ERR Stainless Steel Circular Scraper installed at the WWTP Esple in Waiblingen-Hegnach, Germany


At WWTP Esple the final sedimenation tank with an inner diemater of 40,0m was refitted in 2016. Beside the renovation of the concrete works, also the mechanical installation in the tank was renewed. Tschuda won the tender for the scraping equipment and signed the contract for delivering the circular scraper system.

The scraper is designed – almost in the standard version of ERR Stainless Steel Circular Scrapers – as a truss bridge with stainless steel antislip safety gratings and the light weight scraper blade formed as a logarithmic spiral with an angle of 40° having self adjusting twin wheels. Furthermore RRA Antislip Drive Wheel was installed – instead of a rack-and-pinion drive with hit dip galvanized rails – and is working on the vertical outside wall of the tank.

For scum removal the system is equipped with SSR Screw-conveyor Scum Removers of type SSR-2. Due to special customer wishes the screws move the scum only to the outside of the tank. For easy maintenance and accessability – and also at the customers request – a small operating plattform is installed directly above the sip and suction funnel of the scum removal system. From the plattform the operator can also and very easily descend into the effluent channel.

For cleaning the effluent channel itself, two cleaning brushes with electric drive motor were delivered and are cleaning not only the bottom and the side walls of the channel, but also the concrete slant next to the V-notch overflow weir.

Plant manager Frank Sura describes himself and the whole team of the plant as a demanding customer. During the final acceptance he mentioned that the scraper looks as good as in reality as the prospectus had promised at the beginning and he concluded that the whole scraper system is really great:

“Das ist wirklich eine tolle Kiste!”