Conventional Clarifier design can be quite large. The circular clarifier is similar to the circular thickener but is built with lighter rakes since the underflow slurry is less concentrated.
Spirals or rake at the bottom consolidates the thickened solids and moves them towards a central outlet where they are pumped out. There may also be a skimmer to push surface scum to a discharge box.
The clarified liquid overflows a peripheral or radial weir at the top. Conventional clarifier may be operated with or without flocculants.
The size can be reduced by improving flocculation by better mixing or by growing the flocs. The overflow clarity can also be improved by ensuring efficient flocculation.