Improvements in method and means for coating with particulate materials

摘要

The apparatus of the parent Specification is modified by the provision of a gridlike agitating member having a small cross-sectional area compared with the total cross-sectional area spanned thereby, which corresponds to the internal cross-section of the aerating vessel, allowance being made for the free up-and-down movement of the agitator within the vessel, and means whereby such movement may be brought about. The agitator 8 may comprise a frame 9 connected by struts 11 to a central rod 10 which may be used for lifting and lowering the agitator, with or without additional rotation or swivelling. Additional transverse members 12 may be provided on the frame 9, which, with the members attached thereto, has a downward taper. As shown in Fig. 1, the rod 10 passes through the bottmo of an aerating box 1, and may be raised and lowered with respect thereto by an hydraulic or pneumatic cylinder 13. The aerating cylinder itself may be raised and lowered by one or more hydraulic or pneumatic devices 7 with respect to the funnel 4, 5 on which a pre-heated or adhesive coated pipe 6, to be coated, is mounted. In operation, the agitator is raised and lowered through the particulate coating material contained in the aerating vessel 1, after which the latter is raised to introduce the coating material into the pipe p 6, and lowered after an appropriate interval.