Improvement of the Performances of a Gas-Inducing System for Application in Wastewater Treatment

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Rodolphe Sardeing ◽  
Catherine Xuereb ◽  
Martine Poux
Keyword(s):  
Fluid Dynamics ◽  
Mass Transfer ◽  
Computational Fluid Dynamics ◽  
Wastewater Treatment ◽  
Biological Treatment ◽  
Gas Flooding ◽  
Computational Fluid Dynamics Cfd ◽  
Wastewater Biological Treatment ◽  
New System

Turboxal™, a mixing system used for the oxygenation and the mixing of wastewater biological treatment tanks previously studied, shows a low gas flooding rate. In order to increase the gas flooding rate, two of the three impellers used are replaced by only one new turbine. This new turbine comes from a previous work and has been designed partially by computational fluid dynamics (CFD). The gas flooding rate of the new system, called Turboxal-2™, is increased of about 120% on average compared to the Turboxal™ standard and the mass transfer capacities of the new system are quite similar to those of the previous device.

The Application of Computational Fluid Dynamics (CFD) in Wastewater Biological Treatment Field

2014 ◽  
Vol 507 ◽  
pp. 711-715
Author(s):  
Si Mai Peng ◽  
Yi Di Chen ◽  
Wan Qian Guo ◽  
Shan Shan Yang ◽  
Qing Lian Wu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Membrane Bioreactor ◽  
Flow State ◽  
Activated Sludge Reactor ◽  
Computational Fluid Dynamics Cfd ◽  
Ultimate Purpose ◽  
Wastewater Biological Treatment

Computational fluid dynamics (CFD), which is a widely used technique, has been applied to the wastewater biological treatment field recently. It can clearly reveal the inner flow state that is the hydraulic condition of a biological reactor. In engineering, it is able to guide the optimization, and even the design. This paper reviews the application of CFD in the main biological reactors, including: stabilization pond, membrane bioreactor and activated sludge reactor. In addition, the existing difficulties are thoroughly analyzed from three aspects: the current researches, the limitation of the studies and the reasons of the limitation. The ultimate purpose of this review is to point out the developing direction of the research and to inspire researchers to expand the use of CFD in this field.

CFD Modelling of Multiphase Flows: An Overview

2003 ◽  
Author(s):  
Rajnish K. Calay ◽  
Arne E. Holdo
Keyword(s):  
Fluid Dynamics ◽  
Mass Transfer ◽  
Computational Fluid Dynamics ◽  
Numerical Modeling ◽  
Mathematical Models ◽  
Cfd Modelling ◽  
Two Phase ◽  
Wide Range ◽  
Computational Fluid Dynamics Cfd ◽  
Numerical Modeling Of Flows

The Computational Fluid Dynamics (CFD) is now increasingly being used for modeling industrial flows, i.e. flows which are multiphase and turbulent. Numerical modeling of flows where momentum, heat and mass transfer occurs at the interface presents various difficulties due to the wide range of mechanisms and flow scenarios present. This paper attempts to provide a summary of available mathematical models and techniques for two-phase flows. Some comments are also made on the models available in the commercially available codes.

The use of computational fluid dynamics (CFD). Technique for evaluating the efficiency of an activated sludge reactor

1999 ◽  
Vol 39 (10-11) ◽  
pp. 329-332 ◽  
Author(s):  
A. B. Karama ◽  
O. O. Onyejekwe ◽  
C. J. Brouckaert ◽  
C. A. Buckley
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Computational Techniques ◽  
Activated Sludge Reactor ◽  
Computational Fluid Dynamics Cfd ◽  
The Cost ◽  
New Generation

Adequate models for wastewater treatment are limited by the cost of constructing them. Many a time, studies carried out on wastewater treatment plants have not been very useful in enhancing their performance. As a result, numerous mathematical models presented by different researchers on sedimentation tanks and clarifiers have not been getting much attention. Recently, improvement in computers and computational techniques have led to the development of a new generation of highly efficient programs for simulating real fluid flow within any type of geometry including clarifiers and activated sludge reactors. Herein, a computational fluid dynamics code, PHOENICS, is used to determine the performance of an anaerobic zone in an activated sludge reactor. Plausible results were achieved when experimental data were compared with numerical results.

Numerical Flow Analysis of Hydrate Formation in Offshore Pipelines Using Computational Fluid Dynamics (CFD)

2016 ◽  
Author(s):  
Eugenio Turco Neto ◽  
M. A. Rahman ◽  
Syed Imtiaz ◽  
Salim Ahmed
Keyword(s):  
Fluid Dynamics ◽  
Mass Transfer ◽  
Computational Fluid Dynamics ◽  
Reaction Kinetics ◽  
Formation Process ◽  
Formation Rate ◽  
Experimental Studies ◽  
Hydrate Formation ◽  
Computational Fluid Dynamics Cfd ◽  
Hydrate Formation Process

Hydrate formation is one of the major challenges faced by the Oil and Gas industry in offshore facilities due to its potential to plug wells and reduce production. Several experimental studies have been published so far in order to understand the mechanisms that govern the hydrate formation process under its thermodynamic favorable conditions; however, the results are not very accurate due to the uncertainties related to measurements and metastable behavior observed in some cases involving hydrate formation. Moreover, thermodynamic models have been proposed to overcome the latter constraints but they are formulated assuming thermodynamic equilibrium, which such condition is difficult to be achieved in flow systems due to the turbulence effects. Due to the low solubility of methane in water, the mass transfer effects can possibly control several mechanisms that are still unknown about the hydrate formation process. Also, the reaction kinetics plays a major rule in minimizing hydrate formation rate. The objective of this work is to develop a mechanistic Computational Fluid Dynamics (CFD) model in order to predict the formation of hydrate particles along the pipeline from a hydrate-free gas dominated stream constituted by methane and water only. The transient simulations were performed using a commercial CFD software package considering the multiphase hydrate chemical reaction and mass transfer resistances. The geometry used was a straight pipe with 5 m length and 0.0254 m diameter. The results have shown the appearance of regions in the pipeline at which hydrate formation is controlled either by the mass transfer or reaction kinetics. The rate of hydrate formation profile has shown to be high at the inlet even though the temperature at that regions was high, which can be a possible explanation for metastable region encountered in most of recent phase diagrams.

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