| 摘要 |
The proposed extruder is in the form of a ball-and-screw mechanism with recirculating balls or rollers. A groove is provided in the inner surface of the extruder cylinder along which the rollers move from an inlet to an outlet point, and the shape of the extruder screw is adapted to the shape of the rollers. Transition curves are provided in the extruder screw at the roller inlet and outlet points. The roller path may extend over all or a part of the extruder length, and more than one roller path may be arranged around the circumference of the extruder cylinder. The proposed system may be applied to conical as well as to cylindrical extruders. Various shapes of rollers may be used. USE/ADVANTAGE - This invention is used in the extrusion of foodstuffs. The customary design of single-screw extruder relies on friction between the foodstuff and the cylinder walls to provide the extrusion force. This invention proposes a single screw extruder which is simple and economical to manufacture, and has the advantages of a double-screw extruder in that it provides positive-displacement extrusion and has a self-cleaning screw. |
