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A mathematical model of mass transport in a long permeable tube with radial convection

Published online by Cambridge University Press:  29 March 2006

Stephen M. Ross
Affiliation:
Department of Mechanical Engineering, State University of New York, Buffalo

Abstract

Laplace transforms and regular double asymptotic expansions are used to solve the problem of ordinary chemical mass transport in a permeable tube, where there is small radial convection through the membrane wall and where the length-to-diameter ratio is large. The system is taken to be dilute and Newtonian and the solution is found to higher order in two small parameters. Results indicate that the exit concentration decreases markedly as the diameter, membrane permeability and tube length increase, and that changes in mass transport owing to variations in radial convection are much more significant than those due to the same order of magnitude changes in the resistance of the chemical solute to passage through the membrane (transmittance). In addition, the maximum effects of changes in the radial convection and transmittance are not at the membrane itself (r = 1), but rather roughly at radial values of 0·6 and 0, respectively.

Type
Research Article
Copyright
© 1974 Cambridge University Press

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References

Aris, R. 1962 Vectors, Tensors and the Basic Equations of Fluid Mechanics. Prentice-Hall.
Berman, A. 1953 Laminar flow in channels with porous walls. J. Appl. Phys. 24, 12321235.Google Scholar
Bird, R., Stewart, W. & Lightfoot, E. 1960 Transport Phenomena. Wiley.
Brian, P. 1966 Mass transport in reverse osmosis. Desalination by Reverse Osmosis (ed. Merten), pp. 161202. MIT Press.
Colton, C., Smite, K., Stroeve, P. & Merrill, E. 1971 Laminar flow mass transfer in a flat duct with permeable walls. Am. Inst. Chern. Eng. 17, 773780.Google Scholar
De Bye, J. & Schenk, J. 1953 AppZ. Sci. Res. A 3, 308.
Goldstein, S. 1938 Modern Developments in Fluid Dynamics, vol. 2. Clarendon Press.
Grimsrud, L. 1966 Ph.D. thesis, University of Washington, Seattle.
Grimsrud, L. & Babe, A.L. 1966 Velocity and concentration profiles for laminar flow of a Newtonian fluid in a dialyzer. Chem. Eng. Prog. Symposium Series, 62, 2031.Google Scholar
Kays, W. 1966 Convective Heat and Mass Transfer. McGraw-Hill.
Liu, M. 1971 Iterative analysis of a continuous system for desalination by reverse osmosis. Desalination, 9, 181191.Google Scholar
Popovich, R.P. 1971 Ph.D. thesis, University of Washington, Seattle.
Popovich, R., Christopher, G. & Babb, A.L. 1971 The effects of membrane diffusion and ultra-filtration properties on hemodialyzer design and performance. Chem. Eng. Prog. Symp. 67, 105115.Google Scholar
Probstein, R. 1972 Desalination : some fluid mechanical problems. Trans. A.S.M.E., J. Basic Eng. D94, 286313.Google Scholar