GB650076A - A process and an apparatus for separating a material into its various grain sizes - Google Patents

Abstract

650,076. Separating solid materials. BORJESSON, K. A. July 5, 1948, Nos. 18067 and 18068. Convention dates, Sept. 27, 1947 and Jan. 28, 1948. [Class 117] A material superphosphate, is separated into its various grain sizes by feeding it on to a vibratory conveyer belt 1 which by its vibrations cause the particles to settle thereon so that the larger particles 20, Fig. 4, are gathered at the top and the smaller ones 19 at the bottom. The material is discharged from the end of the conveyer as it passes over the return roller 3, Fig. 1, the upper larger particles being thrown outwards from the conveyer farther than the smaller ones, to fall down towards a roll 4 rotating in the direction opposite to that in which the particles are discharged, the larger particles being thrown past the roll 4 or impinging over it at such angles as to continue their movement ahead while the smaller particles are caught and carried away by the roll. The vibration of the belt is obtained by supporting it on non- circular, e.g. polygonal, rollers 15. 16. Fig. 4. The conveyer belt may be made of rubber and the belt and roll 4 may be driven at peripheral speeds of 0.5 to 5.0 meters per second. For finer separation several units may be employed, the material from the discharge of one unit being fed to the rear end of the conveyer belt of the next unit. The upper run of the conveyer belt may be bent into the shape of a channel, with a flat base or of arcuate form as shown in Fig. 4 and the roll 4 may have a greater diameter in the middle than at its ends, being of barrel shape in longitudinal section. Alternatively, the roll 4 may have a barrel-shaped middle portion and end portions of stepped down or reduced diameter.