DE102009027721A1 - Headbox for a machine for producing a fiber web - Google Patents

Abstract

The invention relates to a headbox (1) for a machine for producing a fibrous web (3), in particular a paper, cardboard or tissue web, from at least one fibrous suspension (2), with a feed device (4) feeding the at least one fibrous suspension (2) , 5), with one of the feed device (4, 5) in the flow direction (R) of the at least one pulp suspension (2) immediately following and a plurality of rows (Z; Z, Z.1 to Z.3) and in columns (S; S, S.1 to S.4) arranged flow channels (7) having perforated distribution pipe plate (6), with one of the perforated distribution pipe plate (6) in the flow direction (R) of the at least one fiber suspension (2) directly adjoining in the width direction (B) of the headbox (1) extending and two preferably machine-wide walls (9.1, 9.2) having intermediate channel (8), with one of the intermediate channel (8) in the flow direction (R) of the at least one fiber suspension (2) immediately following turbulence generating means (10) with a multiplicity of rows (Z; Z, Z.1 to Z.3) and in columns (S; S, S.1 to S.4) arranged flow channels (11), and with a turbulence generating means (10) in the flow direction (R) of the at least one fiber suspension (2) immediately adjoining headbox nozzle (13) with a nozzle gap (14), the feed device (4, 5), the perforated distributor plate (6) and the intermediate channel (8) ...

Description

The The invention relates to a headbox for a machine for producing a fibrous web, in particular a paper, Carton or tissue web, from at least one pulp suspension, with a feeding the at least one pulp suspension Feeder, with one of the feeder in the flow direction of the at least one pulp suspension immediately following and a variety of in lines and arranged in columns flow channels Distribution well plate, with one of the distribution well plate in the flow direction of the at least one pulp suspension immediately adjoining, in the width direction of the Headbox extending and two preferably machine width Walls having intermediate channel, with a the intermediate channel in the flow direction of the at least one pulp suspension immediately following turbulence generating agent with a plurality of flow channels arranged in rows and in columns, and with the turbulence generating means in the flow direction the at least one pulp suspension immediately subsequent and a nozzle gap having headbox nozzle, the feeder, the distribution well plate and the intermediate channel in a first alignment plane and the Turbulence generating means and the headbox in a second alignment plane are arranged and wherein the two alignment planes an angle in the range of> 90 and <180 °, preferably from ≥ 100 and ≤ 170 °, in particular of ≥ 110 and ≤ 160 °.

One Such headbox has been in the art for many years is known and is for example from the company Voith Paper under the designation "W headbox" built and sold. It is preferably used in paper or board machines with a Fourdrinier, a so-called Fourdriniersieb forming unit used.

generally known have recent developments on the headbox of machines for manufacturing a fibrous web led to that in addition to the actual Pulp suspension needed for the production of the fibrous web is an additional controlled addition of a Fluid, such as water or pulp suspension with different consistency, in professional circles shortly called "dilution water", he follows. This admixture takes place at several over the Width of the headbox distributed places. Here are the amount and / or the property of the dilution water adjustable. By this measure, for example, the basis weight cross profile efficiently regulated and / or the occurrence of cross flows be effectively prevented in the headbox.

Such a headbox with the described Verdünnungswassertechnologie is for example from the document DE 41 19 593 C2 ("ModuleJet") known. The preferably controllable metered addition of the dilution water into partial streams into the at least one pulp suspension takes place through inlet openings in the wall of the mixing chamber or directly into the turbulence generator. In order to limit the effect of the added dilution water locally, in some cases partitions are mounted in the mixing chamber.

One such headbox with the described dilution water technology can also be used with an alternative dilution water system, such as "Jetco", "annular gap dosing" or "Injection System ", be equipped. All known dilution water systems from well-known manufacturers of machines for the production of Fiber webs are systems that meet the requirements of a good Mixing of pulp suspension and dilution water, a sufficient flow constant, a small effective width and a low mapping offset more or less good respectively only partially meet.

Nevertheless The local dosing of dilution water has changed in the headboxes for many applications proved to be particularly favorable. That leaves in such Cases of desire arise, already existing and otherwise still good usable headboxes, especially the beginning described on this new dilution water technology convert. This has to be big and also taken out heavy parts of the headbox and under Acceptance of a high risk during transport to the supplier of the headbox, because usually there only necessary reworking and adjustments can be made. Because of the lack of these parts, the headbox is at this time not usable. Retrofitting the disassembled headbox is also very expensive and possibly also with technological Risks connected.

It So is the object of the invention, a headbox of the beginning mentioned type to improve such that a technically simple and reliable dilution water system realized can be. Moreover, he should be a cost-effective Allow execution and a cheaper retrofit solution with less downtime.

This object is achieved in a headbox of the aforementioned type according to the invention that spaced apart at least one preferably machine-wide wall of the intermediate channel to each other both in the width direction and in the longitudinal direction of the headbox Means for preferably controllable metered addition of a fluid in partial fluid streams are arranged in the at least one pulp suspension, that the individual means for preferably controllable / metered metered addition of the fluid in at least one partial fluid stream in the at least one pulp suspension a Zudosierkanalöffnung and Zudosierkanalmittelline having Zudosierkanal and that the respective Zudosierkanalöffnung the Zudosierkanals the single means for preferably controllable / metered metered addition of the fluid in at least one partial fluid flow in the at least one pulp suspension is aligned so that the Zudosierkanalmittellinie this Zudosierkanals impinges on the turbulence generating means at a point of impact formation. The turbulence generating means is preferably a turbulence generator known to the person skilled in the art.

The inventive object is in this way completely solved.

The inventive headbox improvement of the type mentioned allows the realization a technically simple and reliable dilution water system. Even with possibly locally very different dilution or fluid quantities are a good volume flow constancy over the entire machine width achieved and due to the addition of the Dilution water or fluids in the direct catchment area of turbulence generating means a narrow and sharply demarcated Active response generated in the fibrous web. A "vagrancy" of the partial flow at dilution water or fluid can only in a very small dimensions. By the targeted, local stable and preferably controllable metered addition of the dilution water or the fluid and the intensive mixing in the Zudosierbereich following flow channels of the turbulence generating means with separate guidance of the mixed flows up to the Beginning of the headbox so are the requirements as far as possible to an optimal dilution water system, preferably even completely fulfilled.

Also the improvement according to the invention is suitable the headbox of the type mentioned as a cheaper Retrofit solution with less downtime in the Comparison with the already known retrofit solutions. Basically, only at least one wall of the intermediate channel with the means for preferably controllable / metered addition of the dilution water or

fluid in partial streams into the at least one pulp suspension be provided. The remaining components and groups of the Previous headbox can without any structural Changes exist and thus continue to be used. The inventive headbox improvement The type mentioned can problem and effortlessly in the local Environment of the existing machine for producing a fibrous web completed become.

In A first preferred embodiment is the respective one Zudosierkanalöffnung the Zudosierkanals the single agent for preferably controllable metered addition of the fluid in at least a partial flow of fluid into the at least one pulp suspension aligned so that the Zudosierkanal centerline of this Zudosierkanals preferably approximately centrally, in particular centrally between the columns of two adjacent flow channels on the turbulence generating means in forming a point of impact incident. There is a division of the metered partial fluid flow. There the metered partial fluid flow is not directly into at least one flow channel of the turbulence generating means, become very stable Ratios achieved with respect to the volume flow constancy. moreover will be water jet pumping effects and similar phenomena largely avoided and perform even with changing Volumes of the fluid partial flows only to small influences.

A further preferred embodiment provides that the flow channels arranged in a row of the turbulence generating means have a line division of the flow channels and in that the Zudosierkanalmittellinien the Zudosierkanäle the spaced in the width direction of the headbox means for preferably controllable metered addition of the fluid in partial fluid streams in the at least one Pulp suspension, which are associated with the arranged in this row flow channels of the turbulence generating means, a line division of Zudosierkanalmittellinenien, wherein the line division of the Zudosierkanalmittellinien preferably assumes the same or double value of the line division of the flow channels. If the two line divisions now assume the same value, exactly one line of metering channels is assigned to each line of flow channels. On the other hand, if the line division of the metering channel centerlines assumes twice the line splitting of the flow channels, only one line of metering channels is assigned to each second row of flow channels. The line division of the flow channels may, for example, assume a value of 25, 33, 50, 66 or 100 mm. A further preferred embodiment provides that the respective metering channel opening of the metering channel of the individual means for preferably controllable metered addition of the fluid in at least one partial fluid flow is aligned in the at least one pulp suspension so that the Zudosierkanalmittellinie this Zudosierkanals outside or within the line of the adjacent flow channels on the Turbulence generating means impinges upon formation of a point of impact. The out-of-phase impact of the metering channel center line can assume a value of up to 50% of the column pitch of the flow channels. As a result, the effective impact surface can be effectively increased, so that once again very stable conditions with regard to the volume flow constancy are achieved.

The Metering channel centerline of the metering channel can of course also within the line of the adjacent flow channels on the turbulence generating means at the formation of the impact point incident. In this possible embodiment is aligned then the impact point of Zudosierkanalmittellinie the Zudosierkanals the agent with the two adjacent flow channels turbulence generating means.

Further have the flow channels arranged in a column the turbulence generating means a column pitch of the flow channels and the metering channel centerlines at different heights opening Zudosierkanäle the means for preferably controllable metered addition of the fluid in partial fluid streams in the at least one pulp suspension, which arranged in this column Flow channels of the turbulence generating means are assigned, a column pitch of Zudosierkanalmittellinien on, wherein the column pitch of Zudosierkanalmittellinen the same or double value of the column pitch of the flow channels assume can. Now assume the two column divisions the same value, so every column of flow channels is accurate a column assigned to Zudosierkanälen. Takes the column division the metering channel centerlines, however, the double value of the column division the flow channels, so only every second Column on flow channels one column on Zudosierkanälen assigned.

The respective Zudosierkanalöffnung the Zudosierkanals the individual By means of preferably controllable / controllable metered addition of the fluid in at least one partial fluid flow into the at least one pulp suspension Of course, it can also be arranged so that the Dosing channel centerline of this Zudosierkanals centered or approximate centrally, possibly also slightly offset to a flow channel the turbulence generating means when forming a point of impact incident.

Also can flow channels arranged in two adjacent rows the turbulence generating means offset from one another, preferably centrally offset from each other, be arranged. This will change the distance between the flow channels arranged in adjacent rows of the turbulence generating means markedly increased. And this in turn leads to an advantageous magnification the effective impact area, so that in turn very stable Ratios achieved with respect to the volume flow constancy become.

The arranged in two adjacent rows flow channels of the turbulence generating means can of course be arranged without offset to each other. It thus arises a rectangular array grid for the flow channels turbulence generating means.

In In another embodiment, the metering channels the arranged in a column means for preferably controllable / controllable Metering of the fluid in partial fluid streams in the at least a pulp suspension with a common supply channel connected. This is a technically elegant, fluidic and technologically not disadvantageous and cost-effective Achieved execution of the agent.

In an alternative embodiment, each Zudosierkanal the individual agent for preferably controllable / metered addition of the fluid in partial fluid streams into the at least one pulp suspension connected to its own supply channel. This technically more elaborate Execution provides the advantage of larger ones Design options, especially during the Operation of the machine for producing a fibrous web.

And the respective Zudosierkanalöffnung the Zudosierkanals of individual means for preferably controllable / metered addition of the fluid in at least one partial fluid flow into the at least one Pulp suspension is preferred to the turbulence generating agent a vertical and the same or approximately the same Distance in the range from 1 to 50 mm, preferably from 3 to 30 mm, especially from 10 to 30 mm, on. This provides the advantage of one Space-saving design with fluidic and technological optimal operating conditions of the machine for producing a Fibrous web.

Further can the respective Zudosierkanal the means for preferably controllable / regulated Metering of the fluid in at least one partial fluid flow in the at least one fibrous suspension at least partially a constant or a preferably gradually widening cross-sectional inner surface exhibit. This can improve the distribution in the z-direction be obtained.

The respective means for preferably controllable metered addition of the fluid in at least one partial stream of fluid into the at least one pulp suspension preferably comprises a metering tube. This form of means has fluidically op In addition, it is also suitable for use in particular with respect to manufacturing aspects. The metering tube can in this case have any known tube cross-section, namely round, approximately round, oval, triangular, rectangular, square and the like.

Farther can the respective Zudosierkanal the metering tube along its Zudosierkanalmittellinie a rotationally symmetrical cross-sectional inner surface and the single metering tube may be a preferably rotationally symmetric Outer surface with a diameter in the range of 3 to 25 mm, preferably from 4 to 16 mm, in particular from 5 to 10 mm. The fluidic properties of the agent can be further improved.

The Fluid is preferably water, especially clear water, or from a pulp suspension, in particular white water whose Focusing on the average concentration of at least one pulp suspension flowing in the headbox different. These types of fluids have similar Applications already well proven.

Of the Headbox according to the invention is in excellent Way for use in a machine for producing a fibrous web, in particular a paper, cardboard or tissue web. The in the machine with at least one headbox according to the invention produced fibrous web has consistently excellent properties, among other things, the regulation of both their Faserorientierungsquerprofils as well as their basis weight cross profile possible is.

Further Features and advantages of the invention will become apparent from the following Description of several preferred embodiments with reference to the drawing.

It demonstrate

1 a vertical and schematic longitudinal sectional view of an embodiment of a headbox for a machine for producing a fibrous web according to the prior art;

2 a partial and schematic sectional view of a first embodiment of a headbox according to the invention for a machine for producing a fibrous web;

3 a partial and schematic sectional view of a second embodiment of a head box according to the invention for a machine for producing a fibrous web;

4 a representation of a first Zudosierkonzept a headbox according to the invention for a machine for producing a fibrous web; and

5 a representation of a second Zudosierkonzept a headbox according to the invention for a machine for producing a fibrous web.

The 1 shows a vertical and schematic longitudinal sectional view of an exemplary embodiment of a headbox 1 for a machine for producing a fibrous web 3 from a pulp suspension 2 , The illustrated headbox 1 can of course also be designed as a multi-layer casserole, the at least two different pulp suspensions for the production of the fibrous web 3 used. The fibrous web 3 may be in particular a paper, board or tissue web.

The headbox 1 has a pulp suspension 2 feeding feeder 4 For example, in the embodiment of a transverse distribution pipe shown 5 or a rotary distributor, not shown, with a plurality of hoses on.

The feeder 4 closes in flow direction R (arrow) of the pulp suspension 2 Immediately, for example, a three-piece distribution well plate 6 on, a plurality of in three rows Z and in several columns S arranged flow channels 7 having. Of course, the number of lines Z can also be less than or greater than three in a manner not shown.

Again in the flow direction R (arrow) of the pulp suspension 2 closes immediately in the width direction B (arrow) of the headbox 1 extending and two preferably machine-wide walls 9.1 . 9.2 having intermediate channel 8th at.

And the intermediate channel 8th closes in flow direction R (arrow) of the pulp suspension 2 directly a, for example, three-line turbulence generating agent 10 with a plurality of flow channels arranged in three rows Z and in several columns S. 11 on (cf. 4 and 5 ). Of course, the number of lines Z can also be less than or greater than three in a manner not shown.

During operation of the headbox 1 becomes the pulp suspension 2 in the turbulence generating means 10 divided into pulp suspension sub-streams and after exiting the turbulence generating means 10 in a machine-wide chamber 12 in an embodiment of a nozzle gap 14 having headbox nozzle 13 together again led to the formation of a machine-wide fibrous web 3 to enable. The flow channels 6 turbulence generating means 10 are preferably formed in a known manner as thin-walled turbulence tubes and / or turbulence tube inserts with at least partially constant, at least partially diverging, at least partially converging and / or discontinuous cross-sectional inner surfaces.

The headbox 13 is optional outlet side optionally with at least one dashed line indicated aperture 15 Mistake.

Also, in the headbox 13 at least one, the expert well-known and not explicitly shown separating element, in particular a blade be arranged. Should several separating elements, in particular slats in the headbox nozzle 13 may be arranged, they may have different lengths and possibly also different properties, such as surface contours and the like.

Moreover, the feeding device 4 , the distribution hole plate 6 and the intermediate channel 8th in a first alignment plane AE.1 and the turbulence generating means 10 and the headbox nozzle 13 arranged in a second alignment plane AE.2. The two alignment planes AE.1, AE.2 include an obtuse angle α in the range of> 90 and <180 °, preferably of ≥ 100 and ≦ 170 °, in particular of ≥ 110 and ≦ 160 °. The headbox 1 So has a significant diversion 16 on.

The 2 shows a partial and schematic sectional view of a first embodiment of a head box according to the invention 1 for a machine for producing a fibrous web from a pulp suspension 2 (Arrow). The extract shown is in the 1 indicated by a dashed circle K.

The basic structure of this excerpt and schematically illustrated head box 1 corresponds essentially to the basic structure of the in the 1 schematically illustrated head box 1 , so that reference is also made to this description of the figures.

It is clearly evident that the intermediate channel 8th in a first alignment plane AE.1 and the turbulence generating means 10 is arranged in a second orientation plane AE.2. The two alignment planes AE.1, AE.2 include an obtuse angle α in the range of> 90 and <180 °, preferably of ≥ 100 and ≦ 170 °, in particular of ≥ 110 and ≦ 160 °. The headbox 1 So has a significant diversion 16 on.

On the upper and preferably machine-wide wall 9.2 of the intermediate channel 8th are several both in the width direction B (arrow) and in the longitudinal direction L (arrow) of the headbox 1 spaced apart means 17 for preferably controllable metered addition of a fluid 18 in partial fluid streams 18.T (Arrows) in the pulp suspension 2 Arranged (arrow). Due to the metered addition of the fluid 18 (Arrow) in partial fluid streams 18.T (Arrow) in the pulp suspension 2 (Arrow) are then mixed partial flows 2.1 (Arrow), which are then merged in the headbox to a combined mixed stream. The means for preferably controllable / controllable metered addition of the fluid 18 in partial fluid streams 18.T (Arrow), such as valves, are well known to the skilled person and thus not shown explicitly.

The single agent 17 for preferably controllable / controllable metered addition of the fluid 18 in at least one partial fluid flow 18.T (Arrow) in the at least one pulp suspension 2 includes a metering channel opening 19.I and a metering channel centerline 19.M having metering channel 19 ,

The respective means 17 for preferably controllable / controllable metered addition of the fluid 18 in at least one partial fluid flow 18.T (Arrow) in the at least one pulp suspension 2 includes a dosing tube 17.1 ,

The respective metering channel 19 of the dosing tube 17.1 owns along its metering center axis 19.M a rotationally symmetrical cross-sectional inner surface 19.I , And the single metering tube 17.1 also has a preferably rotationally symmetrical outer surface 19.A with a diameter 19.D in the range of 3 to 25 mm, preferably from 4 to 16 mm, in particular from 5 to 10 mm.

In addition, the respective Zudosierkanal 19 of the agent 17 at least in regions, a constant or preferably an abruptly widening cross-sectional inner surface 19.I on.

And the respective Zudosierkanalöffnung 19.1 of the metering channel 19 of the single agent 17 for preferably controllable / controllable metered addition of the fluid 18 in at least one partial fluid flow 18.T (Arrow) in the at least one pulp suspension 2 is aligned so that the metering channel centerline 19.M this metering channel 19 on the turbulence generating means 10 impinges on the formation of an impact point AP (cross).

Furthermore, the Zudosierkanäle 19 the arranged in a column S means 17 for preferably controllable / controllable metered addition of the fluid 18 in partial fluid streams 18.T (Arrow) in the at least one pulp suspension 2 with a common supply channel 20 connected. The supply channel 20 is again with a supply system, not shown for the fluid 18 connected, preferably in the supply channel 20 and / or in the supply system, a known to those skilled and thus not explicitly shown means, such as a valve, for controllable / controllable metered addition of the fluid 18 Arrow is present.

Of course can each Zudosierkanal the individual means for preferably controllable metered addition of the fluid in partial fluid streams in the at least one pulp suspension in not shown Way also be connected to its own supply channel.

Further, the respective Zudosierkanalöffnung 19.1 of the metering channel 19 of the single agent 17 for preferably controllable / controllable metered addition of the fluid 18 in at least one partial fluid flow 18.T (Arrow) in the at least one pulp suspension 2 to the turbulence generating means 10 a vertical and equal or approximately equal distance A in the range of 1 to 50 mm, preferably from 3 to 30 mm, in particular from 10 to 30 mm. The metering channel opening 19.1 of the respective metering channel 19 of the single agent 17 is therefore parallel or approximately parallel to the inlet side 10.e turbulence generating means 10 arranged. Of course, it may also be arranged in a manner not shown at an angle to the inlet side of the turbulence generating means.

And the 3 shows a partial and schematic sectional view of a second embodiment of a head box according to the invention 1 for a machine for producing a fibrous web from a pulp suspension 2 (Arrow). The extract shown is in the 1 indicated by a dashed circle K.

The basic structure of this excerpt and schematically illustrated head box 1 corresponds essentially to the basic structure of the in the 1 schematically illustrated head box 1 , so that reference is also made to this description of the figures.

It is clearly evident that the intermediate channel 8th in a first alignment plane AE.1 and the turbulence generating means 10 is arranged in a second orientation plane AE.2. The two alignment planes AE.1, AE.2 include an obtuse angle α in the range of> 90 and <180 °, preferably of ≥ 100 and ≦ 170 °, in particular of ≥ 110 and ≦ 160 °. The headbox 1 So has a significant diversion 16 on.

On the upper and preferably machine-wide wall 9.2 of the intermediate channel 8th are several both in the width direction B (arrow) and in the longitudinal direction L (arrow) of the headbox 1 spaced apart means 17 for preferably controllable metered addition of a fluid 18 in partial fluid streams 18.T (Arrows) in the pulp suspension 2 Arranged (arrow). Due to the metered addition of the fluid 18 (Arrow) in partial fluid streams 18.T (Arrow) in the pulp suspension 2 (Arrow) are then mixed partial flows 2.1 (Arrow), which are then merged in the headbox to a combined mixed stream. The means for preferably controllable / controllable metered addition of the fluid 18 in partial fluid streams 18.T (Arrow), such as valves, are well known to the skilled person and thus not shown explicitly.

The single agent 17 for preferably controllable / controllable metered addition of the fluid 18 in at least one partial fluid flow 18.T (Arrow) in the at least one pulp suspension 2 includes a metering channel opening 19.1 and a metering channel centerline 19.M having metering channel 19 ,

The respective means 17 for preferably controllable / controllable metered addition of the fluid 18 in at least one partial fluid flow 18.T (Arrow) in the at least one pulp suspension 2 includes a dosing tube 17.1 ,

The respective metering channel 19 of the dosing tube 17.1 owns along its metering center axis 19.M a rotationally symmetrical cross-sectional inner surface 19.Ι , And the single metering tube 17.1 also has a preferably rotationally symmetrical outer surface 19.A with a diameter 19.D in the range of 3 to 25 mm, preferably from 4 to 16 mm, in particular from 5 to 10 mm.

In addition, the respective Zudosierkanal 19 of the agent 17 at least in regions, a constant or preferably an abruptly widening cross-sectional inner surface 19.Ι on.

And the respective Zudosierkanalöffnung 19.1 of the metering channel 19 of the single agent 17 for preferably controllable / controllable metered addition of the fluid 18 in at least one partial fluid flow 18.T (Arrow) in the at least one pulp suspension 2 is aligned so that the metering channel centerline 19.M this metering channel 19 on the turbulence generating means 10 impinges on the formation of an impact point AP (cross).

Furthermore, the Zudosierkanäle 19 the arranged in a column S means 17 for preferably controllable / controllable metered addition of the fluid 18 in partial fluid streams 18.T (Arrow) in the at least one pulp suspension 2 with a common supply channel 20 connected. The supply channel 20 is again with a versor, not shown system for the fluid 18 connected, preferably in the supply channel 20 and / or in the supply system, a known to those skilled and thus not explicitly shown means, such as a valve, for controllable / controllable metered addition of the fluid 18 Arrow is present.

Of course can each Zudosierkanal the individual means for preferably controllable metered addition of the fluid in partial fluid streams in the at least one pulp suspension in not shown Way also be connected to its own supply channel.

Further, the respective Zudosierkanalöffnung 19.1 of the metering channel 19 of the single agent 17 for preferably controllable / controllable metered addition of the fluid 18 in at least one partial fluid flow 18.T (Arrow) in the at least one pulp suspension 2 to the turbulence generating means 10 a vertical and equal or approximately equal distance A in the range of 1 to 50 mm, preferably from 3 to 30 mm, in particular from 10 to 30 mm. The Zudosierkanalöffnung the respective Zudosierkanals 19 of the single agent 17 is parallel or nearly parallel to the inside 9.2.Ι the upper and preferably machine-wide wall 9.2 of the intermediate channel 8th arranged. Of course, it may also be arranged in a manner not shown at an angle to the inlet side of the turbulence generating means.

The two 4 and 5 show two Zudosierkonzepte a headbox according to the invention 1 for a machine for producing a fibrous web. The flow channels 11 turbulence generating means 10 are arranged by way of example in three rows Z.1 to Z.3 (Z) and four meander-shaped columns S.1 to S.4 (S).

In both concepts, the flow channels arranged in two adjacent rows Z.1, Z.2 and Z.3 are 11 turbulence generating means 10 staggered to each other. In the two present illustrations, they are arranged centrally offset from one another, so that the flow channels 11 the bottom line Z.1 and the flow channels 11 the upper line Z.3 the same arrangement in width directions B (double arrow) of the headbox 1 exhibit.

The arranged in two adjacent rows flow channels of the turbulence generating agent can in not shown Way, of course, be arranged without offset to each other. It thus creates a rectangular array grid for the flow channels of the turbulence generating means.

Furthermore, the Zudosierkanalöffnungen 19.1 the metering channels 19 a dashed line and as dosing 17.1 trained agent 17 for the preferably controllable metered addition of the fluid in partial fluid streams into the at least one pulp suspension.

The single metering channel opening 19.1 of the metering channel 19 of the agent 17 is aligned so that the Zudosierkanalmittellinie 19.M each metering channel 19 of the agent 17 approximately centrally, in particular centrally between the columns S.2 and S.3 of two adjacent flow channels 11 on the turbulence generating means 10 impinges upon formation of a respective impact point AP.

Furthermore, the flow channels arranged in a row Z.1, Z.2 and Z.3 have 11 turbulence generating means 10 a line division of the flow channels TZ.11. The line division of the flow channels may, for example, assume a value of 25, 33, 50, 66 or 100 mm. The metering channel centerlines 19.M the metering channels 19 in the width direction B (arrow) of the headbox 1 spaced apart means 17 , the flow channels arranged in this line Z.1, Z.2 and Z.3 11 turbulence generating means 10 are assigned, have a line division of Zudosierkanalmittellinien TZ.19.M on. In the two present representations, the line division of the metering channel center lines TZ.19.M assumes twice the value of the line division of the flow channels TZ.11. Of course, the two line divisions TZ.19.M and TZ.11 can also assume the same value.

Furthermore, the flow channels arranged in a column S.2 and S.3 have 11 turbulence generating means 10 a column pitch of the flow channels TS.11. And the metering channel centerlines 19.M the Zudosierkanäle opening at different heights 19 of the agent 17 , the flow channels arranged in this column S.2 and S.3 11 turbulence generating means 10 are assigned, have a column pitch of Zudosierkanalmittellinien TS.19.M on.

In the presentation of the 4 , So the first concept, the column pitch of Zudosierkanalmittellinien TS.19.M assumes the same value of the column pitch of the flow channels TS.11. So there are all rows Z.1, Z.2 and Z.3 of flow channels 11 turbulence generating means 10 one line each at Zudosierkanälen 19 of the agent 17 assigned. Thus, the whole amount of pulp suspension is supplied with the fluid in partial fluid streams.

And in the presentation of 5 , So the second concept, the column pitch of Zudosierkanal Mittellienien TS.19.M takes twice the value the column pitch of the flow channels TS.11. So there are only the lines Z.1 and Z.3 of flow channels 11 turbulence generating means 10 one line each at Zudosierkanälen 19 of the agent 17 assigned. Thus, only 2/3 of the amount of pulp suspension are supplied with the fluid in partial fluid streams.

Also, the single metering channel opening is 19.1 of the metering channel 19 of the agent 7 in the 4 and 5 aligned so that the Zudosierkanal centerline 19.M this metering channel 19 outside the lines Z.1, Z.2 and Z.3 ( 4 ) or Z.1 and Z.3 ( 5 ) of the adjacent flow channels 11 on the turbulence generating means 10 impinges upon formation of the impact point AP.

The Dosing channel center line of Zudosierkanals can not shown in Of course, also within the line of the neighboring ones Flow channels on the turbulence generating means impinge upon the formation of the point of impact.

That in the embodiments of the 2 . 3 . 4 and 5 used fluid 18 consists of at least water, in particular white water or clear water, or at least one pulp suspension whose concentration is different from the average concentration of the at least one in the headbox 1 flowing pulp suspension 2 (Arrow) differs.

The in the 2 . 3 . 4 and 5 each illustrated and described headbox 1 is particularly suitable for use in a machine for producing a fibrous web 3 , in particular a paper or board web, of at least one pulp suspension 2 (Arrow).

And the characteristics of in the 2 . 3 . 4 and 5 illustrated and described embodiments of the headbox 1 may also be at least partially combined with one another for the skilled person in a suitable manner.

In summary It should be noted that a headbox of the invention initially mentioned type is improved so that a technical simple and reliable dilution water system is feasible. Moreover, it allows a cost-effective Execution and provides a cheaper retrofit solution with less downtime.

LIST OF REFERENCE NUMBERS

1

headbox

2

Fibrous suspension (Arrow)

2.1

mixed stream (Arrow)

3

Fibrous web

4

feeder

5

transverse distribution

6

distribution pipe

7

channel

8th

intermediate channel

9.1

Wall; bottom wall

9.2

Wall; upper wall

9.2.I

inside

10

Turbulence generator

10.e

inlet side

11

flow channel

12

machine width chamber

13

headbox

14

die gap

fifteen

cover

16

redirection

17

medium for preferably controllable metered addition of a fluid in Partial fluid streams

17.1

dosing

18

fluid

18.T

Fluid part stream (Arrow)

19

Zudosierkanal

19.1

Zudosierkanalöffnung

19.2

Zudosierteil

19.A

outer surface

19.D

diameter

19.I

Section inner surface

19.M

Zudosierkanalmittellinie

20

supply channel

A

distance

AE.1

First orientation plane

AE.2

Second orientation plane

AP

of impact (Cross)

B

width direction (Arrow; double arrow)

K

circle

L

longitudinal direction

R

flow direction (Arrow)

S; S.1

column

S; S.2

column

S; S.3

column

S; S.4

column

TS.11

column division the flow channels

TS.19.M

column division the metering channel centerlines

TZ.11

line pitch the flow channels

TZ.19.M

line pitch the metering channel centerlines

Z; Z.1

Row; bottom line

Z; T.2

Row; top line

Z; Z.3

Row; middle line

α

angle

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 4119593 C2 [0004]

Claims (15)

Headbox ( 1 ) for a machine for producing a fibrous web ( 3 ), in particular a paper, cardboard or tissue web, from at least one pulp suspension ( 2 ), with at least one pulp suspension ( 2 ) feeding device ( 4 . 5 ), with one of the feeding device ( 4 . 5 ) in the flow direction (R) of the at least one pulp suspension ( 2 ) immediately adjacent and a plurality of in rows (Z; Z, Z.1 to Z.3) and in columns (S; S, S.1 to S.4) arranged flow channels ( 7 ) distribution well plate ( 6 ), with one of the distribution well plate ( 6 ) in the flow direction (R) of the at least one pulp suspension ( 2 ) immediately adjacent, in the width direction (B) of the headbox ( 1 ) extending and two preferably machine-wide walls ( 9.1 . 9.2 ) having intermediate channel ( 8th ), with an intermediate channel ( 8th ) in the flow direction (R) of the at least one pulp suspension ( 2 ) directly adjoining turbulence generating means ( 10 ) having a multiplicity of flow channels arranged in rows (Z; Z, Z.1 to Z.3) and in columns (S; S, S.1 to S.4) ( 11 ), and with a turbulence generating means ( 10 ) in the flow direction (R) of the at least one pulp suspension ( 2 ) immediately adjacent and a nozzle gap ( 14 ) headbox ( 13 ), wherein the feeding device ( 4 . 5 ), the distribution well plate ( 6 ) and the intermediate channel ( 8th ) in a first orientation plane (AE.1) and the turbulence generation means (AE) 10 ) and the headbox nozzle ( 13 ) are arranged in a second alignment plane (AE.2) and wherein the two alignment planes (AE.1, AE.2) have an angle (α) in the range of> 90 and <180 °, preferably of ≥ 100 and ≤ 170 °, in particular of ≥ 110 and ≤ 160 °, include, characterized in that (at least one preferably machine-wide wall 9.2 ) of the intermediate channel ( 8th ) several both in the width direction (B) and in the longitudinal direction (L) of the headbox ( 1 ) spaced apart means ( 17 . 17.1 ) for preferably controllable metered addition of a fluid ( 18 ) in partial fluid streams ( 18.T ) into the at least one pulp suspension ( 2 ), that the individual means ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 ) in at least one partial fluid flow ( 18.T ) into the at least one pulp suspension ( 2 ) has a metering channel opening ( 19.1 ) and a metering channel centerline ( 19.M ) having Zudosierkanal ( 19 ) and that the respective metering channel opening ( 19.1 ) of the metering channel ( 19 ) of the individual agent ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 ) in at least one partial fluid flow ( 18.T ) into the at least one pulp suspension ( 2 ) is aligned so that the metering channel centerline ( 19.M ) of this metering channel ( 19 ) on the turbulence generating means ( 10 ) impinges upon formation of an impact point (AP). Headbox ( 1 ) according to claim 1, characterized in that the respective Zudosierkanalöffnung ( 19.1 ) of the metering channel ( 19 ) of the individual agent ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 ) in at least one partial fluid flow ( 18.T ) into the at least one pulp suspension ( 2 ) is aligned so that the metering channel centerline ( 19.M ) of this metering channel ( 19 ) preferably approximately centrally, in particular centrally between the columns (S.2 and S.3) of two adjacent flow channels ( 11 ) on the turbulence generating means ( 10 ) impinges upon formation of an impact point (AP). Headbox ( 1 ) according to claim 1 or 2, characterized in that in a row (Z, Z.1 to Z.3) arranged flow channels ( 11 ) of the turbulence generating agent ( 10 ) have a line division of the flow channels (TZ.11) and that the Zudosierkanalmittelinien ( 19.M ) of the metering channels ( 19 ) in the width direction (B) of the headbox ( 1 ) spaced apart means ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 ) in partial fluid streams ( 18.T ) into the at least one pulp suspension ( 2 ), which in this line (Z, Z.1 to Z.3) arranged flow channels ( 11 ) of the turbulence generating agent ( 10 ), having a line pitch of the metering channel centerlines (TZ.19.M), the line pitch of the metering channel centerlines (TZ.19.M) assuming the same or twice the row splitting of the flow channels (TZ.11). Headbox ( 1 ) according to one of the preceding claims, characterized in that the respective metering channel opening ( 19.1 ) of the metering channel ( 19 ) of the individual agent ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 ) in at least one partial fluid flow ( 18.T ) into the at least one pulp suspension ( 2 ) is aligned so that the metering channel centerline ( 19.M ) of this metering channel ( 19 ) outside or within the line (Z.1, Z.2, Z.3, Z.1, Z.3) of the adjacent flow channels ( 11 ) on the turbulence generating means ( 10 ) impinges upon formation of an impact point (AP). Headbox ( 1 ) according to one of the preceding claims, characterized in that the flow channels arranged in a column (S, S.1 to S.4) ( 11 ) of the turbulence generating agent ( 10 ) have a column pitch of the flow channels (TS.11) and that the metering channel centerlines (TS.11) 19.M ) of the metering channels opening at different heights ( 19 ) of the agent ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 .) In partial fluid streams ( 18.T ) into the at least one pulp suspension ( 2 ), the in this column (p.2, p.4) arranged flow channels ( 11 ) of the turbulence generating agent ( 10 ), have a column pitch of the metering channel center lines (TS.19.M), the column pitch of the metering channel centerlines (TS.19.M) assuming the same or double value of the column pitch of the flow channels (TS.11). Headbox ( 1 ) according to one of the preceding claims, characterized in that the flow channels arranged in two adjacent rows (Z.1, Z.2, Z.2, Z.3) ( 11 ) of the turbulence generating agent ( 10 ) offset from one another, preferably centrally offset from each other, are arranged. Headbox ( 1 ) according to one of the preceding claims, characterized in that the metering channels ( 19 ) of the means arranged in a column ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 ) in partial fluid streams ( 18.T ) into the at least one pulp suspension ( 2 ) with a common supply channel ( 20 ) are connected. Headbox ( 1 ) according to one of claims 1 to 6, characterized in that each Zudosierkanal ( 19 ) of the individual agent ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 ) in partial fluid streams ( 18.T ) into the at least one pulp suspension ( 2 ) with its own supply channel ( 20 ) connected is. Headbox ( 1 ) according to one of the preceding claims, characterized in that the respective metering channel opening ( 19.1 ) of the metering channel ( 19 ) of the individual agent ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 ) in at least one partial fluid flow ( 18.T ) into the at least one pulp suspension ( 2 ) to the turbulence generating means ( 10 ) has a perpendicular and the same or approximately the same distance (A) in the range of 1 to 50 mm, preferably from 3 to 30 mm, in particular from 10 to 30 mm. Headbox ( 1 ) according to one of the preceding claims, characterized in that the respective metering channel ( 19 ) of the agent ( 17 . 17.1 ) for preferably controllable metered addition of the fluid ( 18 ) in at least one partial fluid flow ( 18.T ) into the at least one pulp suspension ( 2 ) at least in regions a constant or preferably an abruptly widening cross-sectional inner surface ( 19.I ) having. Headbox ( 1 ) according to one of the preceding claims, characterized in that the respective means ( 17 ) for preferably controllable metered addition of the fluid ( 18 ) in at least one partial fluid flow ( 18.T ) into the at least one pulp suspension ( 2 ) a dosing tube ( 17.1 ). Headbox ( 1 ) according to claim 11, characterized in that the respective metering channel ( 19 ) of the metering tube ( 17.1 ) along its metering channel centerline ( 19.M ) a rotationally symmetrical cross-sectional inner surface ( 19.I ) having. Headbox ( 1 ) according to claim 11 or 12, characterized in that the individual metering tube ( 17.1 ) a preferably rotationally symmetrical outer surface ( 19.A ) with a diameter ( 19.D ) in the range from 3 to 25 mm, preferably from 4 to 16 mm, in particular from 5 to 10 mm. Headbox ( 1 ) according to one of the preceding claims, characterized in that the fluid ( 18 ) at least from water, in particular white water or clear water, or from at least one pulp suspension whose concentration is different from the average concentration of the at least one in the headbox ( 1 ) flowing pulp suspension ( 2 ) differs. Machine for producing a fibrous web, in particular a paper, board or tissue web, with at least one headbox ( 1 ) according to one of claims 1 to 14.

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