Unsteady Mass Transfer From Oil Sand Spheres in Convective Streams at Low Reynolds Number

1990 ◽  
Vol 112 (4) ◽  
pp. 260-263
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Mass Transfer ◽  
Reynolds Number ◽  
Atmospheric Pressure ◽  
Oil Sands ◽  
Spherical Particles ◽  
Stream Velocity ◽  
Oil Sand ◽  
Experimental Conditions ◽  
Hot Air ◽  
Air Streams

The process of transient mass transfer in and around oil sand spheres was investigated experimentally. Preshaped molded spherical particles of Athabasca oil sands were subjected to hot air streams at atmospheric pressure and constant temperature ranging from 150°C up to 475°C with a uniform stream velocity covering the range 0.15 m/s up to 1.7 m/s and Reynolds number over the range 33–1650. The rate of mass loss due to fluid volatilization for each set of experimental conditions was established and correlated with the residence time in terms of dimensionless groupings.

A Study of Mass Transfer Around Oil Sand Fragments in High Temperature Atmospheres

1989 ◽  
Vol 111 (2) ◽  
pp. 97-99
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Reynolds Number ◽  
High Temperature ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Oil Sands ◽  
Simple Expression ◽  
Convective Mass Transfer ◽  
Oil Sand

An approximate approach was formulated to estimate the coefficient of convective mass transfer from small preshaped rectangular fragments of oil sands when subjected to hot streams of products of combustion of lean mixtures to hydrogen in air at low Reynolds number and at temperatures up to 1000 K. A simple expression which was derived to correlate the mass transfer coefficient in terms of the connective stream temperature was shown to fit the experimental data well.

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.

Heat Transfer in the Flow of Gases Around Oil Sand Spheres

1988 ◽  
Vol 110 (4) ◽  
pp. 276-278
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Heat Transfer ◽  
Oil Sands ◽  
Reynolds Numbers ◽  
Spherical Particles ◽  
Dimensionless Temperature ◽  
Convective System ◽  
Oil Sand ◽  
Low Reynolds Numbers ◽  
Convection Heating ◽  
Free And Forced Convection

An experimental study was conducted for the combined free and forced convection heating of preshaped molded spherical particles of Athabasca oil sands in hot gaseous streams of air at low Reynolds numbers. Based on a quasi-steady system, the lumped-heat-capacity approximation was employed to estimate the heat transfer coefficient of the transient convective system for each prescribed set of experimental stream conditions. Correlation of the results was made in terms of the dimensionless Nusselt number as a function of the particle Reynolds number and a dimensionless temperature difference. The simple closed-form analytical expression of the correlation was shown to fit the experimental data well.

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.

Effect of Flow Angle-of-Attack on the Local Heat/Mass Transfer From a Wall-Mounted Cube

1994 ◽  
Vol 116 (3) ◽  
pp. 552-560 ◽  
Author(s):  
V. Natarajan ◽  
M. K. Chyu
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Reynolds Number ◽  
Angle Of Attack ◽  
Convective Transport ◽  
Stream Velocity ◽  
Flow Angle ◽  
Local Study ◽  
Local Mass ◽  
Local Mass Transfer

An experimental study of the local mass transfer over the entire surface of a wall-mounted cube is performed with a particular emphasis on the effects of flow angles-of-attack (0 deg ≤ α ≤ 45 deg). Invoking an analogy between heat transfer and mass transfer, the presently obtained mass transfer results can be transformed into their heat transfer counterparts. Reynolds number based on the cube height and mean free-stream velocity varies between 3.1 × 104 and 1.1 × 105. To substantiate the mass transfer results, streakline patterns are visualized on the cube surfaces as well as the endwall using the oil-graphite technique. Significantly different flow regimes and local mass transfer characteristics are identified as the angle-of-attack varies. The overall convective transport is dominated by three-dimensional flow separation that includes multiple horseshoe vortex systems and an arch-shaped vortex wrapping around the rear portion of the cube. In addition to the local study, power correlations between the surface-resolved mass transfer Sherwood number and the Reynolds number are presented for all α values studied. Mass transfer averaged over the entire cube is compared with that of its two-dimensional counterpart with crossflow around a tall prism.

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.

An Analytical Study of Heat and Mass Transfer Within an Oil Sand Bed

1987 ◽  
Vol 109 (2) ◽  
pp. 66-70
Author(s):  
M. A. Abdrabboh ◽  
G. A. Karim
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Oil Sands ◽  
Operating Conditions ◽  
Oil Sand ◽  
Mass Transfer Processes ◽  
Wide Range ◽  
Gaseous Stream ◽  
Fluid Concentration ◽  
Experimental Values

The physical processes that occur typically within an oil sand bed are considered when the bed is subjected to a hot gaseous stream. In this study, the extent of fluid volatilization was obtained from a consideration of the simultaneous heat and mass transfer processes within the oil sands. The resulting system of equations together with the boundary conditions were solved numerically using an implicit finite difference method. The transient fluid concentration and temperature distributions within the oil sand bed were then obtained under a wide range of operating conditions. The resulting theoretical rates of volatilization and temperatures show generally good agreement with corresponding experimental values that were obtained for the purpose.

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.

Modeling mass transfer and substrate utilization in the boundary layer of biofilm systems

1998 ◽  
Vol 37 (4-5) ◽  
pp. 139-147 ◽  
Author(s):  
Harald Horn ◽  
Dietmar C. Hempel
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Reynolds Number ◽  
Film Theory ◽  
Substrate Utilization ◽  
The Other ◽  
Concentration Profiles ◽  
Hydrodynamic Conditions ◽  
Time Axis ◽  
Transfer Coefficients

The use of microelectrodes in biofilm research allows a better understanding of intrinsic biofilm processes. Little is known about mass transfer and substrate utilization in the boundary layer of biofilm systems. One possible description of mass transfer can be obtained by mass transfer coefficients, both on the basis of the stagnant film theory or with the Sherwood number. This approach is rather formal and not quite correct when the heterogeneity of the biofilm surface structure is taken into account. It could be shown that substrate loading is a major factor in the description of the development of the density. On the other hand, the time axis is an important factor which has to be considered when concentration profiles in biofilm systems are discussed. Finally, hydrodynamic conditions become important for the development of the biofilm surface when the Reynolds number increases above the range of 3000-4000.

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