Patent GB-1394687-A (GB)
Title: Particle separator
IPC: B07B1/28
Filed: 1972-08-30
Abstract: 1394687 Wet sieving B L CULP 30 Aug 1972 40239/72 Heading B2H An apparatus for separating a comingled mass containing various sizes of particles of material of various specific gravities into different size fractions comprises a plurality of discs B carried in a vertical stack for receiving the material to be separated, the discs being perforated and having successively decreasing mesh sizes from the top to the bottom disc, means C for immersing the discs in water while separating the material, means D for cyclically rotating the discs through a predetermined angle, so as to cause particles of lighter material to move off the discs, and means E for abruptly stopping the discs between each cycle of rotation so as to cause smaller particles on said discs to pass through the perforations therein to the discs therebelow, the particles above a predetermined size being collected on the discs. The material to be separated, e.g. diamondiferrous gravel mixed with rocks and light debris such as wood and grass, is fed via chute 14 to the upper end of an inclined open-ended perforated drum A rotated by means of a gasoline motor 38' via pulley 36, bolt 35, pulley 34, reduction gear 32, pulley 31, belt 30 and pulley 29 carried on a T-member 25, 26 welded to the lower end 15 of the drum A. Oversize reject material passes from the lower end of the drum into a discharge chute 16. The desired material to be separated passes through the perforations in the drum into a trough 39 which directs it onto the upper disc 48a of the vertical stack of concave perforated discs 48a-48c which are carried within a cylindrical housing 49 provided with slots 50 around its periphery for the discharge of light particles thrown or floated off the discs and with access holes 51 for removal of particles collected on a particular disc. The discs-housing assembly is rotatably mounted on a vertical shaft 54 and immersed during the separating process in water contained in another housing 72. The water is supplied by a centrifugal pump 43 driven through belt and pulley by the motor 38' and connected via a hose 42 to a perforated pipe 41 which sprays the water onto the material fed through the drum A. The housing 49 is caused to rotate cyclically through a predetermined angle by means D consisting of an arm 67 engaging a bearing 68 on a cross-member 52 secured to the housing 49, the arm 67 being mounted on the lower end of a shaft 63 extending through a tubular brace 60 and driven from the reduction gear 32 through chain 65 and sprocket wheels 64, 66. After the housing is rotated through the predetermined angle, the arm 67 rolls off the bearing 68 allowing springs 69, secured to the housing 49 and to frame members 10, to rapidly return the housing 49 to its initial position. In so doing, an abutment 75 on the housing 49 engages rubber pads 76 mounted on vertical angle members 74 secured to the inner wall of the housing 72 whereby the housing 49 and hence the discs 48a-48c are abruptly stopped between each cycle of rotation. A hole 73 is provided at the bottom of housing 72 to allow water and light and small particles to escape from the housing, the hole being small enough to keep the discs immersed in the water in the housing. In operation vibrations of the motor are also transmitted to the screens.