Patent ID: 8186653
Filing Date: 2012-05-29
Classification: B01F

Abstract:
1. A fine bubble generating apparatus comprising a gas swirling shearing unit, the gas swirling shearing unit including: a cylindrical member having a cylindrical inner peripheral surface; a first end wall member configured to close one end of the cylindrical member; a second end wall member configured to close the other end of the cylindrical member; a fluid swirling chamber defined by the cylindrical member, the first end wall member and the second end wall member; a fluid inlet hole extending through a wall of the cylindrical member at a position closer to the second end wall member than a center in an axial direction of the cylindrical member to introduce a gas-liquid mixed fluid into the fluid swirling chamber in a tangential direction thereof; and a fluid outlet hole extending through the second end wall member along a center axis of the inner peripheral surface of the cylindrical member; wherein the fluid inlet hole has an axis intersecting with a hypothetical axis of the fluid inlet hole, that is assumed to intersect with an inner wall surface of the fluid swirling chamber and extend tangentially, at a point where the hypothetical axis touches the inner wall surface at an angle of from 10 to 30 degrees; and wherein the inner peripheral surface of the cylindrical member is mirror-finished, and a portion of the inner peripheral surface of the cylindrical member that circumferentially corresponds to the fluid inlet hole, which opens on the inner peripheral surface, is provided with a plurality of annular grooves spaced from each other in an axial direction of the inner peripheral surface, the annular grooves having a width and a depth that are not more than 1 millimeter.