scholarly journals Mass transfer between a fluid and an immersed object in liquid-solid packed and fluidized beds

2005 ◽  
Vol 70 (11) ◽  
pp. 1373-1379 ◽  
Author(s):  
Nevenka Boskovic-Vragolovic ◽  
Danica Brzic ◽  
Zeljko Grbavcic
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Benzoic Acid ◽  
Fluidized Beds ◽  
Liquid Velocity ◽  
Spherical Particles ◽  
Flowing Water ◽  
Transfer Rates ◽  
Transfer Data ◽  
Dissolution Method

The mass transfer coefficient between fluid and an immersed sphere in liquid packed and fluidized beds of inert spherical particles have been studied experimentally using a column 40 mm in diameter. The mass transfer data were obtained by studying the transfer of benzoic acid from the immersed sphere to flowing water using the dissolution method. In all runs, the mass transfer rates were determined in the presence of inert glass particles 0.50-2.98 mm in diameter. The influence of different parameters, such as: liquid velocity, particles size and bed void age, on the mass transfer in packed and fluidized beds is presented. The obtained experimental data for mass transfer in the packed and particulate fluidized bed were correlated by a single correlation, thus confirming the similarity between the two systems.

Mass Transfer in Oil Sand Fluidized Beds—A Simplified Model

1988 ◽  
Vol 110 (4) ◽  
pp. 279-283
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Closed Form ◽  
Fluidized Bed ◽  
Oil Sands ◽  
Fluidized Beds ◽  
Spherical Particles ◽  
Simplified Model ◽  
Oil Sand ◽  
Uniform Velocity

Experimental data obtained previously relating to the behavior of single spherical particles of oil sands in hot uniform velocity oxidizing gaseous streams were employed and extended to estimate in a preliminary fashion the extent of mass transfer from oil sand fragments in a fluidized bed. This has been done through employing experimental correlations published in the literature on fluidization. A simple closed-form analytical expression was derived for estimating the transient rates of mass transfer in fluidized beds of oil sands in terms of the main controlling parameters.

scholarly journals Wall-to-liquid mass transfer in fluidized beds and vertical transport of inert particles

2007 ◽  
Vol 72 (11) ◽  
pp. 1103-1113 ◽  
Author(s):  
Nevenka Boskovic-Vragolovic ◽  
Radmila Garic-Grulovic ◽  
Zeljko Grbavcic
Keyword(s):  
Mass Transfer ◽  
Reynolds Number ◽  
Transfer Factor ◽  
Fluidized Beds ◽  
Liquid Velocity ◽  
Spherical Particles ◽  
Hydraulic Transport ◽  
Transfer Coefficients ◽  
Flowing Fluid ◽  
Inert Particles

Mass transfer coefficients in single phase flow, liquid fluidized beds and vertical hydraulic transport of spherical inert particles were studied experimentally using 40 mm and 25.4 mm diameter columns. The mass transfer data were obtained by studying the transfer of benzoic acid from a tube segment to water using the dissolution method. In all runs, the mass transfer rates were determined in the presence of spherical glass particles 1.2, 1.94 and 2.98 mm in diameter. The influence of different parameters, such as liquid velocity, particles size and voids on mass transfer in fluidized beds and hydraulic transport are presented. The data for mass transfer in all the investigated systems are shown using the Sherwood number (Sh) and mass transfer factor - Colburn factor (jD) - as a function of Reynolds number (Re) for the particles and for the column. The data for mass transfer in particulate fluidized beds and for vertical hydraulic transport of spherical particles were correlated by treating the flowing fluid-particle mixture as a pseudo fluid by introducing a modified mixture Reynolds number (Rem). A new correlation for the mass transfer factor in fluidized beds and in vertical hydraulic transport is proposed.

scholarly journals Mass transfer from the wall of a column to the fluid in a fluidized bed of inert spherical particles

2004 ◽  
Vol 58 (2) ◽  
pp. 69-72
Author(s):  
Danica Brzic ◽  
Nevenka Boskovic-Vragolovic ◽  
Zeljko Grbavcic
Keyword(s):  
Mass Transfer ◽  
Reynolds Number ◽  
Benzoic Acid ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Single Phase ◽  
Spherical Particles ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Transfer Coefficients

Mass transfer in fluidized beds is an important operation for separation processes. Two effects can be achieved by using fluidized beds in mass transfer processes increasing interface area and relative movement between the phases. These effects are both desirable because they lead to greater process rates. This paper presents an experimental investigation regarding mass transfer from the wall of a column to the fluid in a fluidized bed of inert spherical particles. The experiments were conducted in column 40 mm in diameter with spherical particles 0,8-3 mm in diameter and water as one fluidizing fluid. The method of dissolution of benzoic acid was used to provide very low mass flux. The average wall-to-fluid mass transfer coefficients were determined for two systems: single-phase fluid flow and a fluidized bed of inert particles The measurements encompassed a Reynolds number range from 100-4000 for single-phase flow and 600-4000 in fluidized beds. The mass transfer coefficients for both systems were calculated from weight loss of benzoic acid. The effects of superficial liquid velocity and particle diameter on the mass transfer coefficient were investigated. It was found that mass transfer was more intensive in the fluidized bed in comparison with single phase flow. The best conditions for mass transfer were reached at a minimum fluidization velocity, when the mass transfer coefficient had the greatest value. The experimental data were correlated in the form: jd = f(Re), where jd is the dimensionless mass transfer factor and Re the Reynolds number.

Recycling and Extraction of Zinc Ions in Disc-Donut Column Considering Forward Mixing Mass Transfer, Chemical Reaction and Effects of Pulsed and non-Pulsed Condition

2021 ◽  
Author(s):  
Mehdi Asadollahzadeh ◽  
Rezvan Torkaman ◽  
Meisam Torab-Mostaedi ◽  
Mojtaba Saremi
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Flow Rate ◽  
Positive Impact ◽  
Plug Flow ◽  
Model Parameters ◽  
Zinc Ions ◽  
Zinc Extraction ◽  
Balance Equations ◽  
Transfer Rates

Abstract The current study focuses on the recovery of zinc ions by solvent extraction in the pulsed contactor. The Zn(II) ions from chloride solution were extracted into the organic phase containing D2EHPA extractant. The resulting data were characterized for the relative amount of (a) pulsed and no-pulsed condition; and (b) flow rate of both phases. Based on the mass balance equations for the column performance description, numerical computations of mass transfer in a disc-donut column were conducted and validated the experimental data for zinc extraction. Four different models, such as plug flow, backflow, axial dispersion, and forward mixing were evaluated in this study. The results showed that the intensification of the process with the pulsed condition increased and achieved higher mass transfer rates. The forward mixing model findings based on the curve fitting approach validated well with the experimental data. The results showed that an increase in pulsation intensity, as well as the phase flow rates, have a positive impact on the performance of the extractor, whereas the enhancement of flow rate led to the reduction of the described model parameters for adverse phase.

Volatilization of Packed Beds of Oil Sand Particles

1987 ◽  
Vol 109 (2) ◽  
pp. 71-74
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Reynolds Numbers ◽  
Spherical Particles ◽  
Packed Beds ◽  
Oil Sand ◽  
Transfer Coefficients ◽  
Simple Analytical Expression ◽  
Low Reynolds Numbers ◽  
Fixed Beds

Based on a quasi-steady system, published experimental data on mass transfer in packed beds of spherical particles at relatively low Reynolds numbers, were employed to estimate the convective mass-transfer coefficients in the bed in terms of the corresponding values for single particles. The average transient fluid concentrations within the bed of particles were also obtained in terms of the corresponding single-particle concentrations using the lumped-heat-capacity system. Thus, experimental data published on volatilization of single oil sand spheres could then be extended to estimate the rates of volatilization of packed beds of oil sand spheres. A simple analytical expression could, therefore, be derived for estimating the transient mass loss from fixed beds of oil sand spheres in terms of the parameters involved.

scholarly journals Mass Transfer Enhancement in GLS Fluidized Beds using Nanomaterials

2019 ◽  
Vol 8 (3) ◽  
pp. 5763-5766
Keyword(s):  
Mass Transfer ◽  
Benzoic Acid ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Physical Property ◽  
Gas Velocity ◽  
Three Phase ◽  
Unique Physical Property

Nanomaterial has unique physical property which made it important for many applications and that is why the use of nanomaterials rapidly increasing in the field of science and engineering.1 . This work focuses on mass transfer of solids into liquid in three phase fluidized beds in presence of nanomaterial. This include the study of effect of gas velocity, time and different concentration of nanomaterials on mass transfer coefficient in stagnant liquid column in three phase fluidized bed system. To measure coefficient of the mass transfer, known quantity of solid pellets ie benzoic acid and known amount of nanomaterial fraction ie Arachitol nano were charged in the test column of three phase fluidized bed system. At the beginning of each run, test section was partially filled with water which prevent breakage of particles. The experiments were conducted by sequentially varying gas velocity for different volumes of nanomaterial and measuring the rate of mass transfer by collecting samples directly from the outlet ports at the top subsequently analysed by volumetric titration method. The results show enhancement in mass transfer coefficient by addition of nanomaterials. Arachitol nano has been taken in different volumes ie 3ml, 7ml, 10ml and 20ml in (GLS) gas ,liquid and solid fluidized bed with air, water and benzoic acid pellets as three phases respectively in the system. The presence of nanomaterial increases the solid liquid mass transfer coefficient value with increasing fraction of nanomaterial, increasing gas velocity and increasing time although experimental run has been taken only for one hour.

Hydrodynamics and Mass Transfer Simulation in Airlift Bioreactor with Settler using Computational Fluid Dynamics

2017 ◽  
Vol 15 (4) ◽  
Author(s):  
Oscar M. Hernández-Calderón ◽  
Marcos D. González-Llanes ◽  
Erika Y. Rios-Iribe ◽  
Sergio A. Jiménez-Lam ◽  
Ma.del Carmen Chavez-Parga ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Mass Transfer ◽  
Computational Fluid Dynamics ◽  
Liquid Velocity ◽  
Fluid Dynamic ◽  
Gas Holdup ◽  
Airlift Bioreactor ◽  
Cfd Modeling ◽  
Two Phase

Abstract In this work, the effect of inlet-gas superficial velocity over the circulation liquid velocity, gas holdup and mass transfer, from an airlift bioreactor with settler were studied by Computational Fluid Dynamics (CFD) modeling and contrasted with experimental results. Multiphase mixture model and κ-ε turbulence model were used to describe the two phases gas-liquid flow pattern in airlift bioreactor. The hydrodynamic parameters such as liquid circulation velocity and gas holdup were computed by solving the governing equations of continuity, moment and turbulence transport using the finite volume method. Global mass transfer coefficient was evaluated through the Higbie’s penetration theory and the two-phase fluid dynamic theory. Comparison between our numerical data and experimental data previously reported in the literature was done. Numerical and experimental data were very close, and the differences found were discussed in terms of the limitations of this study.

Heat Transfer and Sublimation at a Stagnation Point in Potential Flow

1960 ◽  
Vol 27 (4) ◽  
pp. 613-616 ◽  
Author(s):  
W. W. Short
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Mass Transfer ◽  
Potential Flow ◽  
High Mass ◽  
Fluid Stream ◽  
Simple Analytical Expression ◽  
Transfer Rates ◽  
Transfer Data ◽  
Constant Thermal Conductivity

A simple analytical expression is derived which predicts the effect of mass transfer on countercurrent heat transfer to a vaporizing body. In this theory, the fluid stream is assumed to be inviscid and of constant thermal conductivity. The inviscid theory correlates well with heat-transfer data without mass transfer and is believed to predict heat-transfer rates fairly accurately at high mass-transfer rates.

Experimental Model to Characterize the Evaporative Cooling of Horizontal Roofs

2008 ◽  
Author(s):  
Margarita Gil Samaniego Ramos ◽  
He´ctor Enrique Campbell Rami´rez
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mass Transfer ◽  
Evaporation Rate ◽  
Evaporative Cooling ◽  
Water Evaporation ◽  
Flat Plates ◽  
Transfer Rates ◽  
Dry Conditions ◽  
Models Validation

Heat and mass transfer models were developed experimentally to characterize the evaporative cooling of horizontal roofs, heated by thermal radiation. Surface temperatures of flat plates were evaluated at dry conditions and when humidified with water atomizers. For both conditions, heat transfer rates were calculated, and for the wet case also the mass transfer rates were predicted. Experimental data for models validation were measured at environmental and controlled conditions. Accuracies achieved were 2% for surface temperature and 13% for water evaporation rate.

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