US Patent 7892329 Air dryer cartridge

The present invention provides desiccant cartridge (10) for a vehicle air dryer, the cartridge (10) having a casing comprising a base (12) and a cover (14), the cartridge (10) further having a charge inlet (24) arranged to receive air from a compressor and a charge outlet (22) in fluid communication with the charge inlet (24), the casing containing a coalescing apparatus (20) and a desiccant (18) arranged between the charge inlet (24) and the charge outlet (22) such that air entering the casing via the charge inlet (24) passes sequentially through the coalescing apparatus (20) and desiccant (18) before reaching the charge outlet (22), wherein the cartridge (10) is further provided with a purge outlet (26) disposed in the casing between the coalescing apparatus (20) and desiccant (18), and the charge inlet (24), charge outlet (22) and purge outlet (26) are provided in the base (12) of the cartridge (10).