Dewatering means for dewatering a fibrous web, process for dewatering a fibrous web and machine for producing a fibrous web

Dewatering means for dewatering a fibrous web (1), in particular a paper, board, pulp or the tissue web. The device comprises a suction roll (7) with an evacuated region (8), which one or more suction zones (8a) may include, and is connected to at least one vacuum system. In addition, a first covering (2) which is arranged in the area of ​​the evacuated area (8) between the fibrous web (1) and the suction roll (7). The drainage device is characterized in that it comprises at least one diffuser layer (3) This is at least in the area of ​​the evacuated area (8) between the fibrous web (1) and the surface of the suction roll (7).