Water flow structure optimization between the screenings and grit removals in a wastewater plant

This paper is focused on a problem that may appear in the technological process inside a waste water plant and may disturb the normal water treatment technology. It is a sedimentation process that could appear between the screenings and the grit removals because of low velocity values of the flow. This sedimentation process just before the access area to the grit removals has to be avoided in order to ensure the normal water flow rate. In this paper we have envisaged the possibility to modify the structure of the water flow in order to avoid low velocity values that could increase the sedimentation process. The free surface flow structure will be modified by introducing new wall structures to create new water paths at normal velocities and to avoid low velocities areas. The study is a numerical one using CFD tools. First of all the numerical calculus was directed to point out the areas where the flow velocity is low and the sedimentation could appear and secondly the new system configurations are tested in order to prove the new free surface flow structure. The need of validate the numerical results is also considered in the article.