This study describes the development and application of a mathematical model of the two-phase flow regime found in settling tanks. The phases present are water, the continuous medium, and solid, the dispersed phase. The performance of the model is assessed, applying it to two validation cases using solid suspensions as the working medium. These are; a settling tank measuring velocity and concentration. The calculations are presented for two different dispersed phase densities for the experimentally given density difference between the inlet and outlet. Computational Fluid Dynamics (CFD) simulations are employed to assess the effect of extended a baffle at the feed section of a full-scale sedimentation tank for the improvement of solids settling in potable water treatment in Slovakia. It is found that the baffle decreases the inlet re-circulation zone and enhances the settling of solids by directing them towards the bottom of the tank with high velocities. It is noteworthy that even small differences in the particle velocity can cause large changes in the percent of settled particles; in this work, the overall solids removal efficiency increased when using the baffle from 80% to 98% leading to a reduction of the effluent solids concentration of approximately 85%.
Kris J., Ghawi A. H. Improved, modeling, simulation and operational parameters of settling Tank,
Proceedings of the 6th International Conference of PhD Students University of Miskolc
, Hungary 12–18 August, 2007, pp. 69–75.
Kris J., Ghawi A. H. Design and optimization of sedimentation tank in Slovakia with CFD modeling,
Proceedings of the 10th International Symposium on Water Management and Hydraulic Engineering 2007
(with special emphasis on the impact of hydraulic engineering construction on the environment) 4–9 September 2007, Šibenik, Croatia, 2007, pp. 97–109.
Huggins D.L., Piedrahita R.H., Rumsey T. Use of computational fluid dynamics (CFD) for aquaculture raceway design to increase settling effectiveness,
Vol. 33, 2005, pp. 167–180.
Rumsey T., 'Use of computational fluid dynamics (CFD) for aquaculture raceway design to increase settling effectiveness' (2005) 33Aquacultural Engineering: 167-180.
Rumsey T.Use of computational fluid dynamics (CFD) for aquaculture raceway design to increase settling effectivenessAquacultural Engineering200533167180)| false