| 摘要 |
In order to be able to perform an effective mechanical local exhaustion with simple means, according to the invention there is used a system with an airstream (4) which has a substantially uniform speed at the same distance from the injection, and which cannot be mixed with a central upwardly-directed column of exhaust air (11). This is achieved by positioning the injection nozzles (5, 8), possibly in concentric rings, around the exhaust channel (6, 7), and by allowing the injection and the exhausting to take place in the same plane, and by allowing the direction of injection to run tangentially to the airstream (4). By means of a compact and simple system, a stable flow is hereby ensured over relatively great distances. |
