2. General Descriptions
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Operation
Assume the dryer has completed re-pressurization and the left tower has begun drying. The inlet
compressed air/gas enters the dryer and is diverted to the lift tower to begin the five minute
drying cycle. Approximately five seconds later the right tower purge (regeneration) exhaust valve
will open depressurizing the off-line tower. The purge flow will continue for a period of three
minutes and fifty-five seconds. When regeneration of the off-line tower is complete, the purge
exhaust valve will close, initiating the sixty second re-pressurization phase. After re-
pressurization is complete, the inlet selector valve will switch inlet valves and the inlet air/gas
stream will divert from the left tower to the right tower. After five seconds the left tower purge
exhaust valve will continuously cycle through the sequence described above until power is
removed from the dryer.
(See Appendix Sequence Chart)
The complete standard operating (NEMA) cycle is ten minutes. Under normal conditions and
during normal operation, the dryer should provide on outlet pressure dew point (ADP) of -40
℃
or
below.
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Repressurizing Solenoid Valve
Repressurizing solenoid valve is installed Large capacity model to prevent break of activated
alumina gel.
■
Fault Alarm
Pressure switch will transmit a outlet low pressure signal to DCS or local control panel. Then
Purge solenoid valve is closed by control unit(in local control panel)
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