Mixing apparatus and bottom ribbon blade used therein

摘要

A mixing apparatus includes a bottom ribbon blade adapted for viscous fluid contents. The mixing apparatus includes a vertically positioned mixing vessel including a cylindrical wall and a bottom wall disposed on a lower portion of the cylindrical wall wherein the bottom wall is of a semi-ellipsoid shape, dished shape, or circular cone shape with an obtuse apex angle and each of the convex surfaces of which is oriented downwardly. An impeller shaft is vertically and coaxially aligned within the mixing vessel and a helical ribbon blade is disposed within the mixing vessel in such a manner as to be rotated by a driving mechanism via the impeller shaft. A bottom ribbon blade is connected to a lower end of the helical ribbon blade and disposed in proximity with the bottom wall from its center to its periphery, wherein a centrally located portion of the bottom ribbon blade has its surface substantially perpendicular to the bottom wall, and a lower edge of the bottom ribbon blade is formed in such a manner as to correspond to a logarithmic spiral curve at least for its centrally located portion.