Dmitry V. Voronin *, Vyacheslav L. Istomin and Konstantin A. Khlebus Pages 318 - 325 ( 8 )
Background: One of the labor-consuming and dangerous operations in technological process of processing reactors is the one on transportation of firm wastes, as it is necessary to take into account the danger of materials to an environment and their harmful influence on health of the attendants and population.
Objective: The recent paper is devoted to theoretical and experimental study of two phase (particle/air) media propagation inside a pipeline (part of pulsed pneumatic transport devices where materials are delivered to containers) with attention on possible harm influence of the flow on the tube walls, especially at the pipelines bends.
Methods: Physical model corresponds to experimental study described in the patents. Numerical modeling was performed within the framework of model of non-stationary two-dimensional motion of ideal compressible media on the basis of laws of conservation of mass, momentum and energy. The thermodynamic flow field has been computed both in gas and solid phases.
Results: Processes of particles mutual interactions, coalescence, fragmentation, interaction with a tube surface and motion have been investigated in detail. Interface borders have been considered as contact discontinuity surfaces. Modeling was performed numerically on the basis of the method of individual particles. The comparison of the computational and experimental data stated in patents was executed as well.
Conclusion: It was found that the greater the radius of the pipeline bend R, the smaller value of gas pressure we have in the bend, but this effect becomes insignificant for R > 2.2m. The values of gas velocity at the bend have little variations depending on R. For small values of R (close to right angle of the bend) inverse motion of the particles is possible that may result in blocking of the flow. The formation of jet (consisting of particles) may take place at changing of radius R value (up to R = 1m). This may lead to sufficient damage to pipeline walls. At R > 4m volumetric concentration of particles starts to grow at the outer wall of the bend and effect of fragments dragging takes place that is also harmful for device operation. So if the value of radius R belongs to the interval (1.5; 3.5)m, we have minimal damage for the system operation.
Conservation laws, gas, modeling, particles, pipeline, pneumatic transportation, pressure, velocity.
Lavrentyev Institute of Hydrodynamics of Siberian Branch of Russian Academy of Science, Novosibirsk 630090, Lavrentyev Institute of Hydrodynamics of Siberian Branch of Russian Academy of Science, Novosibirsk 630090, Lavrentyev Institute of Hydrodynamics of Siberian Branch of Russian Academy of Science, Novosibirsk 630090