GB257568A - Improvements in apparatus for classifying materials - Google Patents

Abstract

257,568. Hardinge Co., Inc., (Assignees of Hardinge, H.). Aug. 28, 1925, [Convention date]. Density separators.-An apparatus for separating material from gases or for classifying materials has communicating chambers between which currents of material laden air are passed and given a whirling motion by deflectors. Mechanism is provided to vary the effective surface of the deflectors so as to vary the degree of separation. The separator is shown in Fig. 1 associated with a rotating mill 1 from which a stream of material laden air is drawn. Air is blown into the mill through the pipe 4 and it leaves the mill by passing through the barrel 5 into the conduit leading to the separator. Any material dropped in the barrel falls through a break in the pipe 4 and is carried back into the mill by the air current. A fan 6 driven by a motor 7 draws air laden with powder from the top of the separator through the pipe 8 and discharges it into a collector 9. The separator or classifier has two cones 10, 14 the external one 10 of which is connected by the conduit 11 to the mill. In this conduit is formed a pocket 12 opening into the air feed duct 4 of the mill, which passes all the oversize material back to the mill. A baffle 13 at this point regulates the flow of air through the duct. The inner cone 14 has a different slope from the cone 10 and the opening at its apex is regulated by a conical member 16 which can be moved vertically and then held in position by a locking pin through holes in the neck 20 and rods 17. A tubular member 22 is secured to the inner side of the inner cone so that its upper edge is approximately level with the upper edge of the cone. The outer cone 10 supports the cover 24 which' carries the adjustable outlet sleeve 27 provided at its lower end with a closure member 28 adjustable by nuts 30 to vary the size of the exhaust opening. Twisted deflector blades 31 are secured to the cover 24, their lower parts extending between the concentric walls 15, 22; the area of the blades effective for whirling the stream is varied by raising or lowering the inner cone 14 and tube 22 by means of the nuts 35. The greatest whirling effect is obtained with the cone 14 in its raised position as the whole of the air stream then passes through the parts of the deflectors giving the greatest change in direction. In a modification the deflector blades are arranged between the two cones 10, 14 and are secured to the outer one; the tube 22 is then unnecessary. In another modification the two cones 10, 14 are fixed and the effective area of the deflector blades is varied by a separately actuated tube. The fan employed may maintain a circulation of air through the mill, classifier, and collector, and the system may include a bye-pass conduit to conduct air directly into the classifier.