Patent attributes
In a screw extruder comprising a screw shaft on which at least one screw blade is disposed, a filter screen surrounding the screw shaft and including filter openings is arranged within oppositely located frames and a funnel-shaped filtrate trough is disposed below and on the outer side of the filter screen, the screw shaft is cylindrical in the region of an inlet port, widens conically in its central region, and is cylindrical in the region of the discharge port, and the filtrate trough comprises at least two chambers, which chambers are each provided with a drain for filtrate, and the first chamber in the region of the inlet port has a longitudinal extension corresponding to at least the length of the cylindrical portion of the screw shaft in the same region.