Biflow drier with improved filtration

摘要

A bi-directional filter has a pair of flapper-type check valve assemblies 20, 21 for directing fluid flow unidirectionally through a centrally supported molded desiccant core 22. Each check valve assembly is a three part structure spot-welded into a unitary assembly having a centering support plate, a core support cup and an intermediate flapper valve plate. A depth-type filter media circumferentially surrounds the desiccant core and extends between the check valve assembly on either end of the core for providing filtering for the fluid prior to entering the molded desiccant core. A depth-type filter media 80, 81 is also provided at each axial end of the core for providing fine filtration of the fluid after the fluid has passed through the core. The outer filter media is arranged to allow a portion of fluid therein to bypass the desiccant core.