GB923088A - Particle freeing method and apparatus for particle sizing screens - Google Patents

Abstract

923,088. Screening apparatus. AUSSIE MANUFACTURING Ltd. June 9, 1960, No. 20270/60. Class 117. A screen element 12 which is vibrated longitudinally and vertically is sloped towards its discharge end and is kept free of clogging by a screen of air jets emitted from nozzles spaced along a tube 31 clamped to a head 23 continu-- ously reciprocated laterally. The head is slidably mounted on guide bars 16 extending between end plates 17 on a structure attached to the screen frame 14, and a pin on the head engages a reversing helical groove 24 on a shaft 18 driven by a motor 22 whereby the head is reciprocated. Air is supplied to the tube via a pump 37, heater 35 and pipe lines 36 and 34. In a further embodiment three screens arranged one above the other are each provided with a reciprocatory air tube. In Figs. 6 and 7 the air tube is additionally given an axial reciprocation as it moves laterally, so that each air jet traces a sine-wave path over the screen. The screen frame supports a helically grooved driven shaft 61 and a spline shaft 62 driven therefrom through gearing 63, 64. A carrier 66 slidably rides on rods 67, 68 and is laterally reciprocated by a pin engaging the helical groove as described above. A plate 72, movable between guide rollers, carries the air pipe clamping head and is mounted on the carrier, and is reciprocated axially by a crank arm connected to a drive on a shaft 82. This drive is obtained via a drive from the spline shaft comprising chain sprockets 85 and 87, the latter being movable along the spline shaft as the carrier moves.