WATER TREATMENT DEVICE AND METHOD FOR CLEANING FILTRATION MATERIAL LAYER OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a water treatment device which has improved water treatment efficiency by decreasing a ratio of the amount of washing water to the amount of the water to be treated (filtered) and which has a compact and simplified mechanism and to provide a method for cleaning the water treatment device.SOLUTION: The water treatment device includes: a jet nozzle (7) for a mixed raw water flow; a filtration tank (5) for containing a filtration material layer (4) comprising two layers which are an upper layer (2) and a lower layer (3) and are arranged below the jet nozzle for the mixed raw water flow, the upper layer comprising the filtration material having a smaller specific gravity and a larger particle size than the filtration material of the lower layer; a water collecting/distributing pipe (13) for extracting filtered water and supplying reverse water to the filtration material layer in reverse washing; a filtration material vibrating means for vibrating each particle of the filtration material, the filtration material vibrating means having a vibration element (9) connected to a power source and also having vibration expansion elements (10) embedded in the upper layer (2) in such a manner that the vibration of the vibration element (9) is transmitted to the vibration expansion elements; and a drainage trough (12) arranged above the filtration material layer.