Circular Mechanical Clarifiers are settling tanks that are designed and developed to continuously remove the solids being deposited by sedimentation. Solid particulates and suspended solids from the liquid can be removed for the process of clarification. Concentrated impurities in the form of sludge is removed from the bottom of the tank, i.e., center well, and the particles that remain at the surface of the liquid are called scum, whose removal requires special removal arrangement. Circular in shape, it has scrapers that rotate around the central axis. The scraper blades in Circular Mechanical Clarifiers move slowly so as to minimize the re-suspension of settled solids.
- Waste water in the tank is given an optimal residence time. Larger sized tanks are favoroble when the flow rate through the tank is high.
- As the particles settles down, it is essential that the inlet and outlet velocities of water is reduced so that minimum turbulence is created. It promotes effective settling throughout tank volume. For this purpose, baffles and overflow weirs are used.
- This equipment can be used in potable water treatment, waste water treatment and mining sector for treating suspended solids in mining waste water.
- After the removal of sludge from the bottom of the tank, the remaining water is treated to be reused. Sometimes coagulant and poly-electrolyte are added for enhancing natural settling.