Clarifier design, sedimentation

Rising sludge can also be caused by internal solids overloading and hydraulic overloading to the secondary sedimentation. Poor sedimentation clarifier design and operation in terms of flow-through velocity, weir design, and so on are also possible causes. 

Sedimentation. This is a general term for an operation wherein suspended sulids are removed from a liquid by gravitational settling. The two major forms of sedimentation equipment are (I) thickeners, and (2) clarifiers. The term decanting also is sometimes used In designate sedimentation. 

Clarifier design has traditionally been based on the principle of dilute sedimentation. The design calculations of a clarifier include feed well design, sedimentation basin design (providing enough residence time for the separation), and solid flux (G). The other design parameters, such as the torque requirement and clarifier area, are similar to those of the thickeners, which have been discussed in the previous section (3.2.1). 

There are three basic designs for clarifiers (also known as "gravity clarifiers") solids-contact, inclined-plate settlers, and sedimentation. The advantages of each type of unit are ... 

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