| 摘要 |
PROBLEM TO BE SOLVED: To provide a membrane type air diffusion device capable of generating fine air bubbles excellent in oxygen moving efficiency while suppressing a pressure loss.SOLUTION: A membrane type air diffusion device has an air diffusion film 3 that separates an inner supply gas from an outer target liquid, and the diffusion film 3 is provided with a plurality of air diffusion holes 21 comprising slits 8, 9 and 10. The diffusion film comprises a material having a contact angle &thetas; being a wettability-expressing index of ≤108°, and a slit length D is 0.4 to 1.0 mm. Each of the slits 8, 9 and 10 has an angle between the slit and the longitudinal direction of the diffusion film 3 within the range of 0 to 25°, and the angle is any one of a plurality of different angles. |
