Abstract: Arrangement for the treatment of fluent, thin and highly viscous media, particularly for the fermentation of micro organisms, for mixing, pumping and the dissipation of the medium. The arrangement is based on a novel principle of bladeless mixing and pumping of fluent media of any kind and density. The main part of the arrangement is a hollow rotor with a bottom with at least a single inlet opening in the bottom. The rotor is rotated at a speed at which the treated medium due to centrifugal forces proceeds from one end of the rotor to the other one. The medium is discharged from the rotor through one or more outlet openings in the sides or in the top of the rotor; the medium is either only raised, or is also dissipated below or above the level of the fluent medium.

Abstract: The method of circulation according to the invention consists in causing a part of the liquid part to rotate whereby centrifugal forces causes the rotating part of the liquid phase to form a rotating vortical liquid spindle that exerts a suction effect. The liquid to be circulated is then pumped into the spindle by suction, passes through a cavity destined for deposition of solid phase, said cavity being positioned in the space of the spindle, whereafter the liquid passes to the upper part of the spindle and is drawn back into a liquid phase container.