Influence of Distributions of Specific Energy Dissipation Rate on Mass-Transfer Efficiency in Apparatus with Liquid-Phase Media

A theoretical analysis of the influence of the distribution of the local specific energy dissipation rate on the specific surface area of phase contact and the superficial and volumetric mass-transfer coefficients in devices with heterophase processes and a liquid continuous phase, as well as on the quality of mixing in devices with homophase reactions in the liquid phase, is performed. It is shown that the average value of the specific energy dissipation rate for the volume of the apparatus is not a complete criterion for assessing the useful effect, since it does not take into account, on the one hand, the local level of energy dissipation in the active zones, and on the other hand, the features of the flow structure and the local residence time in the active zones, depending on the geometry of the apparatus and the method of introducing energy into it. Limiting cases are discussed: a non-uniform distribution of energy in the presence of a zone of small volume with a high dissipation rate and an ideally uniform distribution of energy throughout the entire volume of the apparatus. In the first case, a significant portion of the volume is used inefficiently; in the second case, an excessive amount of energy is expended. In this regard, the concepts of dosed distributed energy input for long-term processes and maximum concentration of energy in a microvolume for fast-flowing processes are considered.