Abstract: It is an object of the present invention to provide a stirring apparatus which can exhibit excellent stirring characteristics in a wide range of viscous regions and which can reduce the mixing time. A stirring apparatus includes a stirred tank having a bottomed cylinder shape, a rotation shaft concentrically or substantially concentrically disposed inside the stirred tank, and a bottom blade that extends from the rotation shaft so as to extend in a radial direction and a vertical direction, of the stirred tank, and a lower edge of the bottom blade has a shape conforming to a bottom wall surface of the stirred tank. Here, a clearance is formed between the lower edge of the bottom blade and the lower wall surface and the clearance satisfies the following condition: 1% of the inner diameter of the stirred tank<the clearance<4.5% of the inner diameter of the stirred tank.

Abstract: It is an object of the present invention to provide an agitator equipped with a bottom paddle that has favorable agitation performance also in a streamline flow region of low Re number and to provide an agitation method.

Abstract: A coater head for applying coating to a size press roll of a size press coater, the coater head has a flow passage with a metering device at its outlet end and a metering chamber immediately adjacent to the metering end. A shear developing passage delivers coating to the metering chamber and a mixing passage leading into the metering chamber mixes fresh coating with return coating on the surface of the roll to carry the fresh coating to the outlet end of the metering chamber. The metering chamber is dimensioned to form a stable vortex within the chamber thereby to improve the uniformity of the coating wet film.