| 摘要 |
In order to suppress troublesome noise and the formation of mist at the feed pipe (1) around the outlet orifices (5) through which the water is returned to the aeration tank, one or more covering means (2, 3) are provided. These extend at least as far as the water surface and do not touch the profile of the water jets. In addition, at least one orifice (6) is provided through which air can be drawn in. <IMAGE> |
