STIRRING BLADE

PURPOSE:To enhance stirring effect especially in a gas-liquid mixing stirrer by performing stirring with a stirring blade consisting of blades each having a recessed cross section toward a rotary direction and assymmetric in its cross section with respects to a horizontal axis so that the upper part of the cross section protrudes in the rotary direction as compared with the lower part thereof. CONSTITUTION:Stirring is performed with a stirring blade consisting of blades 8 each having a recessed cross section toward a rotary direction 7 and assymmetric in its cross section with respect to a horizontal axis to that the upper part of the cross section protrudes in the rotary direction as compared with the lower part thereof. That is, the air 12 blown in a stirring tank 1 from an air blowing-in port 3 raises through a liquid 13 and almost all of the air 12 impinges against the blades 8 to be sucked to the insides 11 of the recessed cross sections thereof to be strongly emitted into the liquid 13 resent in the outer peripheral parts 15 of the blades 8 by the centrifugal force generated by the rotation of the blades 8. As a result, the air 12 is uniformly dispersed into the liquid 13 and stirring effect is enhanced to a large extent as compared with a conventional stirring blade.