Gas-liquid membrane contactors offer several practical advantages including high surface area per unit volume; independent control of gas and liquid velocities without any flooding, loading, weeping, or foaming, pre-determined gas–liquid interfacial area, membrane modules, capability of linear scale-up; low corrosion problems, and low operation and capital costs. Two common types of membrane co...

An experimental study has been carried out to characterize bubble formation, growth, and detachment mechanisms in a stagnant liquid column. Both bubble frequency and bubble detachment size were measured in different gas flow rates, injector diameters and orientations, submergence height, and liquid properties. Experiments were performed for air injection flow rate ranges between 200 mlph and 12...

A novel multiple-airlifting membrane bioreactor is built with four sintered stainless steel tubular filters as the risers and downcomers. This work investigates the hydrodynamics including gas holdup, liquid velocity, liquid circulation and mixing times by aerating different number of risers (one to three) at superficial gas velocities of 0.02–0.07m/s The mass transfer phenomena, including oxyg...

In a liquid containing gas bubbles the speed of sound is less tham that in each phase separately. Using the equations of motion for a hõmogeneous liquid containing gas bubbles it is shown that the dominating attenuation of an infinitesimal disturbance is that due to the second viscosity. In the propagation of a finite compressive disturbance an expression for the time required for the disturban...

Abstract:  In this study, the change in the crystalline structure of gas hydrate was predicted for ternary mixture of methane-ethane-water. For this purpose, the tangent plane distance (TPD) minimization method was used. First, the calculations were performed for the binary mixtures of methane-water and ethane-water as the gas and liquid phases. The results show that for a binary mixture of th...

during recent years oil products has decreased because of growing population and increasing demand to oil products and decreasing of crude oil extraction at compare to export. however, to achieve suitable levels of production, the use of improved technologies should be considered. another way to prevent the evaporation and leakage from oil storage tanks and their products are using of storage t...

A three dimensional transient model fully coupling the two phase flow, species transport, heat transport, and electrochemical processes is developed to investigate the liquid water formation and transport in a polymer electrolyte fuel cell (PEFC). This model is based on the multiphase mixture (M2) formulation with a complete treatment of two phase transport throughout the PEFC, including gas ch...

The goal of mechanical ventilation is to maintain adequate gas exchange by opening and stabilizing alveolar units with minimal detriment to the pulmonary and circulatory systems. The optimal ventilatory strategy may be difficult to achieve, especially in patients with respiratory failure. Total liquid ventilation is a process whereby a liquid perfluorocarbon (PFC) replaces both the functional r...

Density functional theory and computer simulation are used to investigate sedimentation equilibria of colloid-polymer mixtures within the Asakura-Oosawa-Vrij model of hard sphere colloids and ideal polymers. When the ratio of buoyant masses of the two species is comparable to the ratio of differences in density of the coexisting bulk (colloid) gas and liquid phases, a stable "floating liquid" p...

Thermodynamics and kinetics of vaporization of lead sulfide from typical copper-smelting mattes of commercial interest are investigated in the temperature range 1388 K to 1573 K by vapor transport technique and plasma arc spectroscopy. The total mass of the dominant vaporizing species PbS that leaves the matte is described by the Newman's numerical solution to the second Fick's law combined wit...