Multistage Fiber Filtering Apparatus Capable of Selectively Filtering

A multistage fiber filtering apparatus, comprising:

• an enclosure configured to include an upper box and a lower box communicating with the upper box;
• a strainer configured to be installed in the upper box along a longitudinal direction;
• a plurality of fiber yarn media configured to be fixed to upper and lower fixing means, each of the upper and lower fixing means coupled to upper and lower portions of the strainer, to form a first filtering layer while surrounding an outer circumferential surface of the strainer;
• and
• a plurality of fiber ball media configured to be built in the lower box to form a second filtering layer;
• wherein a first filtration mode of raw water passing through the fiber ball medium, a second filtration mode of the raw water passing through the fiber yarn medium, or a third filtration mode of the raw water passing through both of the fiber yarn medium and the fiber ball medium, is selectively operated depending on turbidity of the raw water.