Column-Supported Center-Drive Scraper

Column-Supported Center-Drive Scraper – Robust Sludge Removal for Large Clarifiers

 

The Column-Supported Center-Drive Scraper is engineered for circular primary and secondary clarifiers from 20 m to 60 m in diameter. A stationary central column anchors a full-span bridge; the epicyclic gear motor mounted on top rotates a rigid shaft that drives two or four truss-type scraper arms. Adjustable HDPE blades maintain 2–3 mm floor clearance, pushing settled sludge into a central hopper while surface skimmers convey scum to a peripheral trough.

 

The lower shaft runs in a replaceable bronze or polymer bearing located above the hopper, eliminating underwater seals and allowing inspection without tank drainage. Torque is continuously monitored by load cells; overload alarms and a shear-pin safeguard protect the drive train. Optional picket-fence attachments thicken sludge to 3–6 % solids, reducing downstream dewatering costs.

 

Delivered in pre-assembled modules, the unit is simply bolted to the cast-in-situ column and connected to power and sludge piping. With its high-torque capacity, low speed (0.01–0.03 rpm) and corrosion-resistant materials, the Column-Supported Center-Drive Scraper provides decades of reliable, energy-efficient sludge collection for large municipal sewage plants, industrial effluent clarifiers and waterworks sedimentation basins.