Scum collection and removal from clarifiers water surface can be effectively facilitated via a radial surface scum scraper with a hinged skimming mechanism and self flushing scum box.
The radial scum scraper collects scum from the water surface and directs it toward the periphery of the tank. The scum comes off the radial scraper and is caught in a dam made up of the pivoted skimmer blade, the hinged skimmer blade and the peripheral scum baffles. When the hinged skimmer proceeds up onto the scum box the trapped scum is dumped through the scum box.
The scum box outlet pipe is equipped with a mechanically activated reflux valve which has an extension arm fitted to the valve flap spindle. As the bridge passes over the scum box, an actuating angle mounted under the bridge opens the scum valve by striking an extension of the valve spindle. This allows the collected scum along with a quantity of settled effluent to be flushed through and exit the tank.
The inside of the peripheral scum baffle is wiped continuously every revolution, by a rubber wiper attached to the hinged skimmer.