Vortex flow type water surface control device for drainage system

摘要

The present invention addresses the problem of providing a control plate on a suitable position in a rain water discharge chamber. An inflow pipe (2), an intercepting pipe (3) and a discharge pipe (4) are connected to a rain water discharge chamber (10). A vortex flow type water surface control device for a drainage system is provided with: the rain water discharge chamber (10); and a control plate (6) which is arranged in front of an opening (3a) of the intercepting pipe (3) opening to the rain water discharge chamber (10). Assuming that D represents the inner diameter of the opening, X represents the projection length of the control plate (6) with respect to the opening (3a), and Y represents the distance between the control plate (6) and the opening (3a), D, X and Y satisfy: (1) 0.5D≤X≤0.7D and 0.83D≤Y≤1.5D; or (2) 0.4D≤X < 0.5D and 1.0D≤Y≤1.5D. Thus, impurities intrude into the intercepting pipe (3).