| 摘要 |
PURPOSE:To selectively transport only those powdery particles having positive or negative tribo-electric polarity among powdery materials to be transported having selective transportability due to tribo-electric polarity by dividing a string of electrode bunches into a plurality of divisions in the travelling direction of a travelling wave alternate electric-field curtain, impressing in the sequence of phase, multi-phase AC voltages superposed with different DC voltages for different divisions. CONSTITUTION:A string of electrode bunches 1 is divided in the advance direction of a travelling-wave alternate electric-field curtain, and AC voltages from three-phase AC power supplies 6, 8, 11 superposed with DC voltages from DC bias power supplies 10, 13 are impressed one after another to the electrode bunches corresponding to the obtained divisions I, II, III. Now travelling-wave alternate electric-field curtains with different mean potentials are formed for the divisions I, II, III. When a pulverized substance P is supplied from a supply hole 4, the division I transports in the A direction regardless of the tribo-electric polarities, positive or negative, and the division II and thereafter accelerate only negatively charged particles, which are passed and discharged from the discharge hole 5, while positively charged particles build potential barrier to stop transportation. Thus positively or negatively charged particles can be transported selectively. |
