Pulp production arrangement and method

A dewatering roll, comprising

• a roll body;
• a mantle support structure having an outer surface, a pair of axial ends, a central portion, a plurality of support ribs, and ring elements attached to said plurality of support ribs attached, in a radial direction, around said roll body;
• and
• a mantle having an outer surface and an inner surface, attached, in said radial direction, against said outer surface of said mantle support structure;
• said mantle having a plurality of through holes constituting mantle flow paths from, in said radial direction, said outer surface of said mantle to, in said radial direction, said inner surface of said mantle;
• said mantle support structure presenting support flow paths from said outer surface of said mantle support structure, said support flow paths being in fluid contact with said mantle flow paths;
• said outer surface of said mantle support structure having a static geometric shape defining an envelope having a smaller radius in vicinity of each one of said axial ends of said mantle support structure than in vicinity of said central portion of said mantle support structure, whereby said inner surface of said mantle assumes the shape of said envelope.