초록 ▼

An axial flow mixing impeller system for efficient mass transfer by control of size of the bubbles of the fluid which is being dispersed, especially gases and liquids with viscosities greater than the liquid into which dispersion occurs, is obtained by creating passageways through the impeller blade

An axial flow mixing impeller system for efficient mass transfer by control of size of the bubbles of the fluid which is being dispersed, especially gases and liquids with viscosities greater than the liquid into which dispersion occurs, is obtained by creating passageways through the impeller blades for flow between the suction and pressure sides of the blades which disrupts the flow over the suction sides of the blades thereby reducing the tendency for bubbles to grow or coalesce into large bubbles which instead of being dispersed, rise to the surface without effective mass transfer to the liquid which is pumped by the impeller. The blades of the impeller may be slotted inwardly from the tips thereof to provide the passageways or may be formed from segments, gaps between which provide the flow passageways. The segmented blades have the advantage of enabling systems of large diameter impellers, of size approaching the diameter of the tanks or in closed tanks where access is by way of a manway smaller than the impeller blade dimensions, to be assembled within the tank, either upon initial installation or for replacement or retrofit. If the system is not used for gas or liquid dispersion, the segments may be in edge-to-edge abutment. Gas-to-liquid dispersion may also be improved by sparging below the impeller at the bottom of the tank and between the impellers in the tank, as with sparge rings of diameter less than the diameter of the impellers enabling gas supply at different pressures commensurate with the depth of the sparge rings, sufficient to overcome the head at the depth of the sparge ring.

대표청구항 ▼

[ What is claimed is:] [10.]10. An impeller system for carrying out mass transfer between a first fluid and a second fluid different from said first fluid, in a tank in which said fluids are contained, said system comprising:at least one axial flow impeller on a shaft with which said impeller is dri

[ What is claimed is:] [10.]10. An impeller system for carrying out mass transfer between a first fluid and a second fluid different from said first fluid, in a tank in which said fluids are contained, said system comprising:at least one axial flow impeller on a shaft with which said impeller is driven so as to pump fluid in a direction axially of said shaft, said impeller having blades with suction sides and pressure sides, said pressure sides being spaced by a thickness of said blades away from said suction sides in a direction of an axial flow, andat least one opening disposed in each of said blades and which extends inwardly of said blades substantially all the way from said outer ends to said inner ends, said openings which disrupt the axial flow over substantially all of the suction sides of said blades thereby preventing formation of bubbles in said second fluid on said suction sides which reduce the axial flow provide ed by said impeller.