Patent ID: 7168641

Claim:
An attrition scrubber for attritioning a fluid, having a vertical axis of rotation, comprising: a first attritioning cell located generally along the vertical axis of rotation having an inlet opening and a width W cell ; a second attritioning cell located generally along the vertical axis of rotation at a position adjacently above the first attritioning cell, wherein the second attritioning cell has a width equal to W cell ; a rotatable shaft disposed within the first and second attritioning cells, wherein the rotatable shaft extends generally parallel to and rotates about the vertical axis of rotation at least partially all the way between first and second attritioning cells; a first orifice plate disposed at an axial location between the first and second attritioning cells to separate the first and second attritioning cells from each other, the orifice plate extending radially inward and having a central orifice through which the shaft passes with a clearance to allow fluid flow through the orifice around the shaft from the first attritioning cell to the second attritioning cell; a first impeller attached to the rotatable shaft at a first axial location within the first attritioning cell, wherein the first impeller pumps fluid along the vertical axis of rotation in a first direction; a second impeller attached to the rotatable shaft at a second axial location within the first attritioning cell, wherein the second impeller pumps fluid along the vertical axis of rotation in a second, opposite direction; a third impeller attached to the rotatable shaft at a third axial location within the second attritioning cell, wherein the third impeller pumps fluid along the vertical axis of rotation in the first direction; a fourth impeller attached to the rotatable shaft at a fourth axial location within the second attritioning cell, wherein the fourth impeller pumps fluid along the vertical axis of rotation in the second, opposite direction, a first dispersion ring disposed in the first attritioning cell, wherein the first dispersion ring is connected to the rotatable shaft at a fifth axial location thereof above the second impeller the fifth axial location being different from the location of the first orifice plate; and a second dispersion ring disposed in the second attritioning cell, wherein the dispersion ring is connected to the rotatable shaft at a sixth axial location thereof above the fourth impeller the sixth axial location being different from the location of the first orifice plate, wherein the first and second dispersion rings each have a diameter D r , wherein the first, second, third, and fourth impellers each have a diameter D i .