| 摘要 |
At the web press section, for the extraction of water from a paper or cardboard web (1), the web is carried through the press gap between two press rollers (2,3) between press belts (4,5). In the movement path (6) on leaving the press gap, the lower press belt (5) travels over at least one suction unit (7) aligned across the web (1), linked to an underpressure source. The suction unit (7) extends over only a part of the movement path (6), in the direction (8) of web (1) travel, and pref. before the end of the path (6). The suction unit (7) is pref. a suction box, at a gap of 40-80 cm from the roller press gap. It has one or more suction slits aligned at the lower press belt (5), and pref. 1-3 slits all with an equal or unequal width of 10-30 mm. The suction unit (7) works at an underpressure of 0.1-0.4 bar, and is on a swing mounting. The suction unit (7) has at least one inner spray tube, to clean its interior and/or the suction slits. The web movement path (6), on leaving the roller press gap, has a length of 100-180 cm. A stripping bar (9) to extract water is in contact with the lower press belt (5) at the start and/or end of the suction unit (7), across the line of the web (1). The stripper bar (9) at the start of the suction unit (7) is structured to deflect water from the lower press belt (5) and, at the same time, deflect water spun from the roller mantle (12) of the lower press roller (3). The suction unit (7) also has a guide plate (18) or guide body, to deflect water spun from the roller mantle (12) of the lower press roller (3). On leaving the movement path (6), the web (1) travels onwards only with the lower press belt (5). The lower press belt (5) passes over a suction roller (10) at the end of the movement path (6), which has a stripper (19) to detach water and air from the suction roller (10). The stripper (19) is pressed against the mantle of the suction roller (10) by an air hose across the machine line, and the stripper (19) is on a separate mounting. A water trap (11), pref. as a catch gutter, is at the upper press belt (4), after the roller press gap. At least the roller mantle (12) of the lower press roller (3) is pressed into the press gap by a support (13,14) which pref. extends the press gap length.
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