How The AHLD E-Series Works
Moisture saturated compressed air enters the coalescing pre filter (F1) where aerosols are coalesced then drained via an automatic drain system. The moist water vapor-laden inlet air free of liquid water flows to the inlet of the dryer through the APV (Automatic Piston Valve) (V1) which diverts the inlet air to one of the towers, in this example tower (T1). Air flows upward through the adsorbent bed removing the moisture vapor, the dried airflow exits the tower through the outlet APV valve (V2) flowing to the outlet particulate after filter (F2) which removes particulates from the air stream. Clean and dry air now flows to the process air distribution system.
As one tower is drying air, the other tower will be regenerating (purging) the adsorbent bed. In this example, tower (T2) will be regenerating. Prior to regeneration, the exhaust valve (V4) is opened and the tower is depressurized to near atmospheric pressure, the tower will now be regenerating. During the regenerating process a small portion of dry outlet compressed air is used, 15% on average. The dry regeneration airflow is channeled through the outlet APV valve to the regenerating tower (T2) removing moisture from the adsorbent bed and exits the regenerating tower (T2) through exhaust valve (V4) and exhaust muffler to ambient. After regeneration cycle is complete, valve (V4) closes causing tower (T2) to repressurize to line pressure.
Next, the towers will switch when exhaust valve (V3) opens causing tower (T1) to depressurize and regenerate, simultaneously the inlet and outlet APV valves (V1) and (V2) will shift the pistons to the low pressure tower (T1) causing the inlet airflow to be diverted to tower (T2) which will now be the drying tower. This switching process will continue repeatedly.
The dryer control system is completely automatic and cycles the system through the drying and regeneration cycles. The standard cycle drying time is 5 minutes, regeneration cycle is 4 minutes, and repressurizing cycle is 1 minute.