GB1014356A - Grain cleaning apparatus - Google Patents

Abstract

1,014,356. Separating granular materials. S. HOWES CO. Inc. May 13, 1964, No. 19924/64 Heading B2H. [Also in Division A2] In apparatus for separating grain &c. into different sizes and types, the grain is fed, at a desired, uniform rate, from a feed box 30, Figs. 1 and 3, provided with fixed baffles 33, 34, a helical distributer 35, another fixed baffle 37, an adjustable baffle 38 and a feed wheel 41, through a suction leg 31 and a shoot 69, on to an inclined, coarse scalper screen 80, which retains the largest pieces of foreign matter and discharges them into a shoot. The grain passes through the screen 80 on to an inclined main screen 81, which retains pieces of foreign matter larger than the particles of grain and discharges this foreign matter into a shoot 83. The grain passes through the screen 81 on to another similarly inclined screen 82, which retains the grain and discharges it, through a shoot 110, into a suction leg 85. Foreign seeds and fine particles of foreign matter, e.g. sand, pass through the screen 82 on to the sloping bottom wall 68 of a housing 65, in which the screens are mounted, and then pass into a discharge duct 84. The housing 65 is suspended, by pairs of flexible steel straps 70, 71, from the frame 20 of the apparatus, and is reciprocated by conventional eccentric mechanism 73. The upper part of the leg 31 is connected, through chambers 26 and 95, to the axial inlet 22 of a centrifugal suction fan 21, whose axis of rotation is generally horizontal and substantially parallel to the path in which housing 65 is reciprocated, so that the rapidly rotating fan gyroscopically stabilizes the frame 20 by damping and counteracting oscillations imposed on it by the reciprocating movements of the housing 65. The fan draws a winnowing stream of air upwardly through the grain falling down the leg 31 and through the scalper screen 80, and thus removes chaff, dust and light impurities, which are collected in a hopper or trap 86 and removed by a screw conveyer 88. The fan 21 has a side outlet 24 and a second axial inlet 23, which is connected. through chambers 96 and 27, to the top of the leg 85 to draw a winnowing stream of air upwardly through the grain being discharged through this leg and thus remove any remaining chaff, dust and light impurities, which are collected in a hopper or trap 87 and discharged by a screw conveyer 89. The under-surface of each screen 81 and 82 is cleaned by brushes 151, Figs. 4 and 5, carried by a frame 150 having end-bearings 160 sliding on tubular shafts 155 and 156, which pass through openings in the two sidewalls 66 of the housing 65 and are secured to the frame 20. The frame 150 is reciprocated by the piston rod 164 of a double-acting cylinder 161, which is actuated by compressed air supplied, from a compressor 181, Fig. 1, through a reservoir 180. At the end of each traverse of the frame 150, an endbearing 160 engages a collar 171 or 172 slidable on the shaft 156. Studs 174, passing through these collars and slots in the hollow shaft 156, engage and move a rod 168 within the shaft 156, which rod actuates a lever 169 of valve mechanism 170, and thus reverses the travel of the piston rod 164 and the brush frame 150. The screens 81 and 82 can be clamped in or raised from their mountings (e.g. to facilitate removal) by bars 125, which can be lowered or raised by turning the handle 137, Fig. 1, of a screw 135 connected, through lever and link mechanism, arms 128 and yokes 126, to the bars.