ISSN 0040-5795, Theoretical Foundations of Chemical Engineering, 2016, Vol. 50, No. 3, pp. 273–285. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © B.Ch. Balabekov, A.M. Brener, O.S. Balabekov, 2016, published in Teoreticheskie Osnovy Khimicheskoi Tekhnologii, 2016, Vol. 50, No. 3, pp. 281–293.
273
INTRODUCTION
Despite a large number of works devoted to study-
ing the processes of heat and mass transfer that occur
in the working area of heat transfer and heat- and
mass-transfer packing devices, methods of calculating
them from the point of view of general concepts have
remained poorly developed up to now, which allows
for reasonable developments for optimizing operating
and constructive parameters based on relatively simple
mathematical models.
In this regard, the development of effective models
of processes of heat and mass transfer for a wide range
of interaction rates of liquid and gas phases in order to
calculate local and average coefficients of heat and
mass transfer in the gas flow in the packed bed remains
a relevant area of research.
The aim of work is to develop approximate mathe-
matical calculations of the intensity of heat and mass
transfer in the operating zone of the tubular and pack-
ing device. Approaches for assessing the impact of the
layer depth of contact elements in the devices for wet
scrubbing of gases on the structure of gas flow, liquid
droplet trajectories [1], and heat- and mass-transfer
processes are proposed [2]. The obtained results may
be useful for calculations of many technological pro-
cesses carried out in tubular and packing wet-type
devices [3].
In this paper, we solve the problem of modeling
heat- and mass-transfer processes in the devices of
chemical technology under the following simplifying
assumptions [4, 5]:
1) flat flowing is considered;
2) the density of the droplets is much greater than
density of the gas;
3) the there are no large gradients of static pressure;
4) there are no significant gradients of the gas flow
rate, which may create force, perpendicular to the
direction of the relative rate of droplet, comparable in
magnitude to its weight;
5) the surface of the drop is taken to be close to
spherical and there is no primary winding of the drop;
6) heat- and mass-transfer processes that affect the
shape and size of droplet slightly perturb the gas flow
around the droplet at the same time.
Taking into account these assumptions, aerody-
namic drag force and the force of gravity drops acquire
prevail value.
THEORETICAL PART
Structure of the Mathematical Model
The processes of heat and mass transfer in the gas-
drop flow that flow in the packed bed that we consider
to be dry in the simulation are considered. A bundle of
tubes with cylindrical sections is considered to be
packing. The use of contact devices such as the pack-
ing of heat- and mass-transfer devices has been exper-
imentally investigated in the papers of O.S. Balabekov
et al. [6–8].
Numerical Modeling of Heat and Mass Transfer Processes
upon the Flowing of Regular Structures by Gas-Droplet Stream
B. Ch. Balabekov
a
, A. M. Brener
b
, and O. S. Balabekov
c
a
L.N. Gumilev Eurasian National University, Astana, Kazakhstan
b
M.O. Auezov South Kazakhstan State University, Shymkent, Kazakhstan
c
Shymkent State Pedagogical Institute, Shymkent, Kazakhstan
e-mail: chapaevich_62@mail.ru; chapaevich@fromru.com
Received January 12, 2015
Abstract—Approximate models are developed for calculating heat and mass transfer processes in gas-drop
flows that pass over a regular packed bed with cylindrical elements. A number of different flow regimes are
considered: flat laminar flow, the formation of the stationary vortex behind packing element and formation
of nonstationary vortex wake. Criterial equations for calculating corresponding mass transfer parameters are
obtained.
Keywords: mathematical modeling, numerical experiment, regular structures, gas-drop flow, heat and mass
transfer
DOI: 10.1134/S0040579516030039