Patent ID: 8585023
Filing Date: 2013-11-19
Classification: B01F,C02F,Y02W

Abstract:
1. An apparatus for mixing gas and liquid comprising: at least one impeller structured and arranged for submersion in the liquid, wherein the at least one impeller is rotatable at an angular velocity and generates an axial velocity of the liquid; a first draft tube submerged in the liquid; a second draft tube of lesser diameter than the first draft tube concentrically structured inside at least a portion of the first draft tube; a drive at least a portion of which is submerged in the liquid; and at least one gas conduit, wherein the impeller further comprises an inlet side, an outlet side, at least one blade extending radially from a hub and a cylindrical cuff concentric with a center of the impeller and substantially aligned with the second draft tube, the cylindrical cuff separating an outer portion of the at least one blade from an inner portion of the at least one blade, wherein the gas conduit is structured and arranged to deliver gas into the liquid at a location proximal to the inlet side of the inner portion of the at least one impeller, whereby the impeller conveys mixed gas and liquid through the second draft tube and only liquid through the first draft tube.