GB1019440A - Improvements in or relating to irradiation apparatus - Google Patents

Abstract

1,019,440. Screw conveyers; constant head feeder. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Oct. 16, 1964 [Aug. 6, 1963], No. 31045/63. Headings B8A and B8S. [Also in Division H5] Granular material is irradiated by passing it through a series of ducts 2-23 arranged in a vertical bank, across each face of a plate-like y source 1, means being provided to impart helical motion to the granules relative to the axes of the ducts. The material, which may be cylindrical pellets of polythene, is fed into the duct 2 through an inlet pipe 24 at the bottom of which is provided a constant head feeder 34-36, the head of which is determined by the slope of the part 34 (Fig. 6, not shown). The material is carried through the series of ducts by means of rotating stirrers, one in each duct. Each stirrer comprises a shaft 30 carrying a plurality of paddle members 31, joined by a light wire 32 or thin strip, or a number of these, each in the form of a helix. At the downstream end of each duct, the shaft 30 carries a centrifugal impeller 33 to force material through the connecting passage into the next duct. To convey material from the top duct 12 of one bank to the bottom one 13 of the other, the impeller in duct 12 forces material into a vertical passage 25 where the material drops into another constant head feeder for entry into duct 13. The material is finally pushed out of the duct 23 into a delivery pipe 26. Material dropping down the pipes 24, 25 is rotated relative to the axis of the pipe by baffles 29 and 30 respectively, the constant head devices provided in each pipe being necessary to enable easy rotation of the shafts by the drive mechanism.