Apparatus for cleaning fibrous suspensions of low stock consistency

Claim 1

In an apparatus particularly suited for cleaning and sorting fibrous suspensions having a low stock consistency, the combination comprising: a vortex cleaner having a downwardly tapering conical housing with an inlet for the suspension to be cleaned at the upper end and an outlet for the dirt particles removed at the lower end; a pressure screen mounted to the upper end of the vortex cleaner housing, said pressure screen having a stationary and cylindric upright screen basket, a driven rotor within said screen basket, the axes of the screen basket and of the rotor being concentric with said vortex cleaner housing, said rotor having a lower surface with a central opening therein and means to promote the circulation of the suspension flowing into the vortex cleaner, said rotor forming an annular clearance with said screen basket and sealing means for closing the annular clearance between the rotor and the screen basket such that substantially none of said suspension entering said vortex cleaner passes upwardly between said screen basket and said rotor and substantially all of the cleaned suspension leaving said vortex cleaner passes upwardly through the central opening in said lower rotor surface, said central opening comprising means for delivering said cleaned suspension leaving said vortex cleaner to said annular clearance.