GB1228870A - - Google Patents

Abstract

1,228,870. Packaging powdered materials. NIPPON JIDO FUKUROZUMEKI MFG. CO. Ltd. 23 Sept., 1968, No. 45129/68. Heading B8C. An automatic packaging apparatus for powdered material comprises a storage bin 1, an air chamber 3 into which air is fed from pipes 6 for fluidizing the powder, and which is provided with exhaust means 37 for removing excess air after packaging, housing means 4 arranged below the air chamber 3 having air inlet 6 for maintaining the power in a fluidized state and an air supply pipe 11 for directing the material to feed pipe means, flow control means connected between the feed pipe means and filling means 26 for a bag 39, weighing means connected to the flow control means so as to discharge a predetermined weight of material into the bag and means for recycling dust to the hopper. Powdered material is supplied to the air chamber 3 through cone valve 2. The air chamber comprises at its base, air feed pipes 6 opening behind air permeable pad 8 through which air is supplied to fluidize the powder. Exhaust pipes 12 relieve excess air pressure and are connected to pipe 15 for the recovery of entrained powder. A further exhaust pipe 37 connects the air chamber 3 to the hopper 1, and is provided with a compressible section 37a serving as a valve and a flushing pipe 38 for blowing deposited powder therefrom. Air flow in air chamber 3 forces entrained powder into housing 4, which has a similar fluidizing device comprising pad 10, air inlet 6 and exhaust pipe 10. A pipe 11 connected to the airline serves to force entrained powder into the feed pipes. The feed pipes (Fig. 5) comprise a large diameter pipe 16 with a flexible section 20 which can be compressed to close the pipe and a parallel section 17 of small diameter having a constricted inlet 18 and a similar flexible valve section 21. The inlet of the small diameter tube is protected from coarse particles by a screen 19 (not shown) and this pipe provides a slow flow to permit the precise weight of powder to be discharged into the bag. The feed pipes are connected via a flexible coupling 23 to the discharge spout 26 which is surrounded by an outer sleeve 27. The end of the sleeve 27 is closed by a mesh 28 which passes air but not the powder to exhaust pipe 29 and which can be blown free from powder by tube 30. An inflatable seal 31 surrounding the sleeve 27 ensures an airtight joint between the bag 39 and. sleeve 27. The bag 39 rests on weighing platform 40 which is connected by linkages 41, 42, 43 and 44 to a weighing device at A. The weighing device is connected to the flow control valves 20 and 21 and operates to open valve 21 and shut valve 20 when the weight of powder in the bag reaches a predetermined weight, just below the final required value. The slow flow through narrow pipe 17 permits an accurate cut-off when the final weight is reached. The exhaust pipes 29 and 15 are combined in dust chamber 33 and the dust is returned to the hopper through pipe 35 by the action of air jet 34. In an alternative embodiment vertical screw conveyer may be used to convey wet or dry powdered material through the chamber.