Dryer Operation Continued

The right hand tower, as shown, is being regenerated. For this tower, the heating coil is in operation. A slip-stream of dried compressed air is taken from discharge side and routed to this tower through a small valve marked “Purge Needle Valve”. This purge air stream is heated as it flows through the heating coils. After that this stream of air flows through the desiccant and absorbs moisture from it. At the end the moisture-laden purge air is discharged to the atmosphere (opening marked “A”). This purging process removes moisture from the desiccant and prepares it for drying service.