We develop, construct, manufacture and deliver upstream agitators. These types of mixers generate a special upstream which supports the mixing process and stabilize the agitator at the same time.
The US mixer is a low-speed mixer; therefore it works energy-efficient.


The US mixer cannot be used for sludge or higher dry substance contents. We use our mixer for dry substance contents up to appr. 4% and for speeds up to appr. 30 min-1.

It is used in aeration and denitrification tanks, primary anaerobic tanks. For sludge liquor tanks and mixing- and equalizing tanks.

It can be used for max. diameters and edge lengths of 2,0 up to 20,0 m and a max. water depth of 2,0 up to 8,0 m

Tank capacities up to 2000 m³ can be stirred with only one of these type of agitators.


Special Benefits:

  • No or very little sediments on the tank bottom
  • No air input and aerosol discharge through the surface
  • Clam water surface    
  • Vortex-free recirculation
  • On extra using pedestal necessary
  • Individual design and optimised for different customer requirements
  • Slowly turning mechanical agitator with drive in dry arrangement and vertical shaft
  • Welded propeller with 2 blades for all diameters
  • Radius formation adapted to circumferential speed
  • Direct thorough mixing and homogenisation
  • Propeller designed for gentle treatment of floccs
  • Stable spur gear motor with housing in agitator design
  • Installation and removal possible at filled tank
  • Stabilisation through bore-holes in the blade
  • No need for gear dismantling / installation to change oil
  • Left-hand or right-hand rotation available, provided that the agitator is designed accordingly
  • Quick homogenisation with slow rotational speeds caused by turbulences on the back side of the blades

The following materials are available:

  • Steel-galvanized or coated
  • Typical stainless steels (s.s) like s.s. 304 or s.s. 316 / s.s. 316 Ti
  • For special requirements we can even offer special materials like 1.4462, 1.4539 (Duplex) or even higher alloys like Hastelloy

The following options are available:

  • R-US-SB  = special floating sludge destroyer



STB Umwelttechnik GmbH, Copyright © 2016. All Rights Reserved.

STB Umwelttechnik GmbH. Office address: Wetzlarer Straße 23, 35580 Wetzlar-Nauborn, Germany

Tel: ++49-6441-952687, Fax: ++49-6441-952686, E-Mail:, Homepage: