SUCTION ROLL FOR DEWATERING A FIBROUS WEB

The invention relates to a suction roll for dewatering a fibrous web, having a rotatable and perforated suction roll jacket and a suction box connected to a negative pressure source in a way that applies a negative pressure to an inner surface thus enabling a defined surface region to be aspirated. According to the invention, the suction box has a first suction channel which extends in the interior of the roll substantially along the axis of the suction roll, and a second suction channel which extends in the interior of the roll along the inner surface of the suction roll jacket and which is delimited by seals. The first suction channel is connected to the second suction channel by a connecting channel, and leads into the first suction channel above a collection region, such that extracted water can accumulate and does not run off back through the connecting channel. L'invention concerne un cylindre aspirant (12) pour déshydrater une bande de matière fibreuse, comportant une enveloppe (1) de cylindre aspirant rotative et perforée, et un caisson aspirant (7) à l'intérieur du cylindre aspirant (12). Selon l'invention, le caisson aspirant (7) comporte un premier canal aspirant (3) s'étendant à l'intérieur (14) du cylindre, sensiblement le long de l'axe de cylindre aspirant. Le caisson aspirant (7) comporte également un deuxième canal aspirant (4) s'étendant à l'intérieur (14) du cylindre, le long de la surface intérieure (13) de l'enveloppe (1) de cylindre aspirant, et étant délimité par des joints (2, 2a). Le premier canal aspirant (3) est relié au deuxième canal aspirant (4) au moyen d'au moins un canal de liaison (9).