Propeller Bead Filter Operation & Backwash
Normal Operation :
- The Pump (A) is turned on and water enters through Filter Inlet (B) and Diffuser (C).
- Water passes through Bead Bed (D) for bioclarification, then through the Bead Retention Screen (E) and finally exits through Effluent Line (F).
- The Pump (A) is turned off and the Inlet Valve (B) is closed.
- The Mixing Motor (G) is turned on. The propellers agitate the Bead Bed until fluidization occurs (15-45 sec), expanding the bead bed and separating the solids from the beads.
- The Mixing Motor is turned off and the solids are allowed to settle (for 10 min) into the Internal Settling Zone (H).
- The Sludge Valve (I) is opened and the concentrated sludge is allowed to drain from the filter via gravity. Backwash frequency is dependent on the feed rate. Water loss is typically 2-5 gpm/ft3 of bead media.
- After sludge is drained from the filter unit, the Sludge Valve (I) is closed, Inlet Valve (B) is opened and the Pump (A) is turned back on.
- An unscreened Emergency Drain (J) is provided at the bottom of the filter unit.