Patent ID: 8678356

Claim:
A microbubble generating method comprising: supplying a gas to a rotator while rotating the rotator in a liquid; injecting the gas into the liquid from bubble injection holes formed in a circular arrangement in the surface of the rotator; and applying a shear force, produced by the relative movement between the liquid and the rotator, to gas bubbles present on and in the vicinity of the surface of the rotator to generate microbubbles, wherein the bubble injection holes have a same diameter that is less than 1.00 mm and are arranged with a pitch interval greater than 10 mm, the bubble injection section is rotated such that a peripheral speed of the bubble injection holes of the rotator is not more than 6 m/s, and the gas is supplied to the bubble injection holes so that the gas is injected into the liquid through each bubble injection hole at a gas flow rate of less than 0.25 liter/min.