Suspended Center-Drive Sludge Scraper

Suspended Center-Drive Sludge Scraper – Compact, Bearing-Free Clarifier Sludge Removal  

 

The Suspended Center-Drive Sludge Scraper is purpose-built for circular primary and secondary clarifiers up to 18 m diameter. A single epicyclic gear motor, mounted on a half-bridge that spans the tank center, hangs a hollow stainless-steel shaft into the water. Two cantilever scraper arms, fitted with replaceable neoprene blades, are bolted to the lower end of the shaft; no underwater bearings or bushings are required. Rotating at 0.01–0.05 rpm, the arms sweep the 1:10 conical floor and push settled sludge into a central hopper, where it is withdrawn by static head or a suction pipe. Simultaneously, a surface skimmer blade directs floatables to a peripheral scum trough.  

 

 

Because the entire drive train is located above water, maintenance is limited to annual gearbox oil changes and blade inspection, eliminating the need for dewatering or confined-space entry. Torque overload is protected by electronic load cells or a mechanical shear-pin that triggers an alarm and shuts down the motor. The unit is delivered pre-assembled; installation simply involves bolting the bridge to the wall and connecting power and sludge lines. With its bearing-free design, low energy draw (≤ 0.37 kW for a 12 m tank) and minimal civil works, the Suspended Center-Drive Sludge Scraper offers municipalities and industrial plants a cost-effective, long-life solution for continuous sludge collection in small to medium-sized circular clarifiers.