Fluid dynamics in continuous settler

Luna, Flávia Daylane Tavares de; Silva, A.G; Fukumasu, Newton Kiyoshi; Bazan, Ovandir; Gouveia, João Henrique Antoniazzi de; Moraes, Deovaldo de; Yanagihara, Jurandir Itizo; Vianna, Ardson S.

doi:10.1016/j.cej.2019.01.088

Cited by 17 publications

(10 citation statements)

References 25 publications

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“…All simulations were performed considering the BSL RSM turbulence model, which accurately represented the velocity profiles in the settler tank, validated with experimental data from PIV (Particle Image Velocimetry) in a previous paper [22].…”

Section: Resultsmentioning

confidence: 99%

“…For this study, the BSL-RSM turbulence model was used, which is a model capable of accurately predicting the oscillations that were generated from the turbulent flow inside settler tanks [22]. It is based on the solution of a transport equation for each one of the six components of the Reynolds stress tensor (Equation ( 7)), with an additional expression for the turbulent dissipation rate [23] [24].…”

Section: Turbulence Modelmentioning

confidence: 99%

“…The design of the used prototype followed the geometry of the industrial circular clarifiers that can serve as thickeners [26], with a volume of 5.24 × 10 −3 m 3 , also studied by Luna et al [22]. The original settler tank is composed by an inlet located on top of the equipment, and two outlets: one at the top (named here as clarified outlet) and the other at the center of the equipment base (named here as sludge outlet).…”

Section: Geometry and Meshmentioning

confidence: 99%

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The Influence of Geometry on the Fluid Dynamics of Continuous Settler

Luna¹,

Silva²,

Júnior³

2020

OJFD

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Settlers are broadly used by industries for separating components with different densities, because they show operational facilities and high efficiency. As they use the action of gravity, they can treat great quantities of effluents with lower energy expenditure. However, the performance of the settler depends on the streamlines inside the equipment, which, in turn, are influenced by the characteristics of the suspended solids, the geometry, and dimensions of the tank. In this paper, the effect of the settler geometry properties on the hydrodynamic in a vertical circular cylindrical tank was investigated. The evaluated parameters were the feed pipe design, the dimensions of the piece of equipment, and the structure of settler bottom. The numerical simulations were performed using the package ANSYS-CFX 16.0. It was considered a turbulent, isothermal, and stationary flow. The Euler-Euler multiphase model and BSL-RSM model turbulence were applied. The recirculation zones were influenced by the separation tank geometrical form. The modification of the feed pipe in the original project reduced the mixture inside the feedwell. The increase of the sedimentation tank diameter improved the performance of water and solid separation, elevating the efficiency by 10.48%, whilst the increase of the tank depth reduced the separation efficiency by 16.72%, in comparison to the original project.

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Section: Resultsmentioning

confidence: 99%

Section: Turbulence Modelmentioning

confidence: 99%

Section: Geometry and Meshmentioning

confidence: 99%

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The Influence of Geometry on the Fluid Dynamics of Continuous Settler

Luna¹,

Silva²,

Júnior³

2020

OJFD

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“…The computational fluid dynamics (CFD) is the numerical branch of fluid mechanics. The basic equations of mass, momentum, and energy balances are differential equations that may mathematically represent, through the models, a huge number of physical phenomena, such as multiphase flows [27], reactive flows [28,29], and industrial equipment [30].…”

Section: Computational Fluid Dynamicsmentioning

confidence: 99%

Enzymatic Degradation of 2,4,6-Trichlorophenol in a Microreactor using Soybean Peroxidase

et al. 2020

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Soybean peroxidase is an enzyme extracted from soybean seed hulls. In the presence of hydrogen peroxide, the enzyme has the potential to catalyze the biodegradation of toxic substances like chlorophenols. For this reason, its use in wastewater treatment processes is environmentally friendly since the enzyme can be obtained from a renewable and abundant raw material. In this work, enzymatic biodegradation of 2,4,6-trichlorophenol performed by soybean peroxidase in a microreactor was studied experimentally and theoretically. The experimental data set was obtained with a volume of 250 μL by using different soybean peroxidase concentrations and different reaction times. The fluid dynamics of the microreactor was modeled as well, using ANSYS CFX. The simulations exhibited secondary flows, which enhanced mixing. Although the laminar flow was developed, it can be assumed to be a well-mixed medium. The kinetic data were evaluated through a mechanistic model, the modified bi-bi ping-pong model, which is adequate to represent the enzymatic degradation using peroxidases. The model was composed of an initial value problem for ordinary differential equations that were solved using MATLAB. Some kinetic constants were estimated using the least square function. The results of the model fit well the experimental data.

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“…2), что при учете реального профиля несущей среды наблюдается процесс псевдофракционирования монодисперсной взвеси из-за неравномерности профиля скорости. Если определить коэффициент сепарации, как ξ = N (1) /N (2) , и сравнить его значения с результатами пилотного эксперимента [21] по осаждению монодисперсных частиц карбоната кальция размеров 10, 25, 50, 100 и 250 µm в восходящем водном потоке в вертикальном гидроклассификаторе со скоростью v f = 7.5 • 10 −3 m/s (рис. 3), то некоторое отличие для фракции мелких частиц может быть объяснено иным условием входа несущей среды (с разворотом потока), вызывающим отклонение от ламинарного течения дисперсионной фазы [22].…”

Section: анализunclassified

Математическая Модель Фракционирования Малоконцентрированной Дисперсной Фазы Суспензии В Плоском Вертикальном Гидроклассификаторе

Ряжских¹

2020

Журнал Технической Физики

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Based on the hypothesis of a continuous continuum and balance of phase flows, a mathematical model of the transfer of a low-concentration suspension in the absence of mixing in a flat vertical gravity classifier with a laminar flow regime of a carrier medium without limitation on the sedimentation rate of particles is proposed. Analytical relations are obtained for calculating local countable functions of the particle size distribution density. A computational experiment confirmed the fractionation of a monodisperse suspension and the presence of small particles in the “heavy” fraction of polydisperse suspensions due to the small velocity of the dispersion medium in the “wetted” surfaces of the hydroclassifier. The results are consistent with the known experimental data and calculations using classical kinetic models.

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Fluid dynamics in continuous settler

Cited by 17 publications

References 25 publications

The Influence of Geometry on the Fluid Dynamics of Continuous Settler

The Influence of Geometry on the Fluid Dynamics of Continuous Settler

Enzymatic Degradation of 2,4,6-Trichlorophenol in a Microreactor using Soybean Peroxidase

Математическая Модель Фракционирования Малоконцентрированной Дисперсной Фазы Суспензии В Плоском Вертикальном Гидроклассификаторе

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