| 摘要 |
<p>The sewage flows tangentially into a relatively shallow, flat-bottomed, concrete basin with a central discharge pipe for the water and a rotating bridge from which a curved scraper blade is suspended over the flat bottom. The curve is in the shape of a logarithmic spiral and the bridge rotates in the direction of liquid flow. At the edge of the bottom is a drain trap for the sand into e.g. an Archimedean screw separator. The centre drain has a weir and the scraper ends abut against this weir and the rim of the basin. Simple method of eliminating heavy particles to leave the lighter (e.g. scum) for subsequent processing plant.</p> |
