EP0648892A1 - Twin-wire former for a papermachine - Google Patents

Twin-wire former for a papermachine Download PDF

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Publication number
EP0648892A1
EP0648892A1 EP94114686A EP94114686A EP0648892A1 EP 0648892 A1 EP0648892 A1 EP 0648892A1 EP 94114686 A EP94114686 A EP 94114686A EP 94114686 A EP94114686 A EP 94114686A EP 0648892 A1 EP0648892 A1 EP 0648892A1
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EP
European Patent Office
Prior art keywords
sieve
strips
twin
suction
wire former
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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EP94114686A
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German (de)
French (fr)
Inventor
Dieter Egelhof
Volker Schmidt-Rohr
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JM Voith GmbH
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JM Voith GmbH
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Filing date
Publication date
Application filed by JM Voith GmbH filed Critical JM Voith GmbH
Publication of EP0648892A1 publication Critical patent/EP0648892A1/en
Withdrawn legal-status Critical Current

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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F9/00—Complete machines for making continuous webs of paper
    • D21F9/003—Complete machines for making continuous webs of paper of the twin-wire type

Definitions

  • the invention relates to a twin wire former according to the preamble of claim 1.
  • the suction boxes When removing white water or filtrate, the suction boxes are not or only partially filled with water.
  • the papermaker strives to produce paper that is homogeneous in every respect. It should have a uniform profile both across the web width, in terms of its thickness and in terms of its material composition. It should also always have the same properties when viewed in the machine longitudinal direction. Great efforts are being made to this end, particularly in the area of sheet formation, ie on the twin wire former to create all the prerequisites for good paper web quality in the above sense. However, this has not yet been fully successful.
  • the invention is therefore based on the object of providing a twin-wire former which has the prerequisites for a paper web which is uniform in all respects.
  • the inventors have recognized that the above-mentioned drainage boxes are not or not completely filled with white water during the operation of the paper machine.
  • the white water level inside the suction box can fluctuate considerably during operation. There can be phases in which the mirror is almost at the bottom of the box and phases in which it touches the screen more or less.
  • the inventors have found that, under such conditions, water levels within the suction boxes are highly agitated, and that as a result the nascent paper sheet is washed out by the white water sloshing from below, so that the content of fillers and fines is poor. All in all, all of these phenomena lead to disturbances in sheet formation, and thus to a reduction in the uniformity of the paper web being formed.
  • the inventors have also recognized that the interior of the suction box adjacent to the sieve should always be full of water, so that the sieve is always "under water”.
  • the screen should therefore remain constantly wetted, especially across the width of the web.
  • the invention can be used both in so-called hybrid formers and in so-called gap formers. It can be important, among other things, that the suction boxes of one sieve and those of the other sieve face each other in such a way that they at least partially overlap. It can be advantageous that the suction boxes on one side and on the other side of the drainage section are of identical shape.
  • the invention can be applied to both horizontal and vertical drainage sections, but also to a drainage section inclined to the horizontal.
  • FIG. 1 shows schematically seen in side view a twin-wire former with two screens 1, 2, each of which forms a screen loop with one another.
  • the lower of the two sieves namely sieve 1, loops around a sieve table 3 with a curved work surface, then a suction box 4 with a plurality of drainage strips 5, and finally a separating suction device 6.
  • the upper sieve 2 wraps around a suction box 14 with drainage strips 15 located therein.
  • two screen loops are assigned to guide rollers, which, however, play no role in the invention.
  • the drainage strips 5 located within the suction box 4 are pressed elastically against the sieve 1, while the drainage strips 15 of the suction box 14 of the sieve 2 are rigidly supported.
  • the strips 5 and the strips 15 are arranged on a gap.
  • FIG. 2 shows somewhat more precisely the manner in which suction box 14 can be designed.
  • Suction box 14 is through a partition 14.3 divided into two suction boxes 14.1, 14.2. One can also see suction connections 14.4 and 14.5.
  • FIG. 3 and 4 are even more revealing. Both representations are vertical sections through the essentially horizontally arranged drainage section, which is formed from the two screens 1 and 2.
  • 3 is a vertical section in the running direction of the paper web
  • FIG. 4 is a vertical section perpendicular to the running direction of the paper web.
  • the two suction boxes 4, 14, as already indicated in FIG. 1, can again be seen, furthermore the drainage strips 5 and 15, respectively.
  • the lower suction box 4 is connected to a standpipe 4.1, which is in conductive connection with the interior of the suction box here. Standpipe 4.1 has a suction port 4.2. In the standpipe 4.1, a white water level 4.3 is produced by means of negative pressure, which is clearly above the screen 1.
  • the two screens 1 and 2 sandwich the nascent paper web 7 in the manner of a sandwich.
  • Suction box 14 also has a vacuum connection 14.2.
  • the white water level 14.3 of suction box 14 is of course also above sieve 2, which results automatically when using suction boxes in a twin sieve. It is essential, however, that the two suction boxes 4 and 14 lie opposite one another, as can be seen from FIGS. 3 and 4.
  • the invention is applied to a twin wire former with a substantially vertical drainage section.
  • a twin wire former with a substantially vertical drainage section.
  • a suction box 4 with drainage strips 5 which can be adjusted elastically against the inner surface of sieve 1.
  • a drainage box 14 within the screen 2 Drainage strips 15, which are arranged non-resiliently and thus rest against the inner surface of sieve 1 in a stationary manner.
  • the two suction boxes have suction connections 4.4 and 14.4, furthermore stand pipes 8 and 18.
  • the stand pipes have suction connections 8.1 and 18.1, respectively.
  • the negative pressure at the suction connections 8.1 and 18.1 is dimensioned such that the mirror 8.2 or 18.2 in the standpipe in question lies clearly above the upper edge of the suction box in question, so that the two sieves 1, 2 are constantly "under water".
  • the two drainage boxes 4, 14 can be designed with their associated drainage strips 5 and 15 according to FIG. 6.
  • the twin wire former is of course associated with a headbox, of which only the outlet nozzle 10 is shown in FIGS. 1 and 5.
  • the twin units are followed by the usual units, generally a press section, but this is not shown here.

Abstract

The double fourdrinier (1,2) papermaking machine has a number of water extraction bars (5, 15) within the fourdrinier loops, where each lie against the inner surfaces of their fourdriniers, in groups within suction boxes (4, 14). The suction boxes (4, 14) each connected to an underpressure, face each other with at least a partial overlap. The direct or indirect underpressure supplied to the suction boxes (4, 14) is set so that the fourdrinier is constantly wetted as it passes through from water within the suction box. Pref. the separate suction boxes (4, 14) are each connected to a stand pipe (8, 18) with an underpressure which is adjusted to keep the water level (8.2, 18.1) in each stand pipe (8, 18) above the top edge of the suction box (4, 14).

Description

Die Erfindung betrifft einen Doppelsiebformer gemäß dem Oberbegriff von Anspruch 1.The invention relates to a twin wire former according to the preamble of claim 1.

Bezüglich des Standes der Technik wird auf die folgenden Druckschriften verwiesen:

  • (1) DE-PS 682 894
  • (2) WO 91/01408
  • (3) US-A-5 045 153
  • (4) DE-PS 2 023 521
Die Erfindung geht aus von Druckschrift (3). Hierbei sind Leisten in beiden Siebschlaufen angeordnet. Dabei sind die Leisten innerhalb der einen Siebschlaufe den Leisten innerhalb der anderen Siebschlaufe gegenüberliegend angeordnet. Die Leisten der einen wie auch der anderen Gruppe können sich innerhalb von Saugkästen befinden weil die den gesamten Bereich der Leisten mit Unterdruck beaufschlagen, um somit die Entwässerung zu steigern. Die Saugkästen haben entsprechende Sauganschlüsse, an welchen ein Unterdruck angelegt wird, um das Wasser aus den Kästen zu entfernen.With regard to the state of the art, reference is made to the following publications:
  • (1) DE-PS 682 894
  • (2) WO 91/01408
  • (3) US-A-5 045 153
  • (4) DE-PS 2 023 521
The invention is based on document (3). Here, strips are arranged in both sieve loops. The strips within one sieve loop are arranged opposite the strips within the other sieve loop. The strips of the one as well as the other group can be located inside suction boxes because they pressurize the entire area of the strips to increase the drainage. The suction boxes have corresponding suction connections, to which a vacuum is applied in order to remove the water from the boxes.

Bei diesem Abführen von Siebwasser oder Filtrat sind die Saugkästen nicht oder nur teilweise mit Wasser gefüllt.When removing white water or filtrate, the suction boxes are not or only partially filled with water.

Der Papiermacher ist bestrebt, ein Papier zu erzeugen, das in jeder Beziehung homogen ist. Es soll sowohl über die Bahnbreite hinweg ein gleichmäßiges Profil aufweisen, und zwar bezüglich seiner Dicke, als auch bezüglich seiner Stoffzusammensetzung. Auch soll es in Maschinen-Längsrichtung gesehen stets gleichbleibende Eigenschaften aufweisen. Zu diesem Zwecke werden große Anstrengungen unternommen, um insbesondere im Bereich der Blattbildung, d.h. auf dem Doppelsiebformer, alle Voraussetzungen für eine gute Qualität der Papierbahn im obigen Sinne zu schaffen. Dennoch gelingt dies bis heute nicht in vollem Maße.The papermaker strives to produce paper that is homogeneous in every respect. It should have a uniform profile both across the web width, in terms of its thickness and in terms of its material composition. It should also always have the same properties when viewed in the machine longitudinal direction. Great efforts are being made to this end, particularly in the area of sheet formation, ie on the twin wire former to create all the prerequisites for good paper web quality in the above sense. However, this has not yet been fully successful.

Der Erfindung liegt somit die Aufgabe zugrunde, einen Doppelsiebformer zu schaffen, der die Voraussetzungen für eine in jeder Beziehung gleichförmige Papierbahn hat.The invention is therefore based on the object of providing a twin-wire former which has the prerequisites for a paper web which is uniform in all respects.

Diese Aufgabe wird durch die Kombination der in Anspruch 1 enthaltenen Merkmale gelöst.This object is achieved by the combination of the features contained in claim 1.

Die Erfinder haben erkannt, daß die oben genannten Entwässerungskästen während des Betriebes der Papiermaschine nicht oder nicht vollständig mit Siebwasser gefüllt sind. Der Siebwasserspiegel innerhalb des Saugkastens kann während des Betriebes ganz erheblich schwanken. So kann es Phasen geben, in welchen sich der Spiegel fast am Boden des Kastens befindet, und solche, in welchen er das Sieb mehr oder minder berührt. Außerdem haben die Erfinder festgestellt, daß es bei solchen Bedingungen zu stark bewegten Wasserspiegeln innerhalb der Saugkästen kommt, und daß hierdurch das im Entstehen begriffene Papierblatt durch das von unten heranklatschende Siebwasser ausgewaschen wird, so daß der Gehalt an Füllstoffen und Feinstoffen verarmt. Insgesamt gesehen führen alle diese Erscheinungen zu Störungen der Blattbildung, und damit zu einer Minderung der Gleichmäßigkeit der entstehenden Papierbahn.The inventors have recognized that the above-mentioned drainage boxes are not or not completely filled with white water during the operation of the paper machine. The white water level inside the suction box can fluctuate considerably during operation. There can be phases in which the mirror is almost at the bottom of the box and phases in which it touches the screen more or less. In addition, the inventors have found that, under such conditions, water levels within the suction boxes are highly agitated, and that as a result the nascent paper sheet is washed out by the white water sloshing from below, so that the content of fillers and fines is poor. All in all, all of these phenomena lead to disturbances in sheet formation, and thus to a reduction in the uniformity of the paper web being formed.

Die Erfinder haben ferner erkannt, daß der an das Sieb angrenzende Innenraum des Saugkastens ständig voll Wasser sein sollte, so daß das Sieb stets "unter Wasser steht". Das Sieb sollte somit ständig gleichmäßig benetzt bleiben, insbesondere über die Bahnbreite.The inventors have also recognized that the interior of the suction box adjacent to the sieve should always be full of water, so that the sieve is always "under water". The screen should therefore remain constantly wetted, especially across the width of the web.

Die Erfindung läßt sich sowohl bei sogenannten Hybridformern als auch bei sogenannten Gapformern anwenden. Dabei kann unter anderem wichtig sein, daß sich die Saugkästen des einen Siebes und jene des anderen Siebes gegenüberliegen, und zwar derart, daß sie sich wenigstens teilweise überlappen. Es kann vorteilhaft sein, daß die Saugkästen auf der einen und auf der anderen Seite der Entwässerungsstrecke formidentisch ausgebildet sind.The invention can be used both in so-called hybrid formers and in so-called gap formers. It can be important, among other things, that the suction boxes of one sieve and those of the other sieve face each other in such a way that they at least partially overlap. It can be advantageous that the suction boxes on one side and on the other side of the drainage section are of identical shape.

Die Erfindung läßt sich sowohl bei horizontaler als auch bei vertikaler Entwässerungsstrecke anwenden, aber auch bei einer gegen die Horizontale geneigten Entwässerungsstrecke.The invention can be applied to both horizontal and vertical drainage sections, but also to a drainage section inclined to the horizontal.

Die Erfindung ist anhand der Zeichnung näher erläutert. Darin ist im einzelnen folgendes dargestellt:The invention is explained in more detail with reference to the drawing. The following is shown in detail:

Fig.1 zeigt schematisch in Seitenansicht gesehen einen Doppelsiebformer mit zwei Sieben 1,2, die jeweils eine Siebschlaufe miteinander bilden. Das untere der beiden Siebe, nämlich Sieb 1, umschlingt unter anderem einen Siebtisch 3 mit gekrümmter Arbeitsfläche, sodann einen Saugkasten 4 mit einer Mehrzahl von Entwässerungsleisten 5, und schließlich einen Trennsauger 6. Das Obersieb 2 umschlingt einen Saugkasten 14 mit darin befindlichen Entwässerungsleisten 15. Außerdem sind beiden Siebschlaufen Leitwalzen zugeordnet, die aber für die Erfindung keine Rolle spielen.1 shows schematically seen in side view a twin-wire former with two screens 1, 2, each of which forms a screen loop with one another. The lower of the two sieves, namely sieve 1, loops around a sieve table 3 with a curved work surface, then a suction box 4 with a plurality of drainage strips 5, and finally a separating suction device 6. The upper sieve 2 wraps around a suction box 14 with drainage strips 15 located therein. In addition, two screen loops are assigned to guide rollers, which, however, play no role in the invention.

Die innerhalb des Saugkastens 4 befindlichen Entwässerungsleisten 5 sind elastisch gegen Sieb 1 angedrückt, während die Entwässerungsleisten 15 des Saugkastens 14 von Sieb 2 starr gelagert sind. Die Leisten 5 und die Leisten 15 sind auf Lücke angeordnet.The drainage strips 5 located within the suction box 4 are pressed elastically against the sieve 1, while the drainage strips 15 of the suction box 14 of the sieve 2 are rigidly supported. The strips 5 and the strips 15 are arranged on a gap.

Fig. 2 zeigt etwas genauer die Art und Weise, in welcher Saugkasten 14 gestaltet sein kann. Saugkasten 14 ist durch eine Trennwand 14.3 in zwei Saugkästen 14.1, 14.2 unterteilt. Man erkennt ferner Sauganschlüsse 14.4 und 14.5.Fig. 2 shows somewhat more precisely the manner in which suction box 14 can be designed. Suction box 14 is through a partition 14.3 divided into two suction boxes 14.1, 14.2. One can also see suction connections 14.4 and 14.5.

Noch aufschlußreicher sind die Fig. 3 und 4. Beide Darstellungen sind Vertikalschnitte durch die im wesentlichen horizontal angeordnete Entwässerungsstrecke, welche aus den beiden Sieben 1 und 2 gebildet ist. Dabei ist Fig. 3 ein Vertikalschnitt in Laufrichtung der Papierbahn, und Fig. 4 ein Vertikalschnitt senkrecht zur Laufrichtung der Papierbahn. Man erkennt wiederum die beiden Saugkästen 4,14, sowie bereits in Fig. 1 angedeutet, ferner die Entwässerungsleisten 5 bzw. 15. Der untere Saugkasten 4 ist an ein Standrohr 4.1 angeschlossen, das mit dem Innenraum des Saugkastens hier in leitender Verbindung steht. Standrohr 4.1 weist einen Sauganschluß 4.2 auf. Im Standrohr 4.1 wird mittels Unterdruckes ein Siebwasserspiegel 4.3 hergestellt, der deutlich oberhalb des Siebes 1 liegt. Die beiden Siebe 1 und 2 umhüllen sandwichartig die im Entstehen begriffene Papierbahn 7.3 and 4 are even more revealing. Both representations are vertical sections through the essentially horizontally arranged drainage section, which is formed from the two screens 1 and 2. 3 is a vertical section in the running direction of the paper web, and FIG. 4 is a vertical section perpendicular to the running direction of the paper web. The two suction boxes 4, 14, as already indicated in FIG. 1, can again be seen, furthermore the drainage strips 5 and 15, respectively. The lower suction box 4 is connected to a standpipe 4.1, which is in conductive connection with the interior of the suction box here. Standpipe 4.1 has a suction port 4.2. In the standpipe 4.1, a white water level 4.3 is produced by means of negative pressure, which is clearly above the screen 1. The two screens 1 and 2 sandwich the nascent paper web 7 in the manner of a sandwich.

Auch Saugkasten 14 hat einen Unterdruckanschluß 14.2. Der Siebwasserspiegel 14.3 von Saugkasten 14 liegt natürlich ebenfalls oberhalb von Sieb 2, was sich bei Anwendung von Saugkästen in einem Doppelsieb automatisch ergibt. Wesentlich ist allerdings, daß die beiden Saugkästen 4 und 14 einander gegenüberliegen, wie man aus den Fig. 3 und 4 erkennt.Suction box 14 also has a vacuum connection 14.2. The white water level 14.3 of suction box 14 is of course also above sieve 2, which results automatically when using suction boxes in a twin sieve. It is essential, however, that the two suction boxes 4 and 14 lie opposite one another, as can be seen from FIGS. 3 and 4.

In den Fig. 5 und 6 ist die Erfindung bei einem Doppelsiebformer mit im wesentlichen vertikaler Entwässerungsstrecke angewandt. Man erkennt wiederum die Zwei Siebe 1,2, die jeweils eine geschlossene Siebschlaufe bilden. Innerhalb des Siebes 1 befindet sich wiederum ein Saugkasten 4 mit Entwässerungsleisten 5, die elastisch gegen die Innenfläche von Sieb 1 anstellbar sind. Innerhalb von Sieb 2 befindet sich ein Entwässerungskasten 14 mit Entwässerungsleisten 15, die nicht-nachgiebig angeordnet sind und somit ortsfest an der Innenfläche von Sieb 1 anliegen.5 and 6, the invention is applied to a twin wire former with a substantially vertical drainage section. One can again see the two sieves 1, 2, which each form a closed sieve loop. Inside the sieve 1 there is in turn a suction box 4 with drainage strips 5 which can be adjusted elastically against the inner surface of sieve 1. There is a drainage box 14 within the screen 2 Drainage strips 15, which are arranged non-resiliently and thus rest against the inner surface of sieve 1 in a stationary manner.

Die beiden Saugkästen weisen Sauganschlüsse 4.4 und 14.4 auf, ferner Standrohre 8 und 18. Die Standrohre haben Sauganschlüsse 8.1 bzw. 18.1. Dabei wird im Betrieb der Unterdruck an den Sauganschlüssen 8.1 und 18.1 derart bemessen, daß der Spiegel 8.2 bzw. 18.2 in dem betreffenden Standrohr deutlich oberhalb der Oberkante des betreffenden Saugkastens liegt, so daß die beiden Siebe 1,2 ständig "unter Wasser stehen".The two suction boxes have suction connections 4.4 and 14.4, furthermore stand pipes 8 and 18. The stand pipes have suction connections 8.1 and 18.1, respectively. In operation, the negative pressure at the suction connections 8.1 and 18.1 is dimensioned such that the mirror 8.2 or 18.2 in the standpipe in question lies clearly above the upper edge of the suction box in question, so that the two sieves 1, 2 are constantly "under water".

Alternativ zur Ausführungsform gemäß Fig. 5 können die beiden Entwässerungskästen 4,14 mit ihren zugehörenden Entwässerungsleisten 5 bzw. 15 gemäß Fig. 6 ausgebildet werden.As an alternative to the embodiment according to FIG. 5, the two drainage boxes 4, 14 can be designed with their associated drainage strips 5 and 15 according to FIG. 6.

Dem Doppelsiebformer ist selbstverständlich ein Stoffauflauf zugeordnet, von welchem in den Fig. 1 und 5 nur die Auslaufdüse 10 dargestellt ist. Außerdem schließen sich an die Doppelsiebformer die üblichen Aggregate an, im allgemeinen eine Pressenpartie, die aber hier nicht gezeigt ist.The twin wire former is of course associated with a headbox, of which only the outlet nozzle 10 is shown in FIGS. 1 and 5. In addition, the twin units are followed by the usual units, generally a press section, but this is not shown here.

Claims (6)

Doppelsiebformer für eine Papiermaschine 1.1 mit einem ersten und einem zweiten Sieb (1,2), die jeweils eine Siebschlaufe bilden; 1.2 mit einer Vielzahl von Entwässerungsleisten (5,15) innerhalb der beiden Siebschlaufen; 1.3 die Leisten (5) des ersten Siebes (1) liegen an der Innenfläche des ersten Siebes an (erste Leisten), und die Leisten (15) des zweiten Siebes (2) liegen an der Innenfläche des zweiten Siebes (2) an (zweite Leisten); 1.4 die Leisten sind gruppenweise innerhalb von Saugkästen (4,14) angeordnet; 1.5 jeder Saugkasten (4,14) ist an einen Unterdruck anschließbar; 1.6 Saugkästen (4,14) der beiden Siebe (1,2) liegen sich gegenüber, so daß sie sich wenigstens teilweise überdecken; 1.7 jeder Saugkasten (4,14) ist - mittelbar oder unmittelbar - an einen Unterdruck anschließbar; 1.8 der Unterdruck ist derart einstellbar, daß das Sieb vom Siebwasser innerhalb des betreffenden Saugkastens (4) bzw. (14) stets benetzt ist. Twin wire former for a paper machine 1.1 with a first and a second sieve (1,2), each forming a sieve loop; 1.2 with a large number of drainage strips (5.15) within the two sieve loops; 1.3 the strips (5) of the first sieve (1) lie against the inner surface of the first sieve (first strips), and the strips (15) of the second sieve (2) lie against the inner surface of the second sieve (2) (second Afford); 1.4 the strips are arranged in groups within suction boxes (4, 14); 1.5 each suction box (4, 14) can be connected to a vacuum; 1.6 suction boxes (4, 14) of the two screens (1, 2) lie opposite each other so that they overlap at least partially; 1.7 each suction box (4, 14) can be connected - directly or indirectly - to a negative pressure; 1.8 the negative pressure is adjustable so that the sieve is always wetted by the white water within the relevant suction box (4) or (14). Doppelsiebformer nach Anspruch 1, dadurch gekennzeichnet, daß der einzelne Saugkasten (4,14) an ein Standrohr (8,18) angeschlossen ist, an das ein Unterdruck anlegbar ist, und daß der Unterdruck derart einstellbar ist, daß der Flüssigkeitsspiegel (8.2) bzw. (18.2) im betreffenden Standrohr (8) bzw. (18) oberhalb der obersten Kante des Saugkastens (4) bzw. (14) liegt.Twin-wire former according to claim 1, characterized in that the individual suction box (4, 14) is connected to a standpipe (8, 18) to which a vacuum can be applied, and that the vacuum can be adjusted in such a way that the liquid level (8.2) or (18.2) in the relevant standpipe (8) or (18) above the top edge of the suction box (4) or (14). Doppelsiebformer nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Entwässerungsstrecke horizontal verläuft.Twin-wire former according to claim 1 or 2, characterized in that the dewatering section runs horizontally. Doppelsiebformer nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Entwässerungsstrecke vertikal verläuft.Twin-wire former according to claim 1 or 2, characterized in that the dewatering section runs vertically. Doppelsiebformer nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Entwässerungsstrecke unter einem Winkel gegen die Horizontale geneigt verläuft.Twin-wire former according to claim 1 or 2, characterized in that the dewatering section is inclined at an angle to the horizontal. Doppelsiebformer nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Leisten (5) des ersten Siebes (1) nachgiebig an der Innenfläche des ersten Siebes anliegen, und daß die Leisten (15) des zweiten Siebes (2) nicht-nachgiebig an der Innenfläche des zweiten Siebes (2) anliegen.Twin-wire former according to one of claims 1 to 5, characterized in that the strips (5) of the first sieve (1) resiliently rest on the inner surface of the first sieve, and in that the strips (15) of the second sieve (2) are non-resilient rest on the inner surface of the second sieve (2).
EP94114686A 1993-10-16 1994-09-17 Twin-wire former for a papermachine Withdrawn EP0648892A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4335304 1993-10-16
DE19934335304 DE4335304C2 (en) 1993-10-16 1993-10-16 Method for operating a twin wire former

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EP0648892A1 true EP0648892A1 (en) 1995-04-19

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EP (1) EP0648892A1 (en)
JP (1) JPH07150497A (en)
CA (1) CA2118143A1 (en)
DE (1) DE4335304C2 (en)
FI (1) FI944840A (en)

Cited By (2)

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Publication number Priority date Publication date Assignee Title
DE29619709U1 (en) * 1996-11-13 1997-01-09 Voith Sulzer Papiermasch Gmbh Screen section of a paper machine
CN110396850A (en) * 2019-07-10 2019-11-01 湖北金庄科技再生资源有限公司 A kind of method that wire-cloths paper sheet dehydration forming device and page are dehydrated

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Publication number Priority date Publication date Assignee Title
DE4335304C2 (en) * 1993-10-16 1995-04-20 Voith Gmbh J M Method for operating a twin wire former
DE10009362A1 (en) * 2000-02-29 2001-08-30 Voith Paper Patent Gmbh Double fourdrinier section for the wet paper/cardboard web follows a vertical path with weirs at the units to form the web and extract water to reduce the washing out of fine matter and filling materials
SE526787C2 (en) * 2003-10-21 2005-11-01 Metso Paper Karlstad Ab Support for use in e.g. press for dewatering fiber web manufactured in paper manufacturing machine, is movable towards counter-pressure surface, is elastically deformable, and has contact surface adaptable to counter-pressure surface
MXPA06005685A (en) 2003-12-22 2006-08-17 Astenjohnson Inc Hybrid type forming section for a paper making machine.
US8801902B1 (en) * 2013-09-18 2014-08-12 Usg Interiors, Llc Water reduction by modulating vacuum
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FI944840A (en) 1995-04-17
FI944840A0 (en) 1994-10-14
CA2118143A1 (en) 1995-04-17
DE4335304A1 (en) 1994-03-03
DE4335304C2 (en) 1995-04-20
JPH07150497A (en) 1995-06-13

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