Please choose region and language


Germany, Austria, Switzerland


Passavant® Scraper Technology for Circular Tanks

Niederhausen, Germany


The wastewater treatment plant Niedernhausen has two combi tanks which have been equipped with Passavant® scraper technology for circular tanks 20 years ago. The scrapers are made of bent aluminum profiles and have separate, advanced running arms for the floating sludge removal. For winter operation, snow removal units and dosing stations for de-icing agents were installed to enable the scraping operation.
These should be shut down, disassembled and the scraper should be modified, so that a safe winter operation is ensured.


The scraper bridges and, for the first time, the precursor bridges have been installed on rail systems, which guarantee a safe year-round operation via rack-and-pinion drives.
For this purpose, the old, fully-rubberized driving units were dismantled and replaced with new, maintenance-friendly stainless steel units with track rollers and pinions.
The reconstruction was carried out with flooded tanks, in order to keep the failure time as low as possible.


To the fullest satisfaction of the operator, the scrapers now manage the year-round scraping operation. This is independent of ice, snow and rain-wet roadway.
Humidity or temperature measurements to monitor the winter equipment as well as the storage of de-icing fluids and required devices are no longer necessary.
The stress of the concrete top of the tank by anti-freeze and tire pressure was eliminated.

Technical Data

Diameter of the tank: 37 m
Drive power: 0,55 kW

Undercarriages: 1.4301
Rail and rack: galvanized steel


  • Fault-free winter operation
  • Minimum maintenance effort
  • Elimination of antifreeze, brushing, etc.
  • Energy saving to alternative heated driving surface
  • Protection of the  crowning of the tank

Are you interested in more details or do you have any further requests?

Therefore, please get in touch via our general contact form and refer to this specific case study.