| 摘要 |
<p>An airflow classification machine capable of precisely and accurately classifying powder. A classification plate (7) is placed in a casing (2), a coarse- powder discharge opening (8) is formed around the outer periphery of the classification plate (7), and a fine-powder discharge tube (12) is connected to a fine-powder suction opening (11) provided at the center of the classification plate (7). The casing (2) has a skirt section (14) forming a first classification chamber (13) between itself and an outer peripheral portion of the upper side of the classification plate (7), and has a circular tube section (15) forming, in the bore of the skirt section (14), a second classification chamber (16) coaxial with the first classification chamber (13). Ejection nozzles (33) are arranged equidistantly around the first classification chamber (13). Fluid of a solid-air mixture is ejected from each of the ejection nozzles (33) in the circumferential direction of the outer periphery of the primary classification chamber (13), and the mixture is caused to swirl in the primary classification chamber (13) to centrifugally separate powder into coarse powder and intermediate powder that contains fine powder. The intermediate powder is raised while being swirled along peripheral wall inner surface of the secondary classification chamber (16), and moved radially inward along a ceiling surface while being caused to form a strong downward swirl at the center of the secondary classification chamber (16). Thus, the powder is centrifugally separated into the intermediate powder and the fine powder, and the fine powder is sucked into the fine powder discharge tube (12).</p> |
