Conveying, metering, mixing appts. for poor-flow powders e.g. pigments - has laterally=sprung rotating spring within hopper base to prevent bridging, and projecting into outlet e.g. to grooved roller metering device

摘要

A feed hopper (20) has within in base (21) a mixing device consisting of a rotated helical spring (19), which is laterally sprung, and extends across the hopper so that its free end (122) reaches or protrudes through an outlet opening (17). The outlet (17) is pref. offset in a funnel-shaped base (21) with the spring (19) extending close to the base surface from its opposite side. The hopper (20) and/or spring (19) may be vibrated, radially to the spring. The hopper (20) may feed into a metering device consisting of a housing (10), close fitting (12) on a driven horizontal roller (14), with a continuous circumferential groove (32), into which a stripper blade (34) extends. USE/ADVANTAGE - Feeding poorly-flowing powders, e.g. pigments, esp. to plastics processing machines, e.g. extrusion, injection moulding, blow moulding. The rotated helical spring acts as a stirrer to loosen up and convey the powder material, giving improved metering accuracy. Vibration of the hopper and spring avoids agglomeration and bridging of the powder, esp. in filling chute (18).