摘要 |
<p>The sieve screen (3) has openings (5) with shapes other than circular. The openings are: oval, especially elliptical. They are alternatively slots and/or wavy. The sieve is rotationally-symmetrical. The length (L) of each sieve opening relative to the radius (6) running through the sieve center includes an angle between -80[deg] and +80[deg], preferably between -45[deg] and +45[deg]. The leading edge (10) of the rotor blade runs at an acute angle relative to the length of the sieve openings. This angle is preferably between -45[deg] and +45[deg]. The sieve opening length-to-width ratio is preferably at least 3. Maximum opening width (B) is 4-20 mm. Maximum length (L) is 10-100 mm. The openings are milled, stamped, produced by laser, or by steel-casting. The sieve is a combination of a sieve plate (11) with openings, and a support plate (12). The support plate is a frame- or coarse sieve construction. Its outer contours correspond with those of the plate; its openings are larger than those of the sieve.</p> |