensures a stable, corrosion-proof magnetite coating on the inside of the district heating pipes. The pH is adjusted through dosing of sodium hydroxide (NaOH). By using desalinated water, the consumption of NaOH can be reduced by more than 90%. 

If you fail to take proper care of the water, it can be very expensive. So, before we chose the membrane degassing unit, we had a highly beneficial communication with Grundfos. Because it is not just a component you buy and install; it takes a little more than that.
Lars Jørgen Dam, Head of production Skanderborg-Hørning District Heating in Denmark

Improve the water quality with correct water treatment

The main goal of correct water treatment is to prevent corrosion, deposits, and pipe fractures – in short, to extend the life of the plant. By removing salts and oxygen from the district heating water, as well as adjusting the pH value, the basis for corrosion is removed - including microbial corrosion.

Softeners have been a regular part of water treatment at district heating plants for many decades. But once calcium and magnesium is removed from the water, the presence of salts and oxygen will still affect the water quality. The conductivity will therefore be the same after softening. 

Explore softening units

Demineralization by reverse osmosis results in high salt rejection up to 98%. As a bonus, demineralized water makes it easy to detect raw water intrusions so that security of supply can be maintained.

Explore reverse osmosis units

The oxygen can be removed with a membrane degasser. A chemical-free solution, and thus the need for oxygen binder can be reduced by more than 90% and in some cases completely omitted.

Explore membrane degassing units

Reduce magnetite residue with a magnetic insert

Raw water intrusion, corrosion products, and suspended magnetite will inevitably occur in the district heating circuit causing pollution and at worst breakdowns. However, it can be delayed significantly by using the proper technologies.

As a minimum, particle filtration with bag filter and magnetic insert is recommended. A magnetic insert in the particle filter efficiently collects magnetite residue from the circuit water.

Save water and energy with RO-PLUS technology

The RO-PLUS is a reverse osmosis unit optimized for high water recovery and low energy consumption to minimize operational costs. The unit are designed for a recovery rate up to 90%, compromising neither the reliability nor the water quality.

Rent a water treatment system for flexible water supply 

Need reliable water for a limited period? Whether it’s drinking water, disinfected water, softened water or demineralized water, we’ve got the solution to keep your operations running without disruption.

Our mobile water treatment units are ready to deploy, easy to connect and designed to deliver the water quality you need – fast. No delays, no hassle, just a flexible solution that adapts to your situation.

How can we help you?

Whether you’re looking to buy a product or simply seeking advice from a Grundfos expert, we are more than happy to help you get the most out of your water treatment solution! Feel free to get in touch if you need support.