Used Clarifiers & Thickeners

Clarifiers and Thickeners are found in water treatment processes.

The primary function of a continuous thickener is to concentrate suspended solids by gravity settling. Continuous thickeners are used in applications in which large quantities of solids must be concentrated or removed from large volumes of solid-liquid slurries (eg. municipal waste water treatment).

Continuous clarifiers are basically identical to thickeners in design and layout except that they are used in applications where the thickened pulp produced is smaller in volume and lower in suspended-solids concentration because of the large percentage of very fine solids.

Rectangular clarifiers use a “chain-type drag” raking mechanism. The drag moves the deposited pulp to a sludge hopper located at one end using scrapers fixed to endless chains.

Circular clarifiers are available in diameters of 3 to 130 meters (10 to 425 feet) and use a large diameter rake driven by a bridge mounted agitator.

Tilted plate clarifiers like the Lamella brand contain multiple plates inclined at 45 to 60 degrees from horizontal. Various feed methods are used so that the influent passes into each inclined channel with the solids having to settle a short distance in each channel before sliding down the base to the collection zone beneath the plates. The advantage of this type of clarifier is the compact design.