| 摘要 |
PROBLEM TO BE SOLVED: To provide a filter device which can sufficiently exert a filtering function by preventing muddy water from passing through only a specific path in a filter layer allowing the muddy water to easily pass therethrough; and to provide a method for manufacturing the filter device.SOLUTION: An adhesive layer 32 is provided on a wall surface 31 inside a filter tank. Stone pieces 33 having a small diameter are adhered to the adhesive layer 32, and part of the stone pieces 33 are protruded from the adhesive layer 32. Thereby, irregularities are formed on the wall surface 31 inside the filter tank. When filter media are stacked in the filter tank, the irregularities on the wall surface 31 are brought into contact with the filter media, so that gaps formed between them become small and irregular. As a result, muddy water hardly passes along the wall surface 31 as compared to the case in which the wall surface 31 is flat, so that the muddy water can be prevented from passing along the wall surface 31 while remaining as it is. Thus, the muddy water is caused to slowly pass through the whole area of a filter layer 15, and a filtering function by the filter layer 15 is improved. |
