Water extraction zone for a wet paper/cardboard web has a number of units in a water extraction zone where pulsed pressure gas streams displace water from the web

摘要

The station (10) for the extraction of water from a wet paper/cardboard web (12) has a water extraction zone (E), where the water is driven out at least partially by the effects of a displacement gas (14) under pressure. In the water extraction zone (E), the web (12) passes through a number of stages where it is subjected to a number of gas pressure pulses (141-144). Within the water extraction zone (E), a number of extraction stations (16,18,20,22) are at intervals on the web (12) path, where water is displaced from the web. The pressure level can be adjusted for at least one of the gas pulses (141-144), and their pressures can be set independently of each other. The web (12) moves through the water extraction zone (E) together with a membrane (26), which is pressed against the web by the pulsed pressure gas (14). A fourdrinier or blanket (24) is on the other side of the web (12). The gas pulses (141-142) are at different time frequencies. An independent claim is included for a water extraction station (10) for a paper/cardboard web (12), where it is passed through a water extraction zone (E) with a number of spaced extraction units (16,18,20,22), in succession, with displacement gas pulses directed under pressure at the web (12).