Compressed air flows through the pre-filter to remove oil and then enters the on-line Tower 1 through valve (A).
Air moves upward, where the desiccant removes moisture from the airstream and lowers the dew point. The majority of clean, dry compressed air exits valve (C) and cycles through the after filter to the rest of the system.
Tower 2 (shown in regeneration mode) depressurizes to atmosphere through an angle seat valve and muffler (D).
Valves (E & F) open and the heater turns on.
The high efficiency blower pulls in ambient air, moving it through the immersion heater and check valve. The ambient airstream passes through valve (F) and flows downward through the moist desiccant in Tower 2, collecting water vapor before exiting valve (E) and exhausting to atmosphere.
Once Tower 2 exhausts, and the regeneration tower reaches its set point, the heater turns off. This happens regardless of whether the cycle is finished as an energy savings feature of the EMS.
A small amount of air exits Tower 1 through a slipstream (B), where it will join Tower 2 to repressurize and cool the tower.
Ten minutes prior to vessel switchover, the Parallel Cooling Mode will begin (not pictured). Valve (E & H) will close and valves (A & G) will open, allowing incoming air to flow through both towers. This minimizes dew point spikes associated with heated dryers. Parallel Cooling Mode requires no purge air.
At the end of Parallel Cooling Mode, valve (G) will open, valve (A) will close, and place tower 2 online (not pictured). The EMS Settings will determine if this is at a fixed time interval or Demand Control Cycle based on outlet dew point sensor readings.
Operations will switch and Tower 1 will be regenerated.