Apparatus for introducing a gas into a liquid

The appts. comprises a drive motor (16), an air box(18) with an intake pipe (20), and a radial diffusion turbine (12), linked to an ejection turbine (10), with both turbines immersed in the liquid. The diffusion turbine has alternating long and short radial vanes, the latter not extending as far as the turbine shaft, so that a gap is left between the shaft and the inner ends of the vanes, both sets of vanes being mounted below a plate (36) driven by the shaft, and forming extensions to the ejection turbine vanes. The appts. also has discharge vanes (28) for cleaning, and which eliminate particles deposited at the back of the turbine, which are mounted above the plate (36). Both turbines are mounted beneath a hydraulic plate (22) carrying the drive motor, air box and intake pipe.