1) General Description

The AIRMAX surface aerator is a low speed vertical shaft aerator for waste water treatment plants.xmontage.jpg.pagespeed.ic.9i1VvfjfTp

This aerator is designed to produce two different movements in the water:

  • a first movement in the horizontal plane creates the water circulation in an “oxidation ditch” also called Carrousel®.
  • a second movement in the vertical plane mixes the sludge in depth. By the impeller rotation, the water is propelled to the surface from the centre to the exterior of the basin. This flow ensures an excellent mixing of the activated sludge. Depending on impeller' size the water depth can reach up to 6m without additional mixer.

Download AIRMAX brochure

2) Why choose the AIRMAX surface aerators ?

The very low speed vertical shaft aerators AIRMAX are most popular as they have the best oxygen transfer efficiency of all mechanical systems, the highest oxygen transfer capacity per aeration unit and the best mixing and propulsion capacity in tanks and oxidation ditches.
Surface aerator vs Diffuser
Compared with the fine porous systems the very low speed vertical shaft aerator has a lot of advantages too. Surface aerators hardly need any maintenance at all while diffusers have to be inspected and cleaned frequently. The life time of surface aerators is much longer and the reliability higher. The oxygen transfer efficiency in field conditions of the plant operation  is higher than with fine porous systems due to fouling of the porous elements and decrease of efficiency due to alpha factor. The restore of initial "fine bubbles" cannot be reached despite frequent cleaning.  The level of noise of AIRMAX surface aerators can be reduce  to about the same level as for bubble aeration or even much better with the COVERMAX technology. Further blower required for fines bubbles creates also noise and need to be covered inside a building with expensive air filtration systems.
All these considerations were decisive for the choice to put efforts in further development of the low speed surface aerator AIRMAX.


Our engineers can help customer to optimise the basin shapes, thanks to a thorough knowledge of the hydraulic flows generated by the AIRMAX low speed surface aerators. The following shows different layouts in which AIRMAX surface aerators can be used.


  • a) Complete mixed basin 


  • b) Plug flow basin 


  • c) Oxidation ditch 


4) Installation

The AIRMAX low speed surface aerator can be fixed on a bridge, or mounted on a floating unit. This floating construction is designed for lagoons or tanks applications, SBR process, and allows water level variations.

KAMPS proposes moreover to design, manufacture and install steel bridges for the AIRMAX impeller's mounting.

Airmax surface aerator

5) Reduction of disturbances

The AIRMAX low speed surface aerator can be completed covered to limit noise disturbance and aerosols. Kamps provides soundproof cover in accordance with the project’s requirements. Kamps'experience on covering shelters is now more than 20 years.

6) Advantages of the AIRMAX aerator

  • very high oxygen transfer efficiency in standard conditions (reaeration in clear water according to STORA standard or EN 12255-15)
  • stable oxygen input efficiency in time
  • very low maintenance
  • lifetime >20 years
  • large mixing capacity (in depth)
  • easy propulsion capacity (oxidation ditch)
  • power adjustment
  • oxygen transfer of 10 to 450 kg O2 /h per unit in clear water
  • international references

7) Technical specifications

  • Material: carbon steel
  • Bearing lifetime:  50.000-100.000 h
  • Service factor: 1.5-2
  • Protection:
    • SA 21/2
    • Epoxy 300µm
  • Bolting: HDG steel
  • Options:
    • sun canopy   
    • polyester housing
    • floats
    • complete skids
    • frequency variator
    • electric panels
    • draft tubes


Carrousel® is a trade name of DHV