Valmet Corporation

Valmet Paper Machinery Inc.

Markku Salo

Jorma Kolio

Kari Luostarinen

Ari Rousu

Esa Lehtovirta

Jorma Ramstedt

Paavo Ruuska

Tauno Orava

An apparatus for reducing or preventing vibrations of a roll set of a paper making apparatus, wherein the roll set comprises at least two rolls of which at least one is a soft roll coated with a compressible coating and comprising a temperature control system. The natural vibrational frequency of the roll set is changed during the operation of the apparatus by changing the temperature of the coating of the at least one soft roll. The changing of the natural frequency prevents resonance on a natural frequency of the roll set.

Apparatus for preventing vibrations of a roll set

An applicator device for applying a coating agent onto a moving base, such as a paper or board web, onto the face of a film press roll, or equivalent, and a method for correcting for distortions arising from thermal strains in such an applicator device. The applicator device includes an applicator beam arranged in a direction transverse to a running direction of the moving base, a coating-agent feed pipe arranged in the transverse direction and mounted on the applicator beam, and coating members mounted on the applicator beam for applying a coating onto the moving base and spreading and smoothing the coating agent onto the moving base. The coating-agent feed pipe and the coating members are constructed as a single unit. The device also includes mounting members for mounting the single unit of the coating-agent feed pipe and the coating members on the applicator beam. The mounting members include a joint member coupled to the single unit and the applicator beams which permits relative movements arising from thermal expansion between the applicator beam and the single unit in the transverse direction of the machine while substantially preventing relative movements of the applicator beam and the single unit in other directions.

Method and device for applying a coating agent onto a moving base

A method for reducing or preventing vibrations of a roll set of a paper making apparatus, wherein the roll set comprises at least two rolls of which at least one is a soft roll coated with a compressible coating and comprising a temperature control system. The natural vibrational frequency of the roll set is changed during the operation of the apparatus by changing the temperature of the coating of at least one soft roll. The changing of the natural frequency prevents resonance on a natural frequency of the roll set.

Method for preventing vibrations of a roll set

The invention relates to a holder for a cradle of a coating bar or for a coating blade in a coating unit and a method for securing the cradle of the coating bar or the coating blade in a coating device. The coating bar or blade are arranged to spread and smooth a size film or a corresponding layer of coating agent onto a face of a moving base to be coated by loading the coating bar or blade against the moving base. The moving base may be a roll of a size press or the web passed over a back-up roll. The cradle of the coating bar or the coating blade is mounted in a holder arranged in an application beam transverse to the machine direction. A journalling duct transverse to the machine direction is formed in the frame of the holder. An oblong member is arranged rotatably in the journalling duct and comprises a cam-like projection of eccentric section. The member can be rotated for the purpose of fixing the cradle of the coating bar or the coating blade in its place. In this position, the cam-like projection rests against a rear face of the cradle of the coating bar or of the coating blade and secures the cradle or coating blade against a support provided on the application beam.

Holder for a cradle of a coating bar or for a coating blade

An applicator beam in a size press comprising a nip formed by a pair of press rolls between which a paper or board web is passed. The press rolls are provided with coating devices for spreading films of coating agent onto the faces of the rolls. The coating devices are mounted on applicator beams placed in the transverse direction of the machine. The applicator beams are linked pivotally on the frame of the size press or on the loading arms of a displaceable roll by a pivot shaft arranged transverse to the machine direction. The applicator beams are also provided with pivot cylinders by which the applicator beams can be pivoted between a closed position, i.e. the operating position, and an opened position, i.e. the service position. In accordance with the invention, in its cross section taken in a vertical plane in the longitudinal direction of the machine, the applicator beam is shaped so that at least the curved outer face of the applicator beam that is facing away from the corresponding press roll is curved. Moreover, the pivot shaft of the applicator beam is arranged so that when the applicator beam is pivoted around its pivot shaft, the distance from the curved outer face of the applicator beam to the other constructions of the machine placed close to the applicator beam, such as the tending bridge, remains substantially unchanged.

Applicator beam in a size press

A device in a size press comprising a nip formed by press rolls through which a paper or board web is passed. The press rolls are provided with coating devices for spreading films of a coating agent onto faces of the press rolls. The coating devices are mounted on applicator beams arranged transverse to the machine direction. The applicator beams are supported pivotally on the frame of the size press or on the loading arms of a displaceable press roll and are provided with pivot cylinders by which the applicator beams can be opened and closed in relation to the rolls corresponding to them. The applicator beams are further provided with catches supported directly or indirectly on bearings of the corresponding press rolls when the applicator beams are being closed by the pivot cylinders. At least one of the applicator beams of the size press is provided with catches at each end of the applicator beam and positioned in accordance with the position of the applicator beam. The catches are attached to the applicator beam by articulated joints and are interconnected mechanically.

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Muurame, Finland

Markku Salo