摘要:
An arrangement in connection with the press and dryer section of a web-forming machine includes first and second devices for transporting the web. The second device includes a dryer wire and a roll arranged to support it. In the arrangement there is an open gap between the first and second devices, across which the web is arranged to be transferred, so that the web and the dryer wire form a closing throat. The arrangement further includes a deflector before the open gap in the direction of travel of the dryer wire, which is arranged close to the dryer wire, in order to restrict the air layer travelling with the dryer wire, and thus to prevent the formation of an excess pressure in the closing throat.
摘要:
A web is passed over a surface (11) which is at least partly curved in the running direction of the web, which extends across the web in the cross direction, and which is placed at a distance from the web, in which connection an air cushion is formed between the moving web and the curved surface. The temperature and moisture of the web are measured indirectly by measuring the temperature and moisture of the air cushion by several detectors (41) which are in communication with openings (40) formed in the curved surface in spaced relationship with one another in the cross direction of the web.
摘要:
The invention concerns an equipment and a method in the transfer of a paper/board web in a paper or board machine. In an embodiment of the invention, the dryer section comprises at least one group of drying cylinders in which, instead of a conventional wire draw, a transfer belt (H100) is employed, to which the web (W) is affixed by effect of adhesion and which transfer belt is passed over drying cylinders (K1, K2, . . . ) and reversing rolls (E1, E2, . . . ) and further in said group (RI) of drying cylinders in the dryer section. The invention also concerns a method in the transfer of the web (W) in the dryer section (K) of a paper/board machine. In an embodiment of the invention, the web (W) is passed, while meandering in loop shape and while adhering to the face of the transfer belt (H100), from a drying cylinder (K1) in the group (RI) of drying cylinders in the dryer section (K) onto a reversing roll (E1) and further from the reversing roll onto the next drying cylinder (K2) and further in the group (RI) of drying cylinders.
摘要:
The invention relates to a sealing arrangement (7) against a moving fabric (4b) in a paper machine or the like. The sealing arrangement includes a stiff sealing element (9) placed on the fabric's (4b) side on the entire width in connection with a paper sheet (4a) supported by the fabric (4b). The sealing element has been arranged on a support so that the location of the sealing element with respect to the fabric (4b) can be adjusted nearer to or, correspondingly, further from the fabric. As a sealing element there is at least a single-chambered labyrinth sealing (19).
摘要:
The invention relates to a sealing arrangement (7) against a moving fabric (4b) in a paper machine or the like. The sealing arrangement includes a stiff sealing element (9) placed on the fabric's (4b) side on the entire width in connection with a paper sheet (4a) supported by the fabric (4b). The sealing element has been arranged on a support so that the location of the sealing element with respect to the fabric (4b) can be adjusted nearer to or, correspondingly, further from the fabric. As a sealing element there is at least a single-chambered labyrinth sealing (19).
摘要:
An apparatus for a dryer section of a paper or board machine has a drying group (R) and an impingement drying unit (10) which is placed above and/or below a row (DSR) of drying cylinders (3). A drying fabric (1) supported paper or board web (2) is conducted past the impingement drying unit (10) having at least one impingement surface (IP1, IP2) the side profile of which is straight, changeably curved in its radius of curvature, in the shape of a broken line or a selectable combination of these, and that the impingement surface or a tangent line to the impingement surface or a line passing via the beginning and the end of the impingement surface or an extension of the line forms on the impingement side an angle with a horizontal plane parallel to the machine level, which angle is ≦120°, advantageously 120°–60°, most advantageously about 90°.
摘要:
A method and an apparatus for web threading in a drying section of a paper machine or the like. A leader (24) and a so called run-down strip are formed by cutting in the web coming to the drying cylinder in the drying section. An underpressure box (18) is arranged at the opening gap between the drying cylinder (14) and the drying wire, on that side of the wire which is away from the web, whereby this box can direct against the web an underpressure which is controllable in the machine's cross direction. The underpressure box creates an underpressure region (34′) between the leader and the underpressure box, the region having an underpressure p1 at the detachment point, i.e. in the area where the wire is detached from said drying cylinder (14), which underpressure is sufficient to detach the leader from said drying cylinder. A protection zone is created between the underpressure region created at the leader and the run-down strip, which protection zone has a barrier (46) in order to maintain the underpressure p1 in the underpressure region.
摘要:
An arrangement and method for improving runnability, and dryer section length, by using a vertical impingement dryer before a first dryer cylinder of a group of dryer cylinders. After a pressing section, the web is dried with a pre-impingement dryer, closely followed by a vertical impingement dryer, which is closely following by the first dryer cylinder. The pre-impingement dryer and vertical impingement dryer of the first dryer cylinder to have a drying temperature of approximately 80° C. with no undesirable sticking to the dryer cylinder. The pre-impingement dryer can be arranged to dry a first side of the web, and a vertical impingement dryer after the first dryer cylinder is arranged to dry a second side of the web. The impingement drying takes place directly against the web without an intervening fabric.
摘要:
A web (16) running from an opening nip (K1) between a cylinder (10) and a supporting fabric (18) toward a roll (14), is supported by a negative pressure created by a blow box (30). In an intensified negative pressure region (34′), i.e. close to the disengaging point (40) between the supporting fabric and the cylinder, the pressure is greater than at a distance from this disengaging point. The negative pressure is controlled according to parameters which act on the runability of the web and which can be varied, such as web velocity, web solid contents, pulp composition, paper or paper board quality, web grammage, a characteristic of the web, such as porosity, traction acting in the web, or web tension, cylinder temperature, and/or the running situation, such as a web break, a threading situation, or a normal run, so the desired runability is maintained between the cylinder and the roll.
摘要:
In the manufacture of a paper or board web (W), the web is slit or cut, the rising/lowering (H) of the edges of a slit/cut gap (C) formed at the slitting/cutting point or the width (L) of the gap is measured by means of a measurement device (21A; 21B; 21C), and the curl of the paper or board web (W) is regulated based on the result of measurement. A paper or board machine line has means for regulating curl in the web (W); means for slitting or cutting the paper or board web and for measuring the rising/lowering (H) of the edges of a slit/cut gap (C) formed at the slitting/cutting point or the width (L) of the slit/cut gap (C) in connection with the manufacture of the web (W) in order to regulate the curl of the web (W) based on the result of measurement.