Anaerobic digester

摘要

An anaerobic digester for digesting animal manure and other biologically degradable material contains support media (50) for enhancing the contact between the microbes in the digesting mass and the available nutrients, The digester includes a novel fluid circulation and distribution systems. The distribution system prevents build up of heavy material in the bottom of the digester and prevents agglomeration of light material at the top of the digester. The digesting fluid travels over a floating weir (64) into an intake and impeller assembly (68). The impeller drives the fluid through a conduit (80) located adjacent the floor of the digester. Nozzles (98) in the conduit project the fluid downwardly toward the floor thus causing a sweeping action on the floor. Fluid then flows upwardly past the support media. Risers (86, 88, 94) are provided at the ends of the conduit, which terminate in nozzles (90, 92, 96) at the surface of the digesting liquid. The nozzles direct the flow of digesting material back toward the fluid inlet and also sweep the corners of the digester to prevent material accumulation.