| 摘要 |
<p>A vortex grit trap has a tank (11) of circular cross-section including a separation zone (12) having an inlet and an outlet for liquid flow to and from the tank, and in which liquid is circulated about a longitudinal axis of the tank. A grit collection zone (13) is positioned under the separation zone (12) and circular tank divider (18). The divider defines a boundary between the separation and collection zones of the tank and is of a smaller diameter than the adjacent region of the tank so as to define an annulus (23) through which grit passes from the separation zone to the collection zone. In use the trap generates a cloud of gas bubbles, via means (18, 22, 25) which migrate upwards through substantially the whole of the annulus. Grit passing from the separation zone into the collection zone passes through the upwardly moving bubble cloud in the annulus. Organic solids within the grit to be displaced and move upward with the bubbles into the flow within the separation zone while the grit passes through the bubble cloud in the annulus and into the collection zone.</p> |
