A critical review of dispersion in packed beds

نویسنده

  • M. P. Q. Delgado
چکیده

The phenomenon of dispersion (transverse and longitudinal) in packed beds is summarized and reviewed for a great deal of information from the literature. Dispersion plays an important part, for example, in contaminant transport in ground water flows, in miscible displacement of oil and gas and in reactant and product transport in packed bed reactors. There are several variables that must be considered, in the analysis of dispersion in packed beds, like the length of the packed column, viscosity and density of the fluid, ratio of column diameter to particle diameter, ratio of column length to particle diameter, particle size distribution, particle shape, effect of fluid velocity and effect of temperature (or Schmidt number). Empirical correlations are presented for the prediction of the dispersion coefficients (DT and DL) over the entire range of practical values of Sc and Pem, and works on transverse and longitudinal dispersion of non-Newtonian fluids in packed beds are also considered.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Dispersion Coefficients of Supercritical Fluid in Fixed Beds

The axial dispersion coefficient of hexachlorobenzene in supercritical carbon dioxide is investigated in a fixed-bed packed with glass beads. The on-line chromatographic pulse-response experiment is used in order to study the dynamics of a packed column under supercritical conditions. The radial dispersion is assumed negligible because of the packed column geometry. To estimate the axial disper...

متن کامل

CFD Simulation of Parameters Affecting Hydrodynamics of Packed Beds: Effects of Particle Shape, Bed Size, and Bed Length

Packed bed reactors have many applications in different industries such as chemical, petrochemical, and refinery industries. In this work, the effects of some parameters such as the shape and size of particles, bed size, and bed length on the hydrodynamics of the packed beds containing three spherical, cylindrical, and cubic particles types are investigated using CFD. The effect of the combinat...

متن کامل

Numerical simulation of effect of non-spherical particle shape and bed size on hydrodynamics of packed beds

Fluid flow has a fundamental role in the performance of packed bed reactors. Some related issues, such as pressure drop, are strongly affected by porosity, so non-spherical particles are used in industry for enhancement or creation of the desired porosity. In this study, the effects of particle shape, size, and porosity of the bed on the hydrodynamics of packed beds are investigated with three ...

متن کامل

Measurements of dispersion coefficients in porous media by pulsed field gradient NMR

Dispersion in porous media is currently an important subject that occurs in different domains (processes, environment, oil recovery...). We have used the nuclear magnetic resonance, and more precisely the Pulsed Field Gradient (PFG-NMR) techniques to characterize this phenomenon. A PGSTE sequence (Pulsed Field Gradient Stimulated Echo) is used to measure longitudinal and transversal displacemen...

متن کامل

Computational Fluid Dynamics Simulations of Gas-Phase Radial Dispersion in Fixed Beds with Wall Effects

The effective medium approach to radial fixed bed dispersion models, in which radial dispersion of mass is superimposed on axial plug flow, is based on a constant effective dispersion coefficient, DT. For packed beds of a small tube-to-particle diameter ratio (N), the experimentally-observed decrease in this parameter near the tube wall is accounted for by a lumped resistance located at the tub...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2005