Abstract: A managing system for managing slurry, which is used to machine workpieces. The slurry contains dispersion liquid and abrasive grains. Slurry that has been used in machining further includes impurities that are smaller than the abrasive grains. A first decanter centrifugally separates a mixture of impurities and dispersion liquid from the used slurry to recover recyclable abrasive grains from the slurry. A second decanter centrifugally separates impurities from the mixture to recover recyclable dispersion liquid from the slurry. A specific gravity gage and a viscosity gage detect properties of the used slurry. The rotating speeds of the first and second decanters are controlled in accordance with the detected properties of the slurry. This always maintains the separating efficiency of both decanters at an optimal value thus effectively recovering and recycling the abrasive grains and dispersion liquid.

Abstract: A rotary discharge type centrifugal separator having a long service life, an energy saving effect, high performance and a high mechanical strength in which the length of a revolving cylindrical bowl is reduced; a high revolution is possible; sludge can be separated by a large centrifugal force; and a paste-like solid component can be efficiently discharged. The rotary discharge type centrifugal separator comprises a revolving cylindrical bowl having a separating zone and a scraping section a screw conveyor shaft coaxially and rotatably held in the bowl, and a pantograph link type scraper which is mounted on the screw conveyor shaft at a portion corresponding to the scraping section and which has four link bars pivotally connected to each other in a rhomboidal shape so that the link bars are supported symmetrically in a plane perpendicular to the axial center of the screw conveyor shaft.