SEWAGE PURIFYING DEVICE OF FILTER MATERIAL CIRCULATION TYPE

摘要

This invention relates to a sewage purifying device using large size floatable filter materials and is intended for effectively preventing said filter materials from being clogged. The purpose is satisfied by imparting very gentle fluidity to the whole of a filter bed while circulating filter materials with circulating means and further effectively achieved by exfoliating sludge from filter materials while utilizing the circulatory movement of filter materials.