Results 221 to 230 of about 12,329 (259)

Liquid backmixing in bubble columns and the axial dispersion coefficient

AIChE Journal, 1998
AbstractLiquid backmixing in bubble columns is commonly described using the 1‐D axial dispersion model, wherein all the contributing mechanisms leading to liquid macromixing are lumped into a single axial dispersion coefficient. No relationship has been reported that allows the quantification of various fluid‐dynamic contributions to the axial ...
Sujatha Degaleesan, Milorad P. Duduković   +1 more
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Experimental determination of axial dispersion coefficient in a bubble column

Chemical Engineering Science, 1980
Abstract A new graphical method of finding axial dispersion coefficients in a bubble column is developed. This method requires only the area above an experimental curve, thus is simpler than the conventional method of curve fitting. The new method is used to find the dimensionless dispersion number in the bubble column and shows that the dispersion ...
Soon-Jai Khang, Samir P. Kothari
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A general correlation to predict axial dispersion coefficients in aerated channel reactors

Water Research, 2008
Tracer studies have been widely applied to characterize the flow behavior in activated sludge reactors. The channel reactor with bottom aerators is one of the widespread designs in large wastewater treatment plants. Its flow behavior is well modeled either as a plug flow reactor with axial dispersion or as the perfect mixing cells in series.
Le Moullec, Y., Potier, O., Gentric, C., Leclerc, J.-P.   +3 more
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Axial Dispersion Coefficients in Laminar Flows of Water-Distribution Systems

Journal of Hydraulic Engineering, 2011
Because longitudinal dispersion is becoming increasingly germane to the problem of accurately determining water quality, water-resource managers and engineers seeking to represent solute transport in drinking-water systems must be able to compute relevant dispersion coefficients.
Pedro Romero-Gomez, Christopher Y. Choi
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A simplified model for prediction of time-dependent axial dispersion coefficient

Chemical Engineering Science, 1991
Abstract A simple model is proposed for prediction of the axial dispersion coefficient as a function of time. The model contains only a single parameter called the decay time, which is the time required for the mean concentration to approach 1 e of its initial value. The asymptotic value of this coefficient for large times approaches the value
Mohammad Soltanieh, Sasan Sadraei
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Correlation of axial mixing of solids in fluidized beds by a dispersion coefficient

Powder Technology, 1984
Abstract Axial mixing of solids in a 19.3 cm diameter bed was investigated using a tracer technique. Bed material and tracer consisted of ion-exchange resin particles of 0.846 mm and 0.645 mm diameter, respectively. Tracer concentration profiles were measured. The results were expressed as axial dispersion coefficients.
A. Esin, M. Altun
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Behavior of macromolecules in dilute solutions: II—On the axial dispersion coefficient

The Canadian Journal of Chemical Engineering, 1975
AbstractUsing pulse‐input technique, axial dispersion coefficients were determined for polystyrene in tetrahydrofuran, in toluene and in a toluene/methanol mixture flowing in a long capillary tube under conditions such that the Reynolds number was less than 500. Low polydispersity polystyrene materials with nominal molecular weights ranging from 900 to
H. R. Chen, L. P. Blanchard
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Axial dispersion coefficients in packed beds at low reynolds numbers

The Canadian Journal of Chemical Engineering, 1969
AbstractPeclet numbers describing axial dispersion in gas flow through packed beds of spheres were obtained using a two measurement point, pulse technique in a test section four inches inside diameter and 5.14 feet high. Three packing sizes were investigated, corresponding to tube to particle diameter ratios of 6.4, 17, and 66In the experiments the ...
Jack C. Urban, A. Gomezplata
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The simultaneous determination of axial dispersion and mass transfer coefficients

Chemical Engineering Science, 1967
Abstract A method is illustrated for the simultaneous determination of axial dispersion and mass transfer parameters for some continuous flow process operations. The procedure involves the matching of computed and experimental axial concentration profiles.
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Axial Dispersion Coefficients for Laminar Flows in Water Distribution Systems

World Environmental and Water Resources Congress 2009, 2009
A dispersive transport component has recently been incorporated into the constituent transport equation used for modeling water quality in pressurized distribution systems. Among the various issues that arose from this major development, dispersion coefficients (E) relevant to water distribution systems still remain unknown.
P. Romero-Gomez, Z. Li, C. Y. Choi, S. G. Buchberger   +3 more
openaire   +1 more source