Web former in a paper machine.

摘要

The invention concerns a twin-wire (10,20) web former in a paper machine, comprising a single-wire initial portion, after which the twin-wire zone starts in the area of the ribbed deck (22a) of the first forming shoe (22) placed inside one of the wire loops (10). After the first forming shoe (22), a pressure-loaded (pk) dewatering unit (100) is fitted, which is provided with opposite sets of ribs (31,41) and with dewatering chambers (12,13). The first dewatering chamber (12) in this dewatering unit (100) is placed above the first forming shoe (22) so as, through its suction-deflector duct (16), to remove substantially water that drains from the area of the curved ribbed deck (22a) of the first forming shoe (22). The first dewatering chamber (12) is followed by a second dewatering chamber (13), whose lower part is connected with a set of dewatering and guide ribs (41), into whose gap spaces (41R) the drain duct (19) of the second dewatering chamber (13) is opened. Against the set of dewatering and guide ribs (41), a set of loading ribs operates, which is placed inside the opposite wire loop (20) and which operates by means of the medium pressure (pk) of the loading hoses (33). <IMAGE>