Patent attributes
Disclosed is a filter device. The filter device includes a filter housing including an inflow port, through which ballast water flows in, and an outflow port through which the ballast water flows out, a plurality of filter members provided in the filter housing to filter out a foreign substance included in the ballast water, and a backwashing unit coupled to at least one of the plurality of filter members to filter out the foreign substance by using a difference internal pressure and atmospheric pressure. The backwashing unit is provided for the ballast water to flow in so that when it is required for the backwashing unit to remove the foreign substance, at least one of the plurality of filter members coupled to the backwashing unit filters out the foreign substance included in the ballast water.
