22 - EN
4.5 Oxygen Content
The residual oxygen content of the N2 process gas is continually monitored during normal operation. If the oxygen content increases above the
alarm level the nitrogen gas is vented to atmosphere at a reduced flow until the purity recovers.
4.6 Economy Mode
Economy mode is designed to switch the generator into standby mode when there is no demand for gas.
The generator monitors the outlet pressure and, if it exceeds a pre-determined level for a sustained period of time (Economy Period *), the N2
outlet valve will close. The generator will continue to cycle as normal without delivering gas to the application. If the back pressure is maintained
for an additional 5 minutes, the generator will stop cycling and enter Economy mode. If at any time the pressure falls below the regulated outlet
pressure, the generator will resume normal operation.
If the generator is in economy shutdown when the pressure falls it will complete the cycle and then run through the a clean up cycle prior to going
back online..
The Economy over-ride facility (optional) can be used to maintain the beds when the generator is in economy mode. If the over-ride is enabled, a
clean up cycle will be performed once every 20 minutes (default). This allows the generator to go straight on-line when the outlet pressure falls
below the regulated outlet pressure.
*The Economy Period is factory set to 5 minutes.
4.7 Energy Saving Technology - EST
If the generator is not operating at full capacity, it is unlikely that the CMS in the on-line chamber will be fully saturated at the point of changeover.
The EST system is used to monitor the O2 content of the gas at both the outlet of the buffer vessel and directly from the CMS bed. If the O2
content is below the production purity by >5% at the outlet
and
>20% from the CMS bed at the end of the current cycle, the EST system extends
the cycle of the generator and changeover is delayed. Depending upon the production purity requirements, the generator will remain in this state
for up to 300 seconds.
If at any point the O2 content of the gas rises to within 5% (at the outlet)
or
20% (from the CMS bed) of the production purity the generator will
resume normal cyclic operation.
Note.
The economy mode described above will override the EST as required.
The economy mode can be disabled within the customer settings menu, however Parker domnick hunter strongly recommend that this option
remains enabled.
