| 摘要 |
<p>An insulating or semiconductive tube defines a path along which powder flows from a source to an article to be coated therewith. Electrodes that extend circumferentially and are equispaced axially are embedded in the tube wall and are so connected with terminals of an a.c. source that there is a constantly varying potential difference between axially adjacent electrodes, to produce a field that tends to repel powder from the tube wall. A corona discharge electrode, fixed at the outlet end of the tube, is connected with one terminal of a high tension d.c. source. The other d.c. terminal is grounded to the article to be coated.</p> |
