Apparatus for treating a liquid suspension of paper-making material mixed with a large proportion of plastic sheet material to defiber and separate the paper-making material from the plastic, comprising:
- a. casing means including a bottom part forming a collecting trough,
- b. a drum disposed in said casing means, said drum extending along and being rotatable about a generally horizontal central axis and being open at its axial ends, said drum being frusto-conical in shape so that the opening at one axial end of the drum is larger than the opening at the other axial end of said drum, the larger end constituting an inlet end for delivering said liquid suspension to said drum,
- c. said drum including a wall of circular cross-section, said wall extending along a generally horizontal central axis, said wall being open at its axial ends and there being multiple perforations in said wall along substantially the entire length of said wall,
- d. said drum having a plurality of generally axially arranged vane members projecting radially inwardly from said wall along substantially the entire length of said wall,
- e. means supporting said drum for rotation about the central axis of said drum,
- f. inlet means for receiving a liquid slurry of paper-making material and plastic contaminants from a pulper and delivering such slurry to one end of said drum,
- g. means forming a discharge outlet from an end of said drum opposite and distal said one end of said drum arranged to provide for continuous discharge from said drum of solid materials too large to pass through said perforations,
- h. means for rotating said drum about the central axis of said drum to cause said vane members to lift solid materials from said slurry to an upper region in said drum from which upper region said materials fall downwardly,
- i. a rotor mounted to extend within said drum for rotation about a horizontal axis offset from said central axis of said drum and inclined with respect to a vertical plane that contains said central axis of said drum, said axis of said rotor being inclined to said vertical plane at an angle of inclination that is substantially equal to the angle of frusto-conical taper of said drum so that said axis of said rotor is substantially parallel to a line containing a line segment formed by the intersection of a horizontal plane with an inner surface of said drum,
- j. said rotor being of a length equal to a substantial portion of the length of said drum and having radially projecting blades extending axially along said rotor for substantially all of said length of said rotor, said rotor being disposed above the central axis of said drum and adjacent to the upwardly moving side of said drum,
- k. drive means for rotating said rotor to cause said blades to impel said solid materials dropping thereon from said vane members back against said drum wall to assist defibering of the paper making constituents to small particles capable of passing through said perforations into surrounding space within said casing means for collection in and removal from said trough,
- l. said rotor having its maximum diameter such as to provide significant space between said rotor blades and said vane members assuring minimum tendency for comminution of the plastic constituents of said solid materials, and
- m. shower means within said drum for assisting said small particles to pass through said perforations.