Abstract: The invention concerns a method and a device in the dryer section of a paper/board machine. In the dryer section a normal single-wire draw is applied at least partly, in which method the web (W) is passed through the dryer group on support of a drying wire (H). The drying wire (H) presses the web (W) on the drying cylinders (Kn, Kn+1 . . . ) against the heated cylinder faces, and on the reversing cylinders or rolls (Sn, Sn+1 . . . ) between the drying cylinders (10) the web (W) remains at the side of the outside curve. There is one integrated device, through which a support suction and/or blowing is produced in order to improve the runability of the web (W) and to keep the web (W) in contact with the face of the wire, and through which same device, additionally, impingement blowing is produced in order to dry the web (W) and/or to control its tendency of curling.

Abstract: A system and method effectively threading the moist tail of a web through a pulp dryer. A tail threading belt in a closed loop passes the tail of the web through the dryer, and the most tail of the web is transferred from a support wire in the press section of a pulp machine to the tail threading belt. Transfer may be effected using a suction roll with a suction sector and a blower sector, or by using a suction chamber having a perforated escort belt which cooperates with it to engage the tail section on the wire and fully support it during transfer to the threading belt. The threading belt may be folded over to contain the tail web inside it while it passes through the dryer.

Abstract: A sealing nozzle is positioned in a blow box used in the drying section of a paper machine. The blow box is mounted on that side of the supporting fabric, which is away from the web at the opening gap between the supporting fabric and the cylinder and at a distance “D” from the supporting fabric. A passage is formed between the blow box and the supporting fabric, the passage having a negative pressure region having a border with a region outside the negative pressure region. The sealing nozzle is positioned in a wall of the blow box facing the passage at a distance “d” from the supporting fabric. The sealing nozzle includes: a pivotal sealing member mounted at the border, and a transverse support element, the sealing member pivotal about the transverse support element; and a separate nozzle part having at least one nozzle opening (e. g.

Abstract: 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”.

Abstract: A system (20) and associated process for use in the dryer section (18) of a papermachine for promoting complete support of the paper web (32) by the carrier fabric (34) as the fabric and web are transferred between adjacent drying cylinders (22, 24) by way of a turning roll (26) utilizes a blowbox assembly (50) positionable within the pocket region (40) bounded by the drying cylinders and the turning roll. The blowbox assembly is adapted to direct air out of the pocket region to reduce the likelihood of separation of the web from the carrier fabric as the web is moved onto and off of the turning roll.

Abstract: A roll for a paper machine, in particular for a paper drying device, including an axle on whose support the roll revolves, and a surface construction connected to the axle by support members. The openness of the surface construction of the roll is higher than about 10%, preferably higher than about 20%, so that when the roll an effect is produced that sucks air inward into the roll whereby a flow of air through the roll arises. Also, a single-wire draw dryer group for a paper machine having two contact-drying cylinders and one reversing roll wherein a web to be dried is guided on support of a drying wire meandering from one drying cylinder onto the reversing roll and then onto the other drying cylinder so that on the drying cylinders, the web remains between the cylinder face and the drying wire and on the reversing cylinder, the web is situated at the side of the outside curve.

Abstract: A method and device for measuring the permeability of a drying wire to air in which the measurement is carried out continuously while the drying wire moves. The drying wire is guided to run so that it passes over a blow box and a measurement box free of contact, and the pressure in the measurement box and/or the relative change in the pressure is/are measured when the blow box is creating a pressure differential between the blow box and the measurement box in the vicinity of the wire. The pressure and/or the relative change in the pressure is/are compared with earlier measurement results and/or starting values (reference values). The permeability to air of the drying wire is determined on the basis of comparison of the pressure and/or of the relative change in the pressure, and the contact-free measurement is produced by guiding the flow into or out of the measurement box to pass through a gap between the measurement box and the drying wire.

Abstract: A method and device for stabilizing the running of a paper web in a paper machine in connection with a paper guide roll, in particular between a press section and a dryer section. In the method, the paper web is passed over the paper guide roll onto a drying wire or equivalent and negative pressure (suction) in the opening nip of the paper guide roll is lowered until a transition is made to the side of positive pressure in order to press the paper web against the drying wire or equivalent. The device includes a nozzle beam and an air chamber which communicates with a blow air duct. The nozzle beam is placed at the side of the opening nip of the paper guide roll such that the blowing discharged out of a nozzle opening of the nozzle beam is directed at the opening nip in order to press the paper web against the drying wire or equivalent.

Abstract: A method for removing air from a suction roll/suction cylinder and a suction roll/suction cylinder including a roll mantle, end flanges connected to the roll mantle and axle journals for revolvingly supported the roll mantle. The mantle has numerous perforations, holes or equivalent openings passing therethrough. The suction roll/suction cylinder is connected to a suction duct that passes onto the interior of the roll/cylinder and transfers a vacuum force therein. Air is drawn or sucked through the perforations into the interior of the roll mantle so as to press a paper web toward an outer face of the roll mantle. The suction roll/suction cylinder has a system of suction pipes connected with the suction duct and including at least one suction pipe into which air is guided and/or sucked from the vicinity of the inner face of the roll mantle of the roll/cylinder.

Abstract: A method for causing adherence of a web to a drying wire so as to prevent the effects of centrifugal forces and of other air-flow phenomena, which effects attempt to separate the web from the drying wire in dryer groups having a single-wire draw and arranged in a multi-cylinder dryer of a paper machine. The dryer groups include heated drying cylinders, a drying wire for pressing the web against outer cylinder faces of the drying cylinders, and guide cylinders or rolls on which the web runs on the outside face of the drying wire. The guide cylinders have perforations which pass through the cylinder mantle and open into an inside space in the interior of the guide cylinders which is subjected to a vacuum. The vacuum in the guide cylinders is transferred to the outside face through the perforations. The guide cylinders have shafts on which the guide cylinders are mounted revolving.

Abstract: A method and apparatus for ventilating pocket spaces in a multi-cylinder dryer of a paper machine, in particular a high-speed paper machine whose running speed is higher than about 800 meters per minute, in the area of a so-called twin-wire draw. In the twin-wire draw, the drying cylinders in the drying group are arranged in two rows placed one above the other, in which rows the successive cylinders are placed in the upper row and in the lower row as interlocked. In each cylinder group, there are two drying wires, an upper wire and a lower wire for pressing the paper web against heated faces of the drying cylinder while being guided by guide rolls placed in gaps between the cylinders. The paper web runs as free draws between the rows of cylinders.

Abstract: The invention relates to a method and device for stabilizing a paper web in a group of cylinders in the dryer section of a paper machine. The group of cylinders are arranged in a row of drying cylinders and a corresponding row of leading rolls or equivalent placed as interlocked with the drying cylinders. The group of cylinders is provided with a single-wire draw so that the heated drying cylinders in the group are placed outside the loop of the drying wire and the leading rolls in the group are placed inside the loop of the drying wire. The stabilization device is arranged in the area between adjacent drying cylinders and the leading roll or equivalent placed as interlocked between the adjacent drying cylinders in the group of cylinders. Air is blow from the device and directed in the direction opposite to the running direction of the paper web.

Abstract: The invention concerns a method and an apparatus in a paper machine, in particular in its drying section, for intensification of the drying of the paper. In the method the paper web (W) is passed on support of a drying fabric onto a drying cylinder (K). In the method, in connection with the drying cylinder (K), a separate suction device (10) is employed, which is fitted at a distance (F) from the drying fabric, e.g. a wire (H), which follows the face of the drying cylinder. In the method, by means of the suction device (10), the boundary layer (S.sub.1) of moist air, which has been formed on the face of the drying fabric (H), is suctioned off, whereby the drying process is promoted.

Abstract: A method and apparatus in a drying section of a paper making machine wherein a so-called single-wire draw is applied and wherein blow boxes (20) are used, which are intended to prevent phenomena that disturb the mutual support contact between the web (W) and the drying wire (12). The blow boxes (20) extend across the entire width of the web (W), and they communicate with members (17, 18, 21, 22) that supply blow air, and they are provided with at least two nozzle slots (13, 14) transverse to the running and longitudinal direction of the web (W) as well as with a carrier face (16) between said nozzle slots. Negative pressure is produced in the space (A-) defined by the carrier face (16) and the drying wire (12) by means of the ejection and prevention effects of the air jets (F.sub.1, F.sub.2) blown through the nozzle slots (13,14). In order to speed the threading of the web (W), in the blow boxes (20) the blow sections (24.sub.k+1. . . 24.sub.

Abstract: Method and device in multi-cylinder dryers of a paper machine, which the dryers comprise two lines of drying cylinders (10,11), in whose connection twin-wire draw is applied, by means of whose drying wire (F1,F2) a closed draw is obtained in the transfer of the paper web (W) from one cylinder line onto the other. In the closed draw, the guide rolls (12/13) of the drying wires (F1/F2) are placed at the proximity of the run of the other wire (F2/F1) on which the drying wire runs from its drying cylinder (11/10) to its guide roll (13/12). For the purpose of ventilation of the pockets (T1,T2) defined by the drying wires (F1,F2) and by the free faces of the drying cylinders (10,11), an air jet or air jets (S1) are blown against the drying wires (F1,F2) within the area in which the drying wire (F1/F2) contacts a portion of the web (W) supported by the other drying wire F2 /F1 which runs over a segment of the circumference of the guide roll (13/12) of the other drying wire F2/F1.

Abstract: A single-wire drying group in a paper machine is disclosed including a plurality of drying cylinders whose axes are situated in a substantially common plane, a drying wire carrying a web between successive drying cylinders, one or more deflection rolls, each situated between a pair of successive drying cylinders and wherein the web-carrying drying wire has an incoming run from a drying cylinder to a deflection roll whereupon the drying wire runs over a deflection sector of the deflection roll and then to a subsequent drying cylinder. A blow box has a wall which defines a gap space with the incoming run of the web-carrying wire and a gas flow is directed through the gap space to induce an under pressure on the incoming run to fix the web on the drying wire.

Abstract: A method of and arrangement for resisting formation of undulations in a fiber/water mixture supplied onto a forming wire at an open planar wire section of a paper-making machine include establishing over the wire an air curtain extending over the full breadth thereof, in the region of which the air mass upon the wire is set in motion. The direction of movement of the air mass is the same as the traveling direction of the wire, and the velocity of the air substantially equals the speed of the wire. The air curtain commences on the planar wire section, in the machine direction, only at a given distance from a lip slice of a headbox of the machine, and the air curtain extends along the traveling direction of the web over the planar wire section over a given distance.

Abstract: Method and Apparatus for Measuring Permeability to Air of a Wall-Like or Sheet-Like Element, comprising the use of a measurement head including a blower having an air-discharge nozzle, a blade wheel and a variable-speed motor for rotating the wheel to produce an air flow which discharges through the nozzle. Pressure in the blower and speed of blade wheel rotation are detected, with appropriate signals indicative thereof being input to a central unit which then appropriately adjusts speed of rotation of the blade wheel to correspond to a predetermined blower pressure value. Permeability value of the element is then determined at the central unit, based on relationship between the speed measurement signal values, and corresponding permeability values.

Abstract: In the drying section of a paper machine, apparatus for preventing conditions tending to deteriorate the contact between a web and a supporting fabric which carries the web from a drying cylinder in one line to a drying cylinder in another line and, in particular, for preventing a positive pressure from being generated in the narrowing gaps defined by the surfaces of the drying cylinders and the web supporting fabric as it approaches and/or moves away from the drying cylinder. The apparatus includes a blow box extending transversely substantially over the width of the web, the blow box including at least two transversely extending gas discharge slots between which a substantially planar carrying surface is provided in opposed, parallel relationship to the web carrying fabric and spaced a distance therefrom which is at least twice, and preferably ten to thirty times, as large as the width of a gas discharge slot.