The contract of Perlen in Switzerland was awarded to VA TECH ESCHER WYSS Ravensburg in March 1998 for the delivery of 3 single regulated, vertical shaft Compact Kaplan Turbines including the synchronous generators, the hydraulic pressure units, the deaeration equipment and the complete electrical equipment including switchgears.
Our customer is the Perlen Holding AG in Perlen, Switzerland. They have another
S-Turbine on the premises of their paper factory in operation, which was also delivered by VA TECH HYDRO and which provides them together with the new turbines a very economical and highly automated solution for power self-sufficiency.
The special feature of the project Perlen is the siphon concept of the turbines. This means, that the highest point of each of the turbine inlets is located well above the headwater level. For start up of the turbines, small size standard vacuum pumps are necessary to suck the water on the start up water level. The normal shutdown is carried out with the runner blades. Thanks to the air-tight spiral casing, the turbine stays filled with water for hours – ready for instant restarting. An emergency shutdown is carried out by aeration with large air valves, which empties the turbine to headwater level. Instead of costly shutoff valves or gates, only fixed stay vanes in connection with the air technology are required. With the fairly constant flow conditions, the single regulated Compact Kaplan Turbine is the optimal solution for the siphon concept.
