CFD modeling of dilute phase pneumatic conveying in a horizontal pipe using Euler–Euler approach
TL;DR: In this article, the behavior of dilute phase pneumatic conveying of plastic pellets in a horizontal circular pipe was investigated, and a simulation was performed to investigate the behavior.
Abstract: Computational fluid dynamics simulations were performed to investigate the behavior of dilute phase pneumatic conveying of plastic pellets in a horizontal circular pipe. The pellets are 200 µm in d...
Citations
More filters
TL;DR: In this paper, a comprehensive validated numerical model simulating the pneumatic transport of fine particles through various geometries has been developed using Computational Fluid Dynamics (CFD).
36 citations
01 Jan 2016
TL;DR: Pneumatic Conveying and Handling of Particulate solids: A Handbook of Pneumatic-Conveying Engineering as discussed by the authors and a Guide for Handling of Bulk Solids.
Abstract: Encyclopedia of Chemical Processing and DesignProceedings of Australian Society of Sugar Cane TechnologistsPneumatic Conveying Design GuideDas Jagdfries des PhilipsgrabesChemical EngineeringPneumatic Conveying of SolidsEncyclopedia of Chemical Processing and DesignPneumatic Conveying SystemsMikrobiologische Analysen: Richtlinien zur QualitätssicherungPneumatic Conveying Design GuideBester Timur EverPlant Equipment & Maintenance Engineering Handbook2nd International Conference Fly Ash Disposal & Utilisation, 2-4 February 2000, New Delhi, IndiaChemical Engineering DesignPneumatic Conveying Design GuideEncyclopedia of Chemical Technology: Composite materials to detergencyChemical Engineering DesignCoco und das Geheimnis des GlücksTransportvorgänge in der VerfahrenstechnikChemical Engineering ProgressHandbook of Conveying and Handling of Particulate SolidsPneumatic Conveying Design GuideBulk Solids HandlingBritish BusinessBulk 2000Chemical Engineering: Chemical engineering designHandling Agricultural MaterialsPneumatic Conveying Design GuideEncyclopedia of Chemical TechnologyHandbook of Pneumatic Conveying EngineeringAbbreviated Guide, Pneumatic Conveying Design GuideAbbreviated GuideJournal of Applied MechanicsMultiphase Flow HandbookConference ProceedingsCharacterisation of Bulk SolidsFreight PipelinesHandbook of Pneumatic Conveying
34 citations
TL;DR: In this paper, the authors investigated the gas-solid flow in a horizontal pipe using the Eulerian-Eulerian modeling approach for a particle size range of 2'μm≤dp≤20'm at solid volume fra...
Abstract: The present work deals with the investigation of the gas-solid flow in a horizontal pipe using the Eulerian-Eulerian modeling approach for a particle size range of 2 μm≤dp≤20 μm at solid volume fra...
13 citations
TL;DR: In this paper, the role of interparticle and particle-wall collisions in conjunction with pertinent parameters in an abrupt expansion pipe was investigated, such as the pressure recovery and the acceleration length.
9 citations
References
More filters
TL;DR: In this paper, the authors studied the flow of an idealized granular material consisting of uniform smooth, but nelastic, spherical particles using statistical methods analogous to those used in the kinetic theory of gases.
Abstract: The flow of an idealized granular material consisting of uniform smooth, but nelastic, spherical particles is studied using statistical methods analogous to those used in the kinetic theory of gases. Two theories are developed: one for the Couette flow of particles having arbitrary coefficients of restitution (inelastic particles) and a second for the general flow of particles with coefficients of restitution near 1 (slightly inelastic particles). The study of inelastic particles in Couette flow follows the method of Savage & Jeffrey (1981) and uses an ad hoc distribution function to describe the collisions between particles. The results of this first analysis are compared with other theories of granular flow, with the Chapman-Enskog dense-gas theory, and with experiments. The theory agrees moderately well with experimental data and it is found that the asymptotic analysis of Jenkins & Savage (1983), which was developed for slightly inelastic particles, surprisingly gives results similar to the first theory even for highly inelastic particles. Therefore the ‘nearly elastic’ approximation is pursued as a second theory using an approach that is closer to the established methods of Chapman-Enskog gas theory. The new approach which determines the collisional distribution functions by a rational approximation scheme, is applicable to general flowfields, not just simple shear. It incorporates kinetic as well as collisional contributions to the constitutive equations for stress and energy flux and is thus appropriate for dilute as well as dense concentrations of solids. When the collisional contributions are dominant, it predicts stresses similar to the first analysis for the simple shear case.
2,631 citations
Additional excerpts
...It is calculated by Lun et al. (1984)....
[...]
...…Þ chs þØgs ð15Þ Diffusion coefficient for granular energy (khs ) is given by Syamlal, Rogers, and O’brien (1993) and the collisional dissipation of energy (chs ) is given by Lun et al. (1984). khs ¼ 15dsqsas ffiffiffiffiffiffiffi hsp p 4 41 33gð Þ � 1þ 12 5 g2 4g 3ð Þasg0;ss þ 16 15p 41 33gð…...
[...]
TL;DR: In this article, the authors propose constitutive relations and boundary conditions for plane shear of a cohesionless granular material between infinite horizontal plates, and show that not all the material between the plates participates in shearing and the solutions for the shearing material are coupled to a yield condition for the non-shearing material to give a complete solution of the problem.
Abstract: Within a granular material stress is transmitted by forces exerted at points of mutual contact between particles. When the particles are close together and deformation of the assembly is slow, contacts are sustained for long times, and these forces consist of normal reactions and the associated tangential forces due to friction. When the particles are widely spaced and deformation is rapid, on the other hand, contacts are brief and may be regarded as collisions, during which momentum is transferred. While constitutive relations are available which model both these situations, in many cases the average contact times lie between the two extremes. The purpose of the present work is to propose constitutive relations and boundary conditions for this intermediate case and to solve the corresponding equations of motion for plane shear of a cohesionless granular material between infinite horizontal plates. It is shown that, in general, not all the material between the plates participates in shearing, and the solutions for the shearing material are coupled to a yield condition for the non-shearing material to give a complete solution of the problem.
1,563 citations
"CFD modeling of dilute phase pneuma..." refers background or methods in this paper
...For higher wall roughness (i.e., higher specularity coefficient), the collision of particles with wall tends to be more diffusive (Johnson and Jackson 1987), producing high shear at the wall....
[...]
...Many of them have found that there is a significant effect on the predicted results from “specularity coefficient” which is implemented in Johnson and Jackson particle–wall boundary conditions (Johnson and Jackson 1987)....
[...]
...According to Johnson and Jackson (1987), the specularity coefficient describes the large-scale roughness of the wall surface, however, according to some other authors, it also depends on particle material properties and pipe orientation (Zhu et al. 2004; Patro and Dash 2014a)....
[...]
...The model developed by Johnson and Jackson (1987) for tangential momentum transfer at the wall is used to calculate the particle slip velocity at the wall....
[...]
01 Dec 1993
TL;DR: This report describes the MFIX (Multiphase Flow with Interphase exchanges) computer model, a general-purpose hydrodynamic model that describes chemical reactions and heat transfer in dense or dilute fluid-solids flows, flows typically occurring in energy conversion and chemical processing reactors.
Abstract: This report describes the MFIX (Multiphase Flow with Interphase exchanges) computer model. MFIX is a general-purpose hydrodynamic model that describes chemical reactions and heat transfer in dense or dilute fluid-solids flows, flows typically occurring in energy conversion and chemical processing reactors. MFIX calculations give detailed information on pressure, temperature, composition, and velocity distributions in the reactors. With such information, the engineer can visualize the conditions in the reactor, conduct parametric studies and what-if experiments, and, thereby, assist in the design process. The MFIX model, developed at the Morgantown Energy Technology Center (METC), has the following capabilities: mass and momentum balance equations for gas and multiple solids phases; a gas phase and two solids phase energy equations; an arbitrary number of species balance equations for each of the phases; granular stress equations based on kinetic theory and frictional flow theory; a user-defined chemistry subroutine; three-dimensional Cartesian or cylindrical coordinate systems; nonuniform mesh size; impermeable and semi-permeable internal surfaces; user-friendly input data file; multiple, single-precision, binary, direct-access, output files that minimize disk storage and accelerate data retrieval; and extensive error reporting. This report, which is Volume 1 of the code documentation, describes the hydrodynamic theory used in the model: the conservation equations,more » constitutive relations, and the initial and boundary conditions. The literature on the hydrodynamic theory is briefly surveyed, and the bases for the different parts of the model are highlighted.« less
930 citations
Additional excerpts
...…¼ 0 ð8Þ r � ðasqs~vs~vsÞ ¼ asrP þr � �ss þ asqs~g Ksg ~vs ~vg � rPs þ~Flift;s þ~Ftd;s ð9Þ �ss ¼ asls r~vs þr~vTs � þ as ks 2 3 ls � � r �~vs�I ð10Þ ls has contributions from collisional (Gidaspow et al. 1992; Syamlal, Rogers, and O’brien 1993) and kinetic (Syamlal, Rogers, and O’brien 1993) parts....
[...]
...3 2 r � qsas~vshsð Þ½ � ¼ Ps�I þ �ss � � : r~vs þr � khsrhsð Þ chs þØgs ð15Þ Diffusion coefficient for granular energy (khs ) is given by Syamlal, Rogers, and O’brien (1993) and the collisional dissipation of energy (chs ) is given by Lun et al. (1984). khs ¼ 15dsqsas ffiffiffiffiffiffiffi hsp p 4…...
[...]
01 Jan 1991
TL;DR: Rigorous methods of kinetic theory were used to derive particular phase viscosities and granular conductivities This new kinetic theory predicted flow behavior and oscillations in a complete loop of a CFB as discussed by the authors.
Abstract: Rigorous methods of kinetic theory were used to derive particular phase viscosities and granular conductivities This new kinetic theory predicted flow behavior and oscillations in a complete loop of a CFB The results were compared to computations with imposed gas phase turbulence in the rise The computations were repeated for production of synthesis gas from char 6 refs, 12 figs, 3 tabs
716 citations
"CFD modeling of dilute phase pneuma..." refers methods in this paper
...Ps ¼ asqshs þ 2qs 1þ essð Þa2s g0;sshs ð20Þ The Gidaspow model (Gidaspow et al. 1991) which is a combination of the Wen and Yu model and the Ergun equation is used for the calculation of gas–solid exchange coefficient....
[...]
TL;DR: In this paper, a measure of random motion of granular particles is introduced as a new internal variable and the constitutive equations for fully fluidized granular materials are derived by using a simple kinematical model of the collision of particles.
Abstract: Equations for fully fluidized granular materials are proposed and are solved in a simple case. In fully fluidized granular materials, the granular particles slip or collide with each other and energy is dissipated. In describing the energy dissipation process characteristic to granular materials, a measure of random motion of granular particles is introduced as a new internal variable. We derive the constitutive equations by using a simple kinematical model of the collision of particles. The set of equations for fully fluidized granular materials obtained has properties similar to the equations that describe turbulence. For reasonable assumptions, these equations predict the results of Bagnold, namely that the shear and normal stress depend upon the square of the velocity gradient. In case of steady one-dimensional gravity flow the calculated flow profiles resemble experimental ones.
395 citations
"CFD modeling of dilute phase pneuma..." refers background in this paper
...The radial distribution function is defined according to Ogawa, Umemura, and Oshima (1980). g0;ss ¼ 1 as as;max � �1...
[...]