摘要:
A blow box used in the drying section of a papermaking machine and a method for sealing a pocket provided with a blow box, and a blow nozzle. The blow box is arranged to eject air away from the space between a wire and the blow box and/or maintain an underpressure zone in this space. In the interface between the desired underpressure zone and an outside volume, the blow box is provided with a sealing element, such as a blow nozzle, protruding towards the wire to a certain distance “d” seen from the wire, for forming a seal between the underpressure zone and the area remaining outside the underpressure zone. The sealing element is connected to the blow box so that the element may be moved away from the wire to a distance “D” by a push and/or by an actuator, the distance “D” being greater than the distance “d”.
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:
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:
A roll in a paper or board machine has a roll frame or center shaft (15) with bearings mounted at its ends and a groove-like surface structure (10). There is a contact between the surface structure and the center shaft so that an essentially closed structure is formed. The roll produces a vacuum that keeps the web attached to the outer surface of a fabric in the fabric wrap area of the roll circle by utilizing the boundary layer airflows of the surface structure flow and/or of the web. A dryer group has at least one contact dryer cylinder and at least one turning roll with a single fabric run arrangement.
摘要:
A roll in a paper or board machine has a roll frame or center shaft (15) with bearings mounted at its ends and a groove-like surface structure (10). There is a contact between the surface structure and the center shaft so that an essentially closed structure is formed. The roll produces a vacuum that keeps the web attached to the outer surface of a fabric in the fabric wrap area of the roll circle by utilizing the boundary layer airflows of the surface structure flow and/or of the web. A dryer group has at least one contact dryer cylinder and at least one turning roll with a single fabric run arrangement.
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:
In a paper or board machine drying line after the wire section, during dewatering a web's (W) width is affected in a direction crosswise to the web's traveling direction. Starting from an edge, at least one device (20A, 20B) brings about a force effect of a desired magnitude which is directed all the way to a desired arbitrary crosswise web position in order to modify web characteristics. A device in a paper or board machine line after the wire section has means for processing the web and for dewatering. The paper or board machine line after the wire section further has at least one device (20A; 20B) for directing a force effect at a desired partial area (WS) of the web (W) in the cross machine direction in order to modify the web's characteristics profile in the cross machine direction.
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:
In a paper or board machine drying line after the wire section, dewatering web's (W) width is affected in a direction crosswise to the web's traveling direction. Starting from an edge, at least one device (20A, 20B) brings about a force effect of a desired magnitude which is directed all the way to a desired arbitrary crosswise web position in order to modify web characteristics. A device in a paper or board machine line after the wire section has means for processing the web and for dewatering. The paper or board machine line after the wire section further has at least one device (20A; 20B) for directing a force effect at a desired partial area (WS) of the web (W) in the cross machine direction in order to modify the web's characteristics profile in the cross machine direction.