Valmet Corporation

Jorma Kolio

Markku Salo

Kari Luostarinen

Esa Lehtovirta

Jorma Ramstedt

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.

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Jyvaskyla, Finland

Jorma Kolio