GB1378799A - Air separators - Google Patents

Abstract

1378799 Air classifier ZANASI NIGRIS SpA 20 Dec 1972 [20 Dec 1971] 58843/72 Headings B2H and B2P An air separator for sorting material consisting of particles or objects of approximately similar shape and size but of different weight comprises a vertical hollow sorting shaft 4 having an annular sorting chamber formed therein by means of a central column 6 and having its lower end 104 connected to a fan 1, for producing an ascending sorting current of air which is whirled, e.g. by means of a ring of guide vanes 5, and to an outlet 13 for the heavier particles- or objects, the upper end of the shaft being connected to a feeding appliance 11 for the material to be sorted, which terminates centrally at a distance above a rebound surface 106 on the upper end of the column 6, and to a separating device 8 for separating the sorting air from the lighter particles or objects. The separator may be used for sorting gelatine capsules C into heavier capsules filled with a pulverulent and/or granular filling material ormedicament and lighter empty and/or insufficiently filled capsules. The air supply may be adjusted byuncovering suction openings 101 of the fan 1 by a regulator flap and the degree of whirling of the ascending air current may be controlled by vanes of adjustable pitch or By having interchangeable vane rings. The guide vanes are radial and inclined to the horizontal to provide a rotating helical air current. The rebound surface 106 is in the form of a circular disc preferably provided with an impact-absorbing lining of foam rubber or foam plastics. The separating device 8 is in the form of a cyclonic chamber bounded by an air-permeable, e.g. wire-mesh, wall and having a generally tangential outlet 12 for the lighter capsules. The feeding appliance 11 consists of an inclined chute 111 formed at least by a sieve and terminating into a vertical drop tube 10. The capsules 10 to be sorted are fed on to the chute 111 where part of the loose pulverulent and/or granular filling and fine materials adhered to the capsules falls through the sieve. The capsules drop from the tube 10 on to the rebound plate 106 and thence enter the annular sorting chamber in the shaft 4 horizontally where they then fall vertically against the ascending whirling air current which cleans the capsules of the remaining fine particles adhering whereto and carry these and the empty and insufficiently filled capsules into the cyclonic chamber 8 where the air and the entrained fine particles are centrifuged through the wire-mesh wall of the chamber into a surrounding dust filter 14 which retains the particles. The lighter capsules are discharged through the generally tangential outlet 12 while the heavier capsules, which fall against the ascending air current, are discharged at the bottom of the shaft through the outlet 13 which is also generally tangential.