Patent attributes
One aspect of the invention is directed to an impeller made of a non-metallic, heat resistant material, comprising a generally cylindrical shaped body, first and second generally planar end faces and a side wall extending between the first and second faces. A plurality of passages have inlets circumferentially spaced apart from each other on the first face, outlets at the impeller sidewall, and connecting portions extending between the inlets and the outlets transverse to the central axis. Another aspect of the invention is directed to an impeller comprising a central hub portion and first and second impeller bases, including end faces, transverse to a central axis. Vanes extend from the central hub portion between the impeller bases. Cavities are formed between the impeller bases and between adjacent vanes. Molten metal inlets on the end faces for molten metal to reach the cavities. Pumps are also disclosed using the inventive impellers.