Pumping stations are essential for water treatment. You’re probably thinking that this is unfortunate, as these systems, which circulate massive amounts of water through the various treatment and purification stages, are prone to failure and consume a great deal of energy. Festo has developed a safe and energy-efficient automation solution for these ‘problematic cases’, which has proven itself around the world hundreds of times over. The check valves are the key here. You won’t need these at all if you are using a Festo solution.
The tirelessly running pumps in a wastewater treatment plant circulate enormous amounts of water. This requires massive machines – and their energy consumption is equally massive. Unsurprisingly, the energy consumed by wastewater treatment plants accounts for up to 20% of municipal electricity costs. A large part of this is due to pressurisation, while the pumping stations are the second cost driver. This is particularly the case when outdated technology is used, especially when several pumps are running at the same time. And when you have to have other pumps on standby for reasons of redundancy.
It is clear that energy-efficient processes are needed and are thus increasingly in demand. We know from experience that most systems offer a huge potential for saving energy. Let’s look at a conventional pumping station first. Or you can skip straight to the Festo solution.
Automated gate valves with pneumatic linear actuators from Festo offer a number of concrete benefits:
To date, Festo has successfully implemented the described solution in over 100 water treatment and more than 200 wastewater treatment plants. For example, at the Sindelfingen wastewater treatment plant. The plant treats the wastewater generated by roughly 250,000 residents in southern Germany. In the pumping station, which feeds the wastewater from the primary settlement tank for biological treatment, there are six centrifugal pumps, each with a power consumption of 90 kW and a pumping capacity of up to 500 l/s at a discharge head of 8 to 9 m. Depending on the volume of wastewater, up to five of these pumps are in operation at any one time. One pump is for redundancy purposes.
Prior to the upgrade, the check valves had to be kept open at all times, but this reduced the flow rate by up to 10%. In addition, the free flow cross section was reduced, and the piping system suffered from water hammer when the check valve closed.
Since we completely replaced the check valves and their functionality by pneumatically automating the existing knife gate valves, the same pump flow rate has been achieved with significantly less energy. The Sindelfingen wastewater treatment plant now saves almost 90,000 kWh of power per year. This corresponds to 2% of the wastewater treatment plant’s total energy requirements and represents an annual saving of over 11,000 euros. The municipal authority invested 25,000 euros in this solution. If you do the maths, you’ll see just how quickly Festo automation pays for itself.