GB842684A - Apparatus for drying and/or cleaning or winnowing of granular material - Google Patents

Abstract

842,684. Sifting apparatus. JONSSON, A. S. June 18, 1958 [June 20, 1957], No. 19498/58. Class 117 [Also in Group XIII] Apparatus for cleaning granular material e.g. grain, comprises an aspirator 10, Fig. 1, having an annular air passage wherein the grain is separated from lighter matter by air which enters the lower portion of the aspirator from a vibratory sieve 14 secured thereto, which sieve has inclined sieve-plates 26 for cleaning the grain which is delivered from the aspirator and which has currents of air, which may be preheated, entering through apertures 58, 62 for drying the grain thereon. The sieves, which are oscillated by a vibrator 48 and which have collecting pipes 45, 47, 49 at their lower ends, are arranged one above the other on a frame which is supported by springs 32 and pivoted at 36 to vary the inclination of the sieves. The vibrator 48 also oscillates a sieve 16 within the aspirator by means of a rod 56 which is connected from the sieve 14 to a frame 54 on which the aspirator rests. A fan 66 withdraws air from the aspirator through a duct 64 and leads it to cyclone separators 70 from which it is returned to the apparatus by a conduit 72 and apertures 62. Air may be led from the conduit through pipes 76 and be cleaned in a wet dust separator 82 before discharge to the atmosphere. In a modification. the vibratory sieve has apertures 133, Fig. 2, in the side walls between sieves 104, 106, 108, 110, 112 arranged in series with each other and alternately slanting in opposite directions and imperforate bottoms 114, 116, 118, 120 beneath each sieve. The sieves and bottoms are secured to end walls 122, 124 by means of hooks 136 and the lower ends of the bottoms have collecting shoots 138 for sieved materials. Deflecting members comprising vanes 140 pivotally mounted at 142 parallel to the discharge ends of the sieves and having separating edges, are directed towards and into the approaching grain layer to deflect the uppermost layer to be the lowermost layer on the next following sieve. In a further modification the inlet to the aspirator comprises telescopic tubes 18a, 18b, Fig. 3, by which the outlet mouth may be set to various distances above the surface 17 of a distributing cone 16<SP>1</SP> to improve uniform dispersion of the grain. A vibrator 21 actuates the cone and annular slots 25, 27 formed in the cone and between the lower edge of the cone and surrounding outer shell 10 respectively allow air to flow upwardly to entrain light impurities.