Crushed Anthracite makes an excellent medium density filtration media. Clack Anthracite is mined from the finest Pennsylvania coal. It is specifically selected for water treatment, and during its production goes through several sizing inspections. Representative samples are randomly chosen for a complete laboratory quality control analysis for effective size, uniformity coefficient, specific gravity, acid solubility and hardness.
Because of its angular shape, some of the sediment penetrates deeper into the bed. When compared to equivalent filter sands, this means longer filter runs and less head loss. Backwash rates are also reduced.
Because of its unique density, Clack Anthracite can be used in multi-media filters. At 50 lbs/ft3, it will hydraulically classify and remain above heavier media such as Filter Sand or Manganese Greensand, providing a prefiltration layer.
Bed depth: 24-36 in., 10-18 in multi bed filters
Freeboard: 50% of bed depth (min.)
Service flow rate: 5 gpm/sq.ft. or higher depending upon local conditions
Backwash flow rate:12-18 gpm/sq.ft.
How does it work?
Water flows into the valve at the top, down through the media and then up through the riser tube in the middle of the vessel. As the water travels through the media the sediment is trapped so only clean clear water flows out to service. There are timer options that can be set to automatically self clean (backwash) and wash away any of the accumulated sediment.