Laboratory investigation on the performances of submerged underflow baffles for the capture of sewer floatables

This paper reports the results of an experimental campaign performed at the Laboratory of Hydraulics of the University of Catania and aimed at the evaluation of baffle performances for the capture of sewer floatables under submerged outflow conditions. The experiments were conducted following the experience of a previous research carried out considering free outflow conditions for the baffles. In particular, artificial floating solids of various sizes and materials were used and their limit equilibrium condition upstream of the baffle was investigated. A dimensionless relationship for the evaluation of the threshold flow velocity beyond which floatables start to escape the baffle was derived as a function of the device geometry and of the characteristics of flow and floatables. The results of the experiments under submerged and free outflow conditions were finally compared in terms of capturing performances.