| 摘要 |
A method and apparatus are disclosed for exposing particles in a gas in order to cause the charge on the particles to change, the apparatus comprising a chamber with an inlet for the gas to enter and an outlet for the gas to exit. The chamber is surrounded by an enclosure with a conductive wall, the wall being held at a ground potential. An electrode with an exposed tip is in contact with the gas in the chamber, the electrode being held at a different potential from the ground potential. The electrode is connected to a source of voltage sufficient to cause a corona discharge to occur forming ions in the chamber, and creating a region of space with a high electric field intensity and another region of space in which the electric field intensity is lower. The inlet and outlet define a gas flow path from the inlet to the outlet such that the gas flow path passes mainly through the region with the lower electric field intensity. |
