Valmet Oy

Metso Paper Inc.

Valmet Paper Machinery Inc.

Erkki Ilmoniemi

Jouni Koskimies

Michael H Odell

Jyrki Huovila

Antti Suonper&auml;

Kari Pitkajarvi

Markku Ronnila

Jaakko Jantunen

Heikki Kaasalainen

Olavi Kokkonen

Esa Ottelin

Johan Gullichsen

Tuulikki Manninen

A headbox, for example, in a pulp or board machine, is suitable for high basis weights which are over 400 g/mand for high fiber suspension consistencies which are in a range of 2&#x2013;5%. The headbox has a turbulence part (), into which a fiber suspension flows from a tube bank (), and a slice part () which is situated after the turbulence part and from which the fiber suspension flows to a forming section of a fibrous web. The turbulence part () of the headbox has at least two passages (), which converge in the flow direction of the fiber suspension towards the slice part (). In that connection, the fiber suspension flow is first fluidized in a tortuous turbulence passage part () and, after that, it decelerates in another widening deceleration passage ().

Headbox for a paper machine, board machine, pulp machine or equivalent

A stock feed system for a multi-layer headbox and a method in the operation of a multi-layer headbox in which into each inlet header of the multi-layer headbox, a stock concept is passed which has been produced out of the same fresh stock by adding the necessary chemicals and fillers to separated portions of the fresh stock.

Stock feed system for a multi-layer headbox and method in the operation of a multi-layer headbox

A profile bar for a discharge opening of a head box of a paper machine, by means of which the profile of the discharge jet from the paper machine is controlled. The profile bar may be connected to adjustment spindles, by means of which the profile bar can be bent in a plane transverse to a direction of flow of the discharge jet. Bending stiffness of the profile bar in the direction of bending to be achieved by means of the adjustment spindles, is arranged to be substantially lower within areas facing the adjustment spindles than at a middle of an area between the adjustment spindles. Transverse sawings or recesses may be made into the profile bar with a spacing substantially denser than the spacing between the adjustment spindles or equivalent. Alternatively, the profile bar may be provided with projections to which the adjustment spindles are attached, with the height of the projections being greater than a maximum height of the profile bar in the space between the projections. Furthermore, the height of the profile bar between the projections may be at a minimum in the longitudinal direction thereof, in a proximity to the projections, and at a maximum at the middle of the area between the adjustment spindles.

Profile bar in a head box of paper machine

Method and apparatus in the head box of a paper machine for controlling the distortion of fibre orientation in the paper web comprise an arrangement wherein by-pass flows of pulp suspension are passed through opposite passages lateral of the turbulence generator preceding the slice portion or discharge channel of the head box. The magnitude and/or the mutual relationship of the by-pass flows is adjusted to control the distortion of the fibre orientation in that the by-pass flows produce a transverse flow in the discharge flow of the pulp suspension from the head box, the speed of which compensates for the distortion of the fibre orientation.

Method and apparatus for controlling distortion of fibre orientation in

Apparatus for damping pressure and consistency perturbations occurring in the pulp suspension flow to the headbox of a paper making machine including an enclosed damping tank defining therewithin a space for a volume of air and a space for the pulp suspension such that the pulp suspension and the air volume have direct interfacing contact. Longitudinally extending distribution and collecting header means are disposed within the tank for conducting the flow of pulp suspension into and out of the tank, respectively. Each of the distribution and collecting header means define a flow passage for the pulp suspension, which passages fluidly communicate with the pulp suspension space within the damping tank through an elongate, continuous slit. Damping or attenuation of the pressure perturbations in the pulp stock flow is achieved through the interaction of the surface of the pulp stock with the air volume while the consistency perturbations are damped through the action of a plural delay principle.

Apparatus for damping pressure and consistency perturbations in a pulp

An approach pipe system which delivers pulp suspension to the headbox of a paper machine includes a tank having in its interior an upper gas space and a lower liquid space adapted to contain a liquid the upper surface of which contacts the gas in the gas space. In its interior this tank carries a flexible diaphragm which defines with the tank a flow space separated from the liquid space by the flexible diaphragm. A supply pipe communicates with this flow space for delivering a pulp suspension thereto while a discharge pipe also communicates with the flow space for receiving a pulp suspension therefrom and for continuing the travel of the pulp suspension to a headbox. The gas in the gas space acts through the liquid in the liquid space on the diaphragm to damp pressure and flow rate disturbances in the pulp suspension flowing toward the headbox.

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Vaajakoski, Finland

Erkki Ilmoniemi