Automatic vacuum dehydrating apparatus in a slurry carrying vessel

Abstract

An improved automatic vacuum dehydrating apparatus in a slurry carrying vessel including a hold for loading slurry therein provided with a plurality of dehydrating ports at its bottom is described herein, which comprises a dehydrating pipe branched at one end and connected to said respective dehydrating ports through respective closure valves individually provided in the respective pipe branches, a vacuum tank adapted to be evacuated and connected to the other ends of said dehydrating pipe, and pressure detector-controller means for detecting a pressure in the vicinity of each said dehydrating port and for controlling said closure valve in response to the detected pressure value. The pressure-controller means is adapted to control each said closure valve in such manner that when said detected pressure exceeds a predetermined value the closure valve in the corresponding dehydrating pipe branch may be closed, and when said detected pressure is further raised up to a preset upper limit value the same closure valve in the corresponding pipe branch may be opened again. In one preferred embodiment, said vacuum pump is in turn connected to a vacuum pump and a drainage pump, and is provided with a water level detector-controller means for detecting a level of water accumulated in said vacuum tank and for selectively controlling said drainage pump and said vacuum pump in response to the detected water level in said vacuum tank, in such manner that when the detected water level in said vacuum tank exceeds a first predetermined level said drainage pump is actuated and said vacuum pump is stopped to drain the accumulated water, whereas when the detected water level in said vacuum tank is lowered under a second predetermined level said vacuum pump is actuated and said drainage pump is stopped to evacuate said vacuum pump.