Benefits of the pneumatic solution

Automated gate valves with pneumatic linear actuators from Festo offer a number of concrete benefits:

• Cost savings: Operators of wastewater treatment plants achieve the same pumping capacity with considerably less energy.
• System safety: Since the gate valves close tightly, no undetected leakages occur during operation.
• System availability: Pneumatically actuated industrial process valves stand out as they are easy to operate and not very susceptible to failure. They also easily overcome high breakaway torques caused by deposits and caking by increasing the air pressure.
• Failure safety: The automated emergency function guarantees a supply of compressed air, even in the event of a voltage drop.
• Stability: Pneumatic actuators are impressive thanks to their sturdiness, long service life and overload protection when the gate valves are opened and closed.
• Working conditions: The noise level is significantly reduced.

Example: Sindelfingen wastewater treatment plant

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.