A clarifier tank having a center column is provided with a center-driven bottom rake mechanism for settled sludge removal, a rotating scum rake mechanism comprised of pipes with longitudinal openings for scum removal via the center column, the rake mechanisms rotating in the same or opposite directions at different speeds, and submerged effluent pipes projecting from the sidewall of the tank toward the center of the tank to drain the clarified sewage into an effluent launder exterior of the tank.
The present invention provides a sludge or the like scraping and collecting apparatus. This apparatus has a whole structure more simplified and can realize a cost-down. Further, it is advantageously installed.The scraping and collecting apparatus comprises a carriage having a main body formed from a single long member constant in section in a front and rear direction. The carrier main body has a front end and a rear end provided with sludge scrapers. These front and rear sludge scrapers are adapted to be able to simultaneously and interlockingly move by a pulling and conveying means through a longitudinally and interlockingly moving member which advances and retreats in parallel with the carriage main body.
It is necessary in sewage-treatment devices to remove from the waste waters to be cleaned besides the sediment mixtures also impurities which are on the surface of the waste water. This floating matter is according to the invention continuously conveyed into an intermediate container by means of a worm conveyor sweeping over the waste water, from which intermediate container the conveyed matter is discontinuously pumped off.
A clarifier in a sewage treatment process includes efficient scum removal within the influent well, with discharge of the scum and other floatables as a dedicated waste stream separate from return activated sludge and biological scum collected in the clarifier. In one embodiment the scum removal system has an inclined scum ramp at the leading edge of each of two scum removal troughs, with a forward edge below the liquid surface. The scum troughs pass through an arc of rotation, building up scum, which accumulates and is pushed forward by the scum ramp. At least once per revolution, the moving scum ramp approaches a stationary scum surface blade that extends partially under the liquid surface and provides a barrier to the forwardly pushed scum. This blade contacts and slides up the ramp, sweeping the scum up the ramp and into the scum trough. The described arrangement greatly reduces the amount of free water with the collected effluent scum as compared to the typical designs and permits scum and gross floatables from the influent well to be trapped and contained and discharged and treated separately.
A clarifier in a sewage treatment process includes efficient scum removal within the influent well, with discharge of the scum and other floatables as a dedicated waste stream separate from return activated sludge and biological scum collected in the clarifier. In one embodiment the scum removal system has an inclined scum ramp at the leading edge of each of two scum removal troughs, with a forward edge below the liquid surface. The scum troughs pass through an arc of rotation, building up scum, which accumulates and is pushed forward by the scum ramp. At least once per revolution, the moving scum ramp approaches a stationary scum surface blade that extends partially under the liquid surface and provides a barrier to the forwardly pushed scum. This blade contacts and slides up the ramp, sweeping the scum up the ramp and into the scum trough. The described arrangement greatly reduces the amount of free water with the collected effluent scum as compared to the typical designs and permits scum and gross floatables from the influent well to be trapped and contained and discharged and treated separately.
