| 摘要 |
<p>The invention relates to a method and apparatus for screening pulverized or chip material, such as fibers or wood chips, free from impurities. The material to be screened is fed onto a roll set formed by a number of adjacent, essentially parallel rolls (1) and is brought to an advantageous movement with the help of said rolls (1), whereby material particles of highest density drift downward closest to the surfaces of the rolls and that the material fraction closest to the roll surfaces can escape the rolls via a gap (B) having a width essentially larger than the gap width (A) of the preceding roll pairs. <IMAGE></p> |
