| 摘要 |
<p>An aeration device for use in water softening or deoxidation installations or in the biological sewage treatment has the filter elements or perforated tubes suspended from a hinged frame. A counterweight keeps the centre plane of the active elements against a stop at an acute angle beyond the vertical plane. Lifting of the active elements can be facilitated by designing the counterweight as a hollow cylinder which can be filled with ballast or with air. This counteracts the buoyancy tendency of filter elements and holds them reliably in the working position. It facilitates their lifting above the water level for inspection or exchange even for heavy active elements.</p> |
