Escher Wyss Limited

Sulzer-escher Wyss Limited

Werner Seider

Alfred Bubik

Rudiger Kurtz

Herbert Holik

Hans K Dahl

Wolf-Gunter Stotz

Elmer Weisshuhn

Robert Trondle

Anton Zembrot

Helmut Storr

Josef Hefter

Werner Meurer

Michael Kochndorfer

In a headbox system for a papermaking machine with an adjustable distribution of the fiber stock suspension or pulp over the web width, the flow in the delivery slice is controlled in such a way that, across the web width, also the distribution of the fibers in respect of fiber orientation and quantity has a desired profile. For this purpose, the flow of the fiber stock suspension is controlled such that in the event of a change in the distribution of the fiber stock suspension across the web width, the horizontal component of the flow direction in the delivery slice remains, at all locations, always in the predetermined machine direction and thus transverse flows are avoided and the flow rate in the delivery slice has a predeterminate profile.

Headbox control apparatus for a papermaking machine

Headbox apparatus for a papermaking machine

In a headbox system for a papermaking machine with an adjustable distribution of the fiber stock suspension or pulp over the web width, the flow in the delivery slice is controlled in such a way that, across the web width, also the distribution of the fibers in respect of fiber orientation and quantity has a desired profile. For this purpose, the flow of the fiber stock suspension is controlled such that in the event of a change in the distribution of the fiber stock suspension across the web width, the horizontal component of the flow direction in the delivery slice remains, at all locations, always in the predetermined machine direction and thus transverse flows are avoided and the flow rate in the delivery slice has a predetermined profile.

Method of operating a headbox apparatus for a papermaking machine

The papermaking machine contains at least one water pervious dewatering wire or the like for forming a fiber web, particularly one layer of a multi-ply fiber web, and at least one headbox for infeeding a fiber stock suspension to be applied in the form of a free jet to the dewatering wire. Between the headbox and a section of the dewatering wire extending along the headbox there is arranged at least one deflecting device for separating and withdrawing a partial flow or stream of the fiber stock suspension. The deflecting device can be inserted into a marginal region of the free stock jet. Such an arrangement enables, for example, a continuous or infinitely variable adjustment of the format width of the fiber web to be produced. During use of the deflecting device, the partial flow or stream of the stock is deflected prior to the formation of the fiber web and is kept away from the following operational or working sections of the papermaking machine, in particular from a second fiber web or ply located thereat. If desired, the deflected partial stock flow can be returned to the fiber stock suspension supply or infeed system preceding or upstream of the headbox for re-use of the unmixed fiber stock material.

Papermaking machine stock trim deflecting device

A longitudinal wire papermaking machine is disclosed wherein the longitudinal wire is guided in a dewatering region, following a pre-dewatering path, out of a wire plane downwardly over a deflection element and then upwardly over a downwardly domed or arched dewatering element towards the wire plane. The deflection element is arranged at a spacing K=approximately 15 to 80 mm from the dewatering element. The longitudinal wire is guided at the inlet section of the dewatering region, located between its outbound or run-off location at the deflection element and its lowest deflection location, over a negative pressure zone, for instance constituted by a suction chamber, which is effective at its underside. Hence, at the inlet section there is obtained a reduction in the suspension pressure and the fiber stock suspension is guided with an approximately constant total thickness lower into the dewatering region, i.e. at a relatively flat angle towards the dewatering element, so that there is avoided any backflow at the surface region of the suspension.

Longitudinal wire papermaking machine

A dewatering apparatus contains a longitudinal wire and an additional wire which is guided, conjointly with the longitudinal wire, along a section of such longitudinal wire over a domed or arched surface. This domed or arched surface is formed, for instance, by the jacket or outer surface of a dewatering cylinder arranged within the wire loop of the longitudinal wire. The longitudinal wire is provided with a headbox and extends forwardly and after the dewatering apparatus essentially in a wire plane, above which upwardly rises the domed surface. Both of the wires are guided out of the wire plane over a dewatering shoe arranged within the wire loop of the additional wire towards the domed surface and from such--if desired over a deflection roll arranged beneath the wire plane--again towards the wire plane, where both wires separate from one another. Due to this arrangement there is realized a guiding of both wires which improves the dewatering action and is extensively independent of the elevational position of the wire plane, and at the same time affords a constructional simplification of the papermaking machine.

Dewatering apparatus for longitudinal wire papermaking machines

A headbox arrangement for a papermaking machine contains a plurality of headboxes forming a group, these headboxes being arranged either essentially in parallelism with regard to one another or in fan-like or spread apart configuration. Between each two neighboring headboxes there is located a flexible divider, particularly in the form of a foil member, which extends past the outlet gap or slice of the headboxes.

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Ravensburg, Germany

Werner Seider