Mixing vessel flow field

A qualitative picture of the flow field created by an impeller in a mixing vessel in a single-phase liquid is useful in establishing whether there are stagnant or dead regions in the vessel, and whether or not particles are likely to be suspended. In addition, the efficiency of mixing equipment, as well as product quality, are influenced by the flow patterns prevailing in the vessel. 

Brucato A, Ciofalo M, Grisafi F, Micale G (1994) Complete Numerical Simulation of Flow Fields in Bathed Stirred Vessels the Inner-Outer Approach. Eight European Conference on Mixing, Cambridge (ISBN 0852953291)... 

Luo JY, Gosman AD, Issa RI, Middleton JC, Fitzgerald MK (1994) Full flow field computation of mixing in baffled stirred vessels. Trans IChemE 71(A) 342-344... 

While attempts have been made to assign axial dispersion coefficients to the gas flow in fluidized beds or to represent the flow field in terms of a series of well-mixed vessels, none of these methods is really satisfactory. Perhaps the most promising approach to the problem of gas flow patterns is provided by a bubbling model [47]. 

High turbulence is required for efficient mixing this is created by the vortex field which forms behind the blades. For all the gas to flow through this region it must enter the vessel close to and preferably underneath the disk hence it is recommended that spargers should always be nearer, about a distance of DJ2 below the agitator, where D( is the impeller diameter. 

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