Energy Dissipation Rate Distribution in Mixing Vessels and Its Effects on Liquid-Liquid Dispersion and Solid-Liquid Mass Transfer

Investigation of micromixing in stirred tank reactors using parallel reactions

“…1, 1994 51 where 0.25 < d/D < 0.60. Okamoto et al (Okamoto et al, 1981) also correlated the results of Sato et al (Sato et 1970) for 0.25 < d/D < 0.70. Their correlation included the data point of d/D = 0.7.…”

Influence of Impeller Type on the Bubble Breakup Process in Stirred Tanks

“…Verschuren et al give a typical value of 7.3 times the mean energy ε in the breakup region . Okamoto shows a value of 11ε, whereas Zhou reports several values for different impellers from 8 to 12ε . Wu et al and Lee et al show values up to 25ε. , The use of the maximum energy instead of the mean energy to study the bubble mean size of dispersions has already been supported by the results from Parthansarathy et al , who found that the bubble mean size of the bubbles generated at the swept volume of the impeller was maintained across the tank.…”

“…Verschuren et al give a typical value of 7.3 times the mean energy ε in the breakup region. 49 Okamoto 55 shows a value of 11ε, whereas Zhou reports several values for different impellers from 8 to 12ε. 51 Wu et al and Lee et al show values up to 25ε.…”

“…57 The term δ, eq 30, although empirical, represents the contribution of different breakup mechanisms to the developing of dispersions as a result of the input power of the impeller. So, it is possible to use the values of We c and ε max proposed by some authors 51,53,55 to explain the physical meaning of δ. Figure 16 plots δ vs We c Two limiting cases can be described regarding the breakup of the bubbles and its contribution to the development of dispersions.…”

Solids Settling Velocity and Distribution in Slurry Reactors with Dilute Pseudoplastic Suspensions

“…The microscale λ was calculated on the basis of average power consumption per unit mass. In view of the two order of magnitude variation of the local dissipation rate in a stirred tank, − this represents a remarkable simplification that calls for improvement and refinement. Despite this weakness, the use of a settling velocity reduced with respect to the terminal onecalculated with the mentioned correlation or its variantsallowed the experimental solids concentration profiles obtained under different operating conditions in equipment of various geometries to be matched with those calculated with simple fluid dynamic models ,− and CFD. − On the contrary, use of the uncorrected terminal settling velocity produced anomalous results. , …”