Search results for "Complete suspension"

showing 4 items of 4 documents

ASSESSMENT OF THE MINIMUM POWER REQUIREMENTS FOR COMPLETE SUSPENSION IN TOP-COVERED UNBAFFLED STIRRED TANKS

2012

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciSettore ING-IND/25 - Impianti ChimiciComplete suspension power number unbaffled stirred tanks solid liquid suspension mixing
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CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of the minimum impeller speed for complete suspension

2012

Abstract In the literature on mechanically agitated solid–liquid systems, several methods are described to estimate the minimum impeller speed Njs at which all particles are suspended, but few studies have been devoted so far to their critical comparative assessment [67] . In the present paper, several alternative Njs prediction methods are applied to CFD results obtained for selected test cases covering a broad range of suspension conditions and impeller speeds. Results are compared with one another and with classic empirical correlations [88] . The aim of the work is to assess the adequacy of different methods for predicting Njs and, more generally, to contribute to a viable CFD-based str…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciWork (thermodynamics)Engineeringbusiness.industrySettore ING-IND/25 - Impianti ChimiciGeneral Chemical EngineeringMixing (process engineering)Mechanical engineeringGeneral ChemistryMechanicsStirred tank Multi-fluid model Computational fluid dynamics Solid–liquid two-phase flow Complete suspension speed Sufficient suspension speed Unsuspended solids criterionComputational fluid dynamicsIndustrial and Manufacturing EngineeringControl volumeImpellerEnvironmental ChemistrySuspension (vehicle)Reynolds-averaged Navier–Stokes equationsbusinessContactorChemical Engineering Journal
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CFD Predictions of Sufficient Suspension Conditions in Solid-Liquid Agitated Tanks

2012

Abstract Most research efforts on mechanically agitated solid-liquid contactors have been devoted to the assessment of the minimum impeller speed for complete off-bottom suspension, N js . Actually, many industrial vessels are operated at impeller speeds slightly lower than N js (Oldshue, 1983; Rieger et al., 1988). This suggests that the sufficient suspension condition, which is quantitatively specified in this paper by introducing a suitably defined quantity N ss , may represent a valid alternative to that of complete suspension. In the present work time-dependent RANS simulations were carried out with the aim of predicting the achievement of sufficient suspension conditions. The Eulerian…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicistirred tank Computational Fluid Dynamics (CFD) solid-liquid suspension complete suspension Unsuspended Solid Criterion (USC) sufficient suspensionMaterials sciencebusiness.industrySettore ING-IND/25 - Impianti ChimiciApplied MathematicsComputational MechanicsGeneral Physics and AstronomyStatistical and Nonlinear PhysicsComputational fluid dynamicsChemical engineeringMechanics of MaterialsModeling and SimulationSettore ING-IND/06 - FluidodinamicabusinessSuspension (vehicle)Engineering (miscellaneous)Solid liquidInternational Journal of Nonlinear Sciences and Numerical Simulation
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Solid–Liquid Suspensions in Top-Covered Unbaffled Vessels: Influence of Particle Size, Liquid Viscosity, Impeller Size, and Clearance

2014

Particle suspension in liquids is a unit operation commonly encountered in the process industry. Although it is usually carried out in baffled stirred tanks, there are some specific applications where the presence of baffles may be undesirable. In the present work solid-liquid suspensions are investigated in a radially stirred unbaffled tank provided with a top cover. The minimum impeller speed at which all solid particles get suspended (Njs) and the relevant power requirements (Pjs) are assessed. The dependence of these two parameters on physical properties (liquid viscosity, particle concentration, and size) and system geometrical configurations (impeller diameter and clearance) is invest…

Work (thermodynamics)Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciMaterials scienceChromatographyGeneral Chemical EngineeringSettore ING-IND/25 - Impianti ChimiciLiquid viscosityBaffleGeneral ChemistryMechanicsUnit operationSOLID-LIQUID SUSPENSIONIndustrial and Manufacturing EngineeringImpellerSOLID-LIQUID MIXINGParticlesolid liquid suspension stirred tank Njs unbaffled vessel complete suspension power requirementsParticle sizeUNBAFFLED STIRRED VESSELSSolid liquid
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