| 摘要 |
PROBLEM TO BE SOLVED: To provide a filter medium cleaning device and a filter medium cleaning method for a double-layer filter device that prevent a granular filter medium from flowing out during cleaning of the filter medium, with simple constitution.SOLUTION: A filter medium cleaning device includes: a pump which is connected to a filter tank 10 below a second filter layer 18, and supplies cleaning water for cleaning a filter medium to the filter tank 10; a drain gutter 30 which is provided above the second filter layer 18 and drains water flowing in itself as the cleaning water is supplied to outside the filter tank 10; a support member which is provided above the drain gutter 30, and has two fitting members separated from each other at an interval wider than the width of the drain gutter 30 with the drain gutter 30 interposed in plan view; and a filter medium flowing-out preventing net 32 spread between the two fitting parts while passing through the lower side of the drain gutter 30. |
