STRAINER FOR UNDERDRAIN SYSTEM

摘要

PURPOSE: Provided is a strainer for an underdrain system, which has a function of collecting filtered water and distributing backwashing water. The strainer combines spirally with the underdrain conduit of an underdrain block equipped between a sand filter and a pressure chamber located at the lower part of the sand layer. CONSTITUTION: The strainer consists of the following parts: several slits(12) at a cylindrical side wall (10); a cap (16) with a flange (14) at the lower part; a hollow body (20) with a flange (18) at the upper part; several slits (24) at the upper closed wall (22) of the cap (16); several inner grooves (32) at the bottom (30) of the flange (18); an annular groove (34) at the upper part of the flange (18) connected from the inner parts (32); and slits (36) at the lower border part of the flange (18) connected from the inner parts (32).