Valmet Paper Machinery Inc.

Valmet Corporation

Valmet-karlstad Ab

Valmet Oy

Antti I Ilmarinen

Antti Kuhasalo

Heikki Ilvespaa

Pertti Heikkila

Jouko Yli-Kauppila

Mikko Karvinen

Nils-Erik Safman

Matti Korpela

Pekka Taskinen

Nils-Erik R Karlsson

Dick Parker

Henrik Petterson

Jorma Laapotti

Jorma Snellman

Erik Brox

Vaino Sailas

Lars O Gustavsson

Veijo Miihkinen

Matti Verkasalo

Ilkka Jokioinen

Carl Zotterman

Kyosti Uuttana

Marku Autio

Juhani Alajoutsijarvi

Carl Zetterman

Malin Kilian

Va/ Ino/ Sailas

Christer Malmros

Iikka Jokioinen

Martti Tissari

Markku Alakoski

Jonas Eriksson

Juha Ehrola

A shoe press unit comprises a support beam, a shoe element movably supported on the beam, a pressing unit arranged between the beam and the shoe element for urging the shoe element away from the beam and toward a counter element, and a flexible belt that is arranged to slide over the pressing surface of the shoe element. An oil evacuation arrangement formed separately from the shoe element is affixed to the shoe element proximate an upstream edge region thereof. The oil evacuation arrangement has an inlet opening located such that a major portion of the excess oil expelled from between the belt and the shoe element passes through the inlet opening with a kinetic energy that is substantially undiminished from the initial kinetic energy of the oil as it exits from between the belt and the pressing surface of the shoe element.

Method and device for oil evacuation from a shoe press unit

A press section of a paper machine, in particular for printing paper qualities whose grammage is in the range of about 40 g/m,to about 80 g/m,is disclosed. The press section comprises a pick-up roll having a suction zone on which a paper web is detached at a pick-up point from a forming wire and is passed on the pick-up felt into a first press nip in the press section. In the first press nip, the pick-up felt acts as a press fabric. The press section further includes an extended nip placed after the first press nip. Into this extended nip, the web is passed as a closed draw on support of a fabric face or roll face. The first nip in the press section is a roll nip with relatively low load and acts as a front nip. In the area of the first press nip, almost or approximately one half of the total amount of the water contained in the web entering into the front nip is removed from the web. The extended nip, which is the second press nip in the press section, is formed against a smooth-faced back-up roll. Only one water-receiving press fabric passes through the press zone of the extended nip. The fabric is arranged preferably at the side of the face of the web opposite to the web face placed at the side of the forming wire from which the web is detached at the pick-up point.

Press section of a paper machine, in particular for printing paper qualities

An extended nip press is provided having an advantageous nip press shoe which generates less heat than conventional press shoes. The nip press shoe includes an inrunning land surface which may be planar or convex. At least one lubrication pocket is downstream of the inrunning land surface and defines a cavity for supporting lubricant to create a hydrostatic lubrication region with a flexible jacket. The pocket has a bottom surface which converges towards the flexible jacket in a downstream direction. The press shoe further includes an outrunning land surface downstream of the lubrication pocket for engaging the flexible jacket against the opposite convex press element at a downstream end of the extended nip press. The outrunning land surface has a radius of curvature greater than the radius of curvature of the convex press element, and is planar in one embodiment, to create an attenuated hydrodynamic lubrication region with the flexible jacket.

Extended nip press

A method and apparatus for reducing the wear of the belt mantle of an extended-nip roll including a resilient belt mantle arranged to revolve on support of bearings around a stationary central axle. The central axle has loading members connected with it, such as a loading shoe, which are pressed by the pressure of a loading medium, such as hydraulic fluid, towards a backup roll, whereby the belt mantle conforms to the shape of the backup roll in the area of the shoe. Actuators connected with the ends of the belt mantle are provided and act with a force upon the ends of the belt mantle of the extended-nip roll so that the direction of stretching of the belt mantle of the extended-nip roll is reversed alternatingly by controlling the actuators and/or locking devices which lock the ends of the belt mantle.

Method and apparatus for reducing wear of a belt mantle of an

A method and device for drying a paper web wherein the paper web is supported on a drying wire without long open draws of the web. The paper web is contact-dried by pressing it with the drying wire onto a face of a contact-drying cylinder whose diameter is greater than about 1.5 m on a sector b whose magnitude is greater than about 180.degree.. The web is evaporation-dried as blowing-on drying and/or as through-drying by means of high-velocity drying-gas jets applied to the web on the drying wire on the face of the following large-diameter cylinder whose diameter is greater than about 2 m on a sector a having a magnitude greater than about 180.degree. while the web is on the side of the outside curve. The web to be dried is passed over a sector c of the suction roll which is subjected to negative pressure while the web is supported on the drying wire at the side of the outside curve. The magnitude of the sector of the suction roll has a magnitude greater than about 160.degree. and the diameter of the suction roll is less than the diameter of the contact-drying cylinder.

Drying method and drying module as well as dryer sections that make use

A press section of a paper machine, in particular for printing paper qualities whose grammage is in the range of about 40 g/m.sup.2 to about 80 g/m.sup.2 is disclosed. The press section comprises a pick-up roll having a suction zone on which a paper web is detached at a pick-up point from a forming wire and is passed on the pick-up felt into a first press nip in the press section. In the first press nip, the pick-up felt acts as a press fabric. The press section further includes an extended nip placed after the first press nip. Into this extended nip, the web is passed as a closed draw on support of a fabric face or roll face. The first nip in the press section is a roll nip with relatively low load and acts as a front nip. In the area of the first press nip, almost or approximately one half of the total amount of the water contained in the web entering into the front nip is removed from the web. The extended nip, which is the second press nip in the press section, is formed against a smooth-faced back-up roll. Only one water-receiving press fabric passes through the press zone of the extended nip. The fabric is arranged preferably at the side of the face of the web opposite to the web face placed at the side of the forming wire from which the web is detached at the pick-up point.

Press section of a paper machine, in particular for printing paper

A dryer section in a paper machine which comprises a number of dryer groups, each having drying cylinders, reversing cylinders arranged between adjacent pairs of drying cylinders and a wire which presses the web against heated cylinder faces of the drying cylinders whereas the web remains at the side of the outside curve on the reversing cylinders. The dryer groups are arranged in two or more stories. Some of the dryer groups in the dryer section are placed in the basement spaces underneath the machine hall level, and some of them are placed on the machine hall level.

Multi-story dryer section in a paper machine

Drying module and dryer sections that make use of same, in particular

A shoe in an extended-nip press arranged to be placed in a nip between a back-up roll and a belt-mantle roll inside the belt mantle. The shoe is pressed by an actuator, e.g., a cylinder device, towards the back-up roll, while the web/felt or felts is/are placed between the back-up roll and the belt mantle. The shoe has at least one chamber provided for hydraulic fluid into which a fluid is passed from a duct. The shoe has a first curved face, whose curve radius is substantially equal to the curve form of the back-up roll. The shoe has a second face which forms the bottom of the chamber provided for hydraulic fluid. The second face joins the first face and has a larger curve radius than the first face. At a joint between the first face and the second face, the tangents of the faces are substantially the same.

Shoe for an extended-nip press

A method and device in the drying of paper, especially of fine paper or newsprint is disclosed. A paper web to be dried is passed over a mantle face of a large-diameter flow-through cylinder. On the flow-through cylinder, a set of drying-gas jets is applied to the free outer face of the web through a nozzle arrangement. Water is evaporated outward from the outer part of the web by means of the set of drying-gas jets. The water vapor thus evaporated is removed through spaces in the blowing-on hood. By means of the set of drying-gas jets, the interior of the web to be dried is also heated. The mantle face of the flow-through cylinder is cooled by means of a medium flow. Water that has been vaporized out of the web and that has been condensed onto the cooled faces is sucked by means of negative pressure present in the interior of the flow-through cylinder.

Method and device for drying paper

A press shoe for a shoe press with extended nip, said press shoe is of combined hydrostatic and hydrodynamic type and has a plurality of hydrostatic pressure pockets, each of which is preceded by a leading land surface and followed by a trailing land surface and into which lubricant is supplied under pressure. Each pressure pocket has a first pocket zone in which a hydrodynamic pressure shall be created and which comprises a bottom surface located at gradually decreasing depth from the concave surface portion of the press shoe seen in the direction of rotation of the belt member, said depth being zero at the trailing end of the pressure pocket. The bottom surface forms an angle .alpha. of from 0.degree. to about 2.degree. with a tangent to the concave surface portion of the press shoe at the trailing end of the pressure pocket. Further the first pocket zone is preceded by a second pocket zone comprising a plane bottom surface forming an angle .beta. of from 0.degree. to about .+-.10.degree. with a plane that coincides with the bottom surface of the first pocket zone.

Press shoe with wedge shaped hydrostatic pocket

The press roll cooperates with a counter roll to form a press with a long nip for paper or board machines. The press roll has two end walls; a flexible jacket secured to the end walls; and support members for the end walls. The end walls have bearings for permitting rotation of the jacket and the end walls in relation to the support members; and a press shoe intended together with the counter roll to form a pressing zone. Attachment assemblies each have a circular clamping member, which includes a wedge body, and a circular groove disposed on the inside of the end wall to receive the edge portions of the jacket and the wedge body, the groove and wedge body being provided with cooperating wedge forming surfaces. Further, the clamping member includes bolts for pulling the wedge body into the groove and retaining it therein in order to clamp the edge portions of the jacket by means of wedge action, against the end wall.

Press roll with wedge clamp for the press jacket edges

In order to increase the life of a flexible jacket in a shoe type press roll having a flexible jacket (11), end wall displacing element (28) and jacket stretching element (27), the end wall displacing element (28) are designed to permit a setting of an arbitrary operating position for one roll end wall (18) between two end positions on one of the two stub shafts (13) of the roll, and the jacket stretching element (27) are designed to maintain the stretching force substantially constant, whereby the other roll end wall (22) will be self-positioning and will automatically follow each axial displacment of said one roll end wall (18). Consequently, it will be possible to let the end walls (18, 22) be placed in one end position during a first period of operation and to displace them, for each subsequent period of operation, an adequate distance towards the other end position, whereby the fatigue and the wear of the roll jacket (11), which occur primarily at the axial end of the press shoe (14), will be spread over an area corresponding to the entire displacement distance between the end positions.

Press roll with displaceable end walls to reduce press jacket wear

Control of detachment of a web from a roll, such as a paper web from a press roll in a paper machine, in particular a so-called closed press section provided with a smooth-faced press roll. The temperature of the surface of the smooth-faced press roll is adjusted, so that adhesion between the roll surface and the paper web to be detached is influenced or affected. Thereby, the detaching angle and/or the detaching tension of the paper web, is set within an optimal range. Temperature profile of the smooth-faced press roll in the axial direction thereof, can also be adjusted with a view to controlling the detaching of the web.

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Jyvaskyla, Finland

Antti I Ilmarinen