sieve trays are widely used in the gas- liquid contactors such as distillation and absorption towers. in this article, a three-dimensional, two phase cfd model using euler-euler framework was developed to simulate a distillation tower with two sieve trays. hydrodynamic simulation of air and water system in different rates of gas phase was carried out and velocity distribution parameters, clear ...

gas-lift pumps are devices for lifting liquid phase incorporating the gas phase to be injected in the bottom of liquid column. they are widely used in various industrial applications such as oil extracting in petroleum industries. gas-liquid flow being the main part of the flow through these systems, flowing in vertical pipes of gas-lift pumps has different regimes namely bubbly, slug, churn an...

A lattice Boltzmann method which can simulate droplet dynamics on partial wetting surface with large liquid-gas density ratio is proposed. The interaction between the fluid-fluid interface and the partial wetting wall is typically considered. Using the method, the dynamics of liquid drops on chemically heterogeneous surfaces are numerically simulated. The corresponding mechanisms including drop...

Vanadium phosphorus oxides (VPO) has been applied as a heterogeneous catalyst in gas phase oxidation reactions and its application is very limited in liquid phase. In this study a series of cobalt-doped vanadium phosphorus oxides (VPO-Co) catalysts with different loading of Co (0.01-1.0 mol ratio of Co/V) were prepared. Oxidation of benzyl alcohol was studied in the liquid phase over VPO and VP...

Sieve trays are widely used in the gas- liquid contactors such as distillation and absorption towers. In this article, a three-dimensional, two phase CFD model using Euler-Euler framework was developed to simulate a distillation tower with two sieve trays. Hydrodynamic simulation of air and water system in different rates of gas phase was carried out and velocity distribution parameters, clear ...

Bubble columns are gas- liquid contactors that are widely used in chemical and bio- chemical industries. High mixing that result in high heat and mass transfer rates are amongst their advantages. Heat transfer in a bubble column having a bundle of heaters investigated and the variation of heat transfer coefficient with variation in heaters pitch to diameter ratios in a bundle of heaters reporte...

in order to increase the rate of gas absorption, chemical reaction in the liquid phase is considered. the purpose of this paper was to simulate gas absorption process by a liquid film over a spherical packing incorporating eddy viscosity and diffusivity. second order chemical reaction for two different cases (fast and slow) were considered. the system partial differential equations obtained was...

Two-phase flows with high density ratio and high shear are known to be challenging to simulate. In this work, two strategies for improving the robustness of high density ratio two-phase flow simulations are investigated. The first method, based on Rudman’s work with the volume of fluid method (Rudman 1998), aims at improving the consistency between interface and momentum transport by using the ...

Molecular dynamics simulations of Lennard-Jones systems are performed to study the effects of dissolved gas on liquid-wall and liquid-gas interfaces. Gas enrichment at walls, which for hydrophobic walls can exceed more than 2 orders of magnitude when compared to the gas density in the bulk liquid, is observed. As a consequence, the liquid structure close to the wall is considerably modified, le...

In recent years, there has been a growing interest in bioreactors, which utilise immobilised enzymes and cells in order to improve the bioprocess productivity. In fact, there are many specific advantages of the immobilised systems in comparison with the more conventional systems, in which the bio-agents are suspended freely (cells) or dissolved in a bulk aqueous medium (enzymes): • high cell de...