Patent ID: 6375722
Filing Date: 2002-04-23
Classification: B01D

Abstract:
A system for drying a gas comprising:a source of gas; a compressor connected to said source; and a dryer connected to said compressor, said dryer comprising a first tower and a second tower, each said tower containing desiccant material past which said gas flows, a dryer outlet, an exhaust outlet, and communication structure being capable of placing the system in each of the following modes at different times: A) connecting said first tower to said compressor, connecting said first tower to said second tower, and connecting said second tower to said dryer outlet, such that said desiccant in said first tower is regenerated when said gas flows through said first tower and such that gas is dried when said gas flows through said second tower; B) connecting said second tower to said compressor, connecting said second tower to said first tower, and connecting said first tower to said dryer outlet, such that said desiccant in said second tower is regenerated when said gas flows through said second tower and such that gas is dried when said gas flows through said first tower; C) connecting said first tower to said compressor and to said dryer outlet such that said gas is dried when said gas flows through said first tower, and connecting said second tower downstream of said first tower and to said exhaust outlet, such that a portion of said dried gas flows through said second tower to said exhaust outlet, said desiccant in said second tower being regenerated as said gas passes therethrough; and D) connecting said second tower to said compressor and to said dryer outlet such that said gas is dried when said gas flows through said second tower, and connecting said first tower downstream of said second tower and to said exhaust outlet, such that a portion of said dried gas flows through said first tower to said exhaust outlet, said desiccant in said first tower being regenerated as said gas passes therethrough.