1. Description of AFM®
AFM®
is
an
amorphous
alumina-silicate
manufactured by up-cycling post-consumer green
glass bottles in a dedicated factory designed and
operated specifically to produce activated glass
water filtration media.
AFM® is manufactured and offered as a direct
replacement for filter sand and used in most types
and designs of sand filter. The one exception is
slow bed sand filters operating as biological filters
at filtration velocities of less than 0.2m/hr. AFM®
rejects the growth of biofilm and as such it is not
suitable for use in slow bed sand filters.
1.1.
Grades & Particle size distribution
The particle shape of AFM® is controlled to maximise surface area and to minimise pressure differential
and bed lensing effects.
The particle size distribution is also controlled to within very tight tolerance. We can control the
sphericity and uniformity coefficient of the grains to maximise particle filtration. While a high sphericity is
beneficial for sand this is not necessarily the case for AFM®.
The higher the uniformity coefficient the better the
filtration performance, but this increases the risk of
bed compaction and lensing. AFM® is
manufactured as opposed to quarried, the particle
size distribution and shape can therefore be
maximised to improve performance as a water
filtration media.
Dryden Aqua Ltd
Butlerfield-Bonnyrigg,
Edinburgh EH19 3JQ Scotland
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AFM® has an optimised uniformity coefficient in
order to maximise filtration performance without
causing pressure drops or bed lensing effects.