GB943085A - Method and apparatus for mixing granular materials - Google Patents

Abstract

943,085. Mixing pulvecular materials. M. LEVA. Jan. 5, 1960 [Jan. 14, 1959], No. 352/60. Heading B1C. A process for mixing or homogenizing granular or pulvercular materials consists in placing them in a container having downwardly converging sides, supplying gas under pressure to the bottom of the container sufficient to fluidize the lower portion only of the materials, and mechanically agitating them. The apparatus described comprises an inverted conical container B to the apex of which compressed air is supplied by a pipe C at a pressure sufficient to fluidize the contained material only in a lower zone 25. An axial vertical rotating agitator shaft 31 has blades 30 at its lower end, perforated at 41, which break up and disperse large bubbles of air; blades 43 (which may be set at an angle to the vertical) for agitating the fluidized material, and blades 54, 55 which act in the unfluidized upper zone 26. The blade 54 is set close to the shaft and angled to urge the material upward; blades 55 are close to the container wall and urge the material downward, there being interchange of materials between zones 25 and 26 in the intermediate zone 27. The container may be emptied by removing the cap 17, which may be replaced by any convenient discharge valve. The process may be operated continuously by withdrawing material continuously from the bottom of the container and replacing it with an equal amount of unmixed material fed to the top of the container. The sides of the cone make an angle of at least 45 degrees and preferably 70 degrees with the horizontal.