US Patent 7997788 Submersible mixing propeller

An aerating propeller for attaching to the end of a drive shaft includes blades having a chamber to receive a flow of fluids from a conduit in a drive shaft. A trailing face of the blade includes a first opening into the chamber to permit the flow of fluids in the chamber to exit the propeller and a tip of the blade includes a second opening extending into the chamber to permit the flow of fluids in the chamber to exit the propeller. The first opening of the first blade is aligned generally in the same plane with the leading face of the second blade which follows the first blade when the propeller is rotated.