ESEL Paper Review_20130106

 

By Hong Guo

Mail: hongguo@gist.ac.kr

Phone: (+82) (0)10 82276568

1, Title and Author

Title: Sedimentation efficiency of two continuously opearating circular settling tanks with different inlet-and outlet arrangemet

Journal: Chemical Engineering Journal

Authors:

Tom Bajcara,* , Franci Steinman b, Brane Sirok a, Tanja Preserenb

a University of Ljubljana, Faculty of Mehcanical Engineering, Askerceva 6, 1000 Ljubljana, Slovenia

b University of Ljublijana, Faculty of Civil and Geodeti Engineering, Haidrihova 28, 1000 Ljubljana, Slovenia

2. Summary of Paper

This papser did an experimental comparative study of the two contnuous circular settling tanks, which are identical in shape, but differ in feed- and draw-off arrangements. The main research points are the flow pattern and their influences on the sedimentation efficiency. The authors focused on the flow kinematics in a qualitive and quantative way.

3. Results

? Time series of measured influent and effluent concentrations for two types of models for each initial concentration (1%, 1.5%, and 2%) are complished

? When the average density inside the inner chamber is close to the water, we could observed that hydrodynamic forces are dominant over the gravitation force. The flwo in the inner chamber fo the thank thus closely resembles the flw with uniform density

? Due to Larger amount of settling mater per unit volume, grativation force influences hydrodynamic forces more significantly, and it results in a changed flow pattern. Low initial concentration of the settling matter (0.5%) the phenomenon is still easily observable.

3. Contribution:

This paper showed the importance of the flow field to the sedimentation tank, which can significantly affect the sedimentatio process and its efficiency. We could found the how the concentration of the settlign matter in the inflow affect the flow pattern and settling pattern.

4. Author information:

Email: j.brdgeman@bham.ac.uk