Experiments were carried out in geometrically similar vessels with diameters of 0.287, 0.495 and 1.1m respectively. Bubble diameter distribution was measured with a dual electric conductivity probe placed in the tanks. Gas holdup was measured by spillover method. Considering the coalescence of bubbles in the upper circulation region of the aeration stirred tank, introducing the concepts of turbulence decay and effective viscosity of gas-liquid system into this work, and taking into account the equilibrium between the surface energy of the bubbles and the energy supplied by agitation, mathematical models for bubble diameter and mean gas holdup were derived. The mathematical models were confirmed by experimental data.

When two small bubbles approach each other, a dimpled thin liquid film is formed between them. A model is developed for the dynamics of the thinning film with mobile interfaces, in which the effects of interfacial mobility and physical properties on the drainage and rupture of a dimpled liquid film are investigated. The model predicts the coalescence time, which is the time required for the thinning and the rupture of the liquid film, given only the radii of the bubbles and the required physical properties of the liquid and the surface, such as surface tension, London-van der waals constant, and surface diffusion coefficient. The predicted result is in agreement with the experimental results in the literature.

Theoretical considerations on diffusion modes of adsorbates in diffusion-cell adsorbers are being investigated. By studying the effects of the operating and model parameters on the response curves calculated by surface diffusion model and pore diffusion model, and noting the differences in the results, the following conditions are recommended for the prediction of the prevailing diffusion mode in diffusion-cell experiments λ≤0.1,BiB≥100,and N≥1 The theoretical prediction thus obtained checks well with experimental data taken from literature. New solutions are also presented for the surface diffusion model and the pore diffusion model with rectangular adsorption isotherm.

High speed microphotographic studies showed that fluid elements injected from a point source tended to exhibit slice-like and strip-like configurations rather than lamellar structure during the turbulent mixing of fluids with Sc〉〉1 . Based on this phenomenon a new micromixing model was developed. The model stated that micromixing was contributed by shrinkage deformation and molecular diffusion on a slab element surrounded by an infinite ambient fluid. Balance between the deformation and the diffusion resulted in an exponential increase in volume for the element. After a certain period of time t_m, the volumetric increase of the feed material would be confined by the development and extension of the turbulent spreading zone. Therefore, three successive downstream regions, with different controlling steps and segregation states, could be recognized. A simplified picture for the point source mixing was then drawn, which might serve as a basis for describing chemical reactions during turbulent mixing.

An integral description of chemical reactions taken place under mixing was formulated on the basis of the three-region model pictured in Part Ⅰ of this study. A mathematically simplified version of the model was developed. It was shown that the converted portion of the material in the dispersion region can be neglected provided that the initial concentration ratio of A and B was less than 0.1, and the effects of micro - and macromixing on the chemical reactions could be represented by two dimensionless numbers: Da and . The model was applied to two reacting systems: competitive-consecutive reactions and parallel reactions. Agreement between model prediction and experimental results demonstrated that the present framework, though in simplified form, is capable of describing reactive mixing without loss of any significant features of the process.

The paper presents a general retention formula for supercritical fluid chromatography at finite concentration. A new chromatographic rate theory based on the fugacities of solutes instead of concentrations is developed, thus relieving the restrictions of linear isothermal distribution and infinite dilution. An expression for retention values of a N component system including solvent is obtained by combining the rate theory with the mass balance equation of solutes in chromatography. It is shown that there are N-1 characteristic retention peaks for N components and the retention time can be calculated directly from the equilibrium properties of the components in both mobile phase and stationary phase at the given conditions. The theory can be reduced to the well known formula for infinite dilution and to the result of step-pulse theory in gas chromatography under low pressure at finite concentration. Supercritical fluid chromatography may eventually prove itself to be a useful reseach tool in the field of phase equilibrium and thermodynamic properties of supercritical fluid system.

Hydrodynamics and mass transfer experiments were carried out in a 0.1m diameter extraction column with a new type (FG) stack packing developed recently in our laboratory.The working systems used were n-Butano1/Succinic acid/water with low interfacial tension of 1.50×10-3N·m-1 and 30% TBP (Kerosene)/Acetic acid/water with interfacial tension of 10.0×10-3N· m-1. Experimental results obtained indicated that (FG) stack packed extraction column was proved to possess high throughput capacity and excellent mass transfer efficiency. Replacing rotary discs with FG packings in a lube furfural extraction tower was quite success with significant economical benefits being claimed.