| 摘要 |
PROBLEM TO BE SOLVED: To clean a filter in a state attached to a predetermined position of a circulation line, while minimizing diffusion of pollutant to the circulation thereof when the pollutant exists in the filter.SOLUTION: A filter cleaning method includes a flashing liquid filling step for filling the inside of a filter (108) with flashing liquid, by supplying the flashing liquid only to a part of a circulation line (104) and to a tank (102), in a state where the filter is installed at a predetermined position of the circulation line, and a flashing liquid discharge step for draining the flashing liquid from the filter by discharging the flashing liquid thus supplied from a drain line connected with a part of the circulation line or the tank. |
