Patent ID: 7479176
Filing Date: 2009-01-20
Classification: B01D

Abstract:
1. A method for controlling gas flow in a multiple bed desiccant drying system, the system including a plurality of desiccant beds disposed in corresponding chambers within a desiccant bed module, each chamber having a multi-position valve controlling gas flow into and from the chamber, comprising the steps of: introducing a gas to an inlet of the desiccant bed module; positioning each of the multi-position valves to cause the gas to pass from the inlet serially through each of a subset of the plurality of desiccant bed chambers, while a remaining one of the desiccant bed chambers is isolated from its adjacent chambers and the gas; passing the gas from the inlet serially through the desiccant bed chambers and out a desiccant bed module outlet; regenerating the desiccant bed in the isolated chamber while the gas is passing serially from the module inlet to the module outlet; and thereafter repositioning the plurality of multi-position valves to simultaneously isolate another of the desiccant bed chambers from its adjacent chambers and the gas, and to the cause the freshly regenerated desiccant bed to be the final desiccant bed through which the gas serially flows before passing out of the desiccant bed module.