Gravimetric metering device of tapered hopper above vibro feeder for ground glass fibres - comprises vertical stirrer blades diverging downwards from hopper wall to prevent compaction and improve feeding accuracy and rate, for plastics mfr.

摘要

Device has tapered storage hopper (3), with vertical stirrer blade (5) close to hopper wall, above vibro-feeder (11). The distance of the blade from the wall increases downwards. Pref. baffle (14) with peg (13) projecting inside the stirrer avoids carrying fibres round the hopper by the stirrer. The length of peg (13) is w.r.t. fibre length and metering rate. A partial horizontal baffle (6) opposite the feeder (11) smooths the outflow; and size is determined by the required conveying force. The vibro-feeder (11) and hopper (3) are mounted on separate weigh cells for differential weigh feeding. An adjustable flap (16) projects into the feeder trough (11) to limit the thickness of the glass fibre layer. Rakes (10,17) of shaped bars are oscillated transversely by drive (15) to loosen the fibres and distribute evenly on the feeder. The drives (12,15) for the vibro-feeder and rakes (10,17) are pref. separately controlled for opt. metering accuracy. The stirrer blade(s) (5) pref. extend from mid-height of hopper (3) to near the bottom, and may rotate or oscillate. ADVANTAGE - Avoids fibre compaction at the wall.