Valmet Paper Machinery Inc.

Valmet Corporation

Juhani Pajula

Mikko Karvinen

Jorma Laapotti

Reima Kerttula

Juha Kivimaa

Pekka Taskinen

Martti Hirsimaki

Martti Hipsimaki

Jorma Lapotti

A press section for a paper machine employing at least two press nips placed one after the other. Of these nips, at least the first nip is an extended nip or an extended roll nip. The last nip in the press section is placed on a level higher than the preceding nip. The first nip and/or, when more than two nips are employed, the nip that immediately precedes the last nip is/are provided with two press fabrics that receive water. The paper web is transferred on the lower fabric of the two press fabrics onto an upper fabric of the last nip. On the lower face of the upper fabric, the web is transferred into the last nip. After the web transfer point, the upper fabric of the last nip has a relatively short upwardly inclined run. After this, the upper fabric is turned and guided by the lower roll of the last nip over a considerable sector thereof. The last nip is placed after, or at the vicinity of, the uppermost point of the lower roll that forms the last nip. The point of transfer of the web onto the drying wire of the first group in the dryer section following after the press section is placed underneath the level of the last nip.

Press section of a paper machine employing two separate press nips

A closed press section in a paper machine including a compact combination of press rolls, some of which define press nips with each other between which the web has a closed draw supported by the face of a fabric. The press section has a center roll in connection with which at least one press nip is formed. A closed loop of a transfer band is passed around the center roll. The web is transferred on an outer face of the transfer band after the last press nip in the compact combination of rolls as a closed and constantly supported draw onto a drying wire in a drying section following after the press section. The transfer band loop is preferably made of a fabric that substantially does not receive water and does not rewet the web. The web-adhesion properties of the outer face of the transfer band are chosen so that, after the last nip, the web follows the transfer band, and so that the web can be transferred as a fully closed draw onto the drying wire. In connection with the loop of the transfer band, means for conditioning/cleaning the band and/or safety devices are provided, by whose means an adequate operation of the transfer band is maintained.

Compact press section in a paper machine

Method and device in the manufacture of paper or board for dewatering of a paper web that is being manufactured. The paper web is transferred from a forming wire onto a wire in the drying section while constantly on support of a fabric that receives water, a transfer fabric, or of any other, corresponding transfer surface as a closed draw, at a particularly high speed, which is higher than about 25-30 m/s. Dewatering of the paper web is carried out by means of at least two subsequent press nips, of which nips at least one press nip is a so-called extended-nip zone, whose length in a machine direction is larger than about 100 mm. The extended-nip zone is formed in connection with a mobile flexible press-band loop. The distribution of the compression pressure employed within said extended-nip press zone is regulated and/or selected both in the transverse direction of the web and in the machine direction so as to set or to control the different profiles of properties of the web.

Device for dewatering of a paper web including prepressing with extended

The invention relates to a closed press section in a paper machine and comprises a compact combination of press rolls. Several of the rolls define press nips with each other, between which nips the web has a closed draw supported by the face of a fabric. The press section has a center roll in connection with which a press nip or press nips are provided. A closed loop of a transfer band is passed around the center roll. The web is transferred on an outer face of the transfer band after the last press nip in the compact combination of rolls as a closed and constantly supported draw onto a drying wire in a drying section following after the press section. The transfer band loop is made of a transfer band fabric that substantially does not receive water and does not rewet the web. The web-adhesion properties of the outer face of the transfer band fabric are chosen so that, after the last nip, the web follows the transfer band fabric, and so that the web can be transferred as a fully closed draw onto the drying wire. In connection with the loop of the transfer band fabric, means for conditioning of the band and/or safety devices are provided, by whose means an adequate operation of the transfer band fabric is maintained.

Compact press section with closed draw of the web in a paper machine

Method for dewatering of a paper web by pressing using an extended nip

Closed press section in a paper machine, comprising a compact combination of press rolls. Certain of rolls define press nips with each other, between which nips the web has a closed draw supported by the face of a fabric. The press section has a center roll in connection with which a press nip or press nips are provided. A closed loop of a transfer band is passed around the center roll. The web is transferred on an outer face of the transfer band after the last press nip in the compact combination of rolls as a closed and constantly supported draw onto a drying wire in a drying section following after the press section. The transfer band loop is made of a transfer band fabric that substantially does not receive water and does not rewet the web. The web-adhesion properties of the outer face of the transfer band fabric are chosen so that, after the last nip, the web follows the transfer band fabric, and so that the web can be transferred as a fully closed draw onto the drying wire. In connection with the loop of the transfer band fabric, means for conditioning of the band and/or safety devices are provided, by whose means an adequate operation of the transfer band fabric is maintained.

Press section of a paper machine provided with a frame construction which includes first a front frame and than a rear frame in a direction of running of a paper web through the machine. Press rolls are mounted on the front and rear frames. Between the front frame and the rear frame, and above the press roll combination, there is an at least partially open space through which at least most of the press rolls can be replaced. The space also facilitates replacement of the upper press fabrics. The press roll which forms the second nip is the press section is attached to a first intermediate frame part separate from the rear and intermediate frames and arranged to be pivotable by means of power units around horizontal articulation shafts in conjunction with the front frame. This press roll is connected to the first intermediate frame part through a second intermediate frame part by means of horizontal joints. The second intermediate frame part can be pivoted around the horizontal articulated joints by means of power units. Between the first intermediate frame part and the front frame, there are openable and lockable intermediate parts by means of which the first intermediate frame part can be rigidly fixed to the front frame. The intermediate parts can be opened so that the first intermediate frame part can be pivoted towards the front frame, at least when the suction roll in the press section is being replaced.

Frame construction of a press section in a paper machine

An adjustable guide assembly for a moving web or fabric. The guide assembly includes a bearing housing adapted to receive a bearing carrying an axle journal of a web or fabric guide roll and a pair of bellows mounted on opposite sides of the bearing housing, and wherein the bearing housing is movable with respect to a fixed frame for positioning the end of the web guide roll through adjustment of the fluid pressure within the bellows. Each of the bellows has a fluid space therewithin in which are situated a first bearing lug which is fixed in position relative to the fixed frame and a second bearing lug fixed to the movable bearing housing, the first and second bearing lugs having pivot points to which a connecting arm member is pivotally connected.

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Jyvaskyla, Finland

Juhani Pajula