Pneumatech PMNG Series, Installation, Operation & Maintenance Manual

Page: 9 / 18

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 in
parallel. On high purity multiple
module systems 99.5% or higher,
they are connected in series or
combination of series and parallel.
High purity systems have separate
permeate 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 essentially
nitrogen plus trace amounts of inert
gasses and the specified oxygen
content. A built-in flow meter is
there to constantly monitor nitrogen
flow. Oxygen content (purity) is
controlled by a manual valve or by
the optional AutoPure™ automatic
purity/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 oxygen
analyzer, comparing it to the set
point (user selectable), and throttling
the automatic valve to match the
purity level to the set point. After the
nitrogen passes this point it goes
through a non-return valve and out
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