Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 3, pp. 523−526.
Pleiades Publishing, Ltd., 2012.
Original Russian Text
A.M. Kagan, A.S. Pushnov, 2011, published in Khimicheskaya Promyshlennost’, 2011, Vol. 88, No. 7, pp. 402−406.
PROCESSES AND DEVICES
OF CHEMICAL MANUFACTURES
Inﬂ uence of the Diameter of Perforation Holes on Operating
Indices of Irregular Heat and Mass Transfer Packing
A. M. Kagan and A. S. Pushnov
Moscow State University of Environmental Engineering, Moscow, Russia
Received July 23, 2011
Abstract—The inﬂ uence of the diameter of perforation holes on the operation main indices of irregular metal heat
and mass transfer packing is considered.
The perforation of irregular heat and mass transfer
packing is widely used as the means of improvement of
their mass exchange and hydrodynamic characteristics.
This, in particular, is discussed in [1–4].
In  the inﬂ uence of the area of perforation, S
But at determination of the necessary perforation the
evaluation of the most rational area of perforation is not
the oly problem. It is also necessary to know the rational
diameter of holes, d
, their number, n, and the place of the
holes location on the surface of the packing. The number
of holes at known value S
can be easily calculated,
if the optimal value d
is known. It seems logical to
determine the position of holes due to following reason:
for each of holes there should be, when possible, equal
fraction of surface of the packing element.
It seems reasonable to make evaluation of the rational
diameter of holes on the basis of consideration of the mo-
tion of ﬂ ows of gas and liquid through a single packing
First of all let us consider the inﬂ uence of d
loss in pressure of non-irrigated packing ΔР
. To simplify
the analysis, let us consider the motion of ﬂ ows in the
packing element in a form of ring, which has horizontal
orientation in the layer of packing (Fig.1).
Both in the case of irrigation and without it, the ele-
ment is almost completely washed by gas (excluding
the area deadened in places of contact of neighboring
elements with each other). The inﬂ uence of dimensions
of holes should be analyzed by comparing the effect of
this inﬂ uence at different values of d
and the constant
area of perforation.
First let us consider the motion of ﬂ ows of gas in
non-irrigated and non-perforated element of the packing
Let us indentify the amount of gas leaving the ele-
ment through its opened ring end G
The amount of
gas leaving the element through its opened ring end is
. For non-perforated packing, obviously, G
The velocity of gas, passing through the element, w, cor-
responds to the amount of gas, coming into the layer of
packing, G, m
/h. Also certain hydraulic resistance of
the dry layer of packing made of non-perforated packing
corresponds to this load.
At the realization of perforation at some dimension
of holes equal d
, at G= const and S
= const G
w remain constant. Therewith, some of gas coming into
the element goes through holes and leaves through them,
decreases with the remaining balance:
. The conditions of gas passing through
the layer of packing become easier and that is why the
losses in pressure in the layer of packing decrease.
Let us discuss what changes occur, when the holes
of perforation are bigger, d
also at G = const and
= const. In this case G
and w should retain their