An interfacial shear rheometer for stressand strain-controlled measurements at liquid interfaces is outlined. Experimental data are reported for the surfactant sorbitan tristearate on κ-carrageenan subphases. A setup combining interfacial rheometry with Brewster-angle Microscopy for realtime imaging of the interface is presented. INTRODUCTION Dynamic processes involving deformable fluid interfa...

In this paper we present a new method for the production of bubble-liquid suspensions ~from now on BLS! composed of micron-sized bubbles and with gas to liquid volume ratios larger than unity. We show that the BLS gas fraction l5Qg /Ql , being Qg and Ql the flow rates of gas and liquid, respectively, is controlled by a dimensionless parameter which accounts for the ratio of the gas pressure ins...

Almost all available literature correlations to predict the volumetric gas /liquid mass transfer coefficient, kLa in agitated reactors are systemsor operating conditions-dependent. In this study, two back-propagation neural networks (BPNNs), one dimensional and one dimensionless were developed to correlate kLa for numerous gas /liquid systems in both surface-aeration reactors (SAR) and gas-indu...

The mass transfer across a sheared gas-liquid interface strongly depends on the Schmidt number. Here we investigate the relationship between mass transfer coefficient on the liquid side, kL, and Schmidt number, Sc, in the wide range of 0.7 ≤ Sc ≤ 1000. We apply a three-dimensional semi direct numerical simulation (SEMI-DNS), in which the mass transfer is solved based on an approximated deconvol...

The effects of different parameters on the hydrodynamics of trickle bed reactors were discussed for Newtonian and non-Newtonian foaming systems. The varying parameters are varying liquid velocities, gas flow velocities and surface tension. The range for gas velocity is particularly large, thanks to the use of dense gas to simulate very high pressure conditions. This data bank has been used to c...

Abstract Experimental investigations were performed on the hollow-cone spray of viscous liquids in high-pressure gas environment, aiming to obtain fundamental knowledge which was indispensable to survey the applicability of non-conventional new liquid fuels for the gas-turbine power-plant. Test liquid employed were water, diesel fuel, palm methyl ester (PME) and silicone-oil #10. The ambient ga...

Frictional resistance across rough surfaces depends on the existence of slip on the liquid-gas interface; therefore, prolonging the existence of liquid-gas interface becomes relevant. In this work, we explore manipulation of the cavity shape in order to delay the wetting transition. We propose that liquid-driven vortices generated in the air cavity dissipate sufficient energy to delay the Cassi...

In a gas-liquid stirred reactor, gas tends to accumulate in low-pressure regions behind the impeller blades. Such gas accumulation forming so-called gas cavities, significantly alters impeller performance characteristics. We have computationally investigated gas-liquid flow generated by a Rushton turbine. Rotating Rushton turbine generates trailing vortices behind the blades, which enhance the ...

The purpose of the present paper is to develop light beam method to measurement of interfacial area in a rectangular gas-liquid bubble column. Total interfacial area can be determined in bubble column filled by transparent liquid by light transmission method. According to pervious researches, the fraction of parallel light is function of interfacial area and optical path l...