Liquid mixing device

Claim 1

A MIXING DEVICE FOR MIXING TWO DIFFERENT MATERIALS, SAID DEVICE INCLUDING TWO CONCENTRIC SHAFTS EACH HAVING IMPELLER END PORTIONS WITH THE INNER SHAFT END PORTION EXTENDING AXIALLY BEYOND THE ADJACENT OUTER SHAFT END PORTION, AN IMPELLER MOUNTED ON EACH END PORTION AND INCLUDING AN INNER MEMBER HAVING A SMALLER DIAMETER END AND BEING CONNECTED TO THE RESPECTIVE SHAFT END PORTION AND LARGER DIAMETER PROXIMATE END FACES SPACED FROM SAID SMALLER DIAMETER END PORTIONS, WHEREBY SAID END FACES ARE MOUNTED IN FACE TO FACE RELATION SEPARATED ONLY BY CLEARANCE FOR ROTATION, SUCH INNER MEMBER PROVIDING AN OUTER PERIPHERAL SURFACE EXTENDING FROM ITS SMALLER DIAMETER END TO ITS LARGER DIAMETER END FACE, EACH IMPELLER INCLUDING A PLURALITY OF VANES PERPENDICULAR TO ITS INNER MEMBER END FACE AND DISPOSED IN EQUALLY ANGULARLY SPACED APART RADIAL PLANES AROUND SAID INNER MEMBER, EACH VANE HAVING AN INNER EDGE FOR CONNECTION TO THE INNER MEMBER OF ITS IMPELLER AND HAVING A PORTION EXTENDING RADIALLY OUTWARDLY AND LYING IN THE PLANE OF THE END FACE THEREOF AND HAVING A SUBSTANTIALLY LARGER DIAMETER THAN SAID END FACE DIAMETER, EACH IMPELLER ALSO INCLUDING A HOUSING COMPRISING A CYLINDRICAL HUB HAVING AN INLET END, AND ALSO HAVING A DOWNSTREAM PORTION, SAID