Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 10, pp. 1827−1830.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
D.I. Misyulya, V.V. Kuz’min, V.A. Markov, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 10, pp. 1688−1691.
PROCESSES AND EQUIPMENT
OF CHEMICAL INDUSTRY
Reduction of Hydraulic Drag of Cyclones
D. I. Misyulya, V. V. Kuz’min, and V. A. Markov
Belarusian State Technological University, Minsk, Belarus
Received October 29, 2009
Abstract—Results of experimental examinations of a cyclone hydraulic drag with a developed new construction
of a untwisting device and elongated exhaust pipe were reported. An optimal number of the blades into the
untwisting device was determined.
One of most known common man-made air pollut-
ants are various kinds of dust contained in waste indus-
trial gases. The dust removal should be conducted in all
processes at which dusting occurs: drying and ﬁ ring of
granular and powder materials, ﬁ ne grinding and classiﬁ -
cation of polydisperse materials, pneumatic transportation
of bulky materials etc.
Cyclones are the widest centrifugal dust collectors.
Therewith they can be applied both as the ﬁ rst stage of
cleaning before ﬁ ne dust collector systems and as a single
cleaning stage .
Hydraulic drag of cyclones usually is essential por-
tion of total pressure loss in the gas cleaning systems .
Therefore an assessment of the cyclone drag and ﬁ nding
ways to reduce it are of great practical interest
Hydraulic drag of the vortex equipments depends on
a kinetic energy loss of rotational motion of an output
cleaned ﬂ ow. The untwisting devices that allow to convert
a rotational ﬂ ow velocity at apparatus outlet in axial and
to increase a static pressure, are used to reduce a drag
coefﬁ cient. In view of the design features and operational
principle the ﬂ ow untwisting devices are installed inside
or at outlet of the cyclone.
According to data of [3–5] the hydraulic losses in the
cyclone can be reduced with the aid of the untwisting
devices installed inside or at outlet of the cyclone with
no change in a puriﬁ cation coefﬁ cient. However there are
other suggestions [2, 5]. Also other methods, such as the
use of the exhaust pipe with slits  and the installation
inside the cyclone of a special rod  were proposed to
reduce the hydraulic drag of the cyclone.
For proper and complete consideration of the total
cyclone resistance the losses in it should be determines
by one of the two existing techniques : (a) the cyclone
is placed onto the blowing line of the fan system and the
gas ﬂ ow from the exhaust pipe is discharged in a large
volume or in environment, in this time we determine dif-
ference between total inlet pressure (in the pressurization
chamber) and a pressure in the volume after the cyclone
(in atmosphere); (b) the cyclone is placed onto any line
of the fan system: suction or injection, and followed by
a long straight section of pipe. Then a difference between
the total pressure at the cyclone inlet and a static pressure
on the wall of a straight outlet section on such a relative
distance when practically complete untwisting of the gas
ﬂ ow occurring (for cyclone TsN-15 this distance should
be at least 30 of the cyclone diameters).
The study of the hydraulic drag of the cyclone with
untwisting device and without it was performed under
the following conditions: dust-free air at 20°С in cyclone
TsN-15 made of Plexiglas, its internal diameter was
0.24 m with given  length of the exhaust pipe and also
with the exhaust pipe elongated from outside by value
equal to the cyclone diameter (0.24 m). The gas velocity