Patent ID: 6308834
Filing Date: 2001-10-30
Classification: B01F,B03D

Abstract:
An impeller for rotation about a substantially upright axis for use with flotation tank apparatus adapted to enhance mixing of a gas and a liquid, the impeller having a substantially upright portion substantially parallel to the axis, and a plurality of vanes extending outwardly therefrom, at least some of the vanes having an upper part exposed to an upper part of the flotation tank apparatus, the upper part of the vanes being adapted to induce liquid flow from the upper part of the flotation tank apparatus generally downwardly towards the impeller, said at least some of the vanes further having a lower part adapted to induce liquid flow from a lower part of the flotation tank apparatus generally upwardly towards the impeller, characterized in that the impeller further comprises barrier means at least partially separating said upper and lower parts, and a gas input situated on the same side of the barrier means as the lower part, the barrier means, in use, serving to guide gas and liquid along a lower surface thereof towards an outer edge thereof so that some gas/liquid mixing may occur between said gas input and said outer edge.