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Filtration Table of Contents
| Air
Filter Supplier
Pleated Filter Supplier
Air Filters, Inc. Air Filters, Inc. is a specialty filter company bringing 50 years of experience to the filtration industry, our highly trained personnel provide expert recommendations on HVAC, industrial ventilation, and air purification systems with a unique ability to satisfy customers with their special filter needs. |
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Mini - Pleated Air filter construction methods
utilize 7/8 to 1 1/4-inch deep pleats
with very narrow air spaces
(1/8-inch) between, making it
possible to pack more filter paper into
the standard frame sizes than can
be done with deep-pleat, corrugated
separators, or even by using
separator-less construction methods.
Abutting folds are separated
by threads, ribbons, tapes,
strips of medium, or continuous
beads of glass, foam, or plastic
spaced across the width of the medium. Mini-pleat filters
contain almost twice as much filter paper as deep-pleat,
corrugated separator filters of equal frame size. They are
rated to have an
airflow resistance of 0.25 Kilopascals (kPa) when operated at
3,060 cubic meters per hour (m3/hr), compared to the same
resistance for a flow
rate of 1,700 to -2,040 m3/hr
for deep-pleat
corrugated separator filters. This
gives the user of mini-pleat filters the
option of utilizing space-saving higher
airflow rates or extending filter life
by operating at lower than rated airflow
capacity. This is called downrating
a filter.
When a mini-pleat filter rated for 3,060
m3/hr
is down rated to service at 1,700
m3/hr,
it theoretically should extend
service life more than threefold before
it reaches its final permissible resistance
increase. In practice, filter life
extension was found to be merely 1.6-fold
because of dust bridging across
the very narrow air passages between
the paper pleats to form a filter
cake covering the face area. An efficient
prefilter might be used to prevent
the formation of a surface filter
cake and extend the service life of the
mini-pleat filter.
Cased mini-pleat HEPA air filters are formed
from sub components assembled
in a continuous “V” array. The
sub components are panels that hold
the pleated filter paper in metal frames approximately 23.62
inches wide, 11.81 inches high, and the depth
of the paper pleats. A seal is made between framed filter
packs and the standard frame using rubber based adhesives,
polyurethane, or some other plastic-based material, all of
which are chemically compounded to
inhibit their support of combustion.
Another mini-pleat filter design is formed by
molding narrow longitudinal ridges into the wet filter paper
at approximately 1-inch
intervals while the paper is still on the papermaking
machine, then folding the paper as it
comes off the machine into mini-pleats that may be 2, 4, or 6
inches deep.18 The
filter pack is mounted into
the filter case perpendicular to the airflow direction
instead of mounting a number of shallow panels arranged
inside the filter frame in a series of “V” formations The
6-inch-deep mini-pleat separator-less filter contains
the same area of filter paper as the 12-inch-deep separator
type.
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