| 摘要 |
A charge injection device is disclosed which issues free charge injected fluid from an orifice (4) into a region of lower pressure downstream. To avoid significant impairment of charge injection level or efficiency by an electrode pair (5, 8) in the region of the orifice (4) due to the reduced downstream pressure, the pressure in the region of orifice (4) is raised, close to the pressure in the charge injection chamber (2), by feeding gas, such as sulfur hexafluoride, to a chamber (18) having an outlet orifice (27) issuing into the lower pressure downstream region. |
