| 摘要 |
<p>Portable screen, for the cleaning of beets, consists of a series of parallel, rotating rollers with horizontal axes placed side by side between side-plates. Each roller has two types of rod which alternate arounds its periphery one consisting of a helicoidal spring, stretched between the side-plates, and the other a balde which is fixed in the side plate by elastic means, e.g. rubber blocks. The sieve is mounted on a wheeled chassis having a feed hopper with an extractor. A conveyor belt evacuates the earth and foreign matter falling through the sieve. The latter also acts as a conveyor which bring the cleaned beets to the outlet chute. In operation, the rubbing of the beets on the springs and the blades detaches the earth which passes through the rollers. Stones or other heavy objects can pass between the rollers by displacing the springs and the blades towards the axes of the rollers. The screen is more efficient than known screens of this type and obviates the risk of damaging the beets.</p> |
