| 摘要 |
Apparatus for defining a confined working area (1) ventilated with a cleansed flow of ventilation air, in which apparatus a first air-stream (8) is generated by a fan (10) and caused to pass an air-stream dividing or distributing means, and in which a first part-flow (12) is evacuated and a second part-flow (14) is passed through a filter (15), to form a cleansed air-flow (16) which is passed to the working area (1). The apparatus is provided with means (49) which co-act with the working area in a manner to supply air to the working area (1) in an amount commensurate with the amount of air evacuated in the first part-flow (12). A filter assembly (20) comprising a filter (15) is detachably connected to a unit (21) in which the confined working area is defined, thereby to form a readily removable and exchangeable assembly. |
