GB779428A - Improved method and apparatus for treating and fiberizing raw fibrous materials suchas asbestos - Google Patents

Abstract

779,428. Screening apparatus. KENNEDY, J. E. Aug. 19, 1955 [Sept. 1,1954], No. 23923/55. Class 117. Fibrous material such as asbestos ore is delivered through a shoot 42 to one end of an elongated inclined screen box 10 housing a screen 24, and shafts 78, 79 connected to the corners of the box at the opposite end are reciprocated by eccentrics 66, 68 on a drive shaft 54 such that a twisting movement is imparted to the box so as to spread the material over the screen. The fiberized cleaned material is drawn by suction into a hood 44 and gang material which does not pass through the screen is delivered to a spout 52. Fines which pass through the screen and through a perforated plate 26, Figs. 2 and 4, fall on to a plate 28 and are also delivered to the spout. Each eccentric comprises a disc wheel eccentrically fixed to the shaft 54, and around which a relatively movable band 72 extends. The shafts 78, 79 are connected to the bands by fittings 76, and the eccentrics are arranged at an angle to each other so that out of phase longitudinal movements of the shafts are produced which causes the vibratory twisting movements of the screen. The box is supported at its corners by shafts 12, 14 which are integral with plates 16 mounted on rubber blocks 20 secured to plates 22 fixed to the box. A vibrator 88 secured to a transverse bracket 86 and operated by compressed air produces up and down vibrations of the screen. Flywheels 64 are carried by the shaft 54 which is driven by a motor 58. Two screen boxes may be operated in series, one above the other, the discharge from the spout of the upper box being fed to the lower screen. In the latter case an additional pair of drive shafts are driven from a separate pair of eccentrics on the shaft 54, and the arrangement is such that the four eccentrics counterbalance. Counterweights may be attached to the spokes 65 of the fllywheels 64.