Air density system with air recirculation and gyrating bar feeder

摘要

An air density separator (20) has a vertical air separation chamber (24) that opens downwardly to allow rejected material (54) to fall out from the chamber (24) through the open bottom. The air density separator (20) is configured to recirculate the air and entrained fines, and so minimizes emissions and costly air treatment processes. The air separation chamber (24) is connected by a first duct (26) to a cyclone (28). A fan (30) is positioned adjacent the lower end (34) of the air separation chamber (24), and draws air through a second duct (27) out of the cyclone (28) for reintroduction into the air chamber (24). The fan (30) by way of the cyclone (28) draws air through the first duct (26) from the air separation chamber (24). The fan (30) exhausts into the vertical air separation chamber (24) below the material infeed (61) through the plenum (31). An oscillation screen (36) composed of bars (38) extends into the separation chamber (24) of the air density separator (20) and is used to disperse material into the separation chamber (24). The bars (38) are spaced apart to allow air to be drawn up through the bars (38) to separate the light component (56) in the feed material (44) from heavier materials (54). A tray (61) to which the bars (38) are mounted are caused to oscillate by an eccentric weight (50) which is mounted to the bars (38) and driven to oscillate in a horizontal plane. The tray (61) is suspended by four universal linkages (47) to a support frame (46), the linkages (47) allowing the tray (61) and attached bars (38) to oscillate.