ISSN 1070-4272, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 10, pp. 1676!1679. + Pleiades Publishing, Ltd., 2007.
Original Russian Text + O.A. Abonosimov, S.I. Lazarev, S.V. Kovalev, 2007, published in Zhurnal Prikladnoi Khimii, 2007, Vol. 80, No. 10,
PROCESSES AND EQUIPMENT
OF CHEMICAL INDUSTRY
A Study of the Longitudinal Agitation Coefficient
in Roll Elements of Baromembrane Apparatus
O. A. Abonosimov, S. I. Lazarev, and S. V. Kovalev
Tambov State Technical University, Tambov, Russia
Received December 25, 2006
Abstract-Longitudinal agitation coefficient in industrial baromembrane roll apparatus was studied for
two types of separating elements in relation to the motion velocity and pressure of the flow in the apparatus.
Dependences of the longitudinal agitation coefficients on hydrodynamic parameters of baromembrane
apparatus were analyzed and explained.
The aim of this study was to examine the effect of
hydrodynamic parameters of industrial baromembrane
apparatus with roll separating elements on the pro-
cesses of substance transfer across membranes.
The hydrodynamic structure of the flow in a mem-
brane unit strongly affects the mass transfer in baro-
membrane separation of solutions. In these units, fluid
flows, as a rule, occupy an intermediate position in
their structure between two idealized limiting cases,
piston-flow and complete-mixing modes.
To evaluate the effect of longitudinal agitation on
the separating characteristics of a baromembrane unit,
it is necessary to have data on longitudinal agitation
coefficients. For this purpose, the longitudinal agita-
tion coefficient in baromembrane units was exper-
To determine the longitudinal agitation coefficient,
we used the known method of introducing a perturba-
tion in a certain cross-section of the flow and record-
ing the consequences (response of the system) in
another cross-section. In experimental studies, we
used the method of pulsed introduction of a tracer
(20% aqueous solution of NaCl), with the elution
curve subsequently recorded at the outlet of the mem-
brane unit. The amount of the tracer introduced was
varied, depending on the unit operation mode, and was
chosen to use 60% of the scale of the measuring in-
strument (KSM-4). This was done because the varia-
tion of the solution concentration in the unit is small
within this range and the displacement of the rhe-
ochord slide is proportional to changes in concentra-
The experimental installation used to determine
the longitudinal agitation coefficient is shown sche-
matically in Fig. 1.
The installation comprised the following elements:
reverse-osmosis separating apparatus 1; input-solution
tank 2; high-pressure pump 3; choke 4; rotameters 5
and 6 for retentate and permeate, respectively; gage 7;
Fig. 1. Schematic of the experimental installation. For
explanations, see text.