Abstract: Apparatus for separating contaminant particles from liquid suspension stock, e.g. in the de-inking of used news print, is characterized by one or more of a plurality of features which contribute to increasing the capacity and effectiveness of the apparatus, including the provision of a cell comprising inner and outer annular chambers of substantially equal depth with the inlet and outlet connections for the stock being located adjacent the bottoms of the two chambers to force the stock to travel through the full depth of each chamber, and also the provision of a baffle of substantial width on the top of the wall between the two chambers to spread the stock overflowing that wall into a thin film.

Abstract: In screening apparatus for paper making stock comprising a cylindrical screening member dividing the interior of a pressure housing into a supply chamber and an accepts chamber, and also comprising a rotor mounted for rotation in the supply chamber and including a plurality of vanes mounted thereon in angularly spaced relation with each other and in relatively closely spaced relation with the screening member, each of the vanes is of generally airfoil shape and is oriented with its leading edge closest to the screening member and with the surface portion thereof trailing the leading edge diverging from the screening member to create a positive pressure force along the leading edge followed by a negative pressure force between the trailing portion and the screening member.