Clack Filter-Ag is a silica, crystalline quartz media whichcan be used as highly efficient filter media for the reductionof suspended matter.
Clack Filter-Ag has many outstandingadvantages over the more commongranular filter medias used for suspendedsolids reduction. Its fractured edges andirregular surface provides a high surfacearea and complex flow path for efficientremoval of suspended matter throughoutthe filter bed, typically reducing suspendedsolids down to the 20-40 micron range.Filter-Ags larger particle size creates lesspressure loss through the filter and allowsdeeper sediment penetration into the bedfor higher sediment loading and longerfilter runs. This large and irregular shapeprevents the screening and caking ofsediment in the top several inches of thefilter bed as happens in the typical sandfilter, thus preventing a rapid buildup ofheadloss and blinding problems. Filter-Ags light weight means lower backwashrates and better bed expansion to releasetrapped sediment and rinse the filtermedia during the backwash cycle. Thisideal combination of particle shape,size and density make it a good choicewhere quality water filtration and waterconservation are important.Although not intended to be aniron reduction media, extensive fieldexperience has shown Filter-Ags roughand jagged surface to be very good atentrapping the fragile iron flock that formsafter dissolved iron has been oxidized.The fragmented edges are apparently goodflock collection points for the precipitatediron. Typical oxidation methods includeaeration, ozonation and chlorination.Substantial savings can be realized whendesigning a system using Clack Filter-Ag.Its low pressure drop, high service flowrates and high bed loadings combinedwith lower backwash rates allow economyin equipment downsizing and reducedpumping requirements. Its light weightalso saves on handling expense andshipping costs.Clack Filter-Ag can be applied to systemsdesigned for either pressure or gravity flow.Because of its unique density, Filter-Agcan also be used in multi-media (gradeddensity) filter designs allowing a moreflexible approach to difficult filtrationproblems.
ADVANTAGES
There is less pressure loss through abed of Filter-Ag than through mostother filter medias
Light weight requires lowerbackwash rates than those requiredfor other filter medias
High service rates result in lowerequipment costs and a savings inspace
High sediment reduction capacityresults in longer filter runs, witha substantial savings in backwashwater and time out of service
Reduced shipping cost due to lightweight/cu. ft.
Replacement of sand with Filter-Agin existing installations may increasefilter capacity 100% or more.(Caution should be taken uponstart-up that the lightweight Filter-Agis not washed to drain.)
PHYSICAL PROPERTIES
Color: Light grey to near white
Bulk Density: 24-26 lbs./cu. ft.
Specific Gravity: 2.25 gm/cc
Mesh Size: 12 x 30
Effective Size: 0.67 mm
Uniformity Coefficient: 1.8
Hardness: 6 (Mohs scale)
CONDITIONS FOR OPERATION
Water pH range: wide range
Maximum water temperature: 140 F/60 C
Bed depth: 24-36 in.
Freeboard: 50% of bed depth (min.)
Service flow rate: 5 gpm/sq. ft., although considerably higher rates are often used
Backwash flow rate: 8-10 gpm/sq. ft.
Backwash bed expansion: 20-40% of bed depth
Upon installation allow bed to soak overnight before backwashing