Fluid mechanics of liquid–solid fluidization in the centrifugal field

The flow pattern in the bed and in the freeboard of a liquid–solid fluidized bed operated in the centrifugal field was investigated. Centrifugal accelerations between 20 and 500 times the gravity were acting on the particles. Both the radius‐dependent centrifugal acceleration and the Coriolis force were found to strongly influence the fluid dynamics. A CFD simulation of the liquid flow in absence of particles showed high tangential velocities which were two orders of magnitude higher than the radially oriented fluidizing velocity. Measurements with a 1 m diameter rotor confirmed the calculations and revealed that also the liquid–solid fluidized bed is moving in the tangential direction although with lower speed than the pure liquid. The bed expansion under these conditions can be described by a Richardson–Zaki type correlation.