Process and system for the dehydration of residues

A system for the dehydration of residues such as sludge or pulpy residues, said system comprising:

• first and second endless filter means between which is fed a residue to be dehydrated, each said filter means being mounted for movement about a respective endless path;
• a plurality of cylindrical members mounted to support both said first and second filter means over portions of the respective endless paths thereof;
• said first and second filter means, with said residue therebetween, passing alternately over portions of the peripheries of said cylindrical members, thereby pressing and dehydrating said residue;
• means for driving first and second adjacent of said cylindrical members at the same speed but in opposite directions, and for thereby driving said first and second filter means;
• means for simultaneously and uniformly tensioning said first and second filter means, said tensioning means comprising a separate fluid operated tensioning assembly for each said filter means, and a single fluid source operatively connected to both said tensioning assemblies to simultaneously and equally control the operation thereof, each said tensioning assembly comprising a tensioning roller over which passes the respective filter means, a pair of first articulated arms supporting opposite ends of said tensioning roller, and a pair of first fluid operated piston-cylinder assemblies, one each connected to one of said arms, both of said first piston-cylinder assemblies of each of said tensioning assemblies being operatively connected to said single fluid source to be simultaneously operated thereby;
• and
• supplemental pressing means for pressing said filter means and said residue against a first of said cylindrical members at a uniform pressure regardless of the thickness of said residue between said first and second filter means, said supplemental pressing means comprising a plurality of pressing rollers supported by mounts about the periphery of said first cylindrical member, and fluid operated means for positioning said pressing rollers at a controlled position from said first cylindrical member, said mounts comprising a pair of links, each supporting opposite ends of said rollers, and a pair of second articulated arms, one each pivotally attached to a respective of said links, said fluid operated means comprising a pair of second piston-cylinder assemblies, both connected to said single fluid source and one each connected to a respective said second articulated arm.