Solids handling specialist, Ajax Equipment, has supplied leading powder processing equipment maker, Hosokawa Micron with an agitated screw feeder, and integral hopper, to handle and control the feed of pharmaceutical powder into a milling machine.
Bulk pharmaceutical compound is tipped from a big bag into the agitated screw feeder’s large hopper section allowing gravity flow to a robust, multi-bladed agitator, and screw feeder. The auger features a stepped shaft with variable pitch, to pick up the cohesive powder progressively from the full length of the agitated feeder outlet.
Designed for clean-in-place, all parts of the agitated screw feeder are constructed of 316L stainless steel, with internal surfaces mechanically polished to provide a crack and crevice free finish. The feeder’s internal geometry prevents dead zones, ensuring hygienic processing of the pharmaceutical powder.
The feeder’s upper hopper section features brackets allowing it to be mounted on load cells bolted to the floor with the rest of the hopper and screw feeder suspended beneath. Changes in weight of the entire assembly allow gravimetric control, ensuring a consistent feed rate to the mill.
The agitated feeder meets the requirements of ATEX Zones 1 & 21 internally and Zones 2 & 22 externally. The agitator and screw feeder drives are controlled by separate invertors to maximise co-ordination between agitation and screw feed for optimum powder discharge. FDA compliant PTFE seals are used throughout.
“Ajax’s experience in agitated feeder design has enabled the best hopper shape possible for gravity flow in the limited head space available,” said Mike Coffey, project manager, Hosokawa Micron Ltd.