scholarly journals The gas holdup in a multiphase reciprocating plate column filled with carboxymethylcellulose solutions

2005 ◽  
Vol 70 (12) ◽  
pp. 1533-1544 ◽  
Author(s):  
Ivica Stamenkovic ◽  
Olivera Stamenkovic ◽  
Ivana Bankovic-Ilic ◽  
Miodrag Lazic ◽  
Vlada Veljkovic ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Power Consumption ◽  
Rheological Properties ◽  
Gas Holdup ◽  
Gas Velocity ◽  
Vibration Intensity ◽  
Three Phase ◽  
Solids Content ◽  
Superficial Gas Velocity ◽  
Plate Column

Gas holdup was investigated in a gas-liquid and gas-liquid-solid reciprocating plate column (RPC) under various operation conditions. Aqueous carboxymethyl cellulose (sodium salt, CMC) solutions were used as the liquid phase, the solid phase was spheres placed into interplate spaces, and the gas phase was air. The gas holdup in the RPC was influenced by: the vibration intensity, i.e., the power consumption, the superficial gas velocity, the solids content and the rheological properties of the liquid phase. The gas holdup increased with increasing vibration intensity and superficial gas velocity in both the two- and three-phase system. With increasing concentration of the CMC PP 50 solution (Newtonian fluid), the gas holdup decreased, because the coalescence of the bubbles was favored by the higher liquid viscosity. In the case of the CMC PP 200 solutions (non-Newtonian liquids), the gas holdup depends on the combined influence of the rheological properties of the liquid phase, the vibration intensity and the superficial gas velocity. The gas holdup in the three-phase systems was greater than that in the two-phase ones under the same operating conditions. Increasing the solids content has little influence on the gas holdup. The gas holdup was correlated with the power consumption (either the time-averaged or total power consumption) and the superficial gas velocity.

scholarly journals Effects of Rashig rings placed in interplate spaces and the rheological properties of the liquid phase on power consumption in a gassed reciprocating plate column

2003 ◽  
Vol 57 (3) ◽  
pp. 107-113
Author(s):  
Mirko Aleksic ◽  
Vlada Veljkovic ◽  
Ivana Bankovic-Ilic ◽  
Miodrag Lazic ◽  
Dejan Skala
Keyword(s):  
Liquid Phase ◽  
Power Consumption ◽  
Rheological Properties ◽  
Newtonian Liquid ◽  
Operating Conditions ◽  
Solid Particles ◽  
Distilled Water ◽  
Gas Velocity ◽  
Superficial Gas Velocity ◽  
Plate Column

The power consumption in a gassed reciprocating plate column with Rashig rings placed in interplate spaces increases with both increasing vibration intensity and content of solid particles but decreases with increasing the superficial gas velocity, regardless of the rheological properties of the liquid phase. Under the same operating conditions, the power consumption is higher when the column is filled with a non-newtonian liquid than with distilled water.

scholarly journals Gas hold-up in a three-phase reciprocating plate column

2005 ◽  
Vol 70 (11) ◽  
pp. 1363-1371 ◽  
Author(s):  
Ljubisa Nikolic ◽  
Vesna Nikolic ◽  
Vlada Veljkovic ◽  
Dejan Skala
Keyword(s):  
Solid Phase ◽  
Liquid System ◽  
Column Diameter ◽  
Gas Velocity ◽  
Vibration Intensity ◽  
Three Phase ◽  
Superficial Gas Velocity ◽  
Phase Column ◽  
Plate Column ◽  
Good Agreement

The influence of the geometry of a reciprocating plate column (diameter), superficial gas velocity, vibration intensity and content of the solid phase in the column on the gas hold-up in a three phase column (G-L-S) were investigated in this study. For comparison, the gas hold-up was also analyzed in a gas-liquid system (G-L) in the same type of column. Good agreement between the experimentally determined values of the gas hold-up and those calculated on the basis of the derived correlation for the G-L and G-L-S system was obtained.

scholarly journals Gas-holdup in a 16.6 cm I.D. reciprocating plate column

2005 ◽  
Vol 59 (9-10) ◽  
pp. 263-266
Author(s):  
Ljubisa Vasic ◽  
Ivana Bankovic-Ilic ◽  
Miodrag Lazic ◽  
Vlada Veljkovic ◽  
Dejan Skala
Keyword(s):  
Power Consumption ◽  
Gas Flow ◽  
Gas Holdup ◽  
Specific Power ◽  
Specific Power Consumption ◽  
Gas Velocity ◽  
Two Phase ◽  
Operation Conditions ◽  
Superficial Gas Velocity ◽  
Plate Column

The effects of operation conditions (the vibration intensity and gas flow rate) on the gas holdup in a 16.6 cm i.d. two-phase reciprocating plate column (RPC) were studied. Distilled water and aqueous solutions of carboxymethyl-cellulose of different concentration were used as the liquid phase and air as the gas phase in this investigation. The gas holdup was measured after the gas flow and the reciprocating action had been stopped. An empirical correlation which correlates the gas holdup with the specific power consumption and the superficial gas velocity showed that the aeration intensity had a greater influence on the gas holdup than the intensity of agitation. Because the gas holdup was approximately the same in RPC's of different diameters, an equation relating the gas holdup with the specific power consumption and the superficial gas velocity was derived. The correlation could be used in the scaling up of reciprocating plate columns.

scholarly journals The effects of operating conditions on the pressure variation at the bottom of a 16.6 cm i.d. reciprocating plate column

2005 ◽  
Vol 11 (4) ◽  
pp. 195-202 ◽  
Author(s):  
Ljubisa Vasic ◽  
Ivana Bankovic-Ilic ◽  
Miodrag Lazic ◽  
Vlada Veljkovic ◽  
Dejan Skala
Keyword(s):  
Liquid Phase ◽  
Free Fraction ◽  
Pressure Variation ◽  
Operating Conditions ◽  
Solid Particles ◽  
Gas Velocity ◽  
Vibration Intensity ◽  
The One ◽  
Superficial Gas Velocity ◽  
Plate Column

The effects of the intensity of vibration, superficial gas velocity, content of solid particles and rheology of the liquid phase on the total and time-averaged pressure variation at the bottom of a 16.6 cm i.d. reciprocating plate column were studied. The total and time-averaged pressure variation at the column bottom were found to increase with increasing vibration intensity, liquid viscosity and content of solid particles, but to decrease with increasing superficial gas velocity. The pressure variation at the column bottom was greater in the column filled with CMC solutions than in the one with distilled water. The pressure variation at the column bottom was correlated with the vibration intensity and the liquid phase hold-up. The pressure variations at the bottom of columns of different diameter were also compared. The orifice coefficient for plates of approximately the same free fraction area was found to decrease with increasing column diameter.

scholarly journals The influence of Rashig rings and the rheological properties of the liquid phase on the pressure drop at the bottom of a reciprocating plate column

2002 ◽  
Vol 56 (10) ◽  
pp. 409-414 ◽  
Author(s):  
Mirko Aleksic ◽  
Vlada Veljkovic ◽  
Ivana Bankovic-Ilic ◽  
Miodrag Lazic ◽  
Dejan Skala
Keyword(s):  
Liquid Phase ◽  
Pressure Drop ◽  
Rheological Properties ◽  
Solid Phase ◽  
Newtonian Liquid ◽  
Solid Particles ◽  
Distilled Water ◽  
Gas Velocity ◽  
Superficial Gas Velocity ◽  
Plate Column

The pressure drop at the column bottom, filled with a Newtonian (distilled water) or non-Newtonian (aqueous solution of carboxymethylcellulose, sodium salt, CMC, 1 %) liquid, in the presence of Rashig rings, made of aluminum (0.8 cm in diameter), regularly distributed in the interplate spaces (volume content of the solid phase: up to 3.2 %) was studied. The average and total pressure drop at the column bottom increased with increasing vibration speed and content of the solid particles, but decreased with increasing superficial gas velocity, indepentently of the rheological properties of the liquid phase. The pressure drop at the column bottom filled with the non-Newtonian liquid was found to be higher than that in the case of distilled water.

scholarly journals Effect of Surfactants on Gas Holdup in Shear-Thinning Fluids

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Shaobai Li ◽  
Siyuan Huang ◽  
Jungeng Fan
Keyword(s):  
Experimental Data ◽  
Liquid Phase ◽  
Sodium Dodecyl ◽  
Shear Thinning ◽  
Gas Holdup ◽  
Bubble Columns ◽  
Gas Velocity ◽  
Shear Thinning Fluids ◽  
Liquid Surface Tension ◽  
Superficial Gas Velocity

In this study, the gas holdup of bubble swarms in shear-thinning fluids was experimentally studied at superficial gas velocities ranging from 0.001 to 0.02 m·s−1. Carboxylmethyl cellulose (CMC) solutions of 0.2 wt%, 0.6 wt%, and 1.0 wt% with sodium dodecyl sulfate (SDS) as the surfactant were used as the power-law (liquid phase), and nitrogen was used as the gas phase. Effects of SDS concentration, rheological behavior, and physical properties of the liquid phase and superficial gas velocity on gas holdup were investigated. Results indicated that gas holdup increases with increasing superficial gas velocity and decreasing CMC concentration. Moreover, the addition of SDS in CMC solutions increased gas holdup, and the degree increased with the surfactant concentration. An empirical correlation was proposed for evaluating gas holdup as a function of liquid surface tension, density, effective viscosity, rheological property, superficial gas velocity, and geometric characteristics of bubble columns using the experimental data obtained for the different superficial gas velocities and CMC solution concentrations with different surfactant solutions. These proposed correlations reasonably fitted the experimental data obtained for gas holdup in this system.

scholarly journals Oxygen mass transfer in a 16.6 cm i.d. multiphase reciprocating plate column

2007 ◽  
Vol 72 (5) ◽  
pp. 523-531 ◽  
Author(s):  
Ljubisa Vasic ◽  
Ivana Bankovic-Ilic ◽  
Miodrag Lazic ◽  
Vlada Veljkovic ◽  
Dejan Skala
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Solid Particles ◽  
Oxygen Mass Transfer ◽  
Column Diameter ◽  
Specific Time ◽  
Gas Velocity ◽  
Vibration Intensity ◽  
Superficial Gas Velocity ◽  
Plate Column

The effects of vibration intensity, superficial gas velocity and content of solid particles on the volumetric oxygen mass transfer coefficient (k 1 a) in a 16.6 cm i.d. multiphase reciprocating plate column were studied. The k 1 a increased with increasing vibration intensity and superficial gas velocity, and decreased with increasing content of solid particles. The k 1 a was correlated with the specific time-averaged power consumtion, the superficial gas velocity, the column diameter and the content of solid particles.

Impact of Dense Internals on Fluid Dynamic Parameters in Bubble Column

2018 ◽  
Vol 16 (12) ◽  
Author(s):  
Dinesh V. Kalaga ◽  
Vishal Bhusare ◽  
H.J. Pant ◽  
Jyeshtharaj B. Joshi ◽  
Shantanu Roy
Keyword(s):  
Liquid Phase ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Liquid Velocity ◽  
Bubble Column ◽  
Vertical Tube ◽  
Gas Holdup ◽  
Gas Velocity ◽  
Cross Sectional ◽  
Superficial Gas Velocity

Abstract Industrial gas-liquid processes such as oxidation, hydrogenation, Fischer-Trospch synthesis, liquid-phase methanol synthesis, and nuclear fission are exothermic in nature; the reactor of choice for such processes is, therefore, a bubble column equipped with heat exchanging internals. In addition to maintaining the desired process temperature, the heat exchanging vertical tube internals are used to control flow structures and liquid back mixing. The present work reports the experimentally measured gas hold-up, mean liquid velocity and liquid phase turbulent kinetic energy, using the Radioactive Particle Tracking (RPT) technique, in a 120 mm diameter bubble column equipped with dense vertical tube internals covering 23 % of the total cross-sectional area of the column. The effect of superficial gas velocity (44–265 mm/s) on gas hold-up, mean liquid velocity and turbulent kinetic energy is presented and discussed. It has been inferred from the experimental results that the vertical tube internal located at the center of the column plays a vital role in affecting the hydrodynamics when compared to the conventional internal configurations reported in the literature. For the chosen dense internal configuration, the cross-sectional distribution of the gas holdup, mean liquid velocity and turbulent kinetic energy show asymmetry for all the superficial gas velocities investigated. The overall gas holdup and the liquid turbulence increases with an increase in the superficial gas velocity. The strong liquid circulation velocities have been seen upon the insertion of the dense internals.

scholarly journals Hydrodynamics and Mass Transfer in a Concentric Internal Jet-Loop Airlift Bioreactor Equipped with a Deflector

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4329
Author(s):  
Radek Šulc ◽  
Jan Dymák
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Liquid System ◽  
Gas Holdup ◽  
Gas Velocity ◽  
Liquid Phase Mass Transfer ◽  
Homogenization Time ◽  
Standard Design ◽  
Superficial Gas Velocity

The gas–liquid hydrodynamics and mass transfer were studied in a concentric tube internal jet-loop airlift reactor with a conical bottom. Comparing with a standard design, the gas separator was equipped with an adjustable deflector placed above the riser. The effect of riser superficial gas velocity uSGR on the total gas holdup εGT, homogenization time tH, and overall volumetric liquid-phase mass transfer coefficient kLa was investigated in a laboratory bioreactor, of 300 mm in inner diameter, in a two-phase air–water system and three-phase air–water–PVC–particle system with the volumetric solid fraction of 1% for various deflector clearances. The airlift was operated in the range of riser superficial gas velocity from 0.011 to 0.045 m/s. For the gas–liquid system, when reducing the deflector clearance, the total gas holdup decreased, the homogenization time increased twice compared to the highest deflector clearance tested, and the overall volumetric mass transfer coefficient slightly increased by 10–17%. The presence of a solid phase shortened the homogenization time, especially for lower uSGR and deflector clearance, and reduced the mass transfer coefficient by 15–35%. Compared to the gas–liquid system, the noticeable effect of deflector clearance was found for the kLa coefficient, which was found approx. 20–29% higher for the lowest tested deflector clearance.

Bubble Diameter and Effective Interfacial Area in a Novel Hybrid Rotating and Reciprocating Perforated Plate Bubble Column

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Dhanasekaran S ◽  
Karunanithi T
Keyword(s):  
Liquid Velocity ◽  
Bubble Column ◽  
Bubble Diameter ◽  
Perforated Plate ◽  
Interfacial Area ◽  
Gas Velocity ◽  
The Mean ◽  
Superficial Gas Velocity ◽  
Plate Column

This investigation reports on the experimental and theoretical investigation carried out to evaluate the bubble diameter and effective interfacial area in a novel Hybrid Rotating and Reciprocating Perforated Plate Bubble Column. Air-water system is used in this investigation. Countercurrent mode is employed. The effects of agitation level, superficial gas velocity and superficial liquid velocity on the bubble size distribution are studied. The mean bubble diameter is predicted using photographic technique. A simple correlation is developed for the determination of mean bubble diameter. It is found that the mean bubble diameter values for hybrid column are 1.8 to 2.5 times smaller when compared with conventional reciprocating plate column. The interfacial area is calculated based on the experimental results of the gas holdup and bubble diameter. Effects of agitation level, superficial gas velocity, superficial liquid velocity and plate free area on the interfacial area have been investigated. Correlations are developed for the determination of interfacial area for both mixer-settler and emulsion regions. It could be noted that the interfacial area for the hybrid column is 3 to 6 times higher in both mixer-settler region and emulsion region than that of conventional reciprocating plate column which is quite large.

Sign in / Sign up

Export Citation Format

Share Document