DUST REMOVER

PURPOSE:To eliminate abnormal water level differences before and behind a dust remover by overloading by a method in which a flapper and a close holder for the flapper are provided on the outside of the opening of the upper horizontal part of a screen frame formed of flat plates, and a foreign matter- preventing fence is provided near the screen frame. CONSTITUTION:An opening 30 is provided near the screen 14 of the upper beam 15 of a screen frame 4, and a flapper 40 is rotationally attached to one end of the screen 14 side on the outside of the opening 30. A pair of comb like foreign matter-preventing fences 60 are provided in ploximity to each screen frame 4 connected by link chains. During usual operation, dust is collected by the bodies 14 of the screen frames 4 and discharged by the upper sprocket during inverting operation. At the time when great amounts of dust occurs, the flapper 40 is opened by water pressure to direct water flow to the opening 30. The water flow is controlled by the fences 60 and during the inverting operation, even dust collected by the screen bodies 14 and the bar row of the opening 30 is discharged.