| 摘要 |
The invention relates to a barrier for draining at the dewatering of fibrous suspensions. The barrier has the object to retain the fibers and to permit the filtrate to be discharged through openings in the barrier. The driving force for the dewatering can be either a mechanical pressure or a hydraulic pressure difference. The problem at dewatering is to retain the fibers and at the same time to facilitate the discharge of the dewatered filtrate from the boundary layer of the formed pulp cake. The device implies that the fiber side of the barrier (1) is provided with a pattern of narrow channels (2, 3) with a width of < 1 mm, preferably < 0.5 mm, which are placed so that the surface layer of the barrier has an openness of at least 20 %, preferably at least 40 %, of the boundary surface toward the fibrous suspension. The filtrate is drained via these channels to openings (4), which permit passage to the filtrate side of the barrier. The channels on the fiber side of the barrier preferably can be intersecting and extend in at least two directions, none of which need to be perpendicular to the direction of movement of the barrier. |
