| 摘要 |
PURPOSE:To feed powder between rollers with excellent nip, by making the lower end opening of a hopper of inverted truncated cone shape having built-in feed screw into a specific ellipse so as to make uniform the feed of powder over whole length of the compressing surfaces of rollers. CONSTITUTION:A hopper 1 is an inverted truncated cone in shape and is equipped with a powder feed inlet 10 and a gas-releasing opening 8 at the upper part, and is installed above the compressing surface 11 of compression rollers 7, 7'. The lower end opening 5 of the hopper 1 is an oblong, or an ellipse, whose bore in the direction of the axis of rollers 7, 7' is equal to the breadth of the rollers 7, 7', and the ratio of the bore in the direction of radius of rollers 7, 7' to that in the direction of roller axis ranges from not smaller than 0.7 to less than 1. Rollers 0.30-0.45 in ratio of the breadth of the rollers to the diameter are used for the compression rollers 7, 7'. An ellipse-shaped opening 5 of the hopper 1 makes short the distance between the lowest end of the hopper and the compressing surface 11 of the rollers, and is effective on uniform feed of powder. |
