All the AST floating bead filter models provide the user with the benefits of granular filtration without the risk of biofouling. The powerful Propeller Washed Filter uses a high speed propeller to dislodge persistent biofilm whenever solids capture is the objective. The High Profile PolyGeysers employ a high frequency pneumatic backwash to manage biofilms.
All AST bead filters operate as bioclarifiers providing powerful biofiltration and granular filtration concurrently. The Recirculating PolyGeysers are specifically designed to supply oxygen in the face of heavy organic or ammonia loadings. These units recycle the wastewater though the bead bed 10-40 times assuring biofiltration objectives are met.
The bead filters conserve water by minimizing backwash water losses. All the AST Propeller Washed Filters bead filters reduce waste loss by at least a factor of 10 over standard sand filter designs. The PolyGeyser lines can reduce water loss a by a factor of 100 by recycling their own backwash waters.
The PolyGeyser filters save energy operating with pressure losses about 10 percent of the pressure loss associated with pressurized sand filtration. The Low Profile PolyGeyser employs airlift exchange with tanks under four feet tall. The Recirculating PolyGeysers employ internal airlifts to aerate and recirculate internally.
All AST bead filters are packed with food grade low density polyethylene as a media with an extended filtration design life (>20years). Filters intended for solids capture only are normally packed with standard media when bioclarification or biofiltration is the objective filters are packed with EN media.
Robust durability describes the AST Floating Bead Filters. The Propeller Washed Filters have demonstrated life spans over 25 years. The High Profile PolyGeysers, Low Profile PolyGeysers, and the Recirculating PolyGeysers operate without moving parts and/or electronics have projected life spans in excess of 30 years in most circumstances.
Control Boxes and control valves can eliminate the need for manual sludge removal on the Propeller Washed Filters and the High Profile PolyGeysers. The Low Profile PolyGeysers and the Recirculating PolyGeysers are routinely configured for pneumatic sludge discharge without electronics, moving parts, or manual intervention.