A sludge supply tank with screw vanes is provided to increase condensation process effect of sludge by separating the sludge and processing water authentically and to improve sludge treatment efficiency by increasing sludge rising efficiency. A sludge supply tank with screw vanes is formed with a cylindrical structure in which a bottom part(12) is opened and a top part(11) is closed. The sludge supply tank includes a body part(10) and the screw vanes(20). The body part comprises an outer wall pipe(13) and an inner wall pipe(14). The outer wall pipe is suspended on an end part of the top part and a side port(13a) is formed therein. The inner wall pipe is suspended on the center part of the top par and covers a power shaft(200) on a flotation tank body. The screw vanes is installed to an upper direction with a spiral shape.
