Risk of uneven air discharge from air diffusers.
Warning from users of imitation OHR and non OHR vertical air diffusers.
Actually, users who use copies or similar products of OHR AERATOR say that "Air doesn’t discharge at all from some of the
installed air diffusers". Also "Air can discharge unevenly like a seesaw”. This means when the air discharges from the air diffusers
installed on the right side of the riser air pipe, air doesn’t discharge from the air diffuser installed on the left side, and
immediately after that, air discharges only from the left side, not from the right side.
Why does this phenomenon occur?
The air discharge resistance is small which means there is a high risk that the air unevenly discharges.
Air diffusers with one large diameter air discharge opening have very low air discharge resistance. For example, the OHR
AERATOR has the smallest air discharge resistance in the world and it has only 20 to 30 mmAq (=resistance of 2 to 3cm water
depth). Small air discharge resistance helps air blower performance. This means a lot of air can be discharged with small power.
But there is a high risk that the air unevenly discharges when the installation number of air diffusers are more than two.
If this phenomenon occurs, you need to do extensive pipe reconfiguration work.
Why is there a high risk that air unevenly discharges when the air discharge resistance of the air diffuser is small?
Please see the figure below.
Porous air diffusers can discharge air evenly with simple piping configuration.
Piping configuration for porous air diffusers is easy. However piping configuration for large diameter air discharge opening air
diffusers is very difficult and requires complex calculations.
Porous air diffusers have a very large air discharge resistance because the air is discharged through small perforated openings.
They have high air discharge resistance of about 500mmAq (=resistance of 50cm water depth) when brand new.
Air is difficult to discharge from the porous air diffusers so air first fills up in the whole air pipe. After the air pressure has built
up enough air discharges simultaneously and evenly from all porous air diffusers even if you don’t pay much attention to the
(*However the porous air diffusers inevitably clog, the airflow resistance increases further and the air blowing amount that is
discharged from the air blower decreases resulting in aeration tank oxygen deficiency. This is a serious problem.)
OHR designs an appropriate air piping configuration calculated according
to your circumstances and fully guarantees even air discharge.
The air piping design for an air diffuser with a large diameter air discharge opening (such as OHR AERATOR) is much more difficult
than conventional porous air diffusers having large air discharge resistance. Calculations according to your circumstances are
essential for even air discharge.
OHR calculates the correct piping configuration for your case and fully guarantees that air evenly discharges even when the
installation number of OHR AERATORs are in the hundreds. In other words, correct calculations are essential for even air discharge
when using "OHR AERATORs".