Patent ID: 7618025

Claim:
Mixing device for mixing air and water in a water purifier, wherein: the mixing device ( 1 ) comprises a water inlet pipe ( 2 ) and an air inlet pipe ( 3 ), the air inlet pipe ( 3 ) extends coaxially within the water inlet pipe ( 2 ) and defines therewith an annular gap ( 4 ) for providing an annular water jet, downstream of the annular gap ( 4 ) there is provided a mixing member ( 6 ) for mixing water and air, and the mixing member ( 6 ) includes a water flow disturbing device ( 7 ) which is provided to be hit by the annular water jet, at least those parts ( 2 a ) of the water inlet pipe ( 2 ) and/or those parts ( 3 a ) of the air inlet pipe ( 3 ) which define the annular gap ( 4 ), consist of plastic material, and the water flow disturbing device ( 7 ) includes at least one helical means ( 8 ) which extends along the inner side of the mixing member ( 6 ) around through-flow portions ( 6 a ) thereof within said helical means ( 8 ) such that helical movements are imparted to the annular jet of water when it flows downwards through said through-flow portions ( 6 a ).