ESEL Paper Review_201200804

 

By Hong Guo

 

1,Title and Author

 

Title: A CFD methodology for the design of sedimentation tanks in potable water treatment. Case study

 

Journal: Chemical Engineering Journal

 

Authors:

 

Athanasia M. Goula, Margaritis Kostoglou, Thodoris D. Karapantsios ^*, Anastasios I. Zouboulis

 

Division of Chemical Technology, School of Chemistry, Aristotle University, University Box 116,541 24 Thessalonik, Greece

 

2.  Summary of Paper

 

The author applied the CFD methodology to the sedimentation tank study. They compared a standard and a baffle-equipped tank. The authors found that the baffle decreases the inlet recirculation zone and increases the efficiency of settling of the solids by directing them toward the bottom of the tank with high velocities. In addition, even the small differences in particles velocity can cause large changes in the percent of settled particles.  The overall solids removal efficiency is increased from 90.4% to 98.6% by apply the baffle design.

 

3.  Results

 

The author used the Fluent 6.2.16 to do the simulation work. At first, the simulation of the streamlines had done. Generally, the flow pattern is characterized by a large recirculation region spanning a large part of the tank from top to bottom. There are three smaller recirculation regions are found, two were at the top and one was on the bottom. Adding the particles to the tank; it was found that the flow field was not affected by the particles on the standard tank or modified baffle-equipped tank due to the small particle loading.

 

On the whole, the simulation results show that quantitatively the drastic effect of particle velocity particle velocity on sedimentation effectiveness. Higher settling velocities lead to more effective sedimentation. However, the parcel velocity affects the large changes in the percent of settled particles should be concerned.

 

4.  Contribution:

 

The paper show that extended baffle forces the solids to move faster towards the bottom of the tank and decreases the inlet recirculation zone. Thus yielding significantly enhanced sedimentationAnd it gives the insight, which can be used to investigate novel designs or operating condition for future study for our research.

Optimization operation condition would be our research point and we would find the other impact factors for this field research.