| 摘要 |
<p>An apron for use to circulate a liq. in a circular or annular basin, e.g. the sewage in an aeration bed, consists of a crossbeam carrying a frame in which several horizontal flaps are hinged. The frame is clearly smaller in depth and width than the section of the channel, leaving a clearance to the sides and the bottom of 0.25 m. This reduces the power required to start the movement of the apron and needs a less massive structure. In case of trouble the apron moving mechanism can be stopped and the opening flaps prevent the inertia of the moving liq. mass from destroying it.</p> |
