GB1249437A - A winnowing machine - Google Patents

Abstract

1,249,437. Pneumatic separators. T. SATAKE. 8 April, 1970 [25 April, 1969; 28 Jan., 1970], No. 16737/70. Heading B2H. In a winnowing apparatus for separating husks from husked grain, e.g. rice, a mixture of husks and husked grain from a husker 9 passes through an opening 16 in a top wall of the apparatus and falls by gravity through a vertical passage defined by wind-shielding plates 17, 18. Currents of air produced by air sucked in by means of a fan 36 through an open front side wall, which may be provided with a screen 15, and through passages 19, 20, 21 pass transversely through the mixture stream. The husks and the unripe husked grain pass with the air into a winnowing chamber 24 while the fine husk grain falls straight down into a channel 23 provided with a discharge screw conveyor 22 In the chamber 24 the unripe grain hits against an inclined plate 25 and descends along the surface thereof into a gathering channel 26. The husks are entrained by the air through a passage 28 defined between the top wall of the apparatus and an uppermost curved portion 27 of the plate 25 and enter with the air into settling chamber 29 which is outwardly bound by a curved rear side wall 13 of the apparatus. Due to the curvature of the wall 13 and of the plate portion 27 the mixture of air and husks is subjected in the chamber 29 to centrifugal separation. The air passes inwardly to an opening 32 which is connected to the fan 36 by a conduit 37 air-tightly fitted through a downwardly inclined guide plate 33, 34. The husks are thrown by centrifugal force against the curved wall 13 and slide down the latter into a collecting channel 31 from which they are discharged by means of a screw conveyor 30 into a central conduit 41, Fig. 5, connected to a discharge conduit 38 for the fan. A rotary valve 40 in the conduit 41 prevents air being blown back from the conduit 38 to the settling chamber 29. The conduit 38 is connected to a cyclone (42), Fig. 1 (not shown), in which the husks are separated from the air. In a modification, Fig. 4 (not shown), the channels 23 and 26 are interconnected by a screen (43) instead of a solid wall so as to provide an additional passage for the air.