Patent ID: 8192624

Claim:
A filtering apparatus comprising: cylindrical inner and outer screens which are concentrically disposed such that centers of the inner and outer screens are set along a vertical direction; and at least one spiral fixed wall which is provided in a filtering room between the inner screen and the outer screen, the spiral fixed wall being extended in a direction along the center of the inner screen while revolving around the inner screen, wherein the inner screen and the outer screen are rotated around the center thereof while the spiral fixed wall is not rotated, a treated liquid is delivered from a lower end side of the filtering room, a filtrate having passed through the inner screen and the outer screen is discharged to an outside, a cake formed by the filtering is elevated along the fixed wall and discharged to an upper side of the filtering room, and the inner screen and the outer screen are integrally coupled to each other; and wherein the inner screen and the outer screen are integrally coupled to each other below the lower end of the fixed wall, and the inner screen and the outer screen are not coupled above their coupled positions so as to be opened in a ring-like shape; and the fixed wall is coupled to the upper portion of the filtering apparatus so as to be suspended therefrom through the ring-shaped opening which is above the filtering room.