Installation, Adjustment, Test And The Calculation Of Key Parameters For RIM-FLO Secondary Clarifiers

In recent years, the high hydraulic performance of peripheral-feed and peripheraltakeoff secondary clarifier has been recognized with the more use of foregineadvanced eqiupment in wastewater treatment plants. New projects are no longer usingtraditional center-feed secondary clarifier only. However, the technology forperiphery-feed secondary clarifier has been monoplized by the foreign manufacturer,and there is no mature design and manufacture experience in China. Particularly, thecalculation method for equally water distributing by influent trough is patent andbusiness secret. In recent years, some researchers have begun to study this topic andpublished papers about periphery-feed secondary clarifier. Some of the authors putforward to foresighted point of views, however, those views are exploratory. Untilnow, no mature calculation method is provided for designers.The author investigated the processes of installation, adjustment and performancetests for Rim-Flo peripheral-feed and peripheral takeoff secondary clarifier and itsaccessory Two-Bro sludge remover, digested and absorbed the advanced technology,and concluded some engineering experience for the readers'references. In the meanwhile, the author analyzed the hydraulic feature of peripheral-feed and peripheraltakeoff secondary clarifier by combining hydrodynamics theories with the author'ssite working practice, and explored the calculation methods for influent trought.In this paper, two calculation methods for influent trought parameters were developed.In the first method, the diameter and pitch of orifices are consistant, and only thewidth of the influent trought is varied. However, it is not easy to ensure accuracy ofthe width curve in the conceret construction process. Therefore, the author developedanother more practical calcualtion method so that the construction process can beconvinient and the accuracy can be ensured. In the second method, the width ofinfluent trought varys linearly, and the diameter and pitch of orifices varys with thevariation of total headwater for submerged orifice.