Anaerobic effluent digester - has rectangular settling tank above it with endless scraper belt between inlet and recycling slots at ends

摘要

The installation for anaerobic purification of effluent, comprises a digesting tank sepd. by a horizontal or near- horizontal partition from a sedimentation tank above it. A sludge scraper is movable over the bottom, the sludge/water mixture entering from below via an overflow, and settled sludge returns to the digester via a passage. Gas generated in the digester is prevented from entering this passage by a flow diverter. The entry and exit passages are each formed by a slot at opposite ends of the rectangular partition and the scraper extends over the full widht of this partition and moves from the entry to the exit passage. Sludge/water mixt. enters at low speed over full width of settling tank so that sedimentation starts immediately after entry. Low and optimally adjustable scraper speed, constant at all point (as opposed to rotary scraper) and slot-shaped outlet prevent stirring up of settled sludge and give uniform flow pattern and settling.