Patent ID: 6488849
Filing Date: 2002-12-03
Classification: B01D,G21C,G21F,Y02E,Y02W

Abstract:
Rotating device for continuously filtering a liquid such as a solution containing a precipitate, the device comprising:a cylindrical, horizontal-axis drum of revolution, said drum having a rectangular longitudinal section with a vertical wall, a cylindrical wall and an axial opening defined by an annular flange extending the cylindrical wall, a drive system for rotating said drum, said drive system comprising a drive shaft coaxial and fast with said drum at the level of said vertical wall located on the side of the drum opposite said opening, a system for supplying liquid to be filtered, entering via said opening inside said drum, a plurality of filtering elements each disposed axially, forming at least a part of the cylindrical wall of the drum, said filtering elements each being connected to a process conduit through which a filtrate issued from the filtration of said liquid will pass, a system for evacuating the cake formed at the filtration of said liquid, a system for evacuating said filtrate passing through said process conduits and a hydraulic supply assembly, said hydraulic supply assembly comprising a pulsed compressed air supply and means forcing the passage of said liquid through the filtering elements, said means forcing the passage of said liquid through the filtering elements comprising a source of depression for filtration connected to said system for evacuation of the filtrate and placing the interior of said filtering elements under depression with respect to the interior of the drum a connecting system for communication between said supply assembly and said process conduits by allowing an angular distribution of the operations effected by said device, these operations comprising at least the filtration of the liquid and the separation of the cake from said filtering elements by cleaning, wherein said system for evacuating the cake functions by gravity and presents a collecting hopper located inside the drum substantially beneath the uppermost part and connected to a spout extending out of the drum via said opening, wherein said process conduits extend in said vertical wall of the drum and present, on the one hand, a first end opening out in a filtering element and, on the other hand, a second end opening out in the outer vertical face of said vertical wall, wherein said connecting system comprises a first disc fast with the drum about the drive shaft and pierced with a plurality of connection openings which are connected one by one to the second ends of said process conduits, and a second fixed disc coaxial with and adjacent said first disc and provided with angular slots in register with said supply assembly and disposed radially opposite said connection openings, an angular filtration slot being located at least partially in the lower part of the second disc and connected to said source of depression for the filtration of the liquid, and an angular cleaning slot being located substantially in the uppermost angular sector of the second disc and connected to said compressed air supply for the separation of the cake from each filtering element.