KKR Plastic Chain Scrapers installed in 15,1m wide tanks


On 19.07.2016 the first KKR Plastic Chain Scraper was put into operation on the main sewage treatment plant of the German city Trier in a 15,1m wide and 76,2m long final sedimentation tank. Five more tanks will be equipped until end of June 2017.

Due to the fact that most of the parts were preassembled as much as possible in Tschuda’s shop floor, the installation of the chain and flight scraper system together with an SSR Screw-conveyor Scum Remover could be finished after little bit more than one week.

After the subsequent installation of a new switch cabinet and the onsite control cubicles, the tank was first filled with clear water and then was immediately activated for normal operation.


For the especially wide tanks Tschuda adapted the design of the scraper flights and moved the position of the scraper flights’ chain attachment links to the middle of the tank.

Lowest driving force due to roller guide and weight reduced scraper flights

Though the ultimate principle of tight welded and therefore weight reduced scraper flights with carrying and lateral guiding wheels was not changed.

Already at the first dry-run of the system it was evident, that due to the low rolling friction of the scraper flights and despite the enormous tank width the necessary driving force for the whole system would also be very low.

Within the first hours of normal operation it was determined that due to the weight reduced, nearly buoyant design of the scraper flights, the drive motor does not have more power consumption than it is also needed at much shorter and smaller tanks!