OPERATION METHOD FOR CIRCULATING AND PURIFYING BATH WATER

摘要

PROBLEM TO BE SOLVED: To loosen a stuck filter medium easily and in a short time. SOLUTION: In this operating method of bath water circulation and purification, backwashing (A) wherein after washing in which bath water is discharged from a drain pipe 6b is performed in the normal direction, the bath water is jetted directly into a filter bed 11 through a washing water pipe 5 and the bath water after washing is discharged from both of the drain pipes 6a, 6b is performed and then, backwashing (B) wherein washing bath water is fed to the bottom part of a purification tank 10 through a first return pipe 4a and is discharged from the drain pipe 6a is performed. After this pattern is repeated plural times, normal purifying operation is shifted.