| 摘要 |
PROBLEM TO BE SOLVED: To provide a filter device which has a cleaning effect capable of being stably used for a long period while preventing breakage due to usage thereof, and to provide a ballast water treatment apparatus using the filter device.SOLUTION: A filter device is manufactured by using a pleat filter in which filter base material having folds so as to repeat mountain parts and valley parts are formed into such a cylindrical shape that the ridge line direction of the folds are set as the axial direction, as a filter membrane. Therein, the pleat filter can be rotated around a cylinder shaft of the cylindrical shape as the center, a nozzle which is disposed opposite to the outer circumferential surface of the pleat filter and ejects liquid toward the outer circumferential surface is provided and, when the pleat interval on the outer circumference side folds is p, the length of the ridge line direction effective for filtration is h, the opening width vertical to the ridge line direction on the opening part of the nozzle is W and the length of an opening in the ridge line direction is L, the following relations are satisfied: 4p≤W, and h/5≤L≤h/2. |
