| 摘要 |
<p>1285014 Mining &c SOUTH AFRICAN INVENTIONS DEVELOPMENT CORP 19 April 1971 [17 March 1970] 23226/71 Heading BIC Apparatus for aerating liquid, such as sewage, comprises a disc 20 rotatable about an axis 22 and having projections 24 which converge in the direction of rotation and draw gas into the liquid during rotation of the disc when partly immersed in the liquid. In a modification (Fig. 6, not shown) the projections are not symmetrical and are arranged in rows which do not pass through the axis. In a further modification (Figs. 8-9 not shown) the projections are formed by triangular prisms fixed in holes and projecting on either side of the disc, the disc also having holes not containing prisms. The discs are of plastics or metal.</p> |
