THE NUMERICAL MODELING OF A FLOW IN PLANE AND RADIAL CONTACT UNITS WITH A STILL GRANULAR LAYER
THE NUMERICAL MODELING OF A FLOW IN PLANE AND RADIAL CONTACT UNITS WITH A STILL GRANULAR LAYER
Дата публикации статьи в журнале: 8.08.2019
Название журнала: Американский Научный Журнал, Выпуск: № (27) / 2019, Том: 1, Страницы в выпуске: 42-45
Автор: Koleskin Vladimir Nikolaevich
Yaroslavl, Yaroslavl State Pedagogical University by K.D. Ushinsky, Cand. Sc. Techn
Yaroslavl, Yaroslavl State Pedagogical University by K.D. Ushinsky, Cand. Sc. Techn
Автор: Lukyanova Antonina Vladimirovna
Yaroslavl, Yaroslavl State Pedagogical University by K.D. Ushinsky, Cand. Sc. Phys.-Math
Yaroslavl, Yaroslavl State Pedagogical University by K.D. Ushinsky, Cand. Sc. Phys.-Math
Анотация: Abstract. Attempts of strict mathematical modeling heterogeneous media that are made in some
investigations are necessarily limited by some prior specified theoretical schemes and this fact requires many
experimental data for a practical realization. The analysis of known works shows that a physical essence of
processes arising at a liquid or gas motion in contact units is insufficiently studied. In articles dealt with a
mechanics of disperse systems, issues of constructing computational and theoretical models of concrete industrial
devices that would took into account basic experimental facts and sufficiently simple from engineer’s point of
view are poorly reflected.
The experience of an operation of chemical reactors shows that technical and economic indicators of an
industrial process are as a rule lower than evaluated values that were obtained during a design step. Now it can be
considered proven that one of the reasons that affects a reactor capacity is heterogeneity of a reagent flow in a
granular catalyst layer.
In some works [1], [2], [3], [4] computational and theoretical models of a filtration mode of a liquid and gas
flow in the still granular layer that is in a stress-strain state under a load from the carrier phase were proposed.
Results calculated according these models are in a qualitative agreement with experimental data and a large-scale
heterogeneity of a velocity profile corresponds to a scale of granular layer structure heterogeneity. But using
Darcy’s law or Ergun’s equation to describe a motion of the carrier phase in an inhomogeneous granular medium
requires a justification because a formation of boundary layersis possible along borders of the areas with a different
permeability.
In radial units with the still granular layer (SGL) it is considered that the large-scale heterogeneity of a radial
component of the velocity in the granular layer is caused mostly by reagent flow features in distributing and
collecting manifolds. So a majority of works dealt with such units investigates a flow with a suction or injection
in channels with perforated walls. A distribution along a distributing manifold length of a cross-section average
value of an axial component of the velocity flow was determined by Meshcherskiy’s equation, an energy approach,
models of potential flows in [5], [6], [7] an so on. The main task was to provide the stable radial velocity at entering
the granular layer.
From the above review a conclusion can be made that physical features of the liquid and gas motion in SGL
are poorly explored both theoretically and experimentally. For example, conflicting results of measuring the
velocity profile in axial units with SGL, a variety of motion equations used for calculation, a lack of information
about a volume structure of the granular layer that arises during loading the unit and so on testify it.
So there is a necessity to construct computational and theoretical models of concrete industrial units that
would took into account basic properties of a technological process and were sufficiently simple engineer’s
solutions for designing new technological systems
Ключевые слова: chemical reactor steam-raw mixture reagent large-scale heterogeneity catalyst perforated channel manifold working area velocity field velocity field
DOI:
Данные для цитирования: Shtern Pavel Gennag’evich Koleskin Vladimir Nikolaevich Lukyanova Antonina Vladimirovna. THE NUMERICAL MODELING OF A FLOW IN PLANE AND RADIAL CONTACT UNITS WITH A STILL GRANULAR LAYER. Американский Научный Журнал. Химические науки. 8.08.2019; № (27) / 2019(1):42-45.