Patent ID: 7637379
Filing Date: 2009-12-29
Classification: B01D

Abstract:
1. A circular secondary clarifier for wastewater treatment, which comprises (a) a circular confinement wall, (b) a circular bottom wall sloping outwardly and downwardly from a center thereof and joined at outer edges thereof with lower portions of said confinement wall to form a containment vessel, (c) a low level wastewater inlet duct positioned below said bottom wall and having an upwardly opening outlet at the center of, and substantially at the level of said bottom wall for the discharge of wastewater upwardly into said containment vessel, (d) a confinement baffle structure positioned centrally in upper portions of said vessel, spaced above said sloping bottom wall and said outlet, (e) said baffle structure being positioned in alignment with a flow of wastewater discharged from said outlet and being operative to substantially confine a plume of solids formed in upwardly flowing liquid discharged from said outlet, whereby said solids are caused to settle downward toward said bottom wall, (f) a rotatable scraper positioned in close relation to central portions of said bottom wall and operative to distribute solids on said central portions radially outward on said bottom wall, (g) a suction manifold positioned over radially outer portions of said bottom wall, (h) said suction manifold being associated with said scraper and being rotatable therewith over said bottom wall, (i) a suction pump connected to said suction manifold through a non-return valve and operative to withdraw settled sludge resting on said bottom wall from said containment vessel, (j) a support structure positioned at an upper portion of said containment vessel and connected to and supporting said scraper and said suction manifold, and (k) a drive motor for controllably rotating said support structure and thereby said scraper and said suction manifold.