Patent ID: 6911118

Claim:
A pulper for producing paper pulp from waste paper containing undesired scrap particles, comprising: a container forming a chamber for receiving waste paper and water, said chamber being defined by a bottom wall and a substantially cylindrical circumferential wall, a paper tearing member, which is arranged in said chamber close to said bottom wall and which is rotatable in a horizontal direction of rotation about a center axis of said cylindrical wall, said bottom wall and said circumferential wall forming a substantially circular peripheral reject chute, which is situated under said paper tearing member for collecting reject including undesired scrap particles and which extends helically in the direction of rotation of said paper tearing member from an upper end of said reject chute downwardly to a lower end of said reject chute, a horizontal discharge pipe connected to said reject chute at said lower end thereof, and a coreless conveyer screw in said horizontal discharge pipe for discharging reject in batches from said reject chute, said coreless conveyor screw having an inlet end and an outlet end, wherein said conveyor screw is journalled in such a manner at said inlet end so that said conveyor screw is radially moveable at said outlet end.