Patent ID: 6094836
Filing Date: 2000-08-01
Classification: B01D

Abstract:
An air dryer having dual canister assemblies and comprising, in combination, first and second valve bodies, each containing a moist air inlet valve, a dried air outlet valve and an exhaust and drain valve assembly, first and second spin-on canister assemblies removably attached to said valve bodies, a single control valve assembly and lines connecting a source of moist compressed air to both said moist air valve bodies, a pair of lines connecting said control valve to each of said exhaust and drain valve assemblies and a line connecting said dried air outlet valves to each other, to the application, and to said control valves for determining the position of said exhaust valves, said moist air inlet valves each being responsive to high external air pressure for biasing said valves open, said dried air outlet valves being biasable under high internal air pressure to an open position to allow dried air to escape from said canisters, and each of said dried air outlet valves having a small orifice therein to allow air to bleed therethrough when said valves are closed, said exhaust and drain valve assemblies being normally closed and being responsive to positive air pressure by opening to allow air and moisture to drain therethrough, each of said canister assemblies having a base plate, a housing fastened to said base plate, an imperforate sleeve being spaced from the inside of said housing, desiccant contained in said sleeve, with at least one aperture in said canister communicating with said moist air space and at least one aperture in said canister leading to said dried air space, whereby, when moist air acts on said one moist air valve to open said moist air valve and causes dry air to exit from said one of said dry air valves, said control valve supplies pressure to said other exhaust and drain valve to open said valve, said other moist air valve closes and bleed air passes backward through said other dry air valve to regenerate said desiccant, and moist air passes out through said other exhaust and drain valve assembly, and when said control valve supplies pressure to said one exhaust and drain valve assembly, said operating cycle reverses.