Saving energy with pneumatics
Right from the time of its foundation over 300 years ago, Saint Petersburg has set standards in architecture and city planning. Now the former capital of the largest country in the world is playing a leading role in the fi eld of drinking water treatment. Pneumatic automation technology from Festo is helping by providing energy-effi cient solutions for new treatment plants.
The most northerly city in the world with a population of a million or more has resolved to implement a programme to increase the energy effi ciency of the drinking water supply for its southern areas. That is why St. Petersburg, the favourite city of the Russian tsars, has invested 2.6 billion roubles (around 65 million euros) over a period of three years. In addition to modernising 34 pumping stations, Vodokanal, Saint Petersburg’s water utility, has set itself the goal of reducing power consumption for drinking water supply by more than a third.
Until now, electric drives were the first choice for Russia’s water treatment plants – for opening and closing the inlets and outlets of sand-bed fi lters or in pumping stations. In St. Petersburg, the use of only electric drives would have meant an installed load of 75 kW. The plant could not have supplied this without an additional power supply. “In order to achieve the energy-saving targets which we had set ourselves, we needed to fi nd new solutions,” explains Maksim Perschin, manager of the plant’s block K-6 at Vodokanal. “During a visit to a trade fair, Vodokanal engineers became aware of the energyeffi cient solutions with pneumatic actuators offered by Festo,” reports Dr. Ivan Znamensky, Festo sales manager for the European part of Russia. A pneumatic system with actuators DAPS, including two air compressors, required an installed load of only 10 kW. “Simply by replacing the electric actuators with 120 pneumatic actuators, we were able to save at least an additional 65,000 euros,” says water expert Perschin delightedly.
The new block K-6 of the Surface Water Treatment Plant South in St. Petersburg includes 20 new sand-bed filters. Each filter tank is assigned six units with actuators and shut-off valves to open and close the inlets and outlets. In addition to units consisting of actuators, shut-off valves and sensor boxes, which Festo supplied ready-to-install, Vodokanal has chosen ready-to-install control cabinets with valve terminals VTSA, pressure and flow sensors and service units from Festo’s MS series. “If we source all the pneumatic automation equipment we need from the same supplier, we simply have fewer problems during operation and maintenance,” says Perschin, “because Festo’s experts are always there when we need them.”
The new block K-6 of the water treatment plant, the most modern in the whole of Russia, is equipped with a central control system at the process control level and allows comprehensive monitoring of the water treatment process. The control system gathers current data and compares this continuously with defined setpoints. The automation technology from Festo is fully integrated into this monitoring process and uses sensor signals to supply up-to-date information on the operating status of individual plant sections.
Water for a boom town
St. Petersburg and the capital Moscow are Russia’s two boom towns. The city is still growing, with constant new housing developments and industrial zones. Vodokanal supplies 4.8 million people with 1.9 million cubic metres of drinking water every day. Block K-6 of the water treatment plant alone provides 350,000 cubic metres of drinking water and conforms to the highest modern standards as regards filter technology and chemical treatment with ozone. The pneumatic automation technology installed in block K-6 also allowed the water utility company to achieve a quantum leap in energy efficiency.