On a rotary screen filtering device for medium to high-viscosity fluids, which comprises a rotary screen mounted for rotation in a housing, which screen has at least one screen element through which fluid can flow, the rotary screen, in the region of its sealing faces and the intermediate plates are fabricated or machined together so that they are of identical height. A gap width compensation layer is then inserted between the inlet plate and the intermediate plate and/or between the outlet plate and the intermediate plate. The package of plates is then pretensioned by means of screw bolts in such a manner that all the plates lie firmly against one another up to a maximum permissible operating pressure. Lubrication gaps of defined width are created between the sealing faces and the opposing inner faces of the inlet and outlet plates.

On a rotary screen filtering device for medium to high-viscosity fluids, which comprises a rotary screen mounted for rotation in a housing, which screen has at least one screen element through which fluid can flow, the rotary screen, in the region of its sealing faces and the intermediate plates are fabricated or machined together so that they are of identical height. A gap width compensation layer is then inserted between the inlet plate and the intermediate plate and/or between the outlet plate and the intermediate plate. The package of plates is then pretensioned by means of screw bolts in such a manner that all the plates lie firmly against one another up to a maximum permissible operating pressure. Lubrication gaps of defined width are created between the sealing faces and the opposing inner faces of the inlet and outlet plates.

Methods for altering feed throat passageway size, shape and position in a pellet fed extruder by means of a removable adapter are disclosed. Adapters chosen for optimal extrusion performance may be removed with little effort in a shorter time and may be more cost effective than other methods for optimization of extrusion including replacing the screw or by replacing the feed throat through purchase of a different extruder.