EP1416084B1 - System and method for feeding pulp suspension to a headbox - Google Patents

System and method for feeding pulp suspension to a headbox Download PDF

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Publication number
EP1416084B1
EP1416084B1 EP03022309A EP03022309A EP1416084B1 EP 1416084 B1 EP1416084 B1 EP 1416084B1 EP 03022309 A EP03022309 A EP 03022309A EP 03022309 A EP03022309 A EP 03022309A EP 1416084 B1 EP1416084 B1 EP 1416084B1
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EP
European Patent Office
Prior art keywords
dilution
pulp suspension
dilution liquid
liquid
aeration
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EP03022309A
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German (de)
French (fr)
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EP1416084A1 (en
Inventor
Karl-Heinz Beuermann
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Voith Patent GmbH
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Voith Patent GmbH
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21D—TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
    • D21D5/00—Purification of the pulp suspension by mechanical means; Apparatus therefor
    • D21D5/26—De-aeration of paper stock
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F1/00—Wet end of machines for making continuous webs of paper
    • D21F1/66—Pulp catching, de-watering, or recovering; Re-use of pulp-water

Definitions

  • the invention relates to a pulp feed system for supplying a pulp suspension to at least one monolayer or multilayer headbox, with or without further dilution device, a paper or board machine with at least a first dilution device, in particular pre-dilution device, and at least one second dilution device, in particular re-dilution device, for diluting the Pulp suspension with a dilution liquid, in particular water, and at least one device for, in particular substantially complete, venting of the pulp suspension and the dilution liquid.
  • the invention relates to a method for feeding a pulp suspension to at least one single- or multi-layer headbox, with or without further dilution device, a paper or board machine, wherein the pulp suspension at least a first dilution, in particular predilution, and at least a second dilution, in particular post-dilution , is subjected to a dilution liquid, in particular water, and in which the pulp suspension and the dilution liquid, in particular substantially completely, are vented.
  • Such material supply systems and methods for operating the same are basically known (see, for example, DE 100 50 109 A1).
  • the principle of pre- and post-dilution is used in conjunction with cleaners and preferably for large headbox volumes and relatively low headbox densities.
  • a large difference between the consistency in the cleaning system and in the headbox is desirable, because this offers a large control potential in the operation of the pulp feed system. This applies even more to headboxes with further dilution device.
  • the feed density in a first cleaner stage can be set, for example, to approximately 0.9% to 0.95%, at which, according to experience, an effective operation of the cleaning device is possible and a good cleaning result is achieved.
  • the consistency can then be adjusted to the desired headbox density of, for example, about 0.65% or, in the case of further dilution in the headbox itself, from about 1% to, for example, about 0.75%.
  • the amount and consistency of the pulp suspension can be flexibly adjusted in the post-dilution cycle and, on the other hand, the cleaner system can be operated with optimum consistency.
  • the invention has for its object to provide a Stoffzu Genevasystem and a method of the type mentioned with pre and thinning of the stock suspension and in particular complete ventilation of the flow to the headbox, which ensure stable operation even with larger headbox and Stoffdichtvariationen and flexible use are.
  • the material supply system according to the invention is characterized in particular by the fact that separate venting devices are provided for the venting of the already once diluted pulp suspension on the one hand and the diluting liquid for the second dilution on the other hand.
  • the already prediluted pulp suspension and the dilution liquid for the subsequent dilution are therefore vented separately from each other.
  • the use of different dilution liquids, in particular different deaerated water qualities for the first dilution, for example, predilution, the second dilution in the main strand, for example, after dilution, and optionally further dilution in the headbox allows.
  • the material supply system according to the invention as a whole has a high degree of flexibility. It can be used both before single-layer and multi-layer headboxes with or without dilution water technology, as well as in separate or connected pulp feed systems for multiple headboxes in the production of multi-ply papers or cartons.
  • a defined mixing point is provided for the second dilution with vented dilution liquid.
  • the redilution of the pulp suspension is thus not carried out according to the invention by the addition of the dilution liquid in a deaeration tank for the pulp suspension, but it takes place in a specially designed, defined mixing point. Due to the defined mixing of deaerated pulp suspension and separately deaerated dilution liquid, a stable operation of the pulp feed system is ensured even with larger headbox volumes and consistency variations. In this case, by a defined introduction of fiber suspension and dilution liquid into the mixing point, a desired mixing ratio or a desired post-dilution of the pulp suspension can be easily checked and ensured. In addition, by the defined mixing point ensures a homogeneous mixing of pulp suspension and dilution liquid.
  • the mixing point between a first, preferably quantity-controlled pump for injecting the deaerated pulp suspension into the mixing point and a second pump, in particular headbox pump, for withdrawing the diluted, in particular nachverPlannten pulp suspension from the mixing point is arranged such that depending on the delivery rate of the first and second pumps automatically adjusts the amount of dilution liquid for the second dilution flowing into the mixing point.
  • the dilution of the pulp suspension is thus self-regulated, that is, no additional control device for the inflowing dilution liquid is required.
  • the amount of the inflowing dilution liquid depends solely on the amount of the pulp suspension supplied to the mixing point and withdrawn from the mixing point. The number of process parameters to be controlled is thus reduced by one parameter according to the invention, as a result of which the monitoring effort is reduced.
  • a common container is provided for venting the pulp suspension and the dilution liquid for the second dilution, which has correspondingly separate compartments and separate overflows.
  • a supply line between the venting device of the dilution liquid for the second dilution and the dilution device of the headbox is provided in a headbox with further dilution device, via which the dilution device of the headbox is supplied with vented dilution liquid.
  • the dilution liquid for the second dilution can be used simultaneously for further dilution of the pulp suspension in the headbox, ie for a third dilution. It is therefore not necessary to prepare and provide an additional dilution liquid for the dilution in the headbox, but the deaerated dilution liquid for the second dilution is used for both. This simplifies the structure of the substance delivery system according to the invention.
  • a further separate venting device for the dilution liquid of the headbox is provided.
  • the additional dilution liquid for the dilution in the headbox independently of the pulp suspension and of other dilution liquids, can be purposefully deaerated and processed, which further increases the flexibility of the system.
  • this allows the use of different, deaerated water qualities, such as white water or sewage water for the first dilution of the pulp suspension, for example predilution, for the second dilution of the pulp suspension in the main strand, for example, after-dilution, and as dilution water for further dilution of the pulp suspension in the headbox.
  • a container common to the venting device for the pulp suspension and / or to the venting device for the dilution liquid for the second dilution which has correspondingly separate compartments and separate overflows.
  • a common vacuum system is provided for the venting of the dilution liquid of the headbox and the pulp suspension and / or the dilution liquid for the second dilution.
  • At least one cleaning device is provided in particular between the first dilution device and the venting device for the pulp suspension.
  • the cleaning device may have one or more purification stages.
  • the system of pre- and post-dilution can be used particularly well when working with cleaning devices that tolerate increased consistency, namely up to about 2%.
  • the system can be operated with pre-dilution and then with a consistency in the headbox to about 1.7%. Due to the possibility of operation up to the above relatively high consistency, the pre- and post-dilution can be widely used in the production of a variety of papers and cartons. This applies both to systems with and without systems.
  • the material delivery system according to the invention is thus particularly flexible. At the same time a significant reduction of investment costs, space requirements and energy can be achieved, that is, the efficiency of the pulp feed system can be increased.
  • Fig. 1 is a schematic representation of a first embodiment of the StoffzuWORKsystems invention.
  • a pulp suspension is fed to a first mixing point 12.
  • the first mixing point 12 serves for a first dilution of the pulp suspension, a so-called predilution.
  • the predilution of the pulp suspension can optionally be carried out by an overflow liquid, which is supplied via a line 14 from a deaerator 16 for the pulp suspension, by an overflow liquid which is supplied via a line 18 from a venting device 20 for a Nachver Mednungswashkeit, or by white water.
  • an overflow liquid which is supplied via a line 14 from a deaerator 16 for the pulp suspension
  • an overflow liquid which is supplied via a line 18 from a venting device 20 for a Nachver Patnungswashkeit
  • white water for dilution of the pulp suspension with white water
  • the first mixing point 12 is connected to a white water tank 22 to which white water can be supplied via a supply line 24.
  • the pulp suspension mixed in the first mixing point 12 with one or more of the aforementioned dilution liquids and thus prediluted is withdrawn from the first mixing point 12 by a pump 26, the so-called cleaner pump, and via a line 28 of a multi-stage cleaning device, the so-called cleaner 30 fed, in which the prediluted pulp suspension is purified.
  • Suitable cleaners are well known and will therefore not be explained here.
  • the pulp suspension is introduced via a line 32 into the venting container 33 of the ventilation device 16 for the pulp suspension.
  • Appropriate venting or degassing devices for this purpose are well known and described for example in EP 1 091 040 A2 or EP 0 501 144 A1.
  • the venting of the pulp suspension is effected by means of a vacuum system 34 in the venting container 33 generated Vacuum. This is in particular a largely complete venting.
  • the term "substantially complete deaeration” as used in this application is to be understood as meaning that the deaeration of the stock suspension is preferably carried out so far that only one minimal amount of residual air remains in the suspension, which is acceptable for process control. Since an increased degree of deaeration is associated with an increased cost, when venting the stock suspension between the degree of ventilation and the efficiency of the deaeration process is to be weighed. This applies analogously to the deaeration of the dilution liquid or dilution liquids described below.
  • the pulp suspension deaerator 33 has an overflow arrangement 36 connected to the conduit 14, via which, as described above, overflow fluid may be supplied to the first mixing station 12.
  • an outlet 38 is provided, to which a main branch line 40 for withdrawing the vented fibrous suspension from the venting container 33 is connected.
  • the prediluted and deaerated pulp suspension flowing through the main branch line 40 is injected into a second mixing point 44 for a second dilution, a so-called after-dilution.
  • the redilution of the pulp suspension in the second mixing point 44 takes place by mixing with a deaerated second dilution liquid, in the case shown with deaerated white water.
  • a separate venting device 20 is provided with a separate vent tank 46, that is, the venting of the pulp suspension and the venting of NachverPmbiswashkeit done separately.
  • the white water intended for subsequent dilution and to be deaerated is fed to the deaeration vessel 46 via a line 48 from the white water tank 22.
  • a similar venting device can be used as for the venting of the pulp suspension. As noted above, such venting devices are known. They will therefore not be explained further here.
  • the deaeration tank 46 for the white water has an overflow arrangement 50, which is connected to the line 18, via which the first mixing point 12 at least optionally deaerated white water for predilution of the pulp suspension can be fed.
  • a first outlet 52 is also provided, to which a supply line 54 is connected. Through the supply line 54 may vented dilution water from the vent tank 46 in the second mixing point 44 for redilution of the pulp suspension to flow.
  • the now nachverPolnte pulp suspension is withdrawn from the second mixing point 44 and fed via a main line 58 to a headbox, not shown.
  • the second pump 42 and the headbox pump 56 are volume controlled, the flow rate of the headbox 56 is greater than that of the first pump 42 and, for example, at least 1500 to 2000 1 / min.
  • the inflow amount of the vented NachverDeutschswassers in the second mixing point 44 is passively controlled, that is, it is depending on the control of the flow rates of the second pump 42 and the headbox 56 automatically. In this way not only the pulp suspension is injected into the mixing point 44 in a defined manner, but also the dilution liquid is supplied in a controlled manner. In the mixing point 44 thus takes place a defined mixing of pulp suspension and dilution water, that is, a defined redilution of the stock suspension.
  • a second outlet 60 through which dilution water deaerated by means of a pump 62 can be supplied via a supply line 64 to another diluting device, not shown here, for further dilution of the pulp suspension in the head box.
  • the material feed system according to the invention is operated as described below.
  • a suitably prepared pulp suspension is diluted in the mixing point 12, for example with white water, in particular prediluted.
  • the diluted pulp suspension is then passed through the cleaner system 30, cleaned in this and finally in a vent 16, in particular completely, vented.
  • the dilution liquid for the second dilution of the pulp suspension, in particular completely is deaerated separately.
  • the deaerated pulp suspension and the deaerated dilution liquid are defined in the second mixing point 44 mixed with each other, resulting in a second dilution, especially post-dilution, the pulp suspension.
  • the now diluted again, in particular nachverPHnte, pulp suspension is then fed by means of the headbox 56 the headbox, where it is optionally diluted once more.
  • the second embodiment of the material feed system according to the invention shown in FIG. 2 differs from the first embodiment shown in FIG. 1 only in that the pulp suspension deaerator 16 and the after-dilution liquid deaerator 20 have a common deaerator tank 66, which is divided by a dividing wall 68 into a first pulp suspension ventilating compartment 70 and a second diluting water ventilating compartment 72.
  • Each compartment 70, 72 has an overflow arrangement 36 and 50, respectively.
  • a spout 38 is provided for withdrawing the deaerated pulp suspension, while in the bottom area of the second compartment 72 two outlets 52, 60 are provided for withdrawing the deaerated dilution water.
  • the vacuum in the venting container 66 is generated by the vacuum system 34, wherein a single vacuum line 74 is sufficient to connect the container 66 to the vacuum system 34.
  • the third embodiment of the substance delivery system according to the invention shown in FIG. 3 differs from the first embodiment shown in FIG. 1 in that the venting container 46 of the afterdilution liquid venting device 20 only has an outlet 52 in its bottom region. At this outlet 52, the supply line 54 is connected to supply the second mixing point 44 for subsequent dilution of the pulp suspension with deaerated NachverPhymbiswashkeit.
  • the dilution liquid to be deaerated is supplied to the venting device 20 via a line 76.
  • the dilution liquid in this embodiment is white water, so that the line 76 can connect the vent tank 46, for example, with the white water tank 22. But it is also conceivable to use another liquid as NachverPhymbiswashkeit, such as sewage or fresh water.
  • a third separate venting device 78 is additionally provided which has a venting container 80 separate from the venting containers 33, 46 of the fibrous suspension and after-dilution liquid.
  • This third venting device 78 serves to vent an additional dilution liquid, which is provided for a further dilution of the pulp suspension in the headbox, not shown.
  • This venting device 78 may be of a known type.
  • the additional dilution liquid is supplied to the deaeration tank 80 via a line 82.
  • the dilution liquid can be white water, sewage water or water of a different quality, the line 82 being connected to a suitable water reservoir, not shown, in the case of white water, for example with the white water container 22.
  • the additional dilution liquid is vented in the deaeration container 80 as well as the venting of the pulp suspension and the venting of NachverPhymbiswashkeit by the generation of a vacuum in the vent tank 80.
  • the same vacuum system 34 is used, which also serves to vent the pulp suspension and the NachverPhymbikeit.
  • the venting container 80 has an overflow arrangement 84, by means of which the overflow of the at least partially vented dilution liquid can be withdrawn from the container 80 and fed via an overflow line 86 to a dilution liquid reservoir (not shown) or, for example, to the first mixing point 12 for predilution of the fibrous stock suspension.
  • an outlet 88 is also provided, to which a supply line 90 is connected.
  • a pump 92 is above the outlet 88 and the supply line 90 in particular completely deaerated dilution liquid from the vent tank 80 removable and, for example, a third dilution device for further dilution of the already nachverPolnten pulp suspension fed in the headbox.
  • the fourth embodiment of the material feed system according to the invention shown in FIG. 4 differs from the third embodiment shown in FIG. 3 in that the pulp suspension deaerator 16, the post-dilution liquid deaerator 20 and the additional dilution liquid deaerator 78 share a common deaerator tank 94 which is divided by two partitions 68, 96 into a first pulp suspension compartment 70, a second compartment 72 for the post-dilution fluid, and a third compartment 98 for the additional dilution fluid.
  • Each of the three compartments 70, 72, 98 has the feed lines 32, 48, 82 already described above, overflow arrangements 36, 50, 84 and outlets 38, 52, 88.
  • the common venting container 94 of all three venting devices 16, 22, 78 is connected via a vacuum line 100 with the common vacuum system 34 to generate the vacuum required for the venting.

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Abstract

A papermaking assembly has a headbox which dispenses a regulated suspension of fibers and fluid to a moving bed. The ratio of fiber to fluid is regulated by first (12) and second (44) dilution assemblies, each with its own air-bleed unit (16, 20). The second dilution station has a defined mixing point (44) located between a volume-regulated pump (42) delivering the mixture as a jet, and a second pump (56). The second pump draws the second-stage suspension at a rate which is dependent upon the operating speed of the first and second pumps, pref. at a rate of 1500 to 2000 litres/min. the mixer station is located immediately prior to the headbox pump (56).

Description

Die Erfindung betrifft ein Stoffzuführsystem zur Zuführung einer Faserstoffsuspension zu mindestens einem ein- oder mehrschichtigen Stoffauflauf, mit oder ohne weitere Verdünnungseinrichtung, einer Papier- oder Kartonmaschine mit mindestens einer ersten Verdünnungseinrichtung, insbesondere Vorverdünnungseinrichtung, und mindestens einer zweiten Verdünnungseinrichtung, insbesondere Nachverdünnungseinrichtung, zur Verdünnung der Faserstoffsuspension mit einer Verdünnungsflüssigkeit, insbesondere Wasser, und mindestens einer Einrichtung zur, insbesondere weitgehend vollständigen, Entlüftung der Faserstoffsuspension und der Verdünnungsflüssigkeit.The invention relates to a pulp feed system for supplying a pulp suspension to at least one monolayer or multilayer headbox, with or without further dilution device, a paper or board machine with at least a first dilution device, in particular pre-dilution device, and at least one second dilution device, in particular re-dilution device, for diluting the Pulp suspension with a dilution liquid, in particular water, and at least one device for, in particular substantially complete, venting of the pulp suspension and the dilution liquid.

Des Weiteren betrifft die Erfindung ein Verfahren zum Zuführen einer Faserstoffsuspension zu mindestens einem ein- oder mehrschichtigen Stoffauflauf, mit oder ohne weitere Verdünnungseinrichtung, einer Papieroder Kartonmaschine, bei welchem die Faserstoffsuspension mindestens einer ersten Verdünnung, insbesondere Vorverdünnung, und mindestens einer zweiten Verdünnung, insbesondere Nachverdünnung, mit einer Verdünnungsflüssigkeit, insbesondere Wasser, unterzogen wird und bei welchem die Faserstoffsuspension und die Verdünnungsflüssigkeit, insbesondere weitgehend vollständig, entlüftet werden.Furthermore, the invention relates to a method for feeding a pulp suspension to at least one single- or multi-layer headbox, with or without further dilution device, a paper or board machine, wherein the pulp suspension at least a first dilution, in particular predilution, and at least a second dilution, in particular post-dilution , is subjected to a dilution liquid, in particular water, and in which the pulp suspension and the dilution liquid, in particular substantially completely, are vented.

Derartige Stoffzuführsysteme und Verfahren zum Betreiben derselben sind grundsätzlich bekannt (siehe z.B. DE 100 50 109 A1). Das Prinzip der Vor- und Nachverdünnung wird in Verbindung mit Reinigungsanlagen (Cleanern) und vorzugsweise bei großen Stoffauflaufmengenvariationen und relativ niedrigen Stoffauflaufdichten angewendet. Dabei ist ein großer Unterschied zwischen der Stoffdichte in der Reinigungsanlage und im Stoffauflauf wünschenswert, weil dies ein großes Regelpotenzial bei dem Betrieb des Stoffzuführsystems bietet. Das gilt umso mehr bei Stoffaufläufen mit weiterer Verdünnungseinrichtung.Such material supply systems and methods for operating the same are basically known (see, for example, DE 100 50 109 A1). The principle of pre- and post-dilution is used in conjunction with cleaners and preferably for large headbox volumes and relatively low headbox densities. In this case, a large difference between the consistency in the cleaning system and in the headbox is desirable, because this offers a large control potential in the operation of the pulp feed system. This applies even more to headboxes with further dilution device.

Durch die Vorverdünnung lässt sich die Zulaufstoffdichte in einer ersten Cleanerstufe beispielsweise auf ungefähr 0,9 % bis 0,95 % einstellen, bei der erfahrungsgemäß ein effektiver Betrieb der Reinigungseinrichtung möglich ist und ein gutes Reinigungsergebnis erzielt wird. Durch die anschließende Nachverdünnung kann die Stoffdichte dann auf die gewünschte Stoffauflaufdichte von beispielsweise ungefähr 0,65 % oder, im Falle einer weiteren Verdünnung im Stoffauflauf selbst von ca. 1 %, auf beispielsweise ungefähr 0,75 % eingestellt werden.Due to the predilution, the feed density in a first cleaner stage can be set, for example, to approximately 0.9% to 0.95%, at which, according to experience, an effective operation of the cleaning device is possible and a good cleaning result is achieved. By subsequent redilution, the consistency can then be adjusted to the desired headbox density of, for example, about 0.65% or, in the case of further dilution in the headbox itself, from about 1% to, for example, about 0.75%.

Durch die voneinander getrennte Vor- und Nachverdünnung kann also einerseits die Menge und Stoffdichte der Faserstoffsuspension im Nachverdünnungskreislauf flexibel eingestellt und andererseits die Cleaneranlage mit einer optimalen Stoffkonsistenz betrieben werden.Due to the separate pre- and post-dilution, on the one hand, the amount and consistency of the pulp suspension can be flexibly adjusted in the post-dilution cycle and, on the other hand, the cleaner system can be operated with optimum consistency.

Bei bekannten Systemen mit Nachverdünnung und Entlüftung der Faserstoffsuspension erfolgt die Zugabe der Nachverdünnungsflüssigkeit, insbesondere des Nachverdünnungswassers, in den Entlüftungsbehälter für die Faserstoffsuspension. Problematisch ist hierbei die Einstellung beziehungsweise Regelung der unterschiedlichen Teilströme, das heißt der eingeleiteten Faserstoffsuspension und der eingeleiteten Nachverdünnungsflüssigkeit, für eine homogene Vermischung der beiden Teilströme. Die Nachverdünnung der Faserstoffsuspension erfolgt in diesen Systemen folglich undefiniert, was zu stochastischen Störungen im Strom führen kann, woraus unter anderem auch unzulässige Staudruckschwankungen resultieren können.In known systems with redilution and venting of the pulp suspension, the addition of the post-dilution liquid, in particular the Nachverdünnungswassers, carried in the vent container for the pulp suspension. The problem here is the setting or control of the different partial streams, that is the initiated pulp suspension and the introduced Nachverdünnungsflüssigkeit for a homogeneous mixing of the two partial streams. The redilution of the pulp suspension is therefore undefined in these systems, which can lead to stochastic disturbances in the stream, which among other things may result in impermissible dynamic pressure fluctuations.

Der Erfindung liegt die Aufgabe zugrunde, ein Stoffzuführsystem und ein Verfahren der eingangs genannten Art mit Vor- und Nachverdünnung der Stoffsuspension und mit insbesondere vollständiger Entlüftung des Stoffstroms zum Stoffauflauf zu schaffen, die einen stabilen Betrieb auch bei größeren Stoffauflaufmengen- und Stoffdichtevariationen sicherstellen und flexibel einsetzbar sind.The invention has for its object to provide a Stoffzuführsystem and a method of the type mentioned with pre and thinning of the stock suspension and in particular complete ventilation of the flow to the headbox, which ensure stable operation even with larger headbox and Stoffdichtvariationen and flexible use are.

Zur Lösung der Aufgabe sind ein Stoffzuführsystem und ein Verfahren mit den Merkmalen der unabhängigen Ansprüche vorgesehen.To achieve the object, a Stoffzuführsystem and a method with the features of the independent claims are provided.

Das erfindungsgemäße Stoffzuführungssystem zeichnet sich insbesondere dadurch aus, dass für die Entlüftung der bereits einmal verdünnten Faserstoffsuspension einerseits und der Verdünnungsflüssigkeit für die zweite Verdünnung andererseits separate Entlüftungseinrichtungen vorgesehen sind.The material supply system according to the invention is characterized in particular by the fact that separate venting devices are provided for the venting of the already once diluted pulp suspension on the one hand and the diluting liquid for the second dilution on the other hand.

Erfindungsgemäß werden die bereits vorverdünnte Faserstoffsuspension und die Verdünnungsflüssigkeit für die Nachverdünnung also getrennt voneinander entlüftet. Auf diese Weise wird die Verwendung unterschiedlicher Verdünnungsflüssigkeiten, insbesondere unterschiedlicher entlüfteter Wasserqualitäten für die erste Verdünnung, beispielsweise Vorverdünnung, die zweite Verdünnung im Hauptstrang, beispielsweise Nachverdünnung, und gegebenenfalls eine weitere Verdünnung im Stoffauflauf ermöglicht.According to the already prediluted pulp suspension and the dilution liquid for the subsequent dilution are therefore vented separately from each other. In this way, the use of different dilution liquids, in particular different deaerated water qualities for the first dilution, for example, predilution, the second dilution in the main strand, for example, after dilution, and optionally further dilution in the headbox allows.

Dadurch kommt dem erfindungsgemäßen Stoffzuführungssystem insgesamt ein hohes Maß an Flexibilität zu. Es ist sowohl vor einschichtigen als auch vor mehrschichtigen Stoffaufläufen mit oder ohne Verdünnungswassertechnik sowie in getrennten oder verbundenen Stoffzuführsystemen für mehrere Stoffaufläufe bei der Produktion von mehrlagigen Papieren oder Kartonen anwendbar.As a result, the material supply system according to the invention as a whole has a high degree of flexibility. It can be used both before single-layer and multi-layer headboxes with or without dilution water technology, as well as in separate or connected pulp feed systems for multiple headboxes in the production of multi-ply papers or cartons.

Vorteilhafte Ausführungsformen der Erfindung sind den Unteransprüchen, der Beschreibung und den Zeichnungen zu entnehmen.Advantageous embodiments of the invention are described in the subclaims, the description and the drawings.

Gemäß einer vorteilhaften Ausführungsform der Erfindung ist für die zweite Verdünnung mit entlüfteter Verdünnungsflüssigkeit eine definierte Mischstelle vorgesehen. Die Nachverdünnung der Faserstoffsuspension erfolgt erfindungsgemäß also nicht durch die Zugabe der Verdünnungsflüssigkeit in einen Entlüftungsbehälter für die Faserstoffsuspension, sondern sie findet in einer eigens dafür eingerichteten, definierten Mischstelle statt. Aufgrund der definierten Vermischung von entlüfteter Stoffsuspension und separat entlüfteter Verdünnungsflüssigkeit ist ein stabiler Betrieb des Stoffzuführsystems auch bei größeren Stoffauflaufmengenund Stoffdichtevariationen gewährleistet. Dabei kann durch eine definierte Einleitung von Faserstoffsuspension und Verdünnungsflüssigkeit in die Mischstelle ein gewünschtes Mischungsverhältnis beziehungsweise eine gewünschte Nachverdünnung der Faserstoffsuspension leicht ein- und sichergestellt werden. Darüber hinaus ist durch die definierte Mischstelle eine homogene Vermischung von Faserstoffsuspension und Verdünnungsflüssigkeit gewährleistet.According to an advantageous embodiment of the invention, a defined mixing point is provided for the second dilution with vented dilution liquid. The redilution of the pulp suspension is thus not carried out according to the invention by the addition of the dilution liquid in a deaeration tank for the pulp suspension, but it takes place in a specially designed, defined mixing point. Due to the defined mixing of deaerated pulp suspension and separately deaerated dilution liquid, a stable operation of the pulp feed system is ensured even with larger headbox volumes and consistency variations. In this case, by a defined introduction of fiber suspension and dilution liquid into the mixing point, a desired mixing ratio or a desired post-dilution of the pulp suspension can be easily checked and ensured. In addition, by the defined mixing point ensures a homogeneous mixing of pulp suspension and dilution liquid.

Bevorzugt ist es, wenn die Mischstelle zwischen einer ersten, vorzugsweise mengengeregelten Pumpe zum Eindüsen der entlüfteten Faserstoffsuspension in die Mischstelle und einer zweiten Pumpe, insbesondere Stoffauflaufpumpe, zum Abziehen der verdünnten, insbesondere nachverdünnten Faserstoffsuspension aus der Mischstelle derart angeordnet ist, dass sich in Abhängigkeit von der Förderleistung der ersten und der zweiten Pumpe automatisch die in die Mischstelle einströmende Menge der Verdünnungsflüssigkeit für die zweite Verdünnung einstellt. Die Verdünnung der Faserstoffsuspension erfolgt somit selbstreguliert, das heißt es ist keine zusätzliche Steuerungsvorrichtung für die einströmende Verdünnungsflüssigkeit erforderlich. Die Menge der einströmenden Verdünnungsflüssigkeit richtet sich allein nach der Menge der der Mischstelle zugeführten und aus der Mischstelle abgezogenen Faserstoffsuspension. Die Anzahl zu kontrollierender Prozessparameter wird erfindungsgemäß also um einen Parameter reduziert, wodurch der Überwachungsaufwand verringert ist.It is preferred if the mixing point between a first, preferably quantity-controlled pump for injecting the deaerated pulp suspension into the mixing point and a second pump, in particular headbox pump, for withdrawing the diluted, in particular nachverdünnten pulp suspension from the mixing point is arranged such that depending on the delivery rate of the first and second pumps automatically adjusts the amount of dilution liquid for the second dilution flowing into the mixing point. The dilution of the pulp suspension is thus self-regulated, that is, no additional control device for the inflowing dilution liquid is required. The amount of the inflowing dilution liquid depends solely on the amount of the pulp suspension supplied to the mixing point and withdrawn from the mixing point. The number of process parameters to be controlled is thus reduced by one parameter according to the invention, as a result of which the monitoring effort is reduced.

Zur Entlüftung der Faserstoffsuspension und der Verdünnungsflüssigkeit für die zweite Verdünnung können getrennte Behälter vorgesehen sein.For venting the pulp suspension and the dilution liquid for the second dilution separate containers may be provided.

Vorzugsweise ist zur Entlüftung der Faserstoffsuspension und der Verdünnungsflüssigkeit für die zweite Verdünnung aber ein gemeinsamer Behälter vorgesehen, der entsprechend getrennte Fächer und separate Überläufe aufweist. Durch diese Zusammenlegung der Entlüftungsbehälter lassen sich der Platzbedarf für das erfindungsgemäße Stoffzuführsystem und somit auch die Investitions- und Betriebskosten verringern.Preferably, however, a common container is provided for venting the pulp suspension and the dilution liquid for the second dilution, which has correspondingly separate compartments and separate overflows. By this combination of the venting container, the space required for the substance delivery system according to the invention and thus also the investment and operating costs can be reduced.

Besonders vorteilhaft ist es, wenn für die Entlüftung der Faserstoffsuspension und der Verdünnungsflüssigkeit für die zweite Verdünnung eine gemeinsame Vakuumanlage vorgesehen ist. Durch diese gemeinsame Nutzung einer einzigen Vakuumanlage für alle Entlüftungsvorgänge lassen sich der Platzbedarf und die Investitions- sowie Betriebskosten des erfindungsgemäßen Stoffzuführsystems noch weiter reduzieren.It is particularly advantageous if a common vacuum system is provided for the venting of the pulp suspension and the dilution liquid for the second dilution. By sharing a single vacuum system for all venting operations, the space required and the investment and operating costs of Stoffzuführsystems invention can be further reduced.

Gemäß einer weiteren bevorzugten Ausführungsform der Erfindung ist bei einem Stoffauflauf mit weiterer Verdünnungseinrichtung eine Versorgungsleitung zwischen der Entlüftungseinrichtung der Verdünnungsflüssigkeit für die zweite Verdünnung und der Verdünnungseinrichtung des Stoffauflaufs vorgesehen, über welche die Verdünnungseinrichtung des Stoffauflaufs mit entlüfteter Verdünnungsflüssigkeit versorgbar ist. In diesem Fall kann die Verdünnungsflüssigkeit für die zweite Verdünnung gleichzeitig für eine weitere Verdünnung der Faserstoffsuspension im Stoffauflauf, das heißt für eine dritte Verdünnung, genutzt werden. Es ist also nicht erforderlich, für die Verdünnung im Stoffauflauf eine zusätzliche Verdünnungsflüssigkeit aufzubereiten und bereitzustellen, sondern die entlüftete Verdünnungsflüssigkeit für die zweite Verdünnung wird für beides genutzt. Dies vereinfacht den Aufbau des erfindungsgemäßen Stoffzuführsystems.According to a further preferred embodiment of the invention, a supply line between the venting device of the dilution liquid for the second dilution and the dilution device of the headbox is provided in a headbox with further dilution device, via which the dilution device of the headbox is supplied with vented dilution liquid. In this case, the dilution liquid for the second dilution can be used simultaneously for further dilution of the pulp suspension in the headbox, ie for a third dilution. It is therefore not necessary to prepare and provide an additional dilution liquid for the dilution in the headbox, but the deaerated dilution liquid for the second dilution is used for both. This simplifies the structure of the substance delivery system according to the invention.

Bei einem Stoffauflauf mit weiterer Verdünnungseinrichtung für die weitere Verdünnung der Faserstoffsuspension im Stoffauflauf kann aber auch eine von der Verdünnungsflüssigkeit für die erste und/oder zweite Verdünnung verschiedene, zusätzliche Verdünnungsflüssigkeit vorgesehen sein, beispielsweise Siebwasser anderer Qualität oder Klärwasser. Die Verwendung einer zusätzlichen Verdünnungsflüssigkeit für die Verdünnung im Stoffauflauf ermöglicht eine unabhängige und gezielte Anpassung der Verdünnung im Stoffauflauf an die jeweiligen Prozessbedingungen und

  • erfordernisse. Dadurch wird die Flexibilität des erfindungsgemäßen Stoffzuführsystems weiter erhöht.
In a headbox with further dilution device for the further dilution of the pulp suspension in the headbox but can also be provided by the dilution liquid for the first and / or second dilution, additional dilution liquid, for example white water of other quality or sewage water. The Use of an additional dilution liquid for the dilution in the headbox allows an independent and targeted adaptation of the dilution in the headbox to the respective process conditions and
  • requirements. Thereby, the flexibility of Stoffzuführsystems invention is further increased.

Vorzugsweise ist dabei eine weitere separate Entlüftungseinrichtung für die Verdünnungsflüssigkeit des Stoffauflaufs vorgesehen. Dadurch lässt sich die zusätzliche Verdünnungsflüssigkeit für die Verdünnung im Stoffauflauf unabhängig von der Faserstoffsuspension und von anderen Verdünnungsflüssigkeiten gezielt entlüften und aufbereiten, was die Flexibilität des Systems weiter erhöht. Außerdem ermöglicht dies den Einsatz unterschiedlicher, entlüfteter Wasserqualitäten, beispielsweise Siebwasser oder Klärwasser, zur ersten Verdünnung der Faserstoffsuspension, beispielsweise Vorverdünnung, zur zweiten Verdünnung der Faserstoffsuspension im Hauptstrang, beispielsweise Nachverdünnung, und als Verdünnungswasser zur weiteren Verdünnung der Faserstoffsuspension im Stoffauflauf.Preferably, a further separate venting device for the dilution liquid of the headbox is provided. As a result, the additional dilution liquid for the dilution in the headbox, independently of the pulp suspension and of other dilution liquids, can be purposefully deaerated and processed, which further increases the flexibility of the system. In addition, this allows the use of different, deaerated water qualities, such as white water or sewage water for the first dilution of the pulp suspension, for example predilution, for the second dilution of the pulp suspension in the main strand, for example, after-dilution, and as dilution water for further dilution of the pulp suspension in the headbox.

Besonders vorteilhaft ist es, wenn zur Entlüftung der Verdünnungsflüssigkeit des Stoffauflaufs ein mit der Entlüftungseinrichtung für die Faserstoffsuspension und/oder mit der Entlüftungseinrichtung für die Verdünnungsflüssigkeit für die zweite Verdünnung gemeinsamer Behälter vorgesehen ist, der entsprechend getrennte Fächer und separate Überläufe aufweist. Der Platzbedarf und auch die Investitions- und Betriebskosten des erfindungsgemäßen Stoffzuführsystems lassen sich auf diese Weise reduzieren.It is particularly advantageous if, for venting the dilution liquid of the headbox, a container common to the venting device for the pulp suspension and / or to the venting device for the dilution liquid for the second dilution is provided which has correspondingly separate compartments and separate overflows. The space requirement and also the investment and operating costs of Stoffzuführsystems invention can be reduced in this way.

Vorzugsweise ist für die Entlüftung der Verdünnungsflüssigkeit des Stoffauflaufs und der Faserstoffsuspension und/oder der Verdünnungsflüssigkeit für die zweite Verdünnung eine gemeinsame Vakuumanlage vorgesehen. Hierdurch lassen sich der Platzbedarf und die Investitions- und Betriebskosten des Systems noch weiter reduzieren.Preferably, a common vacuum system is provided for the venting of the dilution liquid of the headbox and the pulp suspension and / or the dilution liquid for the second dilution. As a result, the space requirements and the investment and operating costs of the system can be further reduced.

Vorteilhafterweise ist insbesondere zwischen der ersten Verdünnungseinrichtung und der Entlüftungseinrichtung für die Faserstoffsuspension mindestens eine Reinigungsvorrichtung vorgesehen. Die Reinigungsvorrichtung kann eine oder mehrere Reinigungsstufen aufweisen. Das System der Vor- und Nachverdünnung lässt sich dann besonders gut verwenden, wenn mit Reinigungsvorrichtungen gearbeitet wird, die eine erhöhte Stoffdichte vertragen, nämlich bis zu ungefähr 2 %. Je nach Schaltung kann das System mit Vor- und Nachverdünnung dann bei einer Stoffdichte im Stoffauflauf bis ungefähr 1,7 % betrieben werden. Durch die Möglichkeit des Betriebs bis zu vorstehender relativ hoher Stoffdichte kann die Vorund Nachverdünnung in weiten Bereichen bei der Herstellung der verschiedensten Papiere und Kartone angewendet werden. Dies gilt sowohl für Systeme mit als auch für Systeme ohne Entlüftung. Das erfindungsgemäße Stoffzuführsystem ist also besonders flexibel einsetzbar. Gleichzeitig kann eine erhebliche Reduzierung von Investitionskosten, Platzbedarf und Energie erzielt werden, das heißt die Wirtschaftlichkeit des Stoffzuführsystems erhöht werden.Advantageously, at least one cleaning device is provided in particular between the first dilution device and the venting device for the pulp suspension. The cleaning device may have one or more purification stages. The system of pre- and post-dilution can be used particularly well when working with cleaning devices that tolerate increased consistency, namely up to about 2%. Depending on the circuit, the system can be operated with pre-dilution and then with a consistency in the headbox to about 1.7%. Due to the possibility of operation up to the above relatively high consistency, the pre- and post-dilution can be widely used in the production of a variety of papers and cartons. This applies both to systems with and without systems. The material delivery system according to the invention is thus particularly flexible. At the same time a significant reduction of investment costs, space requirements and energy can be achieved, that is, the efficiency of the pulp feed system can be increased.

Nachfolgend wird die vorliegende Erfindung rein beispielhaft anhand vorteilhafter Ausführungsformen und unter Bezugnahme auf die beigefügten Zeichnungen beschrieben. Es zeigen:

Fig. 1
ein erfindungsgemäßes Stoffzuführsystem gemäß einer ersten vorteilhaften Ausführungsform mit separaten Entlüftungsbehältern für Faserstoffsuspension und Nachverdünnungsflüssigkeit;
Fig. 2
ein erfindungsgemäßes Stoffzuführsystem gemäß einer zweiten vorteilhaften Ausführungsform mit einem gemeinsamen Entlüftungsbehälter für die Faserstoffsuspension und die Nachverdünnungsflüssigkeit;
Fig. 3
ein erfindungsgemäßes Stoffzuführsystem gemäß einer dritten vorteilhaften Ausführungsform mit jeweils separaten Entlüftungsbehältern für die Faserstoffsuspension, die Nachverdünnungsflüssigkeit und eine zusätzliche Verdünnungsflüssigkeit für eine weitere Verdünnung im Stoffauflauf; und
Fig. 4
ein erfindungsgemäßes Stoffzuführsystem gemäß einer vierten vorteilhaften Ausführungsform mit einem gemeinsamen Entlüftungsbehälter für die Faserstoffsuspension, die Nachverdünnungsflüssigkeit und die zusätzliche Verdünnungsflüssigkeit für die weitere Verdünnung im Stoffauflauf.
Hereinafter, the present invention will be described purely by way of example with reference to advantageous embodiments and with reference to the accompanying drawings. Show it:
Fig. 1
an inventive Stoffzuführsystem according to a first advantageous embodiment with separate venting containers for pulp suspension and Nachverdünnungsflüssigkeit;
Fig. 2
an inventive Stoffzuführsystem according to a second advantageous embodiment with a common venting container for the pulp suspension and the Nachverdünnungsflüssigkeit;
Fig. 3
an inventive Stoffzuführsystem according to a third advantageous embodiment, each with separate venting containers for the pulp suspension, the Nachverdünnungsflüssigkeit and an additional dilution liquid for further dilution in the headbox; and
Fig. 4
an inventive Stoffzuführsystem according to a fourth advantageous embodiment with a common vent container for the pulp suspension, the Nachverdünnungsflüssigkeit and the additional dilution liquid for further dilution in the headbox.

Fig. 1 ist eine schematische Darstellung einer ersten Ausführungsform des erfindungsgemäßen Stoffzuführsystems. Mittels einer Zuführleitung 10 wird eine Faserstoffsuspension einer ersten Mischstelle 12 zugeführt.Fig. 1 is a schematic representation of a first embodiment of the Stoffzuführsystems invention. By means of a feed line 10, a pulp suspension is fed to a first mixing point 12.

Die erste Mischstelle 12 dient einer ersten Verdünnung der Faserstoffsuspension, einer so genannten Vorverdünnung.The first mixing point 12 serves for a first dilution of the pulp suspension, a so-called predilution.

Die Vorverdünnung der Faserstoffsuspension kann wahlweise durch eine Überlaufflüssigkeit, die über eine Leitung 14 aus einer Entlüftungseinrichtung 16 für die Faserstoffsuspension zugeführt wird, durch eine Überlaufflüssigkeit, die über eine Leitung 18 aus einer Entlüftungseinrichtung 20 für eine Nachverdünnungsflüssigkeit zugeführt wird, oder durch Siebwasser erfolgen. Zur Verdünnung der Faserstoffsuspension mit Siebwasser ist die erste Mischstelle 12 mit einem Siebwasserbehälter 22 verbunden, dem über eine Versorgungsleitung 24 Siebwasser zugeführt werden kann.The predilution of the pulp suspension can optionally be carried out by an overflow liquid, which is supplied via a line 14 from a deaerator 16 for the pulp suspension, by an overflow liquid which is supplied via a line 18 from a venting device 20 for a Nachverdünnungsflüssigkeit, or by white water. For dilution of the pulp suspension with white water, the first mixing point 12 is connected to a white water tank 22 to which white water can be supplied via a supply line 24.

Die in der ersten Mischstelle 12 mit einer oder mehreren der voranstehend genannten Verdünnungsflüssigkeiten vermischte und somit vorverdünnte Faserstoffsuspension wird durch eine Pumpe 26, die so genannte Cleanerpumpe, aus der ersten Mischstelle 12 abgezogen und über eine Leitung 28 einer mehrstufigen Reinigungsvorrichtung, dem so genannten Cleaner 30 zugeführt, in der die vorverdünnte Faserstoffsuspension gereinigt wird. Geeignete Cleaner sind hinreichend bekannt und werden deshalb hier nicht näher erläutert.The pulp suspension mixed in the first mixing point 12 with one or more of the aforementioned dilution liquids and thus prediluted is withdrawn from the first mixing point 12 by a pump 26, the so-called cleaner pump, and via a line 28 of a multi-stage cleaning device, the so-called cleaner 30 fed, in which the prediluted pulp suspension is purified. Suitable cleaners are well known and will therefore not be explained here.

Nach der Reinigung im Cleaner 30 wird die Faserstoffsuspension über eine Leitung 32 in den Entlüftungsbehälter 33 der Entlüftungseinrichtung 16 für die Faserstoffsuspension eingeleitet. Hierfür in Frage kommende Entlüftungs- beziehungsweise Entgasungsvorrichtungen sind hinlänglich bekannt und beispielsweise in der EP 1 091 040 A2 oder EP 0 501 144 A1 beschrieben. Die Entlüftung der Faserstoffsuspension erfolgt durch ein mittels einer Vakuumanlage 34 in dem Entlüftungsbehälter 33 erzeugtes Vakuum. Es handelt sich hierbei insbesondere um eine weitgehend vollständige Entlüftung.After cleaning in the cleaner 30, the pulp suspension is introduced via a line 32 into the venting container 33 of the ventilation device 16 for the pulp suspension. Appropriate venting or degassing devices for this purpose are well known and described for example in EP 1 091 040 A2 or EP 0 501 144 A1. The venting of the pulp suspension is effected by means of a vacuum system 34 in the venting container 33 generated Vacuum. This is in particular a largely complete venting.

Angesichts der Tatsache, dass es eine vollständige Entlüftung von Stoffsuspensionen nicht gibt, ist der Begriff der "weitgehend vollständigen Entlüftung", wie er in dieser Anmeldung verwendet wird, so zu verstehen, dass die Entlüftung der Stoffsuspension bevorzugt so weit geführt wird, dass lediglich ein minimaler Anteil von Restluft in der Suspension verbleibt, der für die Prozessführung akzeptabel ist. Da ein erhöhter Entlüftungsgrad mit einem erhöhten Kostenaufwand einhergeht, ist bei der Entlüftung der Stoffsuspension zwischen dem Grad der Entlüftung und der Wirtschaftlichkeit des Entlüftungsprozesses abzuwägen. Dies gilt analog für die weiter unten beschriebene Entlüftung der Verdünnungsflüssigkeit bzw. Verdünnungsflüssigkeiten.In view of the fact that there is no complete deaeration of stock suspensions, the term "substantially complete deaeration" as used in this application is to be understood as meaning that the deaeration of the stock suspension is preferably carried out so far that only one minimal amount of residual air remains in the suspension, which is acceptable for process control. Since an increased degree of deaeration is associated with an increased cost, when venting the stock suspension between the degree of ventilation and the efficiency of the deaeration process is to be weighed. This applies analogously to the deaeration of the dilution liquid or dilution liquids described below.

Der Entlüftungsbehälter 33 für die Faserstoffsuspension weist eine Überlaufanordnung 36 auf, die mit der Leitung 14 verbunden ist, über welche, wie oben beschrieben wurde, Überlaufflüssigkeit der ersten Mischstelle 12 zugeführt werden kann. Im Bereich des Bodens des Entlüftungsbehälters 33 ist ein Auslauf 38 vorgesehen, an den eine Hauptstrangleitung 40 zum Abziehen der entlüfteten Faserstoffsuspension aus dem Entlüftungsbehälter 33 angeschlossen ist.The pulp suspension deaerator 33 has an overflow arrangement 36 connected to the conduit 14, via which, as described above, overflow fluid may be supplied to the first mixing station 12. In the area of the bottom of the venting container 33, an outlet 38 is provided, to which a main branch line 40 for withdrawing the vented fibrous suspension from the venting container 33 is connected.

Durch eine in die Hauptstrangleitung 40 geschaltete zweite Pumpe 42 wird die durch die Hauptstrangleitung 40 strömende, vorverdünnte und entlüftete Faserstoffsuspension für eine zweite Verdünnung, eine so genannte Nachverdünnung, in eine zweite Mischstelle 44 eingedüst.By means of a second pump 42 connected in the main branch line 40, the prediluted and deaerated pulp suspension flowing through the main branch line 40 is injected into a second mixing point 44 for a second dilution, a so-called after-dilution.

Die Nachverdünnung der Faserstoffsuspension in der zweiten Mischstelle 44 erfolgt durch Vermischung mit einer entlüfteten zweiten Verdünnungsflüssigkeit, im dargestellten Fall mit entlüftetem Siebwasser.The redilution of the pulp suspension in the second mixing point 44 takes place by mixing with a deaerated second dilution liquid, in the case shown with deaerated white water.

Für die Entlüftung der zweiten Verdünnungsflüssigkeit, das heißt des Siebwassers, ist eine separate Entlüftungseinrichtung 20 mit einem separaten Entlüftungsbehälter 46 vorgesehen, das heißt die Entlüftung der Faserstoffsuspension und die Entlüftung der Nachverdünnungsflüssigkeit erfolgen voneinander getrennt. Das für die Nachverdünnung vorgesehene und zu entlüftende Siebwasser wird dem Entlüftungsbehälter 46 über eine Leitung 48 aus dem Siebwasserbehälter 22 zugeführt. Für die Entlüftung des Siebwassers kann eine ähnliche Entlüftungseinrichtung verwendet werden wie für die Entlüftung der Faserstoffsuspension. Wie oben bereits bemerkt wurde, sind derartige Entlüftungseinrichtungen bekannt. Sie werden deshalb hier nicht weiter erläutert.For the venting of the second dilution liquid, that is the white water, a separate venting device 20 is provided with a separate vent tank 46, that is, the venting of the pulp suspension and the venting of Nachverdünnungsflüssigkeit done separately. The white water intended for subsequent dilution and to be deaerated is fed to the deaeration vessel 46 via a line 48 from the white water tank 22. For the venting of the white water, a similar venting device can be used as for the venting of the pulp suspension. As noted above, such venting devices are known. They will therefore not be explained further here.

Wie die Entlüftung der Faserstoffsuspension erfolgt die Entlüftung der Nachverdünnungsflüssigkeit durch ein in dem Entlüftungsbehälter 46 erzeugtes Vakuum. Zur Vakuumerzeugung wird die gleiche Vakuumanlage 34 verwendet, die auch zur Entlüftung der Faserstoffsuspension vorgesehen ist.As the venting of the pulp suspension, the venting of Nachverdünnungsflüssigkeit by a vacuum generated in the vent tank 46. For vacuum generation, the same vacuum system 34 is used, which is also provided for venting the pulp suspension.

Der Entlüftungsbehälter 46 für das Siebwasser weist eine Überlaufanordnung 50 auf, die mit der Leitung 18 verbunden ist, über welche der ersten Mischstelle 12 zumindest wahlweise entlüftetes Siebwasser zur Vorverdünnung der Faserstoffsuspension zuführbar ist. Im Bodenbereich des Entlüftungsbehälters 46 ist außerdem ein erster Auslauf 52 vorgesehen, an den eine Versorgungsleitung 54 angeschlossen ist. Durch die Versorgungsleitung 54 kann entlüftetes Verdünnungswasser aus dem Entlüftungsbehälter 46 in die zweite Mischstelle 44 zur Nachverdünnung der Faserstoffsuspension einströmen.The deaeration tank 46 for the white water has an overflow arrangement 50, which is connected to the line 18, via which the first mixing point 12 at least optionally deaerated white water for predilution of the pulp suspension can be fed. In the bottom area of the venting container 46, a first outlet 52 is also provided, to which a supply line 54 is connected. Through the supply line 54 may vented dilution water from the vent tank 46 in the second mixing point 44 for redilution of the pulp suspension to flow.

Durch eine Stoffauflaufpumpe 56 wird die nunmehr nachverdünnte Faserstoffsuspension aus der zweiten Mischstelle 44 abgezogen und über eine Hauptstrangleitung 58 einem nicht gezeigten Stoffauflauf zugeführt.By a headbox 56, the now nachverdünnte pulp suspension is withdrawn from the second mixing point 44 and fed via a main line 58 to a headbox, not shown.

Die zweite Pumpe 42 und die Stoffauflaufpumpe 56 sind mengengeregelt, wobei die Förderleistung der Stoffauflaufpumpe 56 größer als diejenige der ersten Pumpe 42 ist und beispielsweise mindestens 1500 bis 2000 1/min beträgt. Die Zulaufmenge des entlüfteten Nachverdünnungswassers in die zweite Mischstelle 44 ist passiv geregelt, das heißt sie stellt sich je nach Steuerung der Förderleistungen der zweiten Pumpe 42 und der Stoffauflaufpumpe 56 automatisch ein. Auf diese Weise wird nicht nur die Faserstoffsuspension definiert in die Mischstelle 44 eingedüst, sondern auch die Verdünnungsflüssigkeit kontrolliert zugeleitet. In der Mischstelle 44 erfolgt somit eine definierte Vermischung von Faserstoffsuspension und Verdünnungswasser, das heißt eine definierte Nachverdünnung der Stoffsuspension.The second pump 42 and the headbox pump 56 are volume controlled, the flow rate of the headbox 56 is greater than that of the first pump 42 and, for example, at least 1500 to 2000 1 / min. The inflow amount of the vented Nachverdünnungswassers in the second mixing point 44 is passively controlled, that is, it is depending on the control of the flow rates of the second pump 42 and the headbox 56 automatically. In this way not only the pulp suspension is injected into the mixing point 44 in a defined manner, but also the dilution liquid is supplied in a controlled manner. In the mixing point 44 thus takes place a defined mixing of pulp suspension and dilution water, that is, a defined redilution of the stock suspension.

Im Bodenbereich des Entlüftungsbehälters 46 der Entlüftungseinrichtung 20 für die Verdünnungsflüssigkeit ist außerdem ein zweiter Auslauf 60 vorgesehen, durch den mittels einer Pumpe 62 über eine Versorgungsleitung 64 einer weiteren, hier nicht dargestellten Verdünnungseinrichtung entlüftetes Verdünnungswasser für eine weitere Verdünnung der Faserstoffsuspension im Stoffauflauf zugeführt werden kann.In the bottom area of the venting container 46 of the diluting liquid venting device 20, there is also provided a second outlet 60 through which dilution water deaerated by means of a pump 62 can be supplied via a supply line 64 to another diluting device, not shown here, for further dilution of the pulp suspension in the head box.

Das erfindungsgemäße Stoffzuführsystem wird wie nachfolgend beschrieben betrieben. Eine entsprechend aufbereitete Faserstoffsuspension wird in der Mischstelle 12 beispielsweise mit Siebwasser verdünnt, insbesondere vorverdünnt. Die verdünnte Faserstoffsuspension wird dann durch die Cleaneranlage 30 geleitet, in dieser gereinigt und schließlich in einer Entlüftungseinrichtung 16, insbesondere vollständig, entlüftet. Parallel dazu wird separat die Verdünnungsflüssigkeit für die zweite Verdünnung der Faserstoffsuspension, insbesondere vollständig, entlüftet. Die entlüftete Faserstoffsuspension und die entlüftete Verdünnungsflüssigkeit werden in der zweiten Mischstelle 44 definiert miteinander vermischt, was zu einer zweiten Verdünnung, insbesondere Nachverdünnung, der Faserstoffsuspension führt. Die nun nochmals verdünnte, insbesondere nachverdünnte, Faserstoffsuspension wird dann mittels der Stoffauflaufpumpe 56 dem Stoffauflauf zugeführt, wo sie gegebenenfalls ein weiteres Mal verdünnt wird.The material feed system according to the invention is operated as described below. A suitably prepared pulp suspension is diluted in the mixing point 12, for example with white water, in particular prediluted. The diluted pulp suspension is then passed through the cleaner system 30, cleaned in this and finally in a vent 16, in particular completely, vented. In parallel, the dilution liquid for the second dilution of the pulp suspension, in particular completely, is deaerated separately. The deaerated pulp suspension and the deaerated dilution liquid are defined in the second mixing point 44 mixed with each other, resulting in a second dilution, especially post-dilution, the pulp suspension. The now diluted again, in particular nachverdünnte, pulp suspension is then fed by means of the headbox 56 the headbox, where it is optionally diluted once more.

Die nachfolgend beschriebenen weiteren Ausführungsformen des erfindungsgemäßen Stoffzuführsystems ähneln weitgehend der voranstehend erläuterten ersten Ausführungsform. Zur Kennzeichnung gleicher Merkmale werden deshalb gleiche Bezugszeichen verwendet. Bei den weiteren Ausführungsformen werden außerdem nur noch die Unterschiede zu den vorherigen Ausführungsformen hervorgehoben.The further embodiments of the material feed system according to the invention described below are similar in many respects to the first embodiment explained above. To identify the same features, therefore, the same reference numerals are used. In the other embodiments, only the differences from the previous embodiments are highlighted.

Die in Fig. 2 gezeigte zweite Ausführungsform des erfindungsgemäßen Stoffzuführsystems unterscheidet sich von der in Fig. 1 gezeigten ersten Ausführungsform lediglich darin, dass die Entlüftungseinrichtung 16 für die Faserstoffsuspension und die Entlüftungseinrichtung 20 für die Nachverdünnungsflüssigkeit einen gemeinsamen Entlüftungsbehälter 66 aufweisen, der durch eine Trennwand 68 in ein erstes Entlüftungsfach 70 für die Faserstoffsuspension und in ein zweites Entlüftungsfach 72 für das Verdünnungswasser aufgeteilt ist.The second embodiment of the material feed system according to the invention shown in FIG. 2 differs from the first embodiment shown in FIG. 1 only in that the pulp suspension deaerator 16 and the after-dilution liquid deaerator 20 have a common deaerator tank 66, which is divided by a dividing wall 68 into a first pulp suspension ventilating compartment 70 and a second diluting water ventilating compartment 72.

Jedes Fach 70, 72 weist jeweils eine Überlaufanordnung 36 beziehungsweise 50 auf. Im Bodenbereich des ersten Fachs 70 ist ein Auslauf 38 zum Abziehen der entlüfteten Faserstoffsuspension vorgesehen, während im Bodenbereich des zweiten Fachs 72 zwei Ausläufe 52, 60 zum Abziehen des entlüfteten Verdünnungswassers vorgesehen sind. Das Vakuum im Entlüftungsbehälter 66 wird durch die Vakuumanlage 34 erzeugt, wobei zur Verbindung des Behälters 66 mit der Vakuumanlage 34 eine einzige Vakuumleitung 74 ausreicht.Each compartment 70, 72 has an overflow arrangement 36 and 50, respectively. In the bottom area of the first compartment 70, a spout 38 is provided for withdrawing the deaerated pulp suspension, while in the bottom area of the second compartment 72 two outlets 52, 60 are provided for withdrawing the deaerated dilution water. The vacuum in the venting container 66 is generated by the vacuum system 34, wherein a single vacuum line 74 is sufficient to connect the container 66 to the vacuum system 34.

Die in Fig. 3 gezeigte dritte Ausführungsform des erfindungsgemäßen Stoffzuführsystems unterscheidet sich von der in Fig. 1 gezeigten ersten Ausführungsform dadurch, dass der Entlüftungsbehälter 46 der Entlüftungseinrichtung 20 für die Nachverdünnungsflüssigkeit in seinem Bodenbereich lediglich einen Auslass 52 aufweist. An diesen Auslass 52 ist die Versorgungsleitung 54 angeschlossen, um die zweite Mischstelle 44 zur Nachverdünnung der Faserstoffsuspension mit entlüfteter Nachverdünnungsflüssigkeit zu versorgen. Die zu entlüftende Verdünnungsflüssigkeit wird der Entlüftungseinrichtung 20 über eine Leitung 76 zugeführt. Vorzugsweise ist die Verdünnungsflüssigkeit auch bei dieser Ausführungsform Siebwasser, so dass die Leitung 76 den Entlüftungsbehälter 46 beispielsweise mit dem Siebwasserbehälter 22 verbinden kann. Es ist aber auch denkbar, eine andere Flüssigkeit als Nachverdünnungsflüssigkeit zu verwenden, wie beispielsweise Klärwasser oder Frischwasser.The third embodiment of the substance delivery system according to the invention shown in FIG. 3 differs from the first embodiment shown in FIG. 1 in that the venting container 46 of the afterdilution liquid venting device 20 only has an outlet 52 in its bottom region. At this outlet 52, the supply line 54 is connected to supply the second mixing point 44 for subsequent dilution of the pulp suspension with deaerated Nachverdünnungsflüssigkeit. The dilution liquid to be deaerated is supplied to the venting device 20 via a line 76. Preferably, the dilution liquid in this embodiment is white water, so that the line 76 can connect the vent tank 46, for example, with the white water tank 22. But it is also conceivable to use another liquid as Nachverdünnungsflüssigkeit, such as sewage or fresh water.

Bei der dritten Ausführungsform ist zusätzlich eine dritte separate Entlüftungseinrichtung 78 vorgesehen, die einen von den Entlüftungsbehältern 33, 46 der Faserstoffsuspension und Nachverdünnungsflüssigkeit getrennten Entlüftungsbehälter 80 aufweist. Diese dritte Entlüftungseinrichtung 78 dient zur Entlüftung einer zusätzlichen Verdünnungsflüssigkeit, die für eine weitere Verdünnung der Faserstoffsuspension im nicht gezeigten Stoffauflauf vorgesehen ist. Auch diese Entlüftungseinrichtung 78 kann von einer bekannten Art sein.In the third embodiment, a third separate venting device 78 is additionally provided which has a venting container 80 separate from the venting containers 33, 46 of the fibrous suspension and after-dilution liquid. This third venting device 78 serves to vent an additional dilution liquid, which is provided for a further dilution of the pulp suspension in the headbox, not shown. This venting device 78 may be of a known type.

Die zusätzliche Verdünnungsflüssigkeit wird dem Entlüftungsbehälter 80 über eine Leitung 82 zugeführt. Bei der Verdünnungsflüssigkeit kann es sich um Siebwasser, Klärwasser oder Wasser einer anderen Qualität handeln, wobei die Leitung 82 mit einem geeigneten, nicht gezeigten Wasserreservoir verbunden ist, im Falle von Siebwasser beispielsweise mit dem Siebwasserbehälter 22. Die Entlüftung der zusätzlichen Verdünnungsflüssigkeit im Entlüftungsbehälter 80 erfolgt wie auch die Entlüftung der Faserstoffsuspension und die Entlüftung der Nachverdünnungsflüssigkeit durch die Erzeugung eines Vakuums im Entlüftungsbehälter 80. Für die Vakuumerzeugung wird die gleiche Vakuumanlage 34 verwendet, die auch zur Entlüftung der Faserstoffsuspension und der Nachverdünnungsflüssigkeit dient.The additional dilution liquid is supplied to the deaeration tank 80 via a line 82. The dilution liquid can be white water, sewage water or water of a different quality, the line 82 being connected to a suitable water reservoir, not shown, in the case of white water, for example with the white water container 22. The additional dilution liquid is vented in the deaeration container 80 as well as the venting of the pulp suspension and the venting of Nachverdünnungsflüssigkeit by the generation of a vacuum in the vent tank 80. For the vacuum generation, the same vacuum system 34 is used, which also serves to vent the pulp suspension and the Nachverdünnungsflüssigkeit.

Der Entlüftungsbehälter 80 weist eine Überlaufanordnung 84 auf, durch die der Überlauf der zumindest teilweise entlüfteten Verdünnungsflüssigkeit aus dem Behälter 80 abziehbar und über eine Überlaufleitung 86 einem nicht gezeigten Verdünnungsflüssigkeitsreservoir oder beispielsweise der ersten Mischstelle 12 zur Vorverdünnung der Faserstoffsuspension zuführbar ist.The venting container 80 has an overflow arrangement 84, by means of which the overflow of the at least partially vented dilution liquid can be withdrawn from the container 80 and fed via an overflow line 86 to a dilution liquid reservoir (not shown) or, for example, to the first mixing point 12 for predilution of the fibrous stock suspension.

Im Bodenbereich des Entlüftungsbehälters 80 ist außerdem ein Auslauf 88 vorgesehen, an den eine Versorgungsleitung 90 angeschlossen ist. Mittels einer Pumpe 92 ist über den Auslauf 88 und die Versorgungsleitung 90 insbesondere vollständig entlüftete Verdünnungsflüssigkeit aus dem Entlüftungsbehälter 80 abziehbar und beispielsweise einer dritten Verdünnungseinrichtung zur weiteren Verdünnung der bereits nachverdünnten Faserstoffsuspension im Stoffauflauf zuführbar.In the bottom area of the venting container 80, an outlet 88 is also provided, to which a supply line 90 is connected. By means of a pump 92 is above the outlet 88 and the supply line 90 in particular completely deaerated dilution liquid from the vent tank 80 removable and, for example, a third dilution device for further dilution of the already nachverdünnten pulp suspension fed in the headbox.

Die in Fig. 4 gezeigte vierte Ausführungsform des erfindungsgemäßen Stoffzuführsystems unterscheidet sich von der in Fig. 3 gezeigten dritten Ausführungsform dadurch, dass die Entlüftungseinrichtung 16 für die Faserstoffsuspension, die Entlüftungseinrichtung 20 für die Nachverdünnungsflüssigkeit und die Entlüftungseinrichtung 78 für die zusätzliche Verdünnungsflüssigkeit einen gemeinsamen Entlüftungsbehälter 94 aufweisen, der durch zwei Trennwände 68, 96 in ein erstes Fach 70 für die Faserstoffsuspension, ein zweites Fach 72 für die Nachverdünnungsflüssigkeit und ein drittes Fach 98 für die zusätzliche Verdünnungsflüssigkeit aufgeteilt ist. Jedes der drei Fächer 70, 72, 98 weist die jeweils voranstehend bereits beschriebenen Zuleitungen 32, 48, 82, Überlaufanordnungen 36, 50, 84 und Auslässe 38, 52, 88 auf. Der gemeinsame Entlüftungsbehälter 94 aller drei Entlüftungseinrichtungen 16, 22, 78 ist zur Erzeugung des für die Entlüftung erforderlichen Vakuums über eine Vakuumleitung 100 mit der gemeinsamen Vakuumanlage 34 verbunden.The fourth embodiment of the material feed system according to the invention shown in FIG. 4 differs from the third embodiment shown in FIG. 3 in that the pulp suspension deaerator 16, the post-dilution liquid deaerator 20 and the additional dilution liquid deaerator 78 share a common deaerator tank 94 which is divided by two partitions 68, 96 into a first pulp suspension compartment 70, a second compartment 72 for the post-dilution fluid, and a third compartment 98 for the additional dilution fluid. Each of the three compartments 70, 72, 98 has the feed lines 32, 48, 82 already described above, overflow arrangements 36, 50, 84 and outlets 38, 52, 88. The common venting container 94 of all three venting devices 16, 22, 78 is connected via a vacuum line 100 with the common vacuum system 34 to generate the vacuum required for the venting.

BezugszeichenlisteLIST OF REFERENCE NUMBERS

1010
Zuführleitungfeed
1212
erste Mischstellefirst mixing point
1414
Leitungmanagement
1616
Entlüftungseinrichtungvent
1818
Leitungmanagement
2020
Entlüftungseinrichtungvent
2222
Siebwasserbehälterwhite water tank
2424
Versorgungsleitungsupply line
2626
erste Pumpefirst pump
2828
Leitungmanagement
3030
Reinigungsvorrichtungcleaning device
3232
Leitungmanagement
3333
Entlüftungsbehälterbleed tank
3434
Vakuumanlagevacuum system
3636
ÜberlaufanordnungOverflow arrangement
3838
Auslaufoutlet
4040
HauptstrangleitungMain train line
4242
zweite Pumpesecond pump
4444
zweite Mischstellesecond mixing point
4646
Entlüftungsbehälterbleed tank
4848
Leitungmanagement
5050
ÜberlaufanordnungOverflow arrangement
5252
erster Auslauffirst outlet
5454
Versorgungsleitungsupply line
5656
StoffauflaufpumpeHeadbox pump
5858
HauptstrangleitungMain train line
6060
zweiter Auslaufsecond outlet
6262
Pumpepump
6464
Versorgungsleitungsupply line
6666
Entlüftungsbehälterbleed tank
6868
Trennwandpartition wall
7070
erstes Fachfirst subject
7272
zweites Fachsecond compartment
7474
Vakuumleitungvacuum line
7676
Leitungmanagement
7878
Entlüftungseinrichtungvent
8080
Entlüftungsbehälterbleed tank
8282
Leitungmanagement
8484
ÜberlaufanordnungOverflow arrangement
8686
ÜberlaufleitungOverflow pipe
8888
Auslaufoutlet
9090
Versorgungsleitungsupply line
9292
Pumpepump
9494
Entlüftungsbehälterbleed tank
9696
Trennwandpartition wall
9898
drittes Fachthird compartment
100100
Vakuumleitungvacuum line

Claims (14)

  1. A stock supply system for the supply of a pulp suspension to at least one single-layer or multilayer head box, with or without a further dilution device, of a paper or cardboard machine having at least one first dilution device (12), in particular a pre-dilution device, and having at least one second dilution device (44), in particular a post-dilution device, for the dilution of the pulp suspension with a dilution liquid, in particular water, and having at least one device (16, 20, 78) for the de-aeration, in particular the largely complete de-aeration, of the pulp suspension and of the dilution liquid,
    characterised in that
    separate de-aeration devices (16, 20) are provided for the de-aeration of the pulp suspension already diluted once, on the one hand, and of the dilution liquid for the second dilution, on the other hand.
  2. A stock supply system in accordance with claim 1, characterised in that a defined mixing position (44) is provided for the second dilution with de-aerated dilution liquid, with the mixing position (44) in particular being arranged between a first pump (42), preferably a flow rate controlled pump, for the introduction of the de-aerated pulp suspension into the mixing position (44) as a jet and a second pump (56), in particular a head box pump, for the removal of the diluted pulp suspension, in particular post-diluted pulp suspension, from the mixing position (44) such that the quantity of the dilution liquid for the second dilution flowing into the mixing position (44) is adopted automatically in dependence on the conveying rate of the first and second pumps (42, 56), with the output of the second pump (56) furthermore preferably being larger than the output of the first pump (42) and in particular amounting to 1,500 to 2,000 litres per minute.
  3. A stock supply system in accordance with claim 2, characterised in that the mixing position (44) is arranged directly in front of the head box pump (56) viewed in the flow direction of the pulp suspension.
  4. A stock supply system in accordance with any one of the preceding claims, characterised in that separate containers (33, 46) are provided for the de-aeration of the pulp suspension and of the dilution liquid for the second dilution; or in that a common container (66), which has correspondingly separate compartments (70, 72) and separate overflows (36, 50), is provided for the de-aeration of the pulp suspension and of the dilution liquid for the second dilution.
  5. A stock supply system in accordance with any one of the preceding claims, characterised in that a common vacuum plant (34) is provided for the de-aeration of the pulp suspension and of the dilution liquid for the second dilution; and/or in that the dilution liquid for the second dilution is white water.
  6. A stock supply system in accordance with any one of the preceding claims, characterised in that, in a head box comprising a further dilution device, a supply line (64) is provided between the de-aeration device (20) for the dilution liquid for the second dilution and the dilution device of the head box and the dilution device of the head box can be supplied via this with de-aerated dilution liquid; or in that, in a head box comprising a further dilution device for the further dilution of the pulp suspension in the head box, an additional dilution liquid different from the dilution liquid for the first and/or second dilution, for example white water of a different quality or clarified water, is provided, with a further separate de-aeration device (78) preferably being provided for the dilution liquid of the head box.
  7. A stock supply system in accordance with claim 6, characterised in that a separate container (80) is provided for the de-aeration of the dilution liquid of the box head; or in that a container (94) which is common to the de-aeration device for the pulp suspension and/or to the de-aeration device for the dilution liquid for the second dilution and which has correspondingly separate compartments (70, 72, 98) and separate overflows (36, 50, 84) is provided for the de-aeration of the dilution liquid of the box head, with a vacuum plant (34), preferably a common vacuum plant, optionally being provided for the de-aeration of the dilution liquid of the box head and of the pulp suspension and/or of the dilution liquid for the second dilution.
  8. A stock supply system in accordance with any one of the preceding claims, characterised in that at least one cleaning device (30) is provided in particular between the first dilution device (12) and the de-aeration device (16) for the pulp suspension.
  9. A method for the supply of a pulp suspension to at least one single-layer or multilayer box head ,with or without a further dilution device, of a paper or cardboard machine, wherein the pulp suspension is subjected to at least one first dilution, in particular a pre-dilution, and at least one second dilution, in particular a post-dilution, with a dilution liquid, in particular water; and wherein the pulp suspension and the dilution liquid are de-aerated, in particular largely completely de-aerated.
    characterised in that
    the pulp suspension already diluted once, on the one hand, and the dilution liquid for the second dilution, on the other hand, are de-aerated separately.
  10. A method in accordance with claim 9, characterised in that the pulp suspension already diluted once and de-aerated is mixed in a mixing position (44) in a defined manner with the de-aerated dilution liquid for the second dilution, with the pulp suspension preferably being introduced into the mixing position (44) as a jet, in particular with flow rate control, and being removed from the mixing position (44), likewise in particular with flow rate control, so that the quantity of the dilution liquid flowing into the mixing position is adopted automatically in dependence on the quantity introduced as a jet and the quantity removed.
  11. A method in accordance with claim 9 or claim 10, characterised in that the pulp suspension and the dilution liquid for the second dilution are de-aerated in separate containers (33, 46); or in that the pulp suspension and the dilution liquid for the second dilution are de-aerated in a common container (66) having correspondingly separate compartments (70, 72) and separate overflows (36, 50), with the pulp suspension preferably being further diluted in the box head by mixing with the same dilution liquid as for the second dilution.
  12. A method in accordance with any one of the claims 9 to 11, characterised in that the pulp suspension is further diluted in the box head by an additional dilution liquid different from the dilution liquid for the first and/or second dilution, for example white water of a different quality or clarified water, with the dilution liquid for the box head preferably being de-aerated separately.
  13. A method in accordance with claim 12, characterised in that the dilution liquid for the box head is de-aerated in a separate container (80); or in that the dilution liquid for the box head is de-aerated with the pulp suspension and/or with the dilution liquid for the second dilution in a common container (94) which has correspondingly separate compartments (70, 72, 98) and separate overflows (36, 50, 84).
  14. A method in accordance with any one of the claims 9 to 13, characterised in that the pulp suspension and/or the dilution liquid for the second dilution and/or the dilution liquid for the box head are de-aerated by a common vacuum plant (34); and/or in that the pulp suspension is cleaned at least once in particular between the first dilution and the de-aeration.
EP03022309A 2002-10-31 2003-10-02 System and method for feeding pulp suspension to a headbox Expired - Lifetime EP1416084B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10250865A DE10250865B3 (en) 2002-10-31 2002-10-31 System and method for supplying a fiber suspension to a headbox
DE10250865 2002-10-31

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EP1416084B1 true EP1416084B1 (en) 2007-03-07

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FI20031164A (en) * 2003-07-09 2005-01-10 Sulzer Pumpen Ag Method and apparatus for pulping
DE102004042341B4 (en) * 2004-09-01 2007-04-12 Voith Patent Gmbh System and method for feeding a pulp suspension to a headbox
DE102013207639A1 (en) * 2013-04-26 2014-10-30 Voith Patent Gmbh Suspensionsentgasung
CN107913606B (en) * 2017-10-24 2020-07-28 浙江福斯特新材料研究院有限公司 Semipermeable membrane supporting material and preparation method thereof

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US3432036A (en) * 1964-12-09 1969-03-11 Clark & Vicario Corp Conditioning papermaking stock
DE4106140C2 (en) * 1991-02-27 1994-11-24 Escher Wyss Gmbh Device and its application for venting a pulp suspension
FI103677B1 (en) * 1998-06-10 1999-08-13 Valmet Corp Procedure for regulating the surface and texture of a dosing container for a partial mass
DE19947905A1 (en) * 1999-10-06 2001-04-12 Voith Paper Patent Gmbh Device for the gasification of fiber suspensions
DE10050109A1 (en) * 2000-10-09 2002-04-11 Voith Paper Patent Gmbh Preparation of a fiber suspension, as paper/cardboard pulp, has a mixing pipe for the main mixed suspension flow with an elbow where an additional suspension is injected with a bulking agent

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EP1416084A1 (en) 2004-05-06
DE10250865B3 (en) 2004-05-13

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