Centrifugal filtration device

A centrifugal filtration device, including:

• a casing, including an inlet passage and an outlet passage which are arranged along an extension direction;
• a plurality of blades, relative to the extension direction, extending spirally on an inner circumferential wall of the inlet passage;
• a guiding mechanism, including a first tapering portion tapered in a direction toward the inlet passage, disposed in the casing and located between the plurality of blades and the outlet passage;
• wherein the casing further includes a cylinder portion arranged on the extension direction and a particle collection passage transversely connected to the cylinder portion, the particle collection passage is located radially out of the outlet passage, and the particle collection passage at least partially protrudes beyond the cylinder portion toward the extension direction as viewed in an axial direction of the particle collection passage;
• wherein the casing further includes a guiding portion which is obliquely connected between the cylinder portion and the particle collection passage and radially expands outwardly in a direction away from the outlet passage, and the guiding portion is located out of the cylinder portion as viewed in the axial direction of the particle collection passage;
• wherein the guiding mechanism further includes a second tapering portion tapered in a direction toward the outlet passage, as viewed in a radial direction perpendicular to the extension direction, the first tapering portion is non-overlapped with the inlet passage and the second tapering portion is non-overlapped with the outlet passage;
• the guiding mechanism is formed as an oval structure and includes a sharp end and a blunt end which are disposed opposite to each other, the first tapering portion is the sharp end, and the second tapering portion is the blunt end;
• a ratio of a major axis to a minor axis of the oval structure is between 1.1 and 1.5;
• the outlet passage includes a tubular member connected to the cylinder portion and a blocking flange disposed circumferentially around the tubular member, and at least part of the blocking flange is located within the particle collection passage as viewed in the axial direction of the particle collection passage;
• the blocking flange is gradually radially broadened in a direction toward the outlet passage and includes an annular groove open toward the outlet passage;
• a ratio of an inner diameter of the cylinder portion to a radial dimension of the outlet passage is between 1.5 and 2.5;
• the casing further includes a broadened portion which is connected between the inlet passage and the cylinder portion and is gradually broadened in a direction from the inlet passage toward the outlet passage, a maximum diameter portion is defined between the first tapering portion and the second tapering portion, the maximum diameter portion is located in the cylinder portion and adjacent to a junction of the cylinder portion with the broadened portion;
• the guiding mechanism is connected to the outlet passage by at least one supporting member;
• each of the plurality of blades has a side which is adjacent to the first tapering portion and has an end surface flush with an end opening of the inlet passage;
• a distance between the end opening of the inlet passage and the first tapering portion is between 10 mm and 30 mm.