Patent ID: 8888074
Filing Date: 2014-11-18
Classification: B01F

Abstract:
1. An apparatus for producing fine bubbles of a gas in a liquid, the apparatus comprising: a membrane that is not permeable to gas, the membrane including first and second opposite surfaces, the first surface being exposed to the gas and the second surface being exposed to the liquid; a raised nub on the second surface of the membrane, the nub including a base that is proximal the second surface and a tip that is distal with respect to the second surface, the base having a base width and the tip width having a tip width smaller than the base width, the nub having a nub height measured from the base to the tip, the nub including a perforation placing the gas in communication with the liquid through the nub; wherein the ratio of nub height to tip width is in the range 0.5-100; wherein gas flowing through the perforation forms a bubble in the liquid; and wherein the nub has a cross-section selected from the group consisting of trapezoidal, triangular, rectangular, and semi-circular.