Long-lasting Performance for Hydropower Plant

Long-lasting Performance for Hydropower Plant
Impreglon AG Switzerland develops on-site coating method for Straflo Turbines.
The hydropower plant Augst am Rhein, near Basel, produces up to 250 million kw/h of electricity per year. Since 1994, seven Straflo (straight-flow) turbines have been in operation at the modern low-head river power plant. With this specific type of tubular turbine, the turbine and generator form one unit. They are not linked by a drive shaft. This means that the water flows through the generator rotor.
The rotor disk is no more than 2 mm away from the turbine. The excessive force of the water causes the rotor disk sheath to wear, resulting in grooves up to 10 mm deep. When wear is excessive, turbine output falls dramatically. The power plant can no longer generate the anticipated amount of electricity.
The PlasmaCoat^® method enabled the damaged sections to be coated such that the turbines could achieve maximum output for up to 80,000 hours longer. The new coating can be applied without refinishing the parts. It must be applied precisely to ensure that it does not exceed the distance of max. 2 mm between the turbine and the rotor disk. This is possible only with devices developed specifically for this onsite application. With this process, a turbine can be coated within four days, meaning that standstill times are dramatically reduced.
Impreglon Switzerland has treated four rotor disk sheaths on Straflo turbines over the last few years. Special know-how and continuously high output are the key.