| 摘要 |
20. A device for dry grinding solid substances, consisting of a semi-permeable element and at least one stage of rotational grinding arranged in a vertical succession. The grinding stage consists of a fixed and a mobile element with a gap in between, which forms a rotational grinding zone. The device also contains elements for directing solid particles approximately upwards, into the rotational grinding zone. It is characterised in that at least one stage of rotational grinding contains at least one rotating semi-permeable element (60) and elements that form a ring-shaped gap (70B) between a fixed plate (70), with a flat surface and a round opening (70A), and a rotating round full disk (61) in the opening (70A). The rotating semi-permeable element (60) and the ring-shaped gap (70B) are arranged to ensure, that a part of particles going upwards can pass through them. Each rotational grinding stage contains a rotating expelling ventilator (62), located behind a rotating semi-permeable element (60) to screen particles going upwards according to their size. |
