The Decanter Centrifuge is used for continuous separation of 2 or 3 phases: liquid-solid, liquid-liquid-solid.
The heart of the machine is the rotating assembly, consisting of bowl and scroll.
They both rotate at close to similar speeds, e.g. 2,500 rpm, however they do require a differential speed of some tens of rpm to allow the scroll to discharge the solids.
The machine is fed through feed pipe in the center of the scroll.
There are many different machine configurations with variables in bowl cone angle, scroll flight pitch and lead angle. This machine can be fed at low feed solids concentrations.
The Screen Bowl Centrifuge is similar to decanter, but in addition to sedimentation, the machine has a final filtration screen section, which explains the name.
This machine can be fed at low feed solids concentration and allows solids washing and final filtration dewatering.
The machine is usually not used for solids below 150 uM due to final screen section.
Pusher Centrifuges are commonly used for crystalline products. Separation takes place on filtration screen or wedge wire. Solids are conveyed by reciprocating pusher plate.
Machine cannot be fed at low solids concentration, on the other hand allows good solids cake washing and final dewatering.