The compressed air is passed through a Twin Tower PSA
module interconnected with automatic changeover valves.
At the bottom of PSA towers, Activated Alumina is
provided which has tendency of adsorbing moisture from
compressed air. After passing through this bed of
Activated Alumina air gets dried. Supply of dry
compressed air from this layer of desiccant (activated
alumina) will be continuous without any interruption.
Dried compressed air will now come in contact with bed
of carbon molecular sieves (CMS). Carbon Molecular
Sieves are special grade of adsorbant which have the
property of preferential adsorption of oxygen molecules.
At a time one tower remains under nitrogen production
cycle, whereas the other tower undergoes regeneration
which is achieved through depressurization of the tower
to atmospheric pressure.
The two towers of PSA modules
are inter-connected with automatic changeover valves
through pneumatic signal given by solenoid valve which
in turn get the electrical signal from the timer
provided in the control panel. The changeover time cycle
will be 1 + 1 minute. The outgoing nitrogen gas is sent
to a surge vessel where the minimum nitrogen pressure
will be maintained with the help of Back pressure
Regulator. The product nitrogen will now be sent to the
consumer point through a pressure reducing valves at