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Abstract: A computational fluid dynamic (CFD) model has been developed for the simulation of slag foaming on bath smelting slag (CaO–SiO2–Al2O3–FeO) by considering foam as a separate phase. The CFD model has been used to predict the foam height, bubble number density and the multiphase flow phenomena in the system. The height of foam is dynamically balanced by the formation of foam due to transformation of both gas and liquid into foam and its destruction due to liquid drainage and bursting of bubbles, transforming foam back to liquid and gas. The bubble break-up and coalescence were considered in gas–liquid dispersion whereas in the foam layer, the bubble coalescence due to film rupture was incorporated. A population balance modeling was used to track the number density of different bubble classes and fixed pivot method was used to discretize the population balance equation. The model predicted the foam height of the slag system (CaO–SiO2–Al2O3–FeO). The content of FeO was changed and its effect on the foam height predicted. The foaming index was calculated and the results from the model predict that the foaming index decreases with increase of FeO content in slag. The CFD model also predicts that the foaming index of a slag with Al2O3 is higher than that of slag without Al2O3. Dimensionless analysis was performed based on the model available in the literature to correlate the foaming index with the physical properties of the slag. The predicted results from the present study are in reasonable agreement with available experimental data. [Copyright &y& Elsevier]

Highlights: [•] A CFD model was developed with improved source term for bubble break-up and coalescence. [•] The Sauter mean diameter was in good agreement with the experimental data. [•] The velocity profile and time averaged axial liquid hold up conform to the available data in the literature. [ABSTRACT FROM AUTHOR]

Abstract: A combined experiments and mathematical modelling were carried out to study the kinetics of nonylphenol ethoxylation. Experiments were carried out in a well-stirred reactor used in an industrial research laboratory. The governing equations of the kinetic model were solved using . Results were validated against published kinetic data. The experiments and kinetics modelling were extended to account the presence of nitrogen in the vapour phase for a potassium hydroxide catalyzed ethoxylation of nonylphenol in a well-stirred reactor. The modelling results were successfully validated against the experimental data. This model has been successfully used () for optimizing the productivity of the existing alkoxylation reactors and can be used as a tool for the exploration and design of innovative new reactor systems. [Copyright &y& Elsevier]

Abstract: This is a pioneering paper that deals with the semi-steady-state liquid film thickness on a rotating drum partially submerged in liquid using CFD. The CFD predictions have been compared with both experimental results and analytical solutions. The liquid film thickness and the film rising on a circular curved wall were monitored for various rpm of the rotating drum. The 2D simulations were performed neglecting the end effects (assuming the rotating drum is very long). As the rotating drum speed was increased, the film thickness was found to increase at the film rising side and at the minimum film thickness point (top of the rotating drum). There was never been a steady-state condition reached, the opposite was expected as a wiper is used in the CFD calculation (same as the experimental investigation). The liquid that leaves the domain by the wiper (as outflow boundary condition) is forced to enter to the domain from far end to keep the level of the free surface constant. [Copyright &y& Elsevier]