Application of computational fluid dynamics (CFD) to ozone contactor optimization

2006 ◽  
Vol 6 (4) ◽  
pp. 9-16 ◽  
Author(s):  
J. Li ◽  
J. Zhang ◽  
J. Miao ◽  
J. Ma ◽  
W. Dong

Many approaches have been used to model the performance and efficiency of ozone contactors based on some assumptions to characterize the backmixing in fluids. Recently, computational fluid dynamics (CFD) technique has been proposed to simulate and optimize ozone contactors by calculating residence time distribution of fluid. To improve the ozone contactor performance of Bijianshan Water Treatment Plant in Shenzhen in South China, CFD was used for simulation and development of new optimization measures. Results showed that the low depth/length ratio of the contactor chambers in the original design resulted in short circuiting and backmixing, with the T10/HRT being only 0.40. Installation of guide plates substantially reduced short circuiting and backmixing with a much higher T10/HRT (0.66), increased by 73% compared with the original design.

2015 ◽  
Vol 17 (5) ◽  
pp. 745-762 ◽  
Author(s):  
Anastasios Stamou ◽  
Anthoula Gkesouli

A computational fluid dynamics model is presented for the calculation of the flow, suspended solids, and tracer concentration fields in the settling tanks of the water treatment plant of Aharnes, an important component of the water supply system of the greater area of Athens, Greece. The model is applied to investigate the expected negative effect of the wind on the hydraulic and settling performance of the tanks and to evaluate the improvement resulting from the installation of one and two baffles; the wind is modeled using a simple and very conservative approach that involves the setting of a constant horizontal flow velocity on the free surface. The model is calibrated and verified with field turbidity measurements. Calculations show that the effect of wind on the flow field and the hydraulic efficiency is strong, with the creation of massive re-circulation areas with intense mixing and high short circuiting; however, the effect of wind on the settling performance of the tanks is not pronounced. The removal efficiency of the tanks, which is 72.48% in calm conditions, is reduced to 68.07% for windy conditions; moreover, it increases to 70.00 and 71.04%, when one or two baffles are installed, respectively.


2001 ◽  
Vol 43 (8) ◽  
pp. 35-41 ◽  
Author(s):  
I. A. Crossley ◽  
M. T. Valade ◽  
J. Shawcross

The paper describes the method that led to the design of the 1,500 Ml/day dissolved air flotation (DAF) water treatment plant for Boston's water supply. In particular, the topics of flocculation techniques, floated solids removal and DAF recycle as they relate to very large capacity plant design are covered in detail. The use of mathematical models, including computational fluid dynamics (CFD) software, to refine the design is described.


2019 ◽  
Vol 29 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Armando I. Vázquez ◽  
Francisco J. Almazán ◽  
Martín Cruz-Diaz ◽  
José A. Delgadillo ◽  
María I. Lázaro ◽  
...  

1999 ◽  
Vol 40 (4-5) ◽  
pp. 81-89 ◽  
Author(s):  
C. J. Brouckaert ◽  
C. A. Buckley

Computational Fluid Dynamics (CFD) studies of a secondary clarifier at Durban's Northern Wastewater Treatment Works, and of a clarifier at the potable water treatment plant at Umzinto, a small town near Durban, have been undertaken with a view to improving their load capacities. In both cases the units are located in relatively old treatment plants, which face continually increasing loads due to population growth. Increasing the capacity of existing equipment, rather than installing new equipment, constitutes an efficient use of development capital. Although the two clarifiers have considerable design differences, the CFD studies indicated remarkably similar circulating flows, which concentrate up-flow near the outer wall of the clarifier in the region of the clarified water overflow weirs. Baffles were designed to disrupt the circulation so as to distribute up-flow over a wider area, thereby reducing the maximum vertical velocities. In the case of the wastewater secondary clarifier, the modification has been implemented, and evaluated in comparative tests involving an otherwise identical unmodified clarifier. In the case of the potable water clarifier, the modification has still to be implemented.


Water ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 733 ◽  
Author(s):  
Daniel Hernández-Cervantes ◽  
Xitlali Delgado-Galván ◽  
José Nava ◽  
P. López-Jiménez ◽  
Mario Rosales ◽  
...  

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