Cylindrical filter device, manufacturing method and usage of the same, and filter system having the same

A manufacturing method of a cylindrical filter device, comprising:

• (S1000) providing a wavy filter screen, wherein the wavy filter screen comprises a first flexible side, a second flexible side opposite to the first flexible side, and a plurality of wavy structures disposed between the first flexible side and the second flexible side, and ridge lines of the wavy structures are respectively connected with the first flexible side and the second flexible side;
• (S2000) wrapping the wavy filter screen to form a cylindrical structure with respect to an axis so that the ridge lines of the wavy structures are parallel to the axis, directly or indirectly connecting corresponding sides of first and last wavy structures of the plurality of wavy structures in a separable manner, and respectively wrapping the opposite ends of the cylindrical structure to form a first opening and a second opening by the first flexible side and the second flexible side;
• (S3000) disposing the sealing device at the first opening, wherein the sealing device has a first groove, and the first flexible side is able to engage with the first groove with its elasticity and makes the first opening be sealed by the sealing device;
• and
• (S4000) disposing the connecting device at the second opening, wherein the connecting device has a second groove and a port, and the second flexible side is able to engage with the second groove with its elasticity and makes the second opening communicate with the port.