Clack Filter-Ag is a silica, crystalline quartz media which
can be used as highly efficient filter media for the reduction
of suspended matter.
Clack Filter-Ag® has many outstanding
advantages over the more common
granular filter medias used for suspended
solids reduction. Its fractured edges and
irregular surface provides a high surface
area and complex flow path for efficient
removal of suspended matter throughout
the filter bed, typically reducing suspended
solids down to the 20-40 micron range.
Filter-Ag’s larger particle size creates less
pressure loss through the filter and allows
deeper sediment penetration into the bed
for higher sediment loading and longer
filter runs. This large and irregular shape
prevents the screening and caking of
sediment in the top several inches of the
filter bed as happens in the typical sand
filter, thus preventing a rapid buildup of
headloss and blinding problems. Filter-
Ag’s light weight means lower backwash
rates and better bed expansion to release
trapped sediment and rinse the filter
media during the backwash cycle. This
ideal combination of particle shape,
size and density make it a good choice
where quality water filtration and water
conservation are important.
Although not intended to be an
iron reduction media, extensive field
experience has shown Filter-Ag’s rough
and jagged surface to be very good at
entrapping the fragile iron flock that forms
after dissolved iron has been oxidized.
The fragmented edges are apparently good
flock collection points for the precipitated
iron. Typical oxidation methods include
aeration, ozonation and chlorination.
Substantial savings can be realized when
designing a system using Clack Filter-Ag.
Its low pressure drop, high service flow
rates and high bed loadings combined
with lower backwash rates allow economy
in equipment downsizing and reduced
pumping requirements. Its light weight
also saves on handling expense and
shipping costs.
Clack Filter-Ag can be applied to systems
designed for either pressure or gravity flow.
Because of its unique density, Filter-Ag
can also be used in multi-media (graded
density) filter designs allowing a more
flexible approach to difficult filtration
problems.
ADVANTAGES
• There is less pressure loss through a
bed of Filter-Ag® than through most
other filter medias
• Light weight requires lower
backwash rates than those required
for other filter medias
• High service rates result in lower
equipment costs and a savings in
space
• High sediment reduction capacity
results in longer filter runs, with
a substantial savings in backwash
water and time out of service
• Reduced shipping cost due to light
weight/cu. ft.
• Replacement of sand with Filter-Ag
in existing installations may increase
filter capacity 100% or more.
(Caution should be taken upon
start-up that the lightweight Filter-Ag
is 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
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