Collect. Czech. Chem. Commun. 1981, 46, 2032-2042

Process characteristics of screw impellers with a draught tube for Newtonian liquids. Time of homogenization

Pavel Seichter

Research Institute of Chemical Equipment, 638 00 Brno


A conductivity method has been used to assess the homogenization efficiency of screw impellers with draught tubes. The value of the criterion of homochronousness, i.e. the dimensionless time of homogenization, in the creeping flow regime of Newtonian liquids is dependent on the geometrical simplexes of the mixing system. In particular, on the ratio of diameters of the vessel and the impeller and on the ratio of the screw lead to the impeller diameter. Expression have been proposed to calculate the mixing times. Efficiency has been examined of individual configurations of screw impellers. The lowest energy requirements for homogenization have been found for the system with the ratio D/d = 2.