| 摘要 |
<p>Grit is separated from sewage in two stages (Fig. 1), the first comprising a settling tank from whose sump a liquid mixture of settled grit and organic contaminants is pumped to the inlet end of a second stage, which comprises an elongate inclined trough in which the grit settles while the organics are carried along with the liquid flow. The trough 17 may be adjustably inclined, with flow uphill or downhill or horizontal. In Fig. 6 the liquid flows out of the trough to the left of baffle 28, but after some grit has accumulated the flow is stopped and the trough is tilted, pulling its outlet end to the right of baffle 28. The grit is then flushed or scraped out. In Figs. 7, 8 the trough is fixed and grit removed by blades on an endless conveyor or by a screw device lowered into the trough when required. in Fig. 9 grit is flushed from a tilted trough into a hopper with an inclined screw conveyor. The trough may be vibrated in use. <IMAGE></p> |
