Valmet Corporation

Valmet Paper Machinery Inc.

Ville Korhonen

Timo Pirinen

Pekka Koivukunnas

Juhani Niskanen

Juha Kaihovirta

Allan Liedes

Jouko Yli-Kauppila

Pasi Ahonen

Jaakko Kallioniemi

Matti Luontama

Risto Turunen

Juha Honkala

Jorma Ramstedt

A dry end of a paper machine and a method for drying paper in which a paper web to be dried is passed from a press section of the paper machine into a forward dryer section including only single-wire groups with normal single-wire draw. The web is dried from the side of its bottom face in the dryer groups in the forward dryer section. From the forward dryer section, the web is passed into a finishing section in which the web is coated/surface-sized by a coating/surface-sizing device and then dried in an after-dryer by passing through at least one dryer group that applies a normal single-wire draw. Thereafter, the web is calendered and passed to a reeling station. Curling of the web is controlled by the operation or construction of components and/or by assemblies and combinations formed out of these components provided in connection with the forward dryer section and/or the finishing section.

Method for drying paper and a dry end of a paper machine

A calender for a web including a calender frame and a stack of rolls mounted on the frame and consisting of four rolls arranged one above the other. In the stack, adjacent rolls placed one above the other are arrangeable in nip-defining relationship with one another so as to calender the web in the nips. The stack of rolls in the calender is composed of three variable-crown rolls, of which rolls the roll mantle of at least one roll is displaceable in relation to its roll axle in the direction of the nip plane by loading devices arranged inside the roll, and one heatable roll arranged between two variable-crown rolls. The rolls are preferably arranged vertically so that the two lowest rolls and the uppermost roll are variable-crown rolls and that the third roll from the bottom of the stack is a heatable roll.

Mounting arrangement for calendar rolls in a calender

A dryer section of a paper machine including cylinder groups provided with single-wire draw having smooth-faced heated drying cylinders against which a web to be dried enters into direct contact, and reversing rolls. The groups with single-wire draw have a drying wire which is guided in a loop by guide rolls as well as by the drying cylinders and the reversing rolls so that the drying cylinders are placed outside the wire loop, and the reversing rolls are situated in gaps between the drying cylinders inside the drying-wire loop. In order to optimize the drying capacity calculated per unit of length of the dryer section in the machine direction, as the drying makes progress, a different ratio of the drying cylinder diameter to the reversing roll diameter is employed, so that, in the first group or groups in the initial end of the dryer section, the ratio is higher than the corresponding ratio in the groups in the middle area of the dryer section. In the group or groups in the final end of the dryer section, a diameter ratio is used that is higher than the ratio in the middle area of the dryer section.

Dryer section of a paper machine including cylinder groups with

The invention relates to a method and device in a size press in which a nip is formed by a pair of rolls. A paper or board web is passed through the nip. The rolls are provided with surface-sizing units for applying films of size or coating agent onto faces of the rolls. Each surface-sizing unit comprises an application zone defined by a coating member, a front edge of the application zone and a feed chamber. The coating agent, such as a size, is fed, through holes or corresponding nozzles that have been formed into a wall of a feed pipe, into the feed chamber under pressure out of the feed pipe which is arranged transverse to the machine direction. The coating agent is fed out of the feed chamber into the application zone through a throttle placed between the feed chamber and the application zone. The throttle comprises a perforated plate or equivalent which extends across the width of the machine and which is detachably fixed to the frame constructions of the surface-sizing unit by fastening members.

Size press having a detachable throttle

A calender in a paper or board machine comprises a calender frame, at least two soft-faced rolls mounted on the calender frame and at least one hard roll mounted on the calender frame in a manner that allows the hard roll to be displaced between a first position in which it forms calendering nips with the two soft-faced rolls and a second position in which it is spaced from the soft-faced rolls. During threading of the web; while the calender is in operation, the hard roll is shifted to its second position, the web is passed over the soft-faced rolls, and the hard roll is shifted back to its first position and brings the web into the nips between the hard roll and the soft-faced rolls.

Calender with pivotally displaceable roll

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Jyvaskyla, Finland

Ville Korhonen