THICKENER

摘要

A thickener for the concentration of a solids-liquid suspension includes a vessel or tank into which such a suspension is continuously introduced and a rotating rake assembly for exerting mechanical pressure on the solids-sediment layer settling in the bottom of the vessel. The rake assembly is carried by a main shaft which undergoes vertical movement automatically in response to the hydraulic pressure in a fluid supply line feeding a main hydraulic motor drivingly coupled to the main shaft. The variation in the supply line pressure is transferred to a hydraulic chamber of a double-acting cylinder housing a piston which is mechanically coupled to the main shaft for conjoint vertical movement therewith. Air contained within a pneumatic chamber of the double-acting cylinder upwardly of the piston provides a buffer action for such automatic adjustment of the vertical position of the main shaft. Movement of the main shaft also controls an adjustable flow control valve in the fluid supply line to reduce hunting and the fluid discharge line from the main drive motor includes a second hydraulic motor drivingly coupled to a positive displacement pump for affecting the continuous discharge of the solids-sediment from the thickener.