OGSI OG-15, Installation, Operation And Maintenance Manual, Page: 30 / 57

Effective 07/2014 26
Process Flow Description
The normal flow of air through the OG-15/OG-20 and OG-15E/OG-20E
(Compressor-less) units is shown on the previous pages in the Process Flow Schematic
Drawings. As you can see, once the incoming air is filtered and compressed in the
OG-15/OG-20 unit or regulated to the proper pressure in the OG-15E/OG-20E
(Compressor-less) unit, it is directed into one of the two sieve beds. As the air enters the
bed, the nitrogen is adsorbed by the sieve and the oxygen passes through as product gas
to the storage tank. Each bed produces oxygen until the sieve in that bed is saturated with
nitrogen. When this occurs, the feed airflow is directed to the other bed, which continues
the production process. While the second bed is producing oxygen, the first bed is
releasing into the atmosphere the nitrogen it adsorbed, under very low pressure through a
waste gas muffler.
From the storage tank, the oxygen pressure regulator and the flow meter can be
used to set the oxygen delivery pressure and the oxygen flow rate. While it is possible to
set either of these parameters to the maximum levels, they cannot both be maximized at the
same time. Pressure, flow rate and oxygen purity are all interrelated properties. Any
attempt to increase pressure or flow rate will cause a decrease in one (or both) of the
remaining two properties. The rated production capacity of this machine is
15 SCFH (0.4
Nm
3
/h) or 7 LPM at 12 psi (0.83 bar) for OG-15 and 20 SCFH (0.5 Nm
3
/h) or 10 LPM at
20 psi (1.4 bar) for OG-20 . Oxygen purity will suffer in any overdraw conditions.