GB1012847A - Improvements relating to air-classifiers - Google Patents

Abstract

1,012,847. Pneumatic separators; cyclone separators. GEBRUDER BUHLER. Aug. 28, 1964 [Aug. 30, 1963], No. 35434/64. Headings B2H and B2P. An air-classifier comprises a spreader 5, Fig. 2, which directs the material to be separated as an annular veil into an air stream, an exhaust duct 18, first and second fraction collecting means 13, 31, the second 31 of which surrounds the duct 18 within the zone defined by the annular veil, and a further air stream arranged to act on the material in the second fraction collecting means 31. Material introduced at 3 from a pneumatic feeder is directed by the spreader 5 through passages 7, 40 where it is acted upon by an air stream introduced through inlets 11. The heavy fraction falls to a collecting funnel 13 while the remainder is carried upwardly through a passage 38 by the air stream, the light fraction dropping or being deflected by a baffle 39 into a collecting funnel 31 and the dust fraction being carried to the inlet of the duct 18. The light fraction is further acted upon by an air stream directed through passages 35, 33, 20, the passage 35 being adjustable by means of an axially-displaceable ring 32 operable from outside the casing. A member 19 surrounding the inlet of the duct 18 may also be axially adjustable. The air drawn through the classifier is controlled by a valve 17; the air inlets may also be controlled and, if desired, a closed circuit arrangement may be employed. In another embodiment, Fig. 3, the material is fed by a cyclone 51, the material being directed on to the spreader 5 and the air exhausted from the outlet 53 directed down a passage 60 and up a passage 58 and through the veil of material issuing from the passage 7. Modifications may consist of radiusing the shoulder portion 10 at the foot of the passage 7, providing a fixed or movable bafflle-ring beneath the shoulder portion, making the wall 37 of the collecting funnel 31 conical instead of cylindrical, making the plate 32 of the funnel 31 porous for co-operation with a further air stream and dividing up the air passage 33 to provide a number of air passages.