American Manufacturing Company, Inc.’s PercRite® self cleaning filtration systems offers several choices of filtration based on your water quality, budget, design flow, and the desired intervals between service events.
Single filter “Wash Down” filter Systems automatically remove contaminants from the surface of the filter, substantially increasing the time between manual service events in a secondary effluent (<=30mgl TSS) dispersal system.
For septic or secondary effluent quality water (>30mgl TSS), fully automatic systems are self-maintaining and can go years without maintenance. Filters are thoroughly cleaned at the beginning of and during each dose cycle. The filter backwash is adjustable to work with a full range of water quality, from septic effluent to advanced secondary effluent.
Self-cleaning filtration system control panels are based on the American Perc-Rite® Patent operating sequence. Simplex and duplex panels are available that operate on a single or multi-zone configuration. Filtration controls may provide for flow equalization with peak flow management and are designed on a repeat cycle timer basis. When a float signal tells the control panel there is enough water to begin a dose, the timer cycles between a rest time (off time) and a run time (pump on time). Hand-Off-Auto (H-O-A) switches allow running of the pump in hand if the microprocessor becomes inoperable. The controller is flexible to use with either three or four floats.
Filter Backwash Process
Pumps deliver unfiltered effluent to each of the 115-micron disc filters during the normal forward filtration process. Per program, each system goes through a backflush cycle to clean the filters. The filter backflushing schedule is automatically triggered after a specified volume passes forward through the flow meter, after a specified differential pressure reading is detected between the upstream and downstream gauges, or based on time.
One filter valve closes, blocking the flow of unfiltered effluent to that filter. The filtered effluent from the active filter(s) is directed to the outlet manifold to clean the backwashing filter. Filtered water from the outlet manifold flows in the reverse direction through the spine of the filter and into the backflush nozzles, spinning the loosened discs and flushing the captured debris out the drain manifold. The accumulated impurities discharge back into the pretreatment unit. The field-adjustable backflush lasts approximately 15 to 30 seconds before closing the backflush valve.
Once the first filter has completed its backflushing cycle, the next filter begins its backflushing cycle in the same manner as the first. The sequence repeats until all the filters have been backflushed. Effluent will then again be pumped through the clean disc filters, then through the flow meter, and finally through the outlet manifold.