Patent ID: 11919269
Assignee: VALMET AB
Field: Handling (Mechanical engineering)
Classification: CPC B  D | IPC B  D

Claim 0:
1. A screw feeder comprising:
a pipe enclosing a feed screw provided on a rotatory shaft running parallel with a length direction of the pipe, said pipe further comprising a plurality of dewatering holes;
a plurality of anti-rotation bars provided on, and extending along, an inside of said pipe, said anti-rotation bars protruding in a direction towards said feed screw;
an inlet arranged at a first end of said pipe and configured to receive a solid liquid mixture; and
an outlet arranged at a second end of said pipe and configured to discharge an at least partially dewatered solid from said pipe, wherein:
said pipe comprises at least one longitudinal pipe section having a first peripheral zone provided in a vertically lower area of said longitudinal pipe section and provided with dewatering holes but no anti-rotation bars, and a second peripheral zone provided in a vertically upper area of said longitudinal pipe section provided with said anti-rotation bars, wherein an overall pipe profile of said longitudinal pipe section includes two differently shaped pipe profiles, a first pipe profile and a second pipe profile,
said first pipe profile defines a shape of the first peripheral zone and is:
a square-shaped profile,
a profile having a partly circular cross-section with a squashed end or a circle segment removed, or
a partly elliptically-shaped profile; and
said second pipe profile defines a shape of the second peripheral zone;
the shape of said first pipe profile is selected to enable outer edges of said feed screw to remove material overlying said dewatering holes; and
the shape of said second pipe profile is selected so as to prohibit any contact between said outer edges of said feed screw and the anti-rotation bars.