US Patent 7131765 Helical-ribbon mixer

A helical-ribbon mixer having a rotation-symmetrical inner mixing vessel wall (2), a motor-driven central agitator axis (3) therein, on which, on lateral agitator arms (5), at least one helical ribbon (4) is held close to the vessel wall downwardly sloping with a circular slope (SZ) in a direction of rotation (D), wherein the helical ribbon (4), vectorially combined circularly and radially, has a helical ribbon angle of slope (SN) relative to the horizontal that is greater than a gliding angle (G) on the helical ribbon (4) of a material (M) to be mixed.