Intensification of mass transfer in gas-liquid systems by introducing a finely dispersed solid phase

1984 ◽  
Vol 20 (7) ◽  
pp. 337-339
Author(s):  
L. I. Barkar ◽  
N. A. Nikolaev
2006 ◽  
Author(s):  
Bhagavatula Venkata Ramana Murthy

Fluidized beds are widely used in industries for mixing solid particles with liquids as the solid is vigorously agitated by the liquid passing through the bed and the mixing of the solid ensures that there are practically no temperature gradients in the bed even with exothermic or endothermic reactions (Mixing and the segregation in a liquid fluidized of particles with different sizes and densities", The Canadian Journal of Chemical Engineering, 1988). The violent motion of the solid particles also gives high heat transfer rates to the wall or to cooling tubes immersed in the bed. Because of the fluidity of the solid particles, it is easy to pass solid from one vessel to another. In the present experimental work, the relative density between solid and liquid phases on pressure drop under fluidized condition has been studied using the solid-liquid systems namely, glass beads-water, glass beads-kerosene, plastic beads-kerosene and diamond sugar-kerosene. Pressure drop - liquid velocity and void fraction - liquid velocity relationships have been found for all the mentioned solid-liquid systems under fluidized condition and results have been noted. The effect of the nature of the fluid on the minimum fluidization velocity and the pressure drop has been studied. In addition to the pressure drop studies, mass transfer studies have also been conducted with diamond sugar-water system with and without fluidization and results have been obtained. In addition to these, comparison of bed voidage, pressure drop and minimum fluidization velocity between denser and lighter liquids have been studied and the results have been obtained. Also, the value of rate of mass transfer with fluidization is compared that without fluidization for diamond sugar-water system and the results have been obtained.


2007 ◽  
Vol 41 (5) ◽  
pp. 500-505 ◽  
Author(s):  
V. A. Vasilenko ◽  
E. M. Kol’tsova ◽  
V. V. Tarasov ◽  
Zhang Dong Xiang ◽  
L. S. Gordeev

2003 ◽  
Vol 68 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Nada Nikolic ◽  
Mihajlo Stankovic

Dried and milled haulm of potato (Solanum tuberosum L) was used as the solid phase. An ethanolic solution of hydrochloric acid mixed with chloroform in different volume ratios was the liquid phase. The aim of paper was to unite in a single step the processes of glycoalkaloids extraction from haulm, their hydrolysis to solanidine and the extraction of solanidine. This could make the procedure of obtaining solanidine faster and simpler. The best degree of solanidine hydrolytic extraction of 84.5% was achieved using 10% w/v hydrochloric acid in 96% vol. ethanol mixed with chloroform in a volume ratio of 2:3, after 120 min of hydrolytic extraction.


Author(s):  
Rufat Abiev

Analysis of hydrodynamics and mass transfer Taylor flows in micro channels of both gas-liquid and liquid-liquid systems on the basis of classical theoretical approach with some simplifying assumptions was performed. Results of theoretical analysis for description of hydrodynamic parameters and mass transfer characteristics were confirmed by comparison with the author's own and available in literature experimental data. It was shown that the main parameters of two-phase Taylor flows could be quite precisely described theoretically: mean bubble/droplet velocity, liquid film thickness, real gas holdup (which is always smaller than so-called dynamic holdup), pressure drop. Peculiarities of liquid-liquid flows compared to gas-liquid Taylor flows in capillaries are discussed. Wettability effect on hydrodynamics was examined. Tools of mass transfer intensification of gas-liquid and liquid-liquid Taylor flow in micro channels are analyzed. Three-layer model for heat and mass transfer has been proposed and implemented for the case of solid-liquid mass transfer for gas-liquid Taylor flows; optimal process conditions for this process are found theoretically and discussed from physical point of view.


1988 ◽  
Vol 12 (11) ◽  
pp. 1075-1082 ◽  
Author(s):  
M.M.L. Guimarães ◽  
J.J.C. Cruz-Pinto

2020 ◽  
Vol 10 (3) ◽  
pp. 475-490 ◽  
Author(s):  
Pauline Bianchi ◽  
Jason D. Williams ◽  
C. Oliver Kappe

Abstract Oscillatory flow reactors (OFRs) superimpose an oscillatory flow to the net movement through a flow reactor. OFRs have been engineered to enable improved mixing, excellent heat- and mass transfer and good plug flow character under a broad range of operating conditions. Such features render these reactors appealing, since they are suitable for reactions that require long residence times, improved mass transfer (such as in biphasic liquid-liquid systems) or to homogeneously suspend solid particles. Various OFR configurations, offering specific features, have been developed over the past two decades, with significant progress still being made. This review outlines the principles and recent advances in OFR technology and overviews the synthetic applications of OFRs for liquid-liquid and solid-liquid biphasic systems.


Author(s):  
Dmitriy Lazarev ◽  
Valeriy Artemov ◽  
Georgiy Yankov ◽  
Konstantin Minko

A three-dimensional mathematical model of unsteady heat and mass transfer in porous hydrogen-absorbing media, accounting for presence of “passive” gas admixtures, is developed. New technique for evaluation of effective thermal conductivity of porous medium, which consists of microparticles, is suggested. Effect of “passive” gas admixtures on heat and mass transfer and sorption rate in metal hydride reactor is analyzed. It is shown that decrease of effective thermal conductivity and partial hydrogen pressure under decrease of hydrogen concentration effect on the hydrogen sorption rate considerably. It is disclosed that an intensive 3D natural convection takes place in a gas volume of reactor under certain conditions. Numerical analysis of heat and mass transfer in metal-hydride reactor of hydrogen accumulation systems was done. Sorption of hydrogen in cylindrical reactors with external cooling and central supply of hydrogen are analyzed including reactors with finned active volume and tube-shell reactor with external and internal cooling cartridge matrix. Unsteady three dimensional temperature and concentration fields in solid phase are presented. Integral curves representing the dynamic of sorption and desorption are calculated. Data on efficiency of considered reactors are presented and compared.


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