Clarifier with sludge dewatering

摘要

A rectangular clarifying tank has an inclined beach formed of sheet metal and having 575 holes per square inch, each hole having a diameter of 20 thousandths of an inch. Two side chain drives advance several scrapers along the beach. Each scraper has a rotatable knurled pipe which turns the sludge and aids dewatering through the beach. The sludge removed from the clarifier has a solids content of between eight and twelve percent. Additional dewatering may be accomplished by applying a vacuum to the last one-quarter of the beach. A tray positioned beneath the beach collects water which drains through the beach. The drain water may be returned to the clarifier tank or may be directly treated as clarified water.