GRIT REMOVAL SYSTEM

摘要

A grit removal system for tanks with a need to remove settled solids (e.g., anaerobic digester tank) is described. The system is especially suitable for a large tank, preferably having a flat floor, and it works well while submerged under a liquid. Specifically, a periphery-driven rack & pinion mechanism drives a shaft to rotate about a center pivot, and scrapes settled solids towards tank periphery, where the solids fall into a pit on the tank floor. A drainage opening inside the pit, when opened by a valve, is used to flush out the solids through a standpipe into a settlement tank for final dewatering and solid disposal. The system is compatible for continuous tank operation, and is useful for stirring tanks requiring periodic sediment removal.