GB695647A - Deaerating device for pulverulent material - Google Patents

Abstract

695.647. Packaging. ST. REGIS PAPER CO. Dec. 18. 1950 fDec. 17. 1949]. No. 30798/50 Class 94(i) [Also in Group XXX] A method of deaerating finely ground or pulverulent material of a fluffy nature includes the steps of feeding the material to a closed receptacle and agitating it therein under a partial vacuum. Pulverulent material is fed by a screw 18 to a receptacle 16 where it is stirred by an agitator 22, mounted in bearings 22b, 22c, suction being applied to the receptacle at 16c above the level of material therein. The material, deaerated by agitation and suction, passes from the receptacle 16 to a bin 13 where it is distributed by an agitator 14 to a screw 12 which feeds it through a filling tube 11 to a bag. When the material in the receptacle 16 reaches a predetermined level a diaphragm 19b in the receptacle wall at this level actuates a switch to stop an electric motor 19 driving the feed screw 18. The agitator 22 may be in the form of a helix or of blades carried by radial arms extending from a central rod. The receptacle 16 may be horizontal, the suction orifice being arranged above the surface of the material. In a modification, Fig. 2, material is fed by a screw 33, which may be of progressively diminishing pitch, through a throat 31 to a bin 26 having a funnel-shaped lower part 26b leading to a packing unit 27. The unit 27 includes a multi-vaned impeller 28 which forces deaerated material by centrifugal action through a filling tube orifice into a valve bag. Suction is applied to the top of the throat 31 of the bin through an orifice 31a. The agitator comprises a rotating shaft 40 journaled at 41, 42 and carrying a plurality of vertical rods disposed at varying distances therefrom. Some of these rods, 45 extend up to the top of the throat 31, others 47 extend from the level of the journal 42 up to a level above the highest expected level of the material, and others 49-53 are carried by a horizontal arm 54 secured to the lower end of the shaft 40 and depend to the surface of the funnelshaped lower part 26b of the bin, extensions 50c and 51a may be secured to these. A motor 37 driving the feedscrew 33 is controlled by switches 55a, 55b actuated by diaphragms in the bin wall at the highest and lowest levels between which the level of material is maintained.