| 摘要 |
<p>The screw extruder is designed to compress granular or powdered substances, by removal of air, so as to reduce the volume of a substance for packaging or transport. It has a discharge plate mounted across the end of the tube containing the screw. This plate is flexible, and releases pressures built up by the material so that an even flow results. The plate has two cuts across it at right angles, so that four engines are formed, pushed outwards by the pressure of the discharged material. The shape of the opening formed by the engines is given by a formula which relates the size of its section and the angle at which the logues open.</p> |
