Continuously operating sedimentation tank wherein a load yieldable composite rotary rake arm structure is constructed and arranged to conform to the compound slope of the tank bottom, while being dragged over the tank bottom by draft means connecting it to a driving arm spaced upwardly from the rake...http://www.google.com/patents/US4000075?utm_source=gb-gplus-sharePatent US4000075 - Sedimentation tank with rotary yieldable rake arm structure
Sedimentation tank with rotary yieldable rake arm structure
