| 摘要 |
<p>In a rotary screening device the screen or sieve (12) is stretched across the upper end of the drum (1A) which is rotated about the vertical axis, and the walls of the drum (1A) are frusto-conical or of parabolic section, diverging outwardly to its lower end in order to avoid 'caking' of the sieved particles on the inside of the walls. The walls may be polished or coated with PTFE.</p> |
