Water treatment apparatus and a method for cleaning a filter layer of a water treatment apparatus

Abstract

A water treatment apparatus including one or more mixed raw water stream jet nozzles, a filtering tank housing a filter layer disposed below the mixed raw water stream jet nozzle or nozzles, the filter layer having an upper layer and a lower layer, the upper layer containing a filter material with a smaller specific gravity and a larger particle diameter than a filter material of the lower layer, a water collecting and distributing pipe for removing water filtered through the filter layer and supplying reverse stream cleaning water to the filter layer during reverse cleaning, filter material vibrating means for vibrating a filter material of the upper layer including a vibrating element connected to a power source and vibration expanding element buried in the upper layer for transmitting vibration of the vibrating element, and an overflow outlet provided in the filtering tank above the filter layer.