Fine bubble generating method and fine bubble generating apparatus

A fine bubble generating apparatus for generating, in liquid, fine bubbles having nano-order diameters, the fine bubble generating apparatus comprising:

• a gas discharge unit having a gas discharge member in which multiple gas discharge pores are opened in a gas discharge surface, and
• a relative movement unit configured to relatively move liquid along the gas discharge surface of the gas discharge member, wherein:
• the gas discharge member has the gas discharge pores having pore diameters of 1.5 μm or less,
• gas is discharged into the liquid from the gas discharge member while the liquid is relatively moved along the gas discharge surface of the gas discharge member by the relative movement unit such that a velocity relative to the gas discharge member is not less than 1 m/sec,
• the gas discharge unit includes a flow channel forming member that has a groove formed in a surface on which the flow channel forming member contacts with the gas discharge surface of the gas discharge member and that is attached so as to be in surface contact with the gas discharge surface of the gas discharge member, and
• the relative movement unit moves the liquid along the gas discharge surface of the gas discharge member by causing the liquid to flow in a flow channel enclosed by the gas discharge surface of the gas discharge member and the groove of the flow channel forming member.

A fine bubble generating apparatus for generating, in liquid, fine bubbles having nano-order diameters, the fine bubble generating apparatus comprising:

• a gas discharge unit having a gas discharge member in which multiple gas discharge pores are opened in a gas discharge surface, and
• a relative movement unit configured to relatively move liquid along the gas discharge surface of the gas discharge member, wherein
• the gas discharge member has the gas discharge pores having pore diameters of 1.5 μm or less,
• the gas discharge unit and the relative movement unit are configured such that gas is discharged into the liquid from the gas discharge member while the liquid is relatively moved along the gas discharge surface of the gas discharge member by the relative movement unit such that a velocity relative to the gas discharge member is not less than 1 m/sec, and
• a spiral flow channel for the liquid is disposed on the gas discharge surface of the gas discharge member in a state where the liquid flows along a spiral path while in contact with the gas discharge surface, and the liquid is caused to flow along the spiral path in the flow channel and the liquid is thus moved along the gas discharge surface of the gas discharge member.