Annular gap extruder

An annular gap extruder unit comprising:

• a cylindrical housing with an inlet port for receiving feed material at a first end, a compression section for compressing the material and a discharge section with a discharge opening for extruding the compressed material at a second end;
• a conveying screw coaxially located within the cylindrical housing and including an inlet end at the housing inlet port and a discharge end at the housing discharge opening;
• first means, for rotating the conveying screw whereby feed material is conveyed, compressed, and extruded as a result of the rotation of the screw;
• second means, coaxially transversely mounted to the discharge end of the conveying screw for co-rotation therewith near the discharge opening of the housing, thereby defining a radially oriented gap between the second means and the discharge opening;
• sleeve means around the discharge section of the cylindrical housing thereby defining a discharge gap in confronting relation with the second means;
• and
• means for moving the sleeve means laterally along the cylindrical housing, so that said discharge gap can be adjusted.

A method of conditioning and extruding material by rotating a screw within a substantially cylindrical housing, comprising the steps of:

• conveying the material with said screw from an inlet port to a discharge opening in the housing whereby the material is conditioned;
• rotating a resistance plate with the rotating screw at the discharge opening, where a discharge gap is formed in confronting relationship between said plate and the housing such that material extrudes out of the housing substantially radially through said discharge gap;
• and
• adjusting the size of said discharge gap with a cylindrical sleeve to adjust the amount of conditioning of the material.