| 摘要 |
<p>A low pressure dryer for granular or powdery material includes a plurality of hoppers (12) rotatable about a common vertical axis (24) serially among material filling and heating (100), vacuum drying (102) and material discharge positions (104); pneumatic piston-cylinder means (34, 36, 38) for rotating the hoppers about said axis among said filling and heating, vacuum drying and discharge positions; means for heating contents of a hopper at said filling and heating positions; means for sealing a hopper at said vacuum and drying positions; means for drawing vacuum within a hopper at said vacuum drying position and means for selectably permitting downward flow of dried granular or powdery material out of a hopper at said discharge position where said hoppers move collectively and unitarily with one another.</p> |
