Section II - Description
System Description
The DEFENDER™
Series utilizes a hollow
fi ber semi-permeable
membrane for the
separation of nitrogen
and other gases from a
compressed air stream.
The membranes divide
the air into two streams;
one is essentially nitrogen along with argon
and traces of other inert gasses. The other
stream is oxygen plus carbon dioxide,
hydrogen and other trace gases.
While fast gases such as oxygen, carbon
dioxide and water vapor quickly permeate
the membrane surface, most of the nitrogen
fl ows inside the membrane fi ber as a
separate product stream. Millions of fi bers,
about the size of a human hair, can be
packed into a single module. This provides
a very large membrane surface area that
effi ciently produces large quantities of
nitrogen.
This system is designed
to deliver nitrogen plus
other inert gases at
specifi ed concentration.
Because water vapor
is being permeated out
of the gas stream, the
resulting atmospheric
dew point is -85°F (-
65°C) or below.
The system is designed to operate with
feed air from a plant compressed air
system that has been dried to at least
+40°F (4°C) pressure dew point.
The membrane modules are protected from
hydrocarbons by a highly effi cient, six-step
fi ltration system. This system consists of a
combination of particulate, coalescing fi lters
and carbon adsorption. The result is air
purity with a heavy hydrocarbon carryover
at or below 2 parts per billion.
Nitrogen System Description
Inside the DEFENDER™ nitrogen
generator, the compressed air fi rst
comes into contact with the membrane
pre-fi ltration system. On Standard and
Premium Filtration Packages, this consists
of a coalescing fi lter (#1) followed by an
additional high effi ciency coalescing fi lter
(#2). On Standard Filtration Packages, the
fi nal pre-fi lter is a high effi ciency absorbing
fi lter (#3) which removes vapors and
aerosols.
On Premium Filtration Packages, the
second coalescing fi lter is followed by an
oversized carbon bed that eliminates any
vapor or aerosol that may have been left
and a fi nal dust fi lter (#4), installed after
the carbon bed, removes any charcoal
dust before the air reaches the membrane
bundles.
These fi lters are sized for low system
pressure drop (<2 PSI under maximum
conditions – 200 PSIG). Automatic
condensate drains are installed on each
fi lter to discharge oil and water. These
are joined into a common header and
connected to a single drain connection.
After the pre-fi ltration system, the purifi ed
air enters the separation membrane where
oxygen, water vapor, and trace gases
are removed from the air stream and
discharged to atmosphere via a vent on the
membrane module. The nitrogen product
fl ow and purity is controlled by a manually-
adjustable valve. This valve assures a near
constant fl ow, regardless of fl uctuating
downstream pressure. A non-return check
valve keeps nitrogen in the system from
venting back into the generator when unit is
stopped.
AIR
4
Quincy Compressor-DEFENDER™
