Air diffuser for water treatment, chemical reaction.OHR AERATOR

To remove and prevent heavy sludge accumulation

Calcium carbonate accumulation drastically reduced

  • Wastewater: 24,000m3/day.
    Calcium carbonate (CaCO3 with a specific gravity of 2.7) accumulated badly (avg 0.9m,
    max 1.8m), and removal of accumulation two weeks a year was required.
  • After OHR AERATORs replaced the old air diffusers, accumulation was drastically
    reduced and running conditions improved to the point that no accumulation was
    observed even when water was drained from the tank.
  • Installed OHR AERATORs : AE-130N model × 424 units.
Before and after.

Even in a 30% lime slurry tank no clogging for 19 years


  • The MLSS concentration is 15,000mg/L, and lime accounts for 30% of the
    concentration. Water depth is 7.0m which is significantly deeper than the average
    water depth of 4 to 5m for an aeration tank.
  • Before introducing the OHR AERATORs, once a month, conventional air diffusers
    were washed for clogging with high-pressure water.
  • The OHR AERATORs haven’t clogged for 19 years even in an aeration tank with
    30% lime slurry (since Feb. 1998).
  • Installed OHR AERATORs : AE-130 model × 56 units × 2 tanks = 112 units.

For long time uses / power savings

Still running even after 26 years (Installed in 1986).

Even after running for 18 years 12 hours per day,
no clogging.

Photo Photo
  • Chemical plant.
  • Used for churning excess activated sludge in a holding tank (SS: 20,000mg/L).
  • No frictional wear observed in the OHR AERATORs, and so still can be used
    for a long time to come.
  • Sugar plant.
  • Wastewater contains high levels of calcium and magnesium (SS: 30,000mg/L).
  • No clogging after intermittent aeration every 12 hours.
    Still has never been washed. (User’s evidence)

Maintenance free for 20 years.

Maintenance free for 15 years.

Photo Photo
  • Brewery.
  • Installed OHR AERATORs : AE-130 model × 320 units.
  • OHR AERATORs were installed in order to save electricity and be
    maintenance free.
  • Chemical plant.
  • Installed OHR AERATORs : AE-130 model × 20 units.
  • Conventional porous air diffusers were used before but they have low oxygen
    transfer rate, so were replaced with OHR AERATORs. Maintenance free for 15 years.

Maintenance free for 16 years.

  • Dairy industry.
  • Porous air diffusers clogged frequently due to SBR (sequencing batch reactor).
    *SBR is a wastewater treatment method that carries out everything in one tank.
    This means aeration, sedimentation and discharging treated water in one tank.
    Conventional air diffusers clog frequently because of intermittent aeration.
  • Before installing OHR AERATORs, the DO at the tank bottom was zero and bulking
    occurred. SV30 was 95 which means almost no sedimentation.
  • OHR AERATORs keep the DO at the tank bottom approx 3.0mg/L.
    Filamentous bacteria and bulking phenomenon have disappeared so SV30 improved
    significantly from 30 to 50.
    Customer used four aeration tanks which were reduced to just two aeration tanks
    reducing electricity costs by 26.9% annually. Wastewater treatment conditions have
    become stable so the full time staff of two could be reduced to one part timer who
    works only half a day.

Maintenance free for 16 years.

Maintenance free for 17 years.

Photo Photo
  • Dye works.
  • Customer used porous air diffusers that required periodic cleaning once
    a year. OHR AERATORs were introduced to solve clogging problems and
    to save electricity costs.
  • OHR AERATORs reduced two air blowers to one unit, and the air blower’s
    power was reduced to 40Hz by inverter control. Electricity costs
    have been reduced by 70% in total.
  • Food factory.
  • Installed OHR AERATORs : AE-130 model × 36 units.
  • After 17 years of successful operation in their aeration tanks 30 units of the
    AE-130N model were installed in the equalization tanks in April 2015.

Maintenance free for 13 years.

Maintenance free for 10 years.

Photo Photo
  • Brewery.
  • Simple air pipes were used for aeration. The reason is continuous clogging
    problems with porous air diffusers troubled the customer. However the DO
    only increased up to 0.3mg/L even on a non-business day (no wastewater
    inflow day).
  • OHR AERATORs were installed in order to increace DO and be maintenance
    free. DO drastically increased to 0.8~1.9mg/L within 15 hours after aeration
    by OHR AERATORs.
  • After that OHR AERATORs were installed in the equalization tank. Strong
    odors completely disappeared.
  • Concentrated juice factory.
  • Installed OHR AERATORs : AE-130 model × 40 units.
  • Customer installed “Decompo” which is equipment that reduces excess
    activated sludge. The excess activated sludge is decomposed completely
    so a dehydrator is not used at all.

Maintenance free for 6 years.

  • Rendering facility.
  • Surface aerators were used but the aeration tank water sprayed outside
    the tank emitting foul odors affecting the local area. In addition, periodic
    maintenance was problematic and costly. So OHR AERATORs replaced the
    surface aerators.
  • Installed OHR AERATORs : AE-130 model × 48 units.

How to install

No need to drain the tank to install.

Install images.

↑Page Top