Rotary Decanting Scum Pipe with High Hydro-Mechanical Performance
Application
The rotary scum pipe is specially designed for use in sedimentation tanks to remove floating scum, grease, and oil from the upper liquid surface.
Design Overview
The rotary scum pipe is developed based on the operating principle of a rotary decanter. It offers excellent hydraulic and mechanical performance and can effectively remove floating scum and oil from the clarified liquid surface of a sedimentation tank.
The equipment provides efficient scum removal, sensitive and reliable operation, a compact structure, and convenient operation and management.
Structure and Technical Requirements
The rotary scum pipe mainly consists of:
- Manual drive mechanism
- Lifting mechanism comprising a screw assembly and universal guide rods
- Hinged linkage mechanism
- Outlet float
- Underwater bearings
- Scum collection and discharge pipe
Through the drive mechanism and universal guide rods, the linear movement of the screw assembly is converted into the rotary movement of the overflow weir and discharge pipe, allowing the floating scum to be skimmed and discharged.
The float is manufactured with high dimensional accuracy and structural rigidity. It is reliable, durable, and neatly finished.
The complete unit shall operate smoothly and flexibly, without abnormal noise or leakage.
Operating Process
The length of the scum pipe is matched to the dimensions of the sedimentation tank. Multiple weir openings, each with a central angle of 60°, are arranged along the length of the pipe.
The pipe shall have sufficient strength and rigidity, with the following dimensional tolerances:
| Straightness tolerance |
within ±5 mm |
| Length tolerance |
within ±3 mm |
The slotted scum pipe can rotate around its longitudinal axis. During operation, the slot is lowered below the floating oil or scum layer. The hydrostatic head causes the oil, scum, and surface liquid to flow into the pipe and be discharged outside the tank.
Under normal standby conditions, the pipe slot faces upward. When the skimming cycle begins, the drive mechanism rotates the pipe downward until the slot enters the floating scum or oil layer.
After the skimming operation is completed, the drive mechanism reverses and returns the pipe to its standby position.
Main Equipment Performance Requirements
- While the clarified supernatant is being discharged, the rotary scum pipe shall be capable of removing the floating scum layer according to the actual water level.
- The rotary scum pipe shall operate without disturbing or dispersing the floating scum layer.
- During the scum removal cycle, the equipment shall operate in a controlled, smooth, and reliable manner and shall have a long service life.
- The scum collection trough shall be designed with a scientifically optimized and practical profile to minimize hydraulic resistance.
- The operating mechanism of the rotary scum pipe shall be equipped with travel-limit controls to prevent mechanical damage. The drive mechanism shall operate steadily and reliably.
- All underwater rotating components shall have effective sealing. The seals shall have a long service life and be easy to inspect and replace.
