4
System Cycles
Service
Untreated water enters the control valve and is fed down through the entertained
air space into the filtration media, and through the lower distributor plate. It then
runs up the center riser tube and back out through the clean water portions of the
valve.
Air Release
The entrained air above the media is released prior to the backwash cycle.
Backwash
Water is passed upflow through the media to expand the media and release the
oxidized contaminants and to send them to drain. The clean media is now ready
for recharge. A short rest is included to allow the media to settle.
Air Recharge
An air/water mixture is brought down into the media bed forcing the remaining
water down through the bed and down the drain. The purpose here is to gain as
much exposure as possible between the air and the media surface. The oxygen in
the air recharges the media so it can better oxidize the contaminants, making them
insoluble and able to be effectively filtered.
Rapid Rinse
A short downflow rinse is performed to expel the remaining air from the media
bed, along with any iron or other contaminants that may have loosened up during
the Air Recharge process. This short rinse is flushed away to prevent any iron from
entering the home when the unit returns to service. The rinse and service flows are
not sufficient to expel all the air that has been trapped above the media bed, and
that entrained air also helps the oxidation process.
NOTES:
1) The system by-passes untreated water while it is performing the above
sequences, so it is important to choose the time of day for a regeneration
when no water is being used in the home.
2) Since air is used as the method of recharging the media, cloudy (air
entrained) water may be present after the filter.
3) In some homes with copper plumbing, the dissolved oxygen in the water
associated with this treatment process may increase the level of copper
in the effluent water. Adjustments should be made to the regeneration
settings as needed to reduce the dissolved oxygen level.
