Mass transfer mixing system especially for gas dispersion in liquids or liquid suspensions

Claim 1

A mixing system for dispersing a fluid into a liquid which can have solids suspended therein which comprises a tank having a bottom and side walls which extend axially of said tank, said tank containing the liquid to a level above the bottom of said tank, a drive to turn an impeller, impeller means for providing a recirculating, axial flow pattern having principally axial flow components upwardly and downwardly between the bottom of the tank and the level of the liquid therein and a radial flow component in the direction across the bottom of said tank toward the side walls thereof, the outlet flow from said impeller means being a predominately axial flow downwardly towards the bottom of said tank and a predominately radial flow towards the side walls of said tank, means for releasing said fluid in said outlet flow outside where said flow is axial and in said radial flow which is inside where said flow is radial, whereby said fluid is unable to oppose said axial outward flow, said releasing means being in a region of said tank which extends between the bottom of said tank and a plane through said impeller means which plane is perpendicular to the axial direction.