Normal Shutdown - BeaconMedaes 4107 9006 25 Installation, Operation And Maintenance Instructions

"Oil-Less" Scroll Laboratory Air
3.0 System Operation
3.4.2 Dryers
This fully automatic,
alternately cycles the compressed process gas
fl ow through two desiccant charged vessels where
the gas' vaporous moisture content is adsorbed.
One desiccant vessel is always on-line in a drying
cycle throughout normal dryer operation. The
opposite, off -line vessel is in a regeneration cycle
for removal of the previously adsorbed moisture
content, or in a purge saving cycle at line pressure.
When the dryer is in the "Manual" mode, the
dryer will shift towers every 30 seconds. At normal
operating conditions, one tower is approximately
100 psig and the other tower is at 0 psig. Any
condition other than this is not normal and will
cause a high dew point condition. During tower
changeover, the online chamber will exhaust,
and the chamber that is regenerating (purging)
will come to line pressure. There is a 5 second
repressurization cycle. If the dryer is in the
"Manual" mode, the dryer will use 15% of the
system capacity to purge the dryer.
When the dryer is in the "Automatic" mode, the
dew point monitor controls the dryer purge, and
purging depends on the dew point condition.
See Figure 3.7. When the dew point reading is
above the setpoint of -10°C (14˚F), the dryer will
function normally (one tower at system presure,
one tower at 0 psig). When the dew point is below
the setpoint of -10°C (14˚F), the purge valve
will close. In this condition, both towers will be
approximately 100 psig (dependent upon tank
pressure) and the dryer will not shift towers until
the dew point is above -10°C (14˚F).
4107 9006 25.11
heat-less type dryer
Dryer 2 is in Automatic mode, Dryer 1 is in Off position
Figure 3.7 Main Screen - Dryer Operation

3.5 Normal Shutdown

Dryer in Automatic Mode
Disconnect switches-OFF
Main power source-OFF
Facility shutoff valve-CLOSED
Air receiver manual tank drain-OPEN
Pressure gauge decreasing to 0 psi (0 kPa)
Close air receiver manual tank drain when pressure
decreases to 0 psi (0 kPa)
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