Screen for edge of overflow weir

摘要

Screening apparatus comprises a screening element disposed adjacent a weir edge 12 of a channel in which a screenings/liquid mix flows normally beneath the level of the screening element, the screening element being provided internally of the channel and presenting a separation surface to the flow when swollen to a level at which it comes into contact with the screening element, so that any liquid passing over the weir edge has first passed through the screening element. As described the screening element is formed from a plurality of part-cylindrical plates 6 linked together into a closed loop 10 which passes around a a pair of sprockets 26, 28 one or more of which may be driven when the flow contacts the plates. A driven brush 34 may clean the plates and return screenings into the flow. The plates may have holes 6 mm. in diameter. The screening element may extend halfway across the flow channel and its open side may be closed by a fixed plate. In an alternative arrangement the brush 34 is dispensed with.