Patent ID: 8181790

Claim:
A flotation apparatus having a tank for receiving a liquid raw material and introducing air into the tank to generate bubbles, thereby adsorbing print ink in the liquid raw material to the bubbles to float and separate the print ink, comprising: circulating means for circulating the liquid raw material by raising and then lowering the liquid raw material in the tank; an air supply tube for supplying the air into the tank; and an agitating member provided in the tank for receiving the air from the air supply tube and agitating the air for forming the air into fine bubbles, wherein the agitating member has a rotary shaft held horizontally and a plurality of members horizontally separately provided around an outer periphery thereof, on a cross section transverse to a longitudinal direction of the tank, the outer periphery of the agitating member is arranged on a lower side of the tank and at a downstream side of the liquid raw material relative to a vertical line passing through a center of the tank, on a cross section transverse to a longitudinal direction of the agitating member, in a case that the cross section is viewed from a side wherein a rotational direction of the agitating member is a counterclockwise direction, when an orthogonal coordinate wherein a rotational center of the agitating member is an origin, is divided to a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant in a counterclockwise direction, an opposed wall facing the agitating member is positioned within an area of the third quadrant, or in a range between the third quadrant and the fourth quadrant, and an outlet of the air supply tube is positioned between the opposed wall and the agitating member.