Molten metal pump with vaned impeller

A molten metal pump comprising:

• (a) a shaft having first and second ends;
• (b) a means for rotating said shaft in communication with said first end of said shaft;
• (c) an impeller in communication with said second end of said shaft;
• (d) a volute housing said impeller, wherein said volute has a first opening through which molten metal can be drawn and a second opening through which molten metal can be discharged;
• and
• (e) said impeller comprising an imperforate substantially circular base having a surface facing toward a first end of the shaft, and at least two imperforate vanes connected to and extending substantially perpendicular from said surface and extending radially from said shaft or a hub securing said shaft toward a peripheral portion of said base, said vanes being spaced circumferentially apart;
• each vane defining a first edge, a second edge and a third edge;
• said first edge being disposed on said base;
• said second edge defining an inlet end;
• said third edge being a radially outer edge;
• said second edge of adjacent vanes defining an inlet area over their entire radial dimension and being generally planar;
• said third edges of adjacent vanes defining an outlet area;
• and
• said outlet area being greater than said inlet area.