Adsorption dryer PSA
PSA stands for Pressure Swing Adsorption. The cycle times are short (6-16 minutes) and therefor the required amount of drying agent is small. This results in relatively small sized packages and low investments. A disadvantage of this process is that the purge flow required for regeneration is high (15 to 20%). The amount of purge flow is depending on the required dewpoint and the ambient and operating conditions.
The adsorption process for gasdrying applications is based on a design of two purge-regenerated adsorbers filled with an excellent drying agent based on combination of Silica (SiO2) and alumina (Al2O3) or Molecular Sieves.
The selection of the best adsorbent is depending on ambient conditions, dewpoint and adsorption pressure. The used material is capable to adsorb high amounts of moisture and can be regenerated by purging.
The system is designed with two adsorbers one in adsorption phase and one in the regeneration phase. The cycle of the complete process is approx.10 minutes: 5 minutes adsorption/desorption, 0.75 minute pressure built-up and 4.25 minutes regeneration. Other cycle times on request.
The pre-treated wet air is let into the adsorber A and the full capacity is flowing through the adsorber. The dimensions of the adsorber and the amount of drying agent are designed in such a way that the drying process performs optimal and the required dew point is met. The process can be controlled by fixed cycle times or by dew point analyser control (optional).
After the adsorption period is finished the regeneration will start. Regeneration and pressure built-up The regeneration is done in this case with product dry air. First the adsorber needs to be depressurized by relieving the pressure to the atmosphere through a silencer. After this, the regeneration air is purged through the adsorber and the Molecular Sieves are regenerated. After 4.25 minutes the blow-off valve is closed and the pressure built-up starts through the purge valves until the pressure has reached the operating pressure.