Abstract: An upper carriage floats on the surface of a settling pond or tank of liquid containing sedimentation settled out to form a bed of sludge in the bottom of the tank. A scraper assembly is suspended from the upper carriage by flexible cables or chains to a preselected depth in the tank. Scraper blades supported by the scraper assembly extend downwardly into contact with the sludge bed. The carriage is propelled on a looped cable across the surface of the tank and applies a tractive force through the suspension cables to the scraper assembly. As the submerged scraper assembly advances, the scraper blades apply a shear force to dislodge the sludge from the bed and direct the sludge to a pump carried on the submerged scraper assembly. The dislodged sludge is pumped through a hose from the tank.

Abstract: Liquid is removed from a remote location, with control of the system responsive to the supply of the liquid to be removed. Control is accomplished without the need for electrical devices at the remote location by means of a valve in the remote location in the conduit circulating a powering fluid to a pump at the remote location, and the sensing of the accompanying changes in flow or pressure in the powering fluid conduit or output conduit.