Heatless Air Dryer Working & Process
Heatless air / dryer is the simplest form of desiccant type drier for achieving a dew point of -40°C or better for instrument air systems and other gas drying applications .
Process- Wet Incoming Compressed Air Passes Through A Prefilter Where All Liquid Mist Particles Are Coalesced Separated & Collected In The Bottom, Where It Is Discharged In The Drain Via An Auto Drain Valve . After Pre Filter The Air Passes Through An Activated Carbon Filter Where All Oil Vapor Is Adsorbed & The Air Becomes Oil Free . After This The Air Is Directed Towards Adsorber I Where The Compressed Air Passes Upward Through The Desiccant Bed (Activated Alumina Or Molecular Sieves ). Air Drying Takes Place By Adsorption. Dry Compressed Air From Chamber I Then Passes Through The Check Valve Assembly And Then Through The After-Filter To The Application Or Work Area.
While Compressed air is drying in chamber I the desiccant in chamber II where the desiccant has been wetted in the previous cycle is being simultaneously regenerated.
For Regeneration The chamber II is depressurised to the atmosphere through the purge valve in the downward direction. A portion of the dry compressed air passes through the needle valve / orifice plate through the desiccant and flushes out the desorbed moisture.
When the regeneration is complete, the purge valve is closed and the tower is slowly repressurised to line pressure for a smooth changeover. A drying period of 5 minutes provides an outlet dew point of -40°C or better (at atmospheric pressure ).