15
Heatless Regenerative Desiccant Air Dryer
Shut-Down Procedure
At any point during the process of startup or shutdown, you notice anything unusual; we recommend you
refer to the operation manual immediately. If you cannot find the answer in the troubleshooting section,
contact your Aircel representative or the factory at once.
1. Slowly OPEN the by-pass valve.
2. Slowly CLOSE the Inlet and outlet “shut-off” valves.
3. To depressurize the dryer after the Dryer is isolated. Turn Power ON … a purge exhaust valve will
open and the dryer system starts to depressurize, also the manual vent valve on the outlet afterfilter
can be opened to depressurize the Dryer until the tower pressure gauges read ‘0’ psig.
4. Switch off electrical power after both towers have been depressurized.
Sequence of Operation
Step 1:
Vessel 2 Depressurizing (0-5 secs)
Vessel 2 (T2) purge exhaust pilot solenoid valve is energized which
supplies control air to the purge exhaust valve (V4) which opens
slowly, depressurizing vessel 2 (T2). Simultaneously the inlet
and outlet APV (Automatic Piston Valve V1 & V2) shift positions
directing the inlet air to vessel 1 (T1) to be drying the air. The air
flows up through the desiccant bed and exits to the outlet APV
valve (V2) to the outlet particulate filter then to the customer dry
process air system.
Step 2:
Vessel 2 Regenerating (6-240 secs)
Step 2 is a continuation of step 1 except vessel 2 (T2) will be
regenerating, vessel 2 (T2) purge exhaust valve (V4) is still open,
vessel 1 (T1) is drying the inlet air. A small portion of dry outlet air
from vessel 1 (T1) (15% average based on standard design capacity
of 100 psig, 100°F inlet air, 100°F ambient air and PDP of -40°F)
is taken through a small orifice in the outlet APV valve (V2) and
used to regenerate the desiccant bed in vessel 2 (T2)
until 240 seconds has been reached.
Step 3:
Vessel 2 Repressurizing (241-300 secs)
Vessel 2 (T2) purge exhaust pilot solenoid valve will de-energize
causing vessel 2 (T2) purge exhaust valve (V4) to close, this allows
vessel 2 (T2) to repressurize to line pressure, since air continues
flowing though the small orifice in the outlet APV valve (V2)
pressurizing vessel 2 (T2).
Summary of Contents for AHLD E-Series
Page 38: ...38 Electrical Drawings PLC Output Sensors All AHLD E Models Aircel AHLD E Series Models 70 750...
Page 40: ...40 Electrical Drawings Back Panel All AHLD E Models Aircel AHLD E Series Models 70 750...
Page 42: ...42 Service Notes Date Service Performed Notes Aircel AHLD E Series Models 70 750...
Page 43: ...Service Notes Date Service Performed Notes Heatless Regenerative Desiccant Air Dryer 43...
