Hydrocyclones are devices for separating solids and liquids from liquids that do not mix (emulsions) or do not dissolve in the carrier medium (suspensions).
The tangential introduction of the suspension via the inlet nozzle into the cyclone head creates a rotating flow in which the resulting centrifugal acceleration (centrifugal force) concentrates the solids on the wall of the cyclone. The solids slide down the wall and are discharged via the underflow nozzle. The liquid tends to remain in the core area of the cyclone, loses speed and is discharged upwards via the overflow nozzle. Very fine particles remain in the liquid.
It is expedient to use cyclones to separate particles between 0.5 mm and 5 µm.
Compared to gravimetric sedimentation, a 100 to 1000 times faster separation can be achieved with a correspondingly high inlet pressure in cyclones.
In order to increase the throughput capacity, several cyclones are interconnected in a ring battery or multi-cyclone system.
By connecting cyclones in series, both a higher degree of separation and the separation of finer particles can be achieved.