Patent ID: 7241383

Claim:
A fluid treating method comprising the steps of: (a) forming a ring lamination by laminating a plurality of filtering rings with contact surfaces facing each other in a laminating direction, each filtering ring comprising a non-porous metal plate having a central hole therein, the hole extending through the plate in the lamination direction, and each filtering ring having an inner periphery being convexly curved in a radially inward direction and an outer periphery having a wedge shape converging in a radially outward direction; (b) providing at least portions of the contact surfaces of the filtering rings facing each other with a contact surface roughness (Ra) in a range of about 0.01 μm to 20 μm; (c) pressing the ring lamination under a contact surface pressure (p) in a range of about 0 to 177 kg/cm 2 in the laminating direction of the filtering rings to cause the contact surfaces to closely adhere to each other, wherein a gap distance (g) between the portions of the filtering rings closely adhering to and facing each other is in a range of about 0.2 nm to 200 μm; (d) directing an object fluid into an interior of the ring lamination via the central holes of the filtering rings, such that the object fluid enters radially outwardly into gaps formed by contact surfaces of adjacent filtering rings of the ring lamination; (e) dividing the object fluid into a first separated fraction comprising solids and a second separated fraction comprising a fluid, such that the second separated fraction flows through the gaps for removal from an exterior of the ring lamination, while the first separated fraction accumulates on the inner periphery of the filtering rings; and (f) scraping the inner periphery of the filtering rings to remove the solids of the accumulated first separated fraction.