Patent ID: 7179433

Claim:
A stirring apparatus comprising: a vertical cylindrical vessel which is substantially closed; a partitioning cylinder disposed inside the cylindrical vessel which partitions the cylindrical vessel into inner and outer compartments concentric to a center thereof; an inlet through which a process solution is supplied into the outer compartment; an outlet disposed inside the inner compartment through which the process solution is evacuated; stirring blades disposed in the inner and outer compartments respectively, the stirring blade in the inner compartment stirring a process solution therein and the stirring blade in the outer compartment stirring a process solution therein, each of the stirring blades rotating concentrically around the center of the cylindrical vessel; and a rotating shaft for the stirring blade of the outer compartment, fixed thereto, which is disposed above the inner compartment inside the cylindrical vessel and whose lower end is located above the inner compartment and is at a location higher than an upper edge of the partitioning cylinder, wherein the process solution in the outer compartment enters the inner compartment over the upper edge of the partitioning cylinder in a reaction proceeding by the stirring of the blades.