Sewage sludge digester agitators

AAT vertical shaft agitators for new or refurbished sewage sludge digesters.
Each agitator is manufactured to suit the specific project requirements.


  • well suited for flat bottom digesters with flat roof.
  • Installation of a properly designed top agitator blade provides a flow pattern capable of destroying (avoiding) scum layers.
  • well suited for conical bottom digesters with conical roof.
  • Installation of a properly designed top and bottom agitator blades provides a flow pattern capable of destroying (avoiding) scum and sediment layers.

The AAT-Agitator ensures optimal and homogenous digester sludge mixing. Sedimentation and formation of scum layers are prevented.


Advantages AAT sewage sludge digestor agitators


  • Optimal mixing characteristics using minimal electrical power even at high sludge viscosity
  • Optimal process conditions due to well defined mixing resulting in an even digester
  • Temperature and efficient suspension of sediment and back mixing of potentially scum forming material
  • Reliable function - trouble free operation 
  • Robust equipment requiring low maintenance

Technical aspects


  • Process design and dimensioning according to specific site conditions
  • Gear box and bearings are standard components
  • All parts in contact with digester sludge or biogas are SS2343 / 1.4436
  • Liquid seal (water labyrinth)

Unique shaft attachment
enables change of bearing and seal without removal of shaft from digester.

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