Pneumatech PMNG-800HP - Page 9

Page 9 of 18
The nitrogen membrane module(s)
are located in the heated air stream.
On low purity multiple module
systems 99.5% and below, the
membranes are connected i
n
p
arallel. On high purity multiple
module systems 99.5% or higher,
they are connected in series o
r
combination of series and parallel.
High purity systems have separate
p
ermeate connections. One is
strictly waste gas, but the second
one is a line that can be re-circulated
back to the feed compressor intake
to enhance purity and productivity.
After the air passes through the
membrane bundle(s) it is essentiall
y
nitrogen plus trace amounts of iner
t
gasses and the specified oxyge
n
content. A built-in flow meter is
there to constantly monitor nitroge
n
flow. Oxygen content (purity) is
controlled by a manual valve or b
y
the optional AutoPure™ automatic
p
urity/flow control system. If the
unit is fitted with the latter, it will
have a proportionally controlled
valve that gets its control signal
from a dual loop process controller.
The controller constantly monitors
the output signal from the oxyge
n
analyzer, comparing it to the se
t
p
oint (user selectable), and throttling
the automatic valve to match the
p
urity level to the set point. After the
nitrogen passes this point it goes
through a non-return valve and ou
t
via the outlet isolation valve.
Membranes
Non-Return
(Check) Valve
Oxygen Analyzer
System
Nitrogen
Flowmeter
AutoPure™
Valve
Manual Flow Valve
Operator Interface,
Temperature &
Purity Controllers,
Hour meter