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Effect of some solid properties on gas-liquid mass transfer in a bubble column

The knowledge about the effects of solids on gas–liquid systems and the respective physical mechanisms are not yet totally clarified. In this work, the effect of the solids on the mass transfer characteristics in a bubble column was studied experimentally for the systems air/water/expandable polystyrene (EPS) beads and air/water/glass beads. Volumetric liquid side mass transfer coefficient, kLa, was determined ...

Measurement of gas phase characteristics using amonofibre optical probe in a th...

The study of gas–liquid–solid systems structure requires reliable measurement tools. In this paper, preliminary results on the potential use of a monofibre optical probe to investigate such flow are presented. This probe, manufactured at LEGI, allows the simultaneous measurement of the gas phase residence time and gas phase velocity. This specificity makes this probe more interesting than classical single tip p...

The bubble size distribution and O2 mass transfer in an oscillating, meso-scale...

This work aims at characterizing bubble size distribution and its control in a small-scale, constricted tube in the presence of an oscillating flow. From previous works, it became clear that the full modelling of the dispersed gas -liquid flow in the constricted tube requires a deeper clarification of the impact of tube geometry and the hydrodynamic parameters on the observed values of the oxygen mass transfer ...

The intensification of gas–liquid flows with a periodic, constricted oscillator...

The experimental study of gas dispersion in a vertical periodically, constricted, oscillatory meso-tube (OMT) is herein presented. Water was continuously pumped through the OMT in the laminar flow regime along with an oscillatory flow component superimposed into the net flow in a range of fluid oscillation frequency (f) and centre-to-peak amplitude (x0) of and 0–3 mm, respectively, in the presence of a very lo...

Using image analysis in the study of multiphase gas absorption

For the air–water–calcium alginate beads system, the effect of the presence of solids on the mass transfer characteristics in a bubble column was experimentally studied. Volumetric liquid side mass transfer coefficient, kLa, specific interfacial area, a, and hence liquid side mass transfer coefficient, kL, were determined under different solid concentrations (0, 5, and 10 vol%), superficial gas velocities (up t...

Effect of solids on homogeneous–heterogeneous flowregime transition in bubble c...

Experiments were conducted to study the effect of the presence of the solid phase on the homogeneous–heterogeneous flow regime transition in a bubble column 0.14m diameter. Air, distilled water and calcium alginate beads (2.1 mm, 1023 kg/m3) at concentrations c=0–30% (vol.) were the phases. The basic data were the voidage–gas flow rate dependences. The critical point, where the homogeneous regime loses stabilit...

Effect of solids on gas-liquid mass transfer and bubble characteristics in thre...

Comunicação apresentada no "7th World Congress of Chemical Engineering" em Glasgow, Escócia, em Julho de 2005. ; The effect of the solids on the mass transfer characteristics in a bubble column was studied experimentally for the system air/water/beads of calcium alginate. Volumetric liquid side mass transfer coefficient, kLα, specific interfacial area, α, and liquid side mass transfer coefficient, kL, were det...

Effect of solids on flow regime transition in three-phase bubble columns

In bubble column reactors there are two principal flow regimes [1,2,3], the homogeneous (HoR) and the heterogeneous (HeR). These reactors have different behaviour in HoR and HeR, thus the dependences of the rates of mass, heat and momentum transfer on the design and operating parameters (such as reactor geometry, gas and liquid flow rates and properties of the contacting phases) are also very different. Therefo...

Effect of solid particles on flow regimes in bubble columns

Effect of viscosity on homogeneous–heterogeneous flow regime transition in bubb...

Experiments were performed in a cylindrical 0.14m diameter bubble column with a metal perforated plate. Air and aqueous solutions of glycerol with viscosity 1–22mPa s were the phases. Gas holdup was measured and plotted against the gas flow rate. The critical point where the homogeneous–heterogeneous regime transition begins was determined by the drift-flux plot of the primary data. The homogeneous regime stabi...