Drainpipe for a reversible drainpipe filter system

摘要

The drainpipe is of triangular cross-sectional shape and has an oblong slot in the bottom surface which is closed over by a stepped ledge having webs and grooves. The slot and grooves in the ledge form a flow connection between the filter basin and the interior of the drainpipe. The drainpipe is simple to manufacture and dead zones in the filter mass not wetted by the flushing media during back flushing are completely avoided or reduced to a minimum.