Improvement on Lamella Tube Settler
The newly developed settler is an application of the lamella settler, which arranges inclined parallel plates in the vertical direction, contrary to the usual horizontal arrangement. Tube settlers are commonly used in rectangular clarifiers to increase the settling capacity by reducing the vertical distance a suspended particle must travel. High efficiency tube settlers use a stack of parallel tubes, rectangles or flat pieces separated by a few inches (several centimeters) and sloping upwards in the direction of flow. This structure creates a large number of narrow parallel flow pathways encouraging uniform laminar flow .
These structures work in two ways:
They provide a very large surface area onto which particles may fall and become stabilized.Because flow is temporarily accelerated between the plates and then immediately slows down, this helps to aggregate very fine particles that can settle as the flow exits the plates.
Structures inclined between 45° and 60° may allow gravity drainage of accumulated solids, but shallower angles of inclination typically require periodic draining and cleaning.
Tube settlers may allow the use of a smaller clarifier and may enable finer particles to be separated with residence times less than 10 minutes.
Typically such structures are used for difficult-to-treat waters, especially those containing colloidal materials.
Tube settlers capture the fine particles allowing the larger particles to travel to the bottom of the clarifier in a more uniform form. The fine particles then build up into a larger mass which then slides down the tube channels. The reduction in solids present in the outflow allows a reduction in the clarifier footprint when designing.