Desiccant drying apparatus and method for controlling the airflow in the apparatus

摘要

A method and an apparatus for controlling airflow in a desiccant drying system having two desiccant beds (10,12). A first diverter valve (16) communicates with each of the desiccant beds, a regeneration air inlet (22), and a process air outlet (20). A second diverter valve (14) communicates with each of the desiccant beds, a process air inlet (18), and a regeneration air outlet (28). First and second regeneration air control valves (24,30) are also provided which during a cooling phase of the regeneration cycle admit a cooling bleed stream of process air to the desiccant bed being regenerated and then convey the cooling air bleed stream from the desiccant bed and through a heat exchanger (42) back to the process air inlet.