Sludge suckers (suction scrapers) are designed to remove activated sludge from the bottom of secondary clarifiers in biological wastewater treatment systems. SO series suction scrapers are manufactured to fit radial clarifiers of any diameter.
Design and Operating Principle
The secondary radial clarifier suction scraper consists of a central support 1, a walkway bridge with a platform 2, a drive trolley 3, a sludge discharge launder 4, and a scraper-suction system comprising a series of suction headers 5 with scrapers 6, a rotation chamber 7, a central bearing assembly 8, and an influent well (flow dissipator) 9. A coping cleaning brush 10 is provided to clear snow from the clarifier wall. An overflow weir and launder cleaning brush 11 is designed to clean the V-notch weir and the peripheral channel.
The bridge 2 is driven (rotated) by an electric motor through a gearbox via the wheels of the drive trolley 3. The wheels travel along a circular track 12. As it rotates, the bridge 2 moves the suction headers 5 and scrapers 6. Driven by hydrostatic pressure, the activated sludge is fed into the sludge discharge launder 4, then flows into the rotation chamber 7, and is finally directed into the sludge discharge pipe passing inside the central support 1. Upon completion of a full revolution of the bridge 2, the operating cycle repeats.
Specifications
| № | Parameter | Value |
|---|---|---|
| 1 | Sedimentation tank diameter, m | 12...54 |
| 2 | Sedimentation tank depth, m | 2...6 |
| 3 | Rotational speed, rpm (rev/h) | 0,5...4 |
| 4 | Number of gear motors per unit, pcs. | 1-2 |
| 5 | Motor Power, kW | 0,37...0,75 |
| 6 | Frequency, Hz | 50 |
| 7 | Voltage, V | 380 |
| 8 | IP Rating | IP69 |
| 9 | Material | Structural Steel or Stainless Steel Grades AISI 304, AISI 321, AISI 316 |
Automation
The suction scraper is equipped with an automatic drive interlock. In the event of an emergency, the drive is deactivated, a fault alarm is triggered, and a message regarding the equipment shutdown is displayed on the operator's interface.
Equipping the suction scraper with a VFD-controlled (Variable Frequency Drive) electric motor allows for adjusting its rotation speed. It also enables the integration of the equipment suite into a unified system with a centralized control hub and connection to a remote monitoring (telemetry) system. Suction scraper operation can be managed both remotely and via a local control panel.
Features
- Visual Process Monitoring. The open-top discharge launder allows for visual inspection of the sludge collection process and enables cleaning of the suction headers and launder without draining the clarifier.
- Individual Suction Control. Features a manual adjustment system for the suction header orifice, allowing the operator to regulate flow based on visual feedback.
- Self-Adjusting Scraper System. The scrapers automatically adapt to irregular floor profiles, ensuring thorough cleaning of the clarifier bottom.
- Direct Sludge Transfer. Ensures direct flow of sludge from the launder to the central support.
- Automatic Flow Regulation (Optional). The suction scraper can be equipped with a gate valve in the sludge collection launder to automatically adjust sludge discharge based on diurnal variations in wastewater inflow.
- Dual Launder Configuration (Optional). Can be equipped with two discharge launders and suction headers at different heights, significantly increasing efficiency and allowing for wide-range capacity adjustment.
- Anti-Slip Flooring. The bridge and service platform are equipped with anti-slip grating to ensure personnel safety.
- Reliable Power Supply. Power is delivered to the center of the clarifier via a specialized power supply mast.