Abstract
Vortex flow measurements have been carried out with PIV (particle image velocimetry) to understand the flow in a bath with an immersion cylinder under mechanical agitation condition. An impeller is placed on the centerline of the bath and the cylinder is immersed slightly into the bath at an offset radical position. A horizontal rotational motion of water prevails in the absence of the immersion cylinder and the axis of the rotational motion overlaps the centerline of the bath. On the other hand, the axis of the rotational motion inclines in the presence of the immersion cylinder and a strong downward motion of liquid is induced in the bath. This downward motion enhances the entrainment of low-density particles initially placed on the bath surface. The inclination angle decreases with an increase in the rotation frequency of the impeller. Accordingly, the effect of the immersion cylinder becomes weak as the rotation frequency increases under the present experimental conditions.
