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Hitachi Infrastructure Systems (Asia) Pte. Ltd.

This is a multi-function underwater agitator and aerator.


This is a multi-function device that can simultaneously agitate, break up scum, and aerate, with just one unit.

Image: Underwater agitator and aerator(SPAROTOR)


  1. Aerated agitation brings a marked reduction in odors
  2. Aeration improves the sewage DO value, and prevents anaerobic decay.
  3. Provides a significant reduction in the hydrogen sulfide generated in the sewage
  4. Simple structure makes maintenance easy

(in-house comparison)

System & device summary

The underwater SPAROTOR is composed of a hollow-shaft underwater motor, screw, draft tube, and air hose. When the screw rotates it generates water flow in the draft tube. The discharge flow from that agitates the sewage and the surface water flow moves the scum to the draft tube, where it is suctioned off and broken up.
At the same time, the negative pressure at the end of the screw is used to create air suction, which dissolves fine bubbles under the water.

Installation example

Photograph: [Right] After installation [Left] Before installation

Image: Underwater agitator and aerator(SPAROTOR)

Fields of application

  • Pump well
  • Distribution tank
  • Sedimentation tank water conduit