WO2010069651A1

WO2010069651A1 - Headbox for a machine for producing a fibrous web

Info

Publication number: WO2010069651A1
Application number: PCT/EP2009/063839
Authority: WO
Inventors: Wolfgang Ruf; Konstantin Fenkl; Markus Häußler
Original assignee: Voith Patent Gmbh
Priority date: 2008-12-18
Filing date: 2009-10-22
Publication date: 2010-06-24
Also published as: DE102008054893A1

Abstract

The invention relates to a headbox (1) which comprises at least one feed device (3) feeding the at least one fiber suspension (2), and at least one turbulence generator (5, 5.1; 5, 11). A plurality of means (13) for dosing a fluid (14) in partial fluid streams (14.T) to the at least one fiber suspension (2) in a preferably adjustable/controlled manner is arranged upstream from the turbulence generator (5, 5.1; 5, 11), the means having a respective longitudinal direction (L) and being spaced apart from each other in the width direction of the headbox (1) and comprising a plurality of dosing channels (15) having respective dosing channel openings (16) and a dosing channel center line (11.M), arriving at different levels and being connected to a common supply channel (17). The headbox (1) is characterized in that two dosing channel openings (16) each of the means (13) are arranged next to each other, when seen in the longitudinal direction (L), and form an opening plane (18) and their dosing channel center lines (15.M) are arranged relative each other at an angle (α) to feed the fluid (14) to at least three flow channels (6) which are arranged next to each other in a line (Z1 to Z4). The individual dosing channel opening of the two respective adjacent dosing channel openings (16) of the means (13) is oriented in such a way that its dosing channel center line (15.M) is incident on the turbulence generator means (5, 5.1; 5, 11) between the gap planes (S1, S2; S2, S3) of two adjacent flow channels (6) and forms an incidence point (P1, P2).

Description

Headbox for a machine for producing a fibrous web

The invention relates to a headbox for a machine for producing a fibrous web, in particular paper or board web, from at least one pulp suspension, with at least one supplying the at least one pulp suspension feeder and at least one turbulence generating means, in which during operation of the headbox, the at least one pulp suspension through a plurality of flow channels arranged in rows with formation of row levels and in columns in the formation of column planes, each having a channel center line flow streams, thereby divided in a flow direction pulp suspension sub-streams and is recombined after exiting the turbulence generating means in a preferably machine-width chamber, wherein upstream of the turbulence generating means has a plurality of a respective longitudinal direction and spaced in the width direction of the headbox to each other te means for preferably adjustable / controllable metering of a fluid in partial fluid streams are provided in the at least one pulp suspension, each comprising a plurality of each Zudosierkanalöffnung and Zudosierkanalmittel- line and at different levels emptying, connected to a common supply channel Zudosierkanäle.

Such a headbox is known for example from German patent documents DE 44 16 898 A1, DE 44 16 899 A1 and DE 44 16 909 A1.

The German patent application DE 44 16 898 A1 shows a headbox for a paper machine with a feed device for the pulp suspension, with a guide means having a multiplicity of channels, a mixing chamber located upstream of a guide means with a plurality of feed means distributed across the headbox for a material to be mixed different in its properties from the stock suspension and having an exit gap for the stock suspension following the guide means forming nozzle chamber. The feed devices for the fluid to be admixed extend essentially vertically in the mixing chamber and have a plurality of admixed openings arranged one above the other.

And the German patent application DE 44 16 899 A1 shows a headbox for a paper machine with a feed device for the pulp suspension, a first having a plurality of channels guide means, a second plurality of channels having guide means, an intermediate mixing chamber, a subsequent, a Exit slit for the pulp forming nozzle chamber and a plurality of distributed over the headbox feed lines for the admixed fluid, wherein the majority of the channels of the guide means are positioned and dimensioned so that the outlet opening from the upstream guide means is not aligned with an opening in the downstream guide means , The supply lines for the admixing fluid have admixing openings, which for the most part are each aligned with an opening in the downstream guide device.

Furthermore, the German patent application DE 44 16 909 A1 discloses a headbox for a paper machine with a feed device for the pulp suspension, a downstream adjoining provided with a plurality of channels guide means, a downstream thereto, extending across the width of the headbox mixing chamber with a plurality of transverse distributed over the headbox, extending in the flow direction partitions and distributed across the headbox Zuführseinrich- tions for a zuzumischendes fluid with Zumischöffnungen, downstream of another, a plurality of channels having guide means and a subsequent, an outlet gap for the stock suspension forming nozzle chamber. The supply means for the admixed fluid extend into the mixing chamber and the sectional area formed by the partitions in the mixing chamber begins in the region of the admixing openings, from where it extends substantially in the direction of flow up to the second guide means.

In these headboxes shown in the three documents, the number of spaced apart 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 of the number of columns of the flow channels mounted in the turbulence generating means of the headbox corresponds. And in a specific embodiment, as shown in Figure 3 of the third referenced document, the number of spaced apart 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 equal to half the number of columns be the flow channels mounted in the turbulence generating means of the headbox. In this special case, then each means for preferably controllable metering supplies all the flow channels, which are mounted in two adjacent columns in the turbulence generating means of the headbox, with the fluid in partial fluid streams.

It is therefore an object of the invention to improve a headbox of the type mentioned above so that the local admixture of a fluid to the flow direction of at least one pulp suspension can be carried out so that simpler means the admixture of the fluid as uniform as possible and over the whole height of the pulp suspension layer can take place. The addition of the fluid should also be easily influenced at the same time. - -

This object is achieved according to the invention in a headbox of the type mentioned in the introduction in that at least two metering channel openings of the means for preferably regulatable / controllable metering of the fluid in fluid sub-streams into the at least one fibrous suspension - in the longitudinal direction of the agent. controllable metering of the fluid - arranged adjacent to one another when forming an opening plane and their metering channel centerlines are aligned at an angle to feed the fluid at least three flow channels adjacent to one another and that the individual metering channel opening of the means for preferably regulating / controllable metered addition of the fluid in partial fluid streams in the at least one pulp suspension of these two adjacent Zudosierkanalöffnungen is aligned so that their Zudosierkanalmittellinie between the column planes of two adjacent flow channels on the Turbulence generating means impinges upon formation of a point of impact.

The object of the invention is completely solved in this way.

This inventive design of the headbox of the type mentioned above provides the advantage that the local admixture of a fluid to the flow direction of at least one pulp suspension can be carried out so that with simpler means the admixture of the fluid as uniformly as possible and over the entire height of Pulp suspension layer can be done. In addition, the admixture of the fluid is also easily influenced at the same time.

Also, the flow channels can be dimensioned independently of the mean, so that the required for a good volume constancy of the sum of the partial streams and relatively slow flow velocities in both components due to the largest possible flow cross-sections can be achieved at least in the range of preferably adjustable / controllable metering. - -

Furthermore, the headbox invention provides the advantage of the greatest possible degree of freedom in the number, in the arrangement and in the design of both the flow channels and the means.

Also, in the headbox of the head box according to the invention at least one, well-known to those skilled separator, in particular a blade be arranged. If a plurality of separating elements, in particular lamellae, are arranged in the headbox of the headbox according to the invention, then they can have different lengths and possibly also different properties, such as surface contours and the like.

The angle of the agent for the preferably controllable metered addition of the fluid in partial fluid streams into the at least one pulp suspension formed by the metering channel centerlines of the two metering channels arranged in an opening plane preferably has a value in the range from -30 to + 30 °, preferably from 0 to 30 °, in particular from 10 to 30 °, on. These ranges of values continually ensure that the two metering channel centerlines of the two metering port openings arranged in an opening plane are incident on the turbulence generating means as a result of the formation of an impact point, depending on the distance to the downstream turbulence generation means between the slot planes of two adjacent flow channels.

In an advantageous embodiment, the point of impact of the respective metering channel center line of the two metering channels of the means for preferably controllable metered addition of the fluid in partial fluid streams into the at least one pulp suspension lies approximately centrally on the turbulence generating means, preferably centrally between the two slot planes of two adjacent flow channels. This ensures the most uniform possible distribution of the fluid sub-streams to the flow channels of the turbulence generating means to be fed. In a further advantageous embodiment, the point of impact of the respective metering channel center line of the two arranged in an opening plane Zudo- sierkanäle the means for preferably controllable / controllable metered addition of fluid in partial fluid streams in the at least one pulp suspension on the turbulence generating means off-center between the two column planes of two adjacent flow channels. This leads to an uneven distribution of the fluid sub-streams to the flow channels of the turbulence generating means to be fed.

Furthermore, the respective metering channel center line of the two metering channels of the means for preferably controllable metered addition of the fluid in partial fluid streams into the at least one pulp suspension can be approximately centrally, preferably centrally between the two row planes of two adjacent flow channels, by at least three in a first Line adjacent to arranged flow channels and at least three adjacent in a second and the first line adjacent row arranged flow channels with the fluid to feed. In an alternative embodiment, the respective Zudosierkanalmittellinein the two arranged in an opening plane Zudosierkanäle the means for preferably controllable / metered addition of fluid in partial fluid streams in the at least one pulp suspension in or only slightly offset parallel to the line containing the three flow channels lie to at least three adjacent in a row arranged flow channels with the fluid to feed.

The respective metering channel center line of the two metering channels of the means for preferably controllable metering of the fluid in partial fluid streams into the at least one pulp suspension can also extend at an angle to the row plane containing the three flow channels. The angle preferably takes a value in Range from 0 to 25 °, wherein the angle can be directed both upwards and downwards.

Moreover, the metering channel opening of the means for preferably controllable metered addition of the fluid in partial fluid streams into the at least one pulp suspension to the turbulence generating means preferably has a vertical distance in the range of 1 to 100 mm, preferably from 3 to 50 mm, in particular from 5 to 30 mm , on. This distance ranges ensure the necessary mixing quality of the fluid with the pulp suspension, even with different operating parameters, so that the best conditions for the production of a fibrous web with good to very good quality characteristics are given.

The means for preferably controllable metered addition of the fluid in partial fluid streams into the at least one pulp suspension may also be provided with at least one recess in at least one side, preferably bilateral area between two metering channel openings of adjacent metering channels. The recess can - seen in the flow direction of the pulp suspension - be formed, for example, wedge-shaped or groove-shaped. Because of this recess, the region of the means for the preferably controllable metered addition of the fluid into the at least one pulp suspension in the cross section is not restricted, the remainder of the means for the preferably controllable metered addition of the fluid however, already. This results in fluidically improved, even optimal conditions in the region of the means for preferably controllable metered addition of the fluid in partial fluid streams into the at least one pulp suspension.

Furthermore, the metering channel of the agent for the preferably controllable metered addition of the fluid into partial streams of fluid into the at least one pulp suspension can be a constant or preferably at least in regions have a sudden widening cross-sectional area. This can improve the distribution in the z direction.

And the Zudosierkanalöffnungen the means for preferably regulated / controllable metered addition of the fluid in partial fluid streams in the at least one pulp suspension are - viewed in the longitudinal direction of the means for preferably controllable metered addition of the fluid - preferably arranged in a straight line or curved.

In addition, there are several advantageous possibilities for the arrangement and the further alignment of the means for preferably controllable metered addition of the fluid, which can optionally be combined with one another. Thus, adjacent means for preferably controllable metered addition of the fluid can be arranged perpendicular or inclined to the flow direction of the at least one pulp suspension. Also, the adjacent means for preferably controllable metered addition of the fluid in a row or in the flow direction of the at least one pulp suspension can be arranged offset to one another, for example, in at least two rows alternately offset from one another.

The respective means for preferably controllable metered addition of the fluid in partial fluid streams into the at least one pulp suspension preferably comprises a metering blade, as described in the German patent application (Applicant's file: HPA14265 DE and Applicant's working title: "MJ M-DoS-TE- The present disclosure is hereby incorporated by reference in the present specification.

The turbulence generating means, in a practical embodiment, may be a turbulizer or a manifold orifice plate directly or indirectly connected to the feeder, in which the headbox operates the at least one pulp suspension passes through a plurality of flow channels arranged in rows forming row levels and in columns forming column gaps, thereby dividing pulp suspension sub-streams in a flow direction and rejoining them after exiting the turbulence generating means in a preferably machine-width chamber. Both embodiments are already implemented in known headboxes and are thus known to the person skilled in the art.

In the first embodiment, the turbulence generator - as viewed in the flow direction of the at least one pulp suspension - can be preceded by a distribution-well plate connected to the supply device. Between the Verteilrohrlochplatte and the turbulence generator then immediately an intermediate chamber is formed, in which the described, a respective longitudinal direction and provided in the width direction of the headbox spaced apart means for preferably controllable / metered addition of a fluid in partial fluid streams are provided in the at least one pulp suspension , The intermediate chamber may in turn, as already shown in the cited German patent application DE 44 16 909 A1, be provided with several across the headbox distributed and extending substantially in the direction of flow of at least one pulp suspension partitions in forming a sectional area.

The fluid preferably consists of water, in particular clear water, or of a pulp suspension, in particular white water, the concentration of which differs from the average concentration of the at least one pulp suspension in the headbox. These types of fluids have already proven themselves in similar applications.

The headbox according to the invention is outstandingly suitable for use in a machine for producing a fibrous web, in particular dere paper or board web. The fibrous web produced in the machine with at least one headbox according to the invention has consistently excellent properties, since, inter alia, the control of both its fiber orientation transverse profile and its basis weight cross-section is possible.

Further features and advantages of the invention will become apparent from the following description of several preferred embodiments with reference to the drawings.

Show it

Figure 1 is a vertical longitudinal section through a first embodiment of a headbox according to the invention for a machine for producing a fibrous web of at least one pulp suspension; Figure 2 is a fragmentary and exemplary sectional view of the headbox shown in Figure 1;

FIG. 3 is a further sectional and exemplary sectional view of the headbox shown in FIG. 1;

FIG. 4 is a third sectional and exemplary sectional view of the headbox shown in FIG. 1;

FIG. 4A shows a partial view of the means shown in FIG. 4 for the preferably controllable metered addition of a fluid; Figure 5 is a fragmentary and exemplary vertical longitudinal sectional view of the headbox shown in Figure 1; FIG. 6 shows a further partial and exemplary longitudinal section of the headbox shown in FIG. 1; Figure 7 is a vertical longitudinal section through a further embodiment of a headbox according to the invention of a machine for producing a fibrous web from at least one fiber stock suspension; and 8 shows a vertical longitudinal section through a third embodiment of a headbox according to the invention of a machine for producing a fibrous web from at least one pulp suspension.

1 shows a vertical longitudinal section through a first embodiment of a headbox 1 for a machine for producing a fibrous web 9 from a pulp suspension 2. The illustrated headbox 1 can of course also be configured as a multilayer headbox containing at least two different pulp suspensions for the production of Fiber web 9 used. The fibrous web 9 may in particular be a paper, board or tissue web.

The headbox 1 has a feeding device 3 which feeds a pulp suspension 2, for example in the embodiment of an illustrated transverse dividing pipe 4 or a rotary distributor (not shown) with a multiplicity of hoses.

Furthermore, the headbox 1 via a feed device 3 in the flow direction R (arrow) of the pulp suspension 2 downstream turbulence generating means 5 in a configuration known to those skilled Turbulenzerzeugers 5.1, in which during operation of the headbox 1, the pulp suspension 2 by a plurality of lines in training of Row levels and arranged in columns in the formation of column levels and each one symbolically indicated channel center line 6.M having flow channels 6 flows, characterized in a flow direction R (arrow) having pulp suspension part streams divided 2.T (arrow) and after exiting the turbulence generating means 5 in a Machine width chamber 7 in an embodiment of a headbox 8 is brought together again to allow the formation of a machine-wide fibrous web 9. The flow channels 6 are preferably in a known manner as thin-walled Turbulence tubes and / or Turbulenzrohrinserts formed with at least partially constant, at least partially diverging, at least partially converging and / or discontinuous cross-sectional areas. The headbox nozzle 8 may optionally be provided on the outlet side with at least one aperture 10 indicated by a dashed line. Also, in the headbox 8 at least one, the expert well known and not explicitly illustrated separating element, in particular a blade be arranged. If a plurality of separating elements, in particular lamellae, are arranged in the headbox nozzle 8, they can have different lengths and optionally also different properties, such as surface contours and the like.

The turbulence generating means 5 is preceded in the flow direction R (arrow) of the pulp suspension 2 connected to the feeder 3 and known in the art distribution well plate 11, so that between the Verteilrohrlochplatte 11 and the turbulence generating means 5, an intermediate chamber 12 is formed.

In this intermediate chamber 12, ie upstream of the turbulence generating means 5, a plurality of a respective longitudinal direction and in the width direction of the headbox 1 spaced apart and only indicated means 13 for preferably controllable / metered addition of a fluid 14 in partial fluid streams 14.T (arrows ) are provided in the pulp suspension 2. The means 13 each comprise a plurality of metering channels 15 having a respective metering channel opening 16 and metering channel center line 15.M and opening at different heights and connected to a common supply channel 17 (see FIGS. 2 to 4). The purely by way of example a circular cross-sectional area 13.Q having means 13 for preferably controllable / metered metering are perpendicular to the flow direction R (arrow) and arranged in a row. Alternatively, they can also be inclined relative to the flow direction R (arrow). FIG. 2 now shows a fragmentary sectional view X of the head box 1 shown in FIG. 1, wherein only three flow channels 6 adjacent to one row Z are shown with a respective channel center line 6.M of the turbulence generating means 5.

There are now two Zudosierkanalöffnungen 16 of the means 13 for preferably controlled / controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrows) in a pulp suspension 2 - in the longitudinal direction L (arrow) of the means 13 for preferably controllable metered addition of the fluid 14 - arranged adjacent to the formation of an opening plane 18, wherein the opening plane 18 through the two Zudosierkanalmittellinien 15.M the Zudosier- channels 15 is formed. The two Zudosierkanalmittellinien 15.M of the two Zudosierkanäle 15 are aligned at an angle α to each other to feed at least three adjacently arranged in a row Z flow channels 6 with the fluid 14. Furthermore, the individual metering channel opening 16 of the means 13 for preferably controllable metering of the fluid 14 in partial fluid streams 14.T (arrows) is aligned in the pulp suspension 2 of these two adjacent metering channel openings 16 so that their metering channel center line 15.M between the Column planes S1 and S2, S2 and S3 of two adjacent flow channels 6 to the turbulence generating means 5 upon formation of a respective impact point P1, P2 impinges.

The angle α of the means 13 for the preferably controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrows) into the pulp suspension 2 formed by the metering channel center lines 15.M of the two metering channels 15 arranged in an opening plane 18 assumes a value in the range of -30 to + 30 °, preferably from 0 to 30 °, in particular from 10 to 30 °, to. The two Zudosierkanalmittellinien 15.M of the two arranged in an opening plane 18 Zudosierkanäle 15 can thus, as shown, be aligned diverging or converging. - -

Furthermore, the point of impingement P1, P2 of the respective metering channel center line 15.M of the two metering channels 15 of the means 13 arranged in an opening plane 18 for preferably controllable metering of the fluid 14 in partial fluid streams 14.T (arrows) into the pulp suspension 2 lies on the turbulence - Generating means 5 approximately centrally, preferably centrally between the two column levels S1 and S2, S2 and S3 of two adjacent flow channels. 6

The Zudosierkanalöffnungen 16 may have a preferably circular, an elongated, in particular oval or slot-like, a rectangular, in particular square, or similar cross-sectional area 16.A have. The metering channel 15, shown in FIG. 2, of the means 13 for preferably metered / controllable metering of the fluid 14 in partial fluid streams 14.T (arrow) into the pulp suspension 2 has a constant cross-sectional area 15.A. Further, the Zudosierkanalöffnungen 16 of the means 13 for preferably controlled / controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrow) in the pulp suspension 2 - in the longitudinal direction L (arrow) of the means 13 for preferably controllable metered addition of the fluid 14th Seen - arranged in a straight line. The means 13 for preferably controllable metered addition of the fluid 14 has a trapezoidal cross-sectional area 13.Q.

The respective metering channel opening 16 has a vertical distance A to the turbulence generating means 5 in the range from 1 to 100 mm, preferably from 3 to 50 mm, in particular from 5 to 30 mm.

And arranged in the column planes S1, S2, S3 flow channels 6 have a preferably equal pitch T in the width direction of the headbox 1 in the range of 10 to 100 mm, preferably 25, 33, 50 or 66 mm.

The respective means 13 for preferably controllable metered addition of the fluid 14 in partial fluid streams 14. T (arrows) into the one pulp suspension 2 comprises a metering blade 13.1, as described in the German patent application - -

(Applicant's Serial Number: HPA14265 DE and Applicant's Working Title: "MJ N-DoSTE Geometry") with the same filing date as the present patent application is described and shown, the disclosure of which is hereby incorporated by reference.

FIG. 3 shows a further fragmentary sectional view X of the head box 1 shown in FIG. 1, wherein only three flow channels 6 adjacent to one row Z are shown with a respective channel center line 6.M of the turbulence generating means 5.

That of the metering channel centerlines 15.M of the two in an aperture plane

18 arranged Zudosierkanäle 15 formed angle α of the means 13 for preferably adjustable / controllable metered addition of the fluid 14 in partial fluid streams

14.T (arrows) in the pulp suspension 2 takes a value in the range of -30 to + 30 °, preferably from 0 to 30 °, in particular from 10 to 30 °, to. The two Zudosierkanalmittellinien 15.M of the two arranged in an opening plane 18 Zudosierkanäle 15 can thus, as shown, be aligned diverging or converging.

Furthermore, the point of impingement P1, P2 of the respective metering channel center line 15.M of the two metering channels 15 of the means 13 arranged in an opening plane 18 for preferably controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrows) into the pulp suspension 2 lies on the turbulence separator - Means 5 eccentrically between the two column levels S1 and S2, S2 and S3 of two adjacent flow channels. 6

The Zudosierkanalöffnungen 16 may have a preferably circular, an elongated, in particular oval or slot-like, a rectangular, in particular square, or similar cross-sectional area 16.A have. The metering channel 15 of the means 13, shown in FIG. 3, for the preferably controllable metering of the fluid 14 in partial fluid streams 14.T (arrow) into the pulp suspension 2 has a constant or a preferably suddenly expanding cross-sectional surface 15.A at least in regions. Further, the Zudosierkanalöffnungen 16 of the means 13 for preferably controlled / controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrow) in the pulp suspension 2 - in the longitudinal direction L (arrow) of the means 13 for preferably controllable metered addition of the fluid 14th seen - curved arranged. The means 13 for preferably controllable metered addition of the fluid 14 has a circular cross-sectional segmental area 13.Q.

The respective metering channel opening 16 has a vertical distance A to the turbulence generating means 5 in the range from 1 to 100 mm, preferably from 3 to 50 mm, in particular from 5 to 30 mm. And arranged in the column planes S1, S2, S3 flow channels 6 have a preferably equal pitch T in the width direction of the headbox 1 in the range of 10 to 100 mm, preferably 25, 33, 50 or 66 mm.

The respective means 13 for preferably controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrows) into the one pulp suspension 2 comprises a metering blade 13.1, as described in the German patent application (Applicant's file: HPA14265 DE and Applicant's working title: "MJ M-DoS-TE geometry") with the same filing date as the present patent application is described and shown, the disclosure of which is hereby incorporated by reference.

FIG. 4 shows a third fragmentary sectional view X of the head box 1 shown in FIG. 1, wherein only the means 13 for preferably controllable metered addition of the fluid 14 into partial fluid streams 14T (arrows) into the one fibrous stock suspension 2 are shown.

There are again two Zudosierkanalöffnungen 16 of the means 13 for preferably adjustable / controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrows) in a pulp suspension 2 - in the longitudinal direction L (arrow) of the means 13 for preferably controllable metered addition of Fluid 14 seen adjacent to formation of an opening plane 18, wherein the opening plane 18 through the two Zudosierkanalmittellinien 15.M the Zudosier- channels 15 is formed. The two Zudosierkanalmittellinien 15.M of the two Zudosierkanäle 15 are aligned at an angle α to each other to feed at least three adjacently arranged in a row Z and not shown flow channels with the fluid 14.

The angle α of the means 13 formed by the metering channel center lines 15.M of the two metering channels 15 arranged in an opening plane 18 for preferably metered / controllable metering of the fluid 14 in partial fluid streams 14.T (arrows) in the pulp suspension 2 assumes a value in the range from -30 to + 30 °, preferably from 0 to 30 °, in particular from 10 to 30 °. The two Zudosierkanalmittellinien 15.M of the two arranged in an opening plane 18 Zudosierkanäle 15 can thus, as shown, be aligned diverging or converging.

The Zudosierkanalöffnungen 16 may have a preferably circular, an elongated, in particular oval or slot-like, a rectangular, in particular square, or similar cross-sectional area 16.A have. The metering channel 15 of the means 13, shown in FIG. 4, for the preferably controllable metered addition of the fluid 14 into partial fluid streams 14.T (arrow) into the one pulp suspension 2 has a constant cross-sectional area 15.A. Further, the Zudosierkanalöffnungen 16 of the means 13 for preferably controlled / controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrow) in the one pulp suspension 2 - in the longitudinal direction L (arrow) of the means 13 for preferably controllable metered addition of the fluid 14 seen - arranged in a straight line. The means 13 for preferably controllable metered addition of the fluid 14 has a hammer-shaped cross-sectional area 13.Q.

In addition to the means 13 shown in FIGS. 2 and 3 for preferably metered / controllable addition of the fluid 14 into partial fluid streams 14.T. (arrows) into the pulp suspension 2, the means 13 shown here are for the preferably controllable metered addition of the fluid 14 in the two-sided region 20.1, 20.2 between two Zudosierkanalöffnungen 16 of adjacent Zudosierkanälen 15 with a recess 19 is provided. The recess 19 can - seen in the flow direction R (arrows) of the pulp suspension 2 - be formed, for example, wedge-shaped or groove-shaped.

The respective means 13 for preferably controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrows) into the one pulp suspension 2 comprises a metering blade 13.1, as described in the German patent application (Applicant's Serial Number: HPA14265 DE and Applicant's Working Title: "MJ N-DoSTE Geometry") with the same filing date as the present patent application is described and shown, the disclosure of which is hereby incorporated by reference.

FIG. 4A shows a partial view of the means shown in FIG

13 for preferably controllable metered addition of a fluid 14 according to the view arrow B.

This view shows that the means 13 for preferably controllable metered addition of the fluid 14 into the pulp suspension 2 in the two-sided region 20.1, 20.2 between two Zudosierkanalöffnungen 16 of adjacent Zudosierkanälen 15 is provided with a recess 19. The recess 19 can be formed-in the direction of flow of the pulp suspension 2 (cf., FIG. 4) -wisely, for example, wedge-shaped or groove-shaped.

FIG. 5 shows a partial and exemplary longitudinal section of the head box 1 shown in FIG. 1, which has flow channels 6 arranged in four rows Z1 to Z4 with a respective channel center line 6.M of the turbulence-generating means 5.

Also, the means 13 for preferably regulatable / controllable metered addition of the fluid

14 in fluid fractions 14.T (arrow) in the pulp suspension 2 has in four rows Z1 to Z4 arranged Zudosierkanäle 15 with a respective Zudosierka- nal center line 15.M and a respective Zudosieröffnung 16.

The respective Zudosierkanalmittelliniem 15.M of the two arranged in an opening plane 18 Zudosierkanäle 1 5 of the means 13 for preferably controlled / controllable metered addition of the fluid 14 in partial fluid streams 14. T (arrow) in the pulp suspension 2 is in or only slightly offset parallel to the the three flow channels 6 containing row level Z1 to Z4, thus at least at least three adjacent in a row Z1 to Z4 arranged flow channels 6 with the fluid 14 to feed.

The respective means 13 for preferably controllable metered addition of the fluid 14 in partial fluid streams 14. T (arrows) into the one pulp suspension 2 comprises a metering blade 13.1, as described in the German patent application (Applicant's file: HPA14265 DE and Applicant's working title: "MJ N-DoSTE geometry") with the same filing date as the present patent application is described and shown, the disclosure of which is hereby made the subject of the present description.

FIG. 6 shows a further partial and exemplary longitudinal sectional view of the head box 1 shown in FIG. 1, which has flow channels 6 arranged in four rows Z1 to Z4 with a respective channel center line 6.M of the turbulence generating means 5.

However, the means 13 for preferably controllable metered addition of the fluid 14 in partial fluid streams 14.T (arrow) into the pulp suspension 2 only in three rows Z1 to Z3 arranged Zudosierkanäle 15 with a respective Zudosierkanalmittelliniem 15.M and a respective Zudosieröffnung 16 ,

The respective metering channel center line 15.M of the two metering channels 15 of the means 13 arranged in an opening plane 18 for preferably controllable addition of the fluid 14 in partial fluid streams 14.T (arrows) into the pulp suspension 2 lies approximately in the center, preferably in the middle between the two row levels Z2 and Z3 of two adjacent flow channels 6, thus at least three adjacent in a first row Z2 arranged Flow channels 6 and at least three adjacent in a second and the first row Z2 adjacent row Z3 adjacent flow channels 6 to be fed with the fluid 14.

Furthermore, the respective metering channel center line 15.M of the two metering channels 15 of the means 13 arranged in an opening plane 18 for preferably controllable metering of the fluid 14 in partial fluid streams 14.T (arrows) into the at least one fibrous suspension 2 at an angle .beta the three flow channels 6 containing row level Z1 and Z4. In this case, the angle β assumes a value in the range from 0 to 25 °, wherein the angle β can be directed both upwards (compare line Z1 to flow channels 6) and downwards (compare line Z4 to flow channels 6).

The respective means 13 for preferably controllable metered addition of the fluid 14 in partial fluid streams 14. T (arrows) into the one pulp suspension 2 comprises a metering blade 1 3.1, as described in the German patent application (Applicant's file: HPA14265 DE and Applicant's working title : "MJ M-DoS-TE geometry") having the same filing date as the present patent application is described and shown, the disclosure of which is hereby incorporated by reference.

The two FIGS. 7 and 8 show vertical longitudinal sectional representations through two further embodiments of a headbox 1 according to the invention for producing a merely indicated fibrous web 9 from a pulp suspension 2. The two illustrated embodiments represent, in principle, a further development of the headbox 1 shown in FIG that reference is hereby made to its description. Also can - -

in the respective headbox 8 at least one, the expert well-known and not explicitly shown separating element, in particular a blade be arranged. If a plurality of separating elements, in particular lamellae, are arranged in the respective headbox nozzle 8, they can have different lengths and possibly also different properties, such as surface contours and the like.

In the alternative to the figure 1 embodiment of Figure 8, the turbulence generating means 5 is a directly or indirectly connected to the feeder 3 and known in the art distribution well plate 1 1, in which the operation of the headbox 1, the fibrous suspension 2 by a plurality of rows and arranged in columns S and each having a channel center line 6.M having flow channels 6 flows, characterized in a flow direction R (arrow) having pulp suspension part streams divided 2.T (arrow) and after exiting the turbulence generating means 5 in a chamber 7 in an embodiment of an intermediate chamber 12th is brought together again. The intermediate chamber 12 may in this case be sectioned in the machine transverse direction in a known manner with partitions, not shown. Downstream of the intermediate chamber 12, a turbulence generating means 5 is arranged in the form of a turbulence generator 5.1 known to those skilled in the art.

And upstream of the distributor tube plate 5.2 now means 13 for preferably controllable metered addition of at least one fluid 14 in partial fluid streams 14.T (arrows) in the pulp suspension 2 are provided. The means 13 comprise in each case a plurality of superimposing metering channels 15, each one above the other and each having a metering channel center line 15. M The mutually adjacent means 13 for preferably metered / controllable metering are arranged perpendicular to the flow direction R (arrow) and in a row. Alternatively, they can also be inclined relative to the flow direction R (arrow). The individual metering channel opening 16 of the preferably controllable metering means 13 is arranged at an upstream distance A from the flow channel 6 of the turbulence generator 5.1, wherein the upstream distance A has a value in the range from 1 to 100 mm, preferably from 3 to 50 mm, in particular from 5 to 30 mm, assumes. If the means 13 for preferably controllable metered addition are arranged perpendicular to the flow direction R (arrow), the distance A assumes a value from the stated range. On the other hand, if the means 13 for the preferably controllable metered addition are inclined relative to the flow direction R (arrow), the distances A assume a plurality of values from the stated range.

With regard to the further properties and arrangements of the means 13 for preferably controllable metered addition of the fluid 14, reference is made to the other figures.

Finally, the headbox 1 shown in FIG. 8 has a turbulence generating means 5 arranged downstream of the feeder 3 in the flow direction R (arrow) of the pulp suspension 2 in the form of a turbulence generator 5.1 known to the person skilled in the art, in which the one pulp suspension 2 operates during operation of the headbox 1 through a plurality of in rows and in columns S arranged and each having a channel center line 6.M having flow channels 6 flows, characterized in a flow direction R (arrow) having pulp suspension partial streams divided 2.T (arrow) and after exiting the turbulence generating means 5 in a Machine width chamber 7 in an embodiment of a headbox 8 is brought together again to allow the formation of a machine-wide fibrous web 9. The flow channels 6 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 flow cross sections. The headbox 8 may optionally be provided on the outlet side with at least one dashed line indicated aperture 10.

The turbulence generating means 5 is preceded by no distributor tube plate 11 (see FIGS.

Upstream of the turbulence generator 5.1, in turn, means 13 are provided for preferably controllable metered addition of at least one fluid 14 into partial fluid streams 14.T (arrows) into the pulp suspension 2. The means 13 each comprise a plurality of superimposing and each having a Zudosierka- naline 15.M having Zudosierkanäle 15. The mutually adjacent means 13 for preferably adjustable / controllable metering are perpendicular to the flow direction R (arrow) and arranged in a row. Alternatively, they can also be inclined relative to the flow direction R (arrow).

The individual metering channel opening 16 of the preferably controllable metering means 13 is arranged at an upstream distance A from the flow channel 6 of the turbulence generator 5.1, wherein the upstream distance A has a value in the range from 1 to 100 mm, preferably from 3 to 50 mm, in particular from 5 to 30 mm, assumes. If the means 13 for preferably controllable metered addition are arranged perpendicular to the flow direction R (arrow), the distance A assumes a value from the stated range. On the other hand, if the means 13 for the preferably controllable metered addition are inclined relative to the flow direction R (arrow), the distances A assume a plurality of values from the stated range.

With regard to the further properties and arrangements of the means 13 for preferably controllable metered addition of the fluid 14, reference is made to the other figures. The features of the embodiments described in FIGS. 2 to 6 and 4A can also be combined at least partially with one another by the person skilled in the art in a manner which is obvious.

Furthermore, the fluid 14 flowing in the headbox 1 consists at least of water, in particular white water or clear water, or of at least one pulp suspension whose concentration differs from the average concentration of the at least one pulp suspension 2 flowing in the headbox 1.

The headbox 1 shown and described in each case in the figures is particularly suitable for use in a machine for producing a fibrous web 9, in particular paper or board web, from at least one fibrous stock suspension 2.

In summary, it should be noted that a headbox of the type mentioned is improved by the invention so that the local admixture of a fluid to the flow direction of the at least one pulp suspension can be carried out so that with simpler means the admixture of the fluid as evenly as possible and over Whole height of the pulp suspension layer can be done. The admixture of the fluid is also easily influenced at the same time.

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LIST OF REFERENCES

1 headbox

2 pulp suspension

2.T pulp suspension partial flow (arrow)

3 feeder

4 transverse distribution pipe

5 turbulence generating means

5.1 turbulence generator

6 flow channel

6.M channel centerline

7 machine width chamber

8 headbox nozzle

9 fibrous web

10 aperture

11 distribution hole plate

12 intermediate chamber

13 means for preferably regulated / controllable Zudosie tion of a fluid

13.1 Dosing sword

13.Q cross-sectional area

14 fluid (arrow)

14.T partial fluid flow (arrow)

15 metering channel

15.A cross-sectional area

15.M metering channel centerline

16 metering channel opening

16.A cross-sectional area

17 supply channel

18 opening level

19 recess 20.1 One-sided area

20.2 One-sided area

A distance

B view arrow

L longitudinal direction (arrow)

P1 impact point

P2 impact point

R flow direction (arrow)

S column

S1 column level

S2 column level

S3 column level

Z line

Z1 row level; row

Z2 row level; row

Z3 row level; row

Z4 row level; row

T division

X sectional view

α angle ß angle

Claims

Headbox for a machine for producing a fibrous web Patentansprüche

Headbox (1) for a machine for producing a fibrous web (9), in particular paper or board web, from at least one pulp suspension (2), with at least one feed device (3) feeding the at least one pulp suspension (2) and with at least one turbulence generating means (2). 5, 5.1, 5, 11), in which during operation of the headbox (1) the at least one pulp suspension (2) by a plurality of in

Rows (Z) when forming row levels (Z1 to Z4) and flow channels (6) arranged in columns (S) when forming column planes (S1 to S3) and each having a channel center line (6.M), thereby flowing in a flow direction (FIG. R) and divided after the exit from the turbulence generating means (5, 5.1, 5, 11) in a preferably machine-wide chamber (7, 8, 7, 12) is recombined, upstream of the turbulence generating means (5, 5.1, 5, 11) a plurality of a respective longitudinal direction (L) and in the width direction of the headbox (1) spaced from each other means (13) for preferably adjustable / controllable

Metering of a fluid (14) in partial fluid streams (14.T) are provided in the at least one fibrous suspension (2), each having a respective Zudosierkanalöffnung (16) and Zudosierkanalmittelliniem (15.M) and opening at different heights, with a Common supply channel (17) associated Zudosierkanäle (15), characterized in that in each case two metering channel openings (16) of the means (13) for preferably controllable metered addition of the fluid (14) into partial fluid streams (14.T) into the at least one pulp suspension (2) - in the longitudinal direction (L) of the means (13) for preferably metered / controllable metered addition of the fluid (14), are arranged adjacent to one another when forming an opening plane (18) and their metering channel center lines (15.M) are aligned at an angle (α) to each other by at least three in a row (Z1 to Z4) adjacent to arranged flow channels (6) with the fluid (14) to feed, and that the individual Zudosierkanalöffnung (16) of these two adjacent Zudosierkanalöffnungen (16) of the means (13) for preferably controllable metered addition of the fluid (14) in partial fluid streams (14.T) into which at least one pulp suspension (2) is oriented so that its metering channel centerline (15.M) is located between the column planes (S1, S2; S2, S3) of two adjacent St (6) to the turbulence generating means (5, 5.1; 5, 1 1) impinges upon formation of a point of impingement (P1, P2).

2. headbox (1) according to claim 1, characterized in that the Zudosierkanalmittellinien (15.M) of the two in an opening plane (18) arranged Zudosierkanälen (15) formed angle (α) of the means (13) for preferably regular / controllable metered addition of the fluid (14) in partial fluid streams (14.T) in the at least one pulp suspension (2) has a value in the range of -30 to + 30 °, preferably from 0 to 30 °, in particular from 10 to 30 ° ,

3. headbox (1) according to claim 1 or 2, characterized in that the impact point (P1, P2) of the respective Zudosierkanalmittellinie (15.M) of the two arranged in an opening plane (18) Zudosierkanä-

Ie (15) of the means (13) for preferably controllable metered addition of the fluid (14) in partial fluid streams (14.T) into the at least one pulp suspension (2) on the turbulence generating means (5, 5.1, 5, 11) approximately in the middle, preferably in the middle between the two column planes (S1, S2; S2, S3 ) of two adjacent flow channels (6).

4. headbox (1) according to claim 1 or 2, characterized in that the impact point (P1, P2) of the respective Zudosierkanmittellinie (15.M) of the two in an opening plane (18) arranged Zudosierkanä- Ie (15) of the means (13 ) for the preferably controllable metered addition of the fluid (14) in partial fluid streams (14.T) into the at least one pulp suspension (2) on the turbulence generating means (5, 5.1, 5, 11) off-center between the two column planes (S1, S2; S2, S3) of two adjacent flow channels (6).

5. headbox (1) according to one of the preceding claims, characterized in that the respective Zudosierkanalmittellinie (15.M) of the two in an opening plane (18) arranged Zudosierkanäle (15) of the means (13) for preferably controllable metered addition of the Fluid (14) in partial fluid streams (14.T) in the at least one pulp suspension (2) approximately centrally, preferably centrally between the two row levels (Z1, Z2, Z2, Z3, Z3, Z4) of two adjacent flow channels (6) at least three flow channels (6) arranged adjacently in a first row (Z2) and at least three flow channels (6) arranged adjacent to one another in a second row and the first row (Z2) adjacent to the line (Z3) and to the fluid (14) ,

6. Headbox (1) according to one of claims 1 to 4, characterized that the respective Zudosierkanalmittellinie (15.M) of the two in an opening plane (18) arranged Zudosierkanäle (15) of the means (13) for preferably adjustable / controllable metered addition of the fluid (14) in partial fluid streams (14.T) in the at least one pulp suspension (2) in or only slightly offset parallel to the row plane (Z1 to Z4) containing the three flow channels (6) to at least three flow channels (6) arranged adjacent to one another in a row (Z1 to Z4) with the fluid ( 14) to feed.

7. headbox (1) according to any one of the preceding claims, characterized in that the respective Zudosierkanalmittellinie (1.5M) of the two in an opening plane (18) arranged Zudosierkanäle (15) of the means (13) for preferably controllable metered addition of the fluid (14) in Fluidteilströ- men (14.T) in the at least one pulp suspension (2) under a

Angle (ß) to which the three flow channels (6) containing row level (Z 1, Z4) extends.

8. Headbox (1) according to one of the preceding claims, characterized in that the Zudosierkanalöffnung (16) of the means (13) for preferably controllable / controllable metered addition of the fluid (14) in partial fluid streams (14.T) in the at least one pulp suspension (2) to the turbulence generating means (5, 5.1, 5, 11) has a vertical distance (A) in the range of 1 to 100 mm, preferably from 3 to 50 mm, in particular from 5 to 30 mm.

9. headbox (1) according to any one of the preceding claims, characterized in that the means (13) for preferably controllable metered addition of the

Fluids (14) in partial fluid streams (14.T) into the at least one fibrous fluid Pension (2) in at least one side, preferably two-sided area (20.1, 20.2) between two Zudosierkanalöffnungen (16) of adjacent Zudosierkanälen (15) with at least one recess (19) is provided.

10. Headbox (1) according to one of the preceding claims, characterized in that the Zudosierkanal (15) of the means (13) for preferably controllable / controllable metered addition of the fluid (14) in partial fluid streams (14.T) in the at least one pulp suspension (2) at least in regions has a constant or preferably an abruptly widening cross-sectional area (15.A).

11. Headbox (1) according to any one of the preceding claims, characterized in that the Zudosierkanalöffnungen (16) of the means (13) for preferably regula- / controllable metered addition of the fluid (14) in partial fluid streams (14.T) in the at least a pulp suspension (2) - in the longitudinal direction (L) of the means (13) for preferably controllable / controllable metered addition of the fluid (14) seen - are arranged rectilinear or curved.

12. Headbox (1) according to one of the preceding claims, characterized in that the respective means (13) for preferably controllable / metered metered addition of the fluid (14) in partial fluid streams (14.T) in the at least one pulp suspension (2 ) comprises a metering blade.

13. headbox (1) according to any one of the preceding claims, characterized in that the turbulence generating means (5) is a turbulence generator (5.1) or with the feed device (3) directly or indirectly connected distributor tube plate (11), in which during operation of the Headbox (1) the at least one pulp suspension (2) flows through a plurality of flow channels (6) arranged in rows (Z) when forming row levels (Z1 to Z4) and in columns (S) when forming column planes (S1 to S3), thereby in a flow direction Divided (R) having pulp suspension partial streams (2.T) and after the exit from the turbulence generating means (5, 5.1, 5, 11) in a preferably machine-wide chamber (7, 8, 7, 12) is recombined.

14 headbox (1) according to any one of the preceding claims, characterized in that the fluid (14) at least from water, in particular white water or clear water, or from at least one pulp suspension, the concentration of the average concentration of at least one in the headbox ( 1) flowing pulp suspension (2) differs exists.

15. Machine for producing a fibrous web (9), in particular paper or board web, with at least one headbox (1) according to one of claims 1 to 14.