Process and apparatus for removing solids from an aqueous paper fiber suspension

Abstract

Process and apparatus for removing solids from an aqueous fiber suspension in a flotation container that includes a drainage section. The process includes adding gas bubbles to the fiber suspension entering the flotation container, and collecting a flotation foam formed within the flotation container. The flotation foam includes the solids to be removed. The process also includes laterally moving the flotation foam in the drainage section, such that at least a portion of fluid within the flotation foam is drained from the flotation foam, collecting the drained fluid in the drainage section, discharging the drained fluid from the drainage section, discharging the flotation foam as a rejects material, and discharging a purified fiber suspension as an accepted stock suspension. The apparatus includes a flotation container, and a drainage section coupled to the flotation container. The drainage section is arranged to drain at least a portion of fluid from a flotation foam. The apparatus also includes a rejects outlet coupled to the drainage section, an accepts outlet coupled to the flotation container, and a fluid collector coupled to the drainage section for collecting the fluid drained from the flotation foam.

Dependencies are inferred from the claim text.