The effect of inlet and outlet position and sediments concentration on sedimentation tank efficiency

In this study, numerical model has been employed in order to study the effect of inlet and outlet position on sedimentation efficiency of rectangular sedimentation tank. This modified configuration has been tested with different particle size and concentration. Sedimentation efficiency was evaluated by calculation of trap efficiency. Results show that changing inlet and outlet location increase hydraulic performance of the tank. Flow field showed his sensitivity to suspension concentration when inlet and outlet are in the middle of the tank. However inlet and outlet location improve sedimentation efficiency, especially for fine particles. The present model is confirmed by experimentation measurement in Swiss conducted by the Laboratory of Hydraulic Construction of the Swiss Federal Institute of Technology.