ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 6, pp. 1028!1030. + Pleiades Publishing, Inc., 2006.
Original Russian Text + S.I. Lazarev, V.L. Golovashin, V.V. Mamontov, S.V. Kovalev, 2006, published in Zhurnal Prikladnoi Khimii, 2006, Vol. 79,
No. 6, pp. 1038!1039.
A Study of the Diffusion Permeability Coefficient
of a Tubular Membrane Unit in an Aqueous Solution
of Sodium Sulfate
S. I. Lazarev, V. L. Golovashin, V. V. Mamontov, and S. V. Kovalev
Tambov State Technical University, Tambov, Russia
Received December 8, 2005
Abstract-Experimental data on the diffusion permeability coefficient of sodium sulfate in a fluoroplastic
membrane were obtained and analyzed.
Mathematical simulations of the operation of
a membrane apparatus are commonly based on the self-
diffusion coefficient of water and diffusion coefficient
of a substance in the membrane . However, it is
difficult to determine these parameters experimental-
ly, and, therefore, the coefficients of diffusion and
osmotic permeability are used in calculations. With
a knowledge of the diffusion permeability coefficient,
we can evaluate the contribution of the diffusion flux
to the mass transfer. The coefficients of diffusion and
osmotic permeability can be determined experimen-
tally. This is done in membrane cells of various types.
The simplest cell is the flat-chamber cell . A dis-
advantage of this cell is that it does not reflect the hy-
drodynamics of real apparatus, e.g., of tubular type.
This disadvantage is not characteristic of the instal-
lation schematically shown in Fig. 1.
The installation comprises a membrane unit 1, ther-
mostated vessels with pumps for a solution under
study (2) and distilled water (3), and a set of valves 4.
The temperature of the solutions in tubes and inter-
tubular space is monitored with Chromel3Copel ther-
mocouples 5 connected to potentiometers 6, 7.
This installation is intended for studies of the dif-
fusion and osmotic permeability of polymeric mem-
branes for two-, three-, and multiple-component solu-
tions. It can also be used for experiments aimed to
examine the influence exerted by various kinds of
turbulators on the hydrodynamics of the annular chan-
nel and the effect of externally applied magnetic
and temperature fields on a solution being separated.
The membrane unit used in the process is shown in
Fig. 2. It comprises the following elements: cylin-
drical case 1 with flanges 2; porous tube 3 with mem-
Fig. 1. Schematic of a tubular flow-through installation.
For explanations see text; the same for Fig. 2.
Fig. 2. Schematic of the tubular membrane unit.