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Showing papers in "Chemical Engineering Science in 1993"



Journal ArticleDOI
TL;DR: In this paper, the roles of the surfactant are considered, i.e. lowering the interfacial tension and preventing recoalescence, in relation to the time scales of various processes occurring.

841 citations


Journal ArticleDOI
TL;DR: An extensive survey of the results of possibly all available experimental and theoretical studies on gas entrainment by plunging liquid jets has been presented in this paper, where the following aspects of the phenomenon are thoroughly discussed: mechanisms, conditions, conditions of the onset of entrained gas, characteristics of the resulting bubble dispersion, and mass transfer.

310 citations


Journal ArticleDOI
TL;DR: In this article, the present status of estimating gas hold-ups, mass transfer and mixing coefficients of bubble columns is reviewed, and specific recommendations are given for their application, based on proven correlations and recent improvements.

252 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of dissolved salts on the solubilities of gases were analyzed based on a comprehensive set of literature data for the temperature of 298.2 K. A new empirical model was suggested which, at no increase in the number of adjustable parameters, described the data with a lower standard deviation than previously suggested models.

235 citations


Journal ArticleDOI
TL;DR: A critical review on the mass transfer characteristics of gas?liquid slurry reactors is presented in this article, where the authors discuss the influence of the presence of solid particles on the following mass transfer parameters: volumetric gas? liquid mass transfer coefficients (kLa, kGa), liquid-side mass transfer coefficient (kL and kS), and specific gas?slurry contact area (a).

217 citations


Journal ArticleDOI
TL;DR: In this article, the authors consider transport in ordered and disordered rigid porous media and define order and disorder in terms of geometrical integrals that arise naturally in the method of volume averaging.

216 citations


Journal ArticleDOI
TL;DR: A quantitative model describing the flow properties of dissolution patterns, called “wormholes”, is described, which describes both linear geometries for which patterns are nonfractal, and the cylindrical case yielding patterns of fractal geometry, with good accuracy and without any adjustable parameters.

215 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that tip-streaming can occur if interfacial tension gradients can develop, resulting in low interfacial tensor tension at the tips and a higher tension elsewhere.

214 citations


Journal ArticleDOI
TL;DR: In this paper, the authors compared various methods for the estimation of turbulent length scales and/or the rate of dissipation of turbulence kinetic energy (e) in stirred tanks, and evaluated the impact of these assumptions on the final result, in particular, the importance of the trailing vortices, has been evaluated in a quantitative sense.

201 citations


Journal ArticleDOI
TL;DR: In this article, two cross-linked chitosan fibers (ChF-A and ChF-B) were developed for use as adsorbents or ion exchangers for the recovery of dyestuffs.

Journal ArticleDOI
TL;DR: In this article, the mass transfer resistance of microporous membranes placed between a gas and a liquid phase was studied for both wetted and non-wetted membranes, and it was shown that the porosity of a membrane and the tortuosity of the pores can be described according to the film model.

Journal ArticleDOI
TL;DR: In this article, the authors focus on intraparticle diffusion of multicomponent gaseous mixtures in macroporous and microporous media, using a unified, consistent, approach, borrowing ideas and concepts developed more than a century ago by James Clerk Maxwell and Josef Stefan.

Journal ArticleDOI
TL;DR: Experimental data on hydrate formation kinetics, including induction times for methane, ethane and a mixture of the two gases, are presented in this article, where the data were measured using a stirred batch reactor recording the pressure as a function of time at constant temperature.

Journal ArticleDOI
TL;DR: In this paper, local instantaneous and time-averaging suspension densities were determined in a 152 mm diameter by 9.3 m tall circulating fluidized-bed riser using a needle capacitance probe inserted from the side.

Journal ArticleDOI
TL;DR: The particle segregation in fluidised beds consisting of different types of binary mixtures is shown to be governed by the same particle transport processes in this paper, and the significance of the particle transport parameters is discussed.

Journal ArticleDOI
TL;DR: In this paper, the distribution of citric acid between water and trialkylamine C 7 -C 9 dissolved in 7 various diluents (p -xylene, toluene, benzene, MIBK, 1-octanol, methylene chloride, chloroform) was studied.

Journal ArticleDOI
TL;DR: In this paper, a methodology for the simultaneous prediction of absolute permeabilities, formation resistivity factors and drainage capillary pressure curves of sandstones by employing a network model of pore structure based on bond-correlated site percolation concepts is presented.

Journal ArticleDOI
TL;DR: In this article, a modification of the Partial Least-squares (PLS) model is presented which permits incorporation of a dynamic transformation into the standard algebraic form of this model.

Journal ArticleDOI
TL;DR: In this paper, a theory for ultrasonic fragmentation of agglomerate particles suspended in liquids is presented, and an expression for the fragmentation rate as a function of ultra-osnic power and agglerate size is derived.

Journal ArticleDOI
TL;DR: In this paper, the type of dissolution patterns produced by the flow of reactive fluids in porous media when forced convection, molecular diffusion and surface reaction are the only phenomena occurring is investigated.

Journal ArticleDOI
TL;DR: In this article, the effect of oscillatory flow in baffled tubes on the mass transfer of oxygen into water was investigated, where gas bubbles are sparged into a vertical tube and the kinetics of the liquid oxygen concentration followed.

Journal ArticleDOI
TL;DR: In this article, the adsorption isotherms of each Troger's base enantiomers on microcrystalline cellulose triacetate, with ethanol as solvent, were measured using frontal analysis.

Journal ArticleDOI
TL;DR: In this article, a revised approach to modelling turbulent flow in small-diameter (10-44 mm) hydrocyclones is presented and tested quantitatively against experimental measurements, and the model predicts correctly the behaviour of a conventional water-fed hydrocyclone of various geometries, and has also been used to examine how the flow field can be modified by the insertion of a solid rod in place of the central air core in order to sharpen the classification performance of a polycyclone treating particulate suspensions.

Journal ArticleDOI
TL;DR: In this article, a new model for the polymerization of olefins in a loop reactor is presented, which allows important effects such as recycle rate, axial dispersion and heat transfer to be investigated.

Journal ArticleDOI
TL;DR: In this paper, experimental flow pattern and associated residence time distribution measurements for multipass and multitube arrays where periodic baffles and fluid oscillation may be present are reported. And a single parameter axial dispersion coefficient is determined and it is shown that dispersion using oscillatory flow in baffled tubes can be less than axial dispersions for a turbulent net flow.


Journal ArticleDOI
TL;DR: In this article, a nonspherical bubble formation model under constant-flow conditions was developed, and the calculated volumes and shapes of bubbles agreed with both the present experimental results and the previous works.

Journal ArticleDOI
TL;DR: In this paper, an automated non-intrusive image analysis method has been developed for following the course of solids mixing in two-dimensional bubbling fluidized beds, and experimental data have been obtained on the axial mixing of uniform solids.

Journal ArticleDOI
TL;DR: In this paper, a cohesive 1 −45 μm catalyst has been fluidized in a column 145 mm in ID. The column freeboard acted as a guide for the sound waves generated by a loudspeaker located opposite the fluidizing gas distributor.