Valmet Corporation

Valmet Paper Machinery Inc.

Valmet Oy

Oiva Vallius

Lassi Veijonen

Press section in a paper machine and method for replacing press fabrics therein including two separate press nips and a frame part for each press nip. Side frames of both frame parts are interconnected by upper horizontal beams in the machine direction. The upper horizontal beam at the tending side is comprised of two beam parts of which one is situated above the side frames of the frame part of the first nip at the tending side and the other is situated above the side frames of the frame part of the second nip at the tending side. The tending-side beam parts operate as a machine-direction cantilever beam so that a first beam part is supported on the second beam part and thereby on its frame part while the side frames of the first frame part are open for replacement of the fabrics in the first nip. The beam parts operate reciprocally with each other in inverse functions as a cantilever beam and as a support part when the press fabrics in the second nip are being replaced.

Press section in a paper machine and method for replacing press fabrics

A coupling construction between an extended-nip roll including a non-revolving central axle supported by bearings which permit angular deflection of the non-revolving axle and a backup roll. Loading members are mounted on the non-revolving axle for pressing a loading shoe toward the backup roll. The extended-nip roll includes a flexible glide-belt mantle whereby a paper web or board web passes through the nip between the glide-belt mantle and the backup roll. The belt mantle revolves on support of separate bearings. The extended-nip roll and backup roll are interconnected from the bearing housings at the ends of the rolls by tie bolts which include a nut at one end which is threaded onto the threading at the end of the tie bolt. The tie bolt is associated with pre-tightening equipment at the other end of the tie bolt and is passed through bolt holes provided in the bearing housings to be coupled together. The other end of the tie bolt has the threading with which the pre-tightening equipment is coupled.

Coupling construction between an extended-nip roll and a backup roll

A press section of a paper machine through which a paper web has a substantially closed and supported draw including an extended-nip zone and an equalizing-nip zone following the extended-nip zone in the running direction of the web. In the equalizing-nip zone, the asymmetry of roughness is equalized that was formed in the web to be pressed in the preceding press nip or nips, while not dewatering the web to a substantial extent. The extended-nip zone and the equalizing-nip zone are formed between three press components which are interconnected in a compact way so that the extended nip is formed by a press component provided with a flexible mantle together with a press roll provided with a rigid mantle. The press roll with the rigid mantle also forms the equalizing-nip zone together with a smooth-faced equalizing-press roll. After the equalizing-nip zone, the web has at least one free draw or runs on a transfer fabric, on which draw(s) or run, by a difference in speed, the stretch of the web in the machine direction, taking place in the equalizing-press nip is compensated for and the web is kept appropriately tensioned.

Press section with an equalizing nip in a paper machine

An apparatus for interconnecting rolls that form an extended nip in which the extended nip is formed by a back-up roll and an extended-nip roll having a loading shoe and loading members for pressing the loading shoe toward the back-up roll. A resilient belt mantle runs around the extended-nip roll and is pressed against the back-up roll. The extended-nip roll and the back-up roll are interconnected by coupling members at their bearing housings which include displaceable locking shafts.

Method and apparatus for interconnecting rolls in an extended-nip press

A coupling construction for coupling an extended-nip press roll including a loading shoe for loading a belt mantle to press the belt mantle toward a back-up roll. The coupling construction includes pivotally linked tie members for detachably connecting the bearing housings of the extended-nip press roll and the back-up roll so that the tie members are connected with either bearing housing and the roll in the other bearing housing is serviceable.

Arrangement for coupling extended-nip rolls

Method and device in a compact press section of a paper machine for replacement of press rolls and fabrics. Above the compact combination of press rolls, there is an open space between the front frame and the rear frame of the press section. By means of this space, the press rolls and the upper fabrics can be replaced by raising and lowering, e.g. by means of a crane mounted on the ceiling. The press roll that forms the second press nip in the press section together with the center roll is supported on an opening and loading mechanism to which hydraulic cylinders are connected, by means of which cylinders both the second nip is loaded with a suitable linear load and the mechanism is pivoted to the open position or positions. The movements of lateral parts of the mechanism are synchronized with each other by means of a connecting part fitted between them.

Method and device in a compact press section of a paper machine for

Method and device in a compact press section of a paper machine for balancing of its static and dynamic properties as well as for replacing of the press rolls and fabrics. The press rolls form a compact press roll combination. A space is located in and above the press roll combination between the front and rear frame parts which can be opened and closed. By means of this space at least the upper fabrics and the upper press rolls in the press section are replaced by means of a crane mounted on the ceiling or equivalent, preferably substantially by direct raising and lowering. The front and rear frame parts are interconnected rigidly at and above the press roll combination by means of a rigid intermediate frame part. The intermediate frame part operates as the frame part of the tensioning device of the first upper fabric, and the intermediate frame part together with the upper fabric tensioning device and the tensioning roll. The intermediate frame part may be pivotally connected to the front frame part by means of horizontal articulated joints, or shifted to the side substantially linearly, so that at and above the press roll combination a free open space is opened. This space can be utilized in replacement both of the upper press rolls and of the upper fabrics.

Method and device in a compact press section frame construction of a

A method is employed in a press section of a paper machine for changing a pick-up and/or press fabric, the substantial run of which when the fabric is in its normal operating position, passes above a group of nip defining press rollers. Insert members of the machine frame are removed to define gaps therewithin and the press nip or nips through which the fabric passes are open. In the method, upper guide rollers situated within and guiding the loop of the fabric are shifted from an upper operating position occupied thereby when the fabric is in its normal operating position to a lower position and the fabric to be changed is transported with the same being wound in double manner on a changing pole. The fabric is opened and spread out to define a loop which encircles all of the press and guide rollers which will be situated within the fabric loop when the fabric is in its normal operating position. The loop so formed and transported is passed into the machine frame through the gaps defined therein by the removal of the insert members therefrom and into the open press nips. The fabric situated within the machine frame is spread out from the changing pole while the upper guide rollers are shifted from the lower position back to their upper operating position, whereupon the insert members are replaced in the machine frame and the opened press nips are closed.

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Jyvaskyla, Finland

Oiva Vallius