Valmet Paper Machinery Inc.

Valmet Corporation

Metso Paper Inc.

Valmet Oy

Kymmene Oy

Raimo Virta

Vesa Vuorinen

Pekka Eskelinen

Pekka Saarikivi

Reijo Jokinen

Hannu Kokkala

Martti Salmivaara

Kari Juppi

Juha Kaihovirta

Olavi Viitanen

Matti Kurki

Markku Karlsson

Timo Haverinen

Nenad Milosavljevic

Paavo Sairanen

Raimo Rajala

Juhani Jokinen

Reijo Ruottu

Raimo Malkki

Seppo Rantanen

Pentti Raatikainen

Time Tammekas

Pertti Hongisto

Paavo Jaatinen

Seppo Y&ouml;maa

Vesa Koiranen

Kari Lindberg

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 (K , K . . . ) against the heated cylinder faces, and on the reversing cylinders or rolls (S , S . . . ) between the drying cylinders ( ) 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.

Method and device in the dryer section of a paper/board machine

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.

System and method for threading a moist web in a pulp dryer or the like from one section to the following section

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 &ldquo;D&rdquo; 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 &ldquo;d&rdquo; 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. a substantially transverse slit) and disposed in the negative pressure region in front of the pivotal sealing member, the separate nozzle part positioned so that the at least one nozzle opening blows air along a surface of the sealing member from the negative pressure region to the region outside the negative pressure region.

Sealing nozzle arranged in a blow box used in the drying section of a paper machine

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 &ldquo;d&rdquo; 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 &ldquo;D&rdquo; by a push and/or by an actuator, the distance &ldquo;D&rdquo; being greater than the distance &ldquo;d&rdquo;.

Blow box for the drying section of a papermaking machine, method for sealing a pocket with a blow box in the drying section of a papermaking machine, and arrangement in a papermaking machine

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. The blowbox assembly cooperates with the vacuum source (30) associated with the turning roll so that upon a reduction of the energy expended by the vacuum source associated with the turning roll, constant sub-atmospheric conditions can be maintained within the pocket region by increasing the expenditure of energy of the air-directing means by an amount which is less than the amount of the reduction of energy expended by the vacuum source.

Process and system for promoting complete web support within the dryer

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. The reversing roll in the dryer group is an open roll having a surface construction with an openness higher than about 10%, preferably higher than about 20%, so that the flow of air traveling along with the wire passes through the open surface construction of the roll into the interior of the roll and is discharged further out along with the wire as an air flow through the open surface construction of the roll.

Roll for a paper machine, in particular for a paper drying device, and

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.

Method and device for measuring the permeability of a drying wire to air

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.

Method and device for stabilizing the running of a paper web in

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.

Suction roll or cylinder and method for removing air from a suction roll

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. The vacuum level in the guide cylinders is regulated by means of the air quantity in compliance with the threading/running stage and/or running speed and/or with any other process or running parameter of the dryer section of the paper machine so that the effect of the vacuum is sufficient to keep the web in reliable contact with the drying wire.

Method and arrangement in a multi-cylinder dryer of a paper machine

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. Pocket spaces are formed in the area between the free draws of the web and the upper wire and its guide roll and the drying cylinder in the lower row and, in a corresponding manner, adjacent pocket spaces are formed in the area between the free draws of the web, the lower wire, its guide roll, and the drying cylinder in the upper row. The pocket spaces are ventilated by pumping air induced by the wire in the multi-cylinder dryer, wherein, at the inlet side of the guide roll, the wire pumps air into the pocket spaces through the wire and wherein the wire pumps air out of the pocket spaces at the outlet side of the guide roll of the wire. Air being pumped out through the wire on its run at the outlet side from the guide roll to the following cylinder is limited as compared with free pumping-in and pumping-out so as to control the pressure level and/or the flow status in the pocket spaces.

Method and device for ventilating pocket spaces in a multi-cylinder

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. A nozzle opening of the stabilization device is shaped so that the air flow follows a substantially smooth face of the stabilization device while, at the same time, ejecting surrounding air along with it. In preferred embodiments, the smooth face is substantially parallel to the drying wire and the group of cylinders is formed as a compact geometry.

Method and device for stabilization of a paper web in a group of

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.

Method and device in a paper machine

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.N ) that remain outside the transverse area (A) of the leader band (R) are closed. The blowing, which has thereby been intensified, is applied through both of the opposite nozzles (13, 14) of the blow boxes (20) in connection with the threading only within the area (A) comprising the width (L.sub.R) of the leader band (R).

Growing community of inventors

Turku, Finland

Raimo Virta