Precoat Filtration

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Precoat Filtration
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Filteraid ?
? septum
Filter cake ?
PRINCIPLE OF PRECOAT FILTRATION
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Filter aids
Inorganic mineral powders or organic fibrous
materials, used in combination with filtration
hardware to enhance filtration performance.
Commonly used filter aids include diatomite,
perlite, and cellulose. Some of these materials
have been in use for over 75 years.
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Perlite
Perlite in the natural state is a dense glassy
rock formed by volcanic action. When crushed and
heated to over 800C, it pops like popcorn,
expanding to 20 or more times its original
volume. Milling and classifi-cation process
gives perlite filter aids the structure and
correct particle size range distribution needed
for optimum performance.
Perlite is an amorphous mineral consisting of
fused sodium potassium aluminum silicate. The
expansion is due to the presence combined water
in the crude perlite rock.
http//www.unitedperlite.com/perlite.htm http//ww
w.singerprocess.com/perlite.htm http//www.perlite
.dk/filterai.htm
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Performance improvement
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Steel mesh septa
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Polymeric filter septa
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Woven ? Fiber filters ?
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Small filters
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