Patent ID: 7815172
Filing Date: 2010-10-19
Classification: B01F,C02F,Y02W

Abstract:
1. A system for aerating a liquid, comprising: a tank having a bottom, wherein the tank holds a volume of the liquid; a first driven rotative shaft having a longitudinal axis, wherein at least a portion of the shaft extends into the liquid; a rotatable surface aerator mounted to the first driven rotative shaft and at least partially immersible into the liquid, wherein the surface aerator is adapted to rotate about the longitudinal axis of the first driven rotative shaft to move the liquid upward and distribute it over the liquid surface; and an elongate draft tube having a longitudinal axis, a proximal end and a distal end, the draft tube being mountable to the first driven rotative shaft and rotatable about the longitudinal axis of the first driven rotative shaft, wherein the longitudinal axis of the draft tube is substantially co-axial with the longitudinal axis of the first driven rotative shaft; wherein the proximal end of the draft tube underlies the surface aerator, and wherein the distal end of the draft tube is positioned a predetermined distance from the bottom of the tank.