Fine bubble diffusing pipe, fine bubble diffusing apparatus, and submerged membrane separation apparatus

A fine bubble diffusing device comprising:

• at least fine bubble diffusing tubes and gas supply pipes,
• wherein each one of the fine bubble diffusing tubes comprises:
• at least a cylindrical supporting tube, and an elastic sheet with fine slits formed therein, with the elastic sheet being placed so as to cover the outer circumference of the supporting tube, so that, upon supplying a gas to a space between the elastic sheet and the supporting tube, the fine slits of the elastic sheet are opened to generate fine bubbles outside the diffusing tube,
• wherein the supporting tube has a length of 1000 mm or more in the longitudinal direction, with gas supply units serving as flow inlets of the gas, and one of the gas supply units being attached to each of the two ends of the supporting tube, and
• the space between the elastic sheet and the supporting tube is divided into at least two portions in the longitudinal direction by a space dividing means, with the length of each of the divided spaces in the longitudinal direction being set to 1000 mm or less, and
• a plurality of the fine bubble diffusing tubes are disposed virtually in parallel with one another, with the gas supply units attached to the fine bubble diffusing tubes being connected to the gas supply pipes,
• wherein a plurality of the gas supply units, located on one end side of each of the fine bubble diffusing tubes, are all connected to one of the gas supply pipes, and a plurality of the gas supply units, located on the other end side of the fine bubbles diffusing tubes, are all connected to another one of the gas supply pipes.