Chemical and Petroleum Engineering, Vol. 54, Nos. 1–2, May, 2018 (Russian Original Nos. 1–2, Jan.–Feb., 2018)
0009-2355/18/0102-0071 ©2018 Springer Science+Business Media, LLC
Platov South-Russia State Polytechnic University, Novocherkassk, Russia; e-mail: email@example.com. Translated from Khimicheskoe i
Neftegazovoe Mashinostroenie, No. 2, pp. 3–5, February, 2018.
RESEARCH, DESIGN, CALCULATIONS,
AND OPERATING EXPERIENCE
PROCESSES AND EQUIPMENT FOR CHEMICAL
AND OIL-GAS PRODUCTION
HYDRODYNAMIC CHARACTERISTICS OF
CLASSIFICATION PROCESS IN PNEUMATIC
CLASSIFIER WITH CONTINUOUS SHELVES
V. A. Kirsanov and M. V. Kirsanov UDC 66.011:66.021.1
The results of a study of the processes in a gravitational pneumatic classiﬁ er having a cascade of inclined
continuous shelves, which allows determination of the hydrodynamic characteristics of their operation, are
presented. It is shown that local formations with high concentration of particles are formed periodically in the
near-wall region of the apparatuses. Analysis of video recordings of the fast process showed that the descending
near-wall formations exert an adverse effect on the efﬁ ciency of classiﬁ cation of polydisperse materials.
Keywords: air classiﬁ cation, polydisperse material, gravitational pneumatic classiﬁ cation, continuous shelves,
hydrodynamic characteristics of the process, near-wall formation, structure of air ﬂ ow.
Dispersed materials, which are separated into fractions having speciﬁ c properties for technological reasons, are pro-
cessed in many chemical enterprises. Amongst a multiplicity of classifying techniques, apparatuses utilizing the energy of
ascending air ﬂ ow are used widely. Vertical apparatuses having a cascade of inclined continuous plates facilitate generation
of inertial forces, allow enlargement of surface and extension of phase contact time, formation of materials recleaning stages,
substantial shortening of the separation channel height, and provide the possibility of separation process implementation at
increased solid phase concentrations . However, despite the advantage of shelf apparatuses over hollow or zigzag classiﬁ -
ers , the separation efﬁ ciency of shelf apparatuses is not high, so search for ways of enhancing their efﬁ ciency by improv-
ing the shelf design is pressing [3, 4].
Studies of the pattern of two-phase ﬂ ow motion in the shelf space of the air classiﬁ er (based on materials of specially
executed movie recording) [5, 6] showed that the ﬂ ow is not unitary, but is split into individual vortexes. Between the vortexes
occurs directed mass transfer, which ensures the required efﬁ ciency of the process. In this physical pattern  of the separa-
tion process, the inﬂ uence of wall effects (deceleration, near-wall turbulence, descending motion of individual groups of
particles, etc. [3, 7, 8]) on the hydrodynamic conditions in the apparatus is ignored.
In this article, the causes of inadequate efﬁ ciency of operation of pneumatic classiﬁ ers having cascaded continuous
shelves are explained by the peculiarities of the hydrodynamic condition in the separation channel of this apparatus, which exerts
considerable inﬂ uence on the process of suspension and separation of particles. To disclose these peculiarities, the classiﬁ cation
process was video-recorded by a Panasonic 500M video camera at 25 fps, for which the rear wall of a prototype apparatus was