WO2020043370A1 - Turbulence generator - Google Patents

Abstract

A turbulence generator for a headbox of a machine for producing a fibrous web, in particular a paper or cardboard web, comprising an inlet region having inlets distributed in each case in the machine transverse direction in at least one horizontal plane and each guiding a fibrous suspension inlet flow, and an outlet region having a plurality of outlets distributed in the machine transverse direction in at least one horizontal plane and each guiding a fibrous suspension outlet flow. The turbulence generator is designed here such that the inlet flows fed via the inlets of the inlet region are each divided at least in part into at least two partial flows exiting the outlet region via respective outlets in the form of output flows. The invention also relates to a headbox comprising such a turbulence generator.

Description

 TURBULAR INSERT

The invention relates to a turbulence insert for a headbox of a machine for producing a fibrous web, in particular paper or cardboard web. It also relates to a headbox with such a turbulence insert.

By means of a turbulence insert, the total flow of the fiber suspension is separated into a large number of partial flows in a respective headbox, which are finally brought together again in the nozzle of the headbox to form the overall flow. The turbulence insert imposes a microturbulence on the fibrous suspension, which ensures that, despite the existing aligning forces in the flow, the prevailing orientation of the fibrous materials does not come into play. Such a turbulence insert thus contributes to the fact that the respective fibrous web is produced with a quality that is as uniform as possible.

By combining the partial flows, however, a so-called grid-wake flow can occur, which in the free jet, i.e. in the fiber suspension jet emerging from the nozzle of the relevant headbox, depending on the quality of the flow maintenance, becomes visible as a longitudinally oriented jet disturbance.

The smaller the pitch of the turbulence insert, the better the jet quality is with the same length of the headbox nozzle, since the energy and the size of the wake vortices become smaller.

So far, the division T of the flow guidance within a fibrous suspension fed to the turbulence insert TE has been the same on the inlet side and the outlet side of the turbulence insert TE (cf. FIG. 1 of the attached drawing). However, the smaller the pitch T on the inlet side of the turbulence insert TE, the more critical the operation of the relevant headbox with regard to blockages. For smooth operation, the web width S between two adjacent inlets of the turbulence insert TE should therefore not be less than a minimum value in the range from 7 mm to 15 mm. The conditions required for safe operation with regard to the minimum web width and a minimum inlet diameter D1 (e.g. 7 mm to 15 mm) result in a minimal division T of the inlets of 14 mm to 30 mm for the inlet side of the turbulence insert TE.

Due to this relatively large division T, the previously mentioned jet disturbances of the lattice wake flow in the free jet of the headbox cannot be sufficiently prevented with the previous turbulence inserts.

The invention is based on the object of specifying a turbulence insert and a headbox of the type mentioned at the outset with which the disadvantages mentioned above are eliminated. In particular, an improvement in the quality of the fiber suspension jet produced should be achieved while maintaining the minimum web width between the inlets of the turbulence insert, which is required for a safe flow division on the inlet side of the turbulence insert and accordingly for reliable operation.

According to the invention, this object is achieved by a turbulence insert with the features of claim 1 and a headbox with the feature of claim 15. Preferred embodiments of the turbulence insert according to the invention result from the subclaims.

The turbulence insert according to the invention for a headbox of a machine for freezing a fibrous web, in particular paper or cardboard web, comprises an inlet area with inlets distributed in at least one horizontal plane each in the cross-machine direction, each leading a fibrous suspension inlet flow and an outlet area with a plurality of outlets distributed in at least one horizontal plane in the cross-machine direction, each leading a fibrous suspension outlet flow. The turbulence insert is designed in such a way that the inlet flows conducted through the inlets of the inlet area are at least partially divided into at least two partial flows emerging as outlet flows via a respective outlet of the outlet area.

The division of the outlets of the outlet area distributed in the cross-machine direction and arranged in at least one horizontal plane is preferably smaller than the division of the inlets distributed in a respective horizontal plane in the cross-machine direction.

Due to the reduction of the division on the outlet side of the turbulence insert according to the invention compared to the division provided on its inlet side, the quality of the fiber suspension jet to be produced is maintained, while maintaining the minimum web width required for safe flow distribution on the inlet side and correspondingly for reliable operation Inlet of the turbulence insert noticeably improved. The division on the inlet side of the turbulence insert can still be kept relatively large and, for example, larger than 20 mm. After the first separation in the area of the inlets of the turbulence insert, the volume flow is divided again within a respective flow path, so that the division on the outlet side of the turbulence insert is reduced accordingly.

According to a preferred practical embodiment of the turbulence insert according to the invention, a respective inlet with the inlet area in the flow direction of the fiber suspension is viewed in each case with a chamber downstream flow cross-section for the inlet flow coming from the inlet downstream.

Due to the high flow velocity in a respective inlet, which can be greater than 5 m / s for example, such a chamber becomes a turbulence chamber, which causes fluidization of the fiber suspension and keeps the webs between the smaller inlets free.

The partial flows generated from a respective inlet flow are advantageously fed from the chamber.

A respective inlet flow can, for example, be divided into two or four partial flows. In principle, however, it is possible to divide a respective inlet flow into any number of partial flows, which can also be greater than 4, for example. The more partial flows a respective inlet flow is divided into, the greater the grating division on the outlet side compared to the grating division on the inlet side of the turbulence insert.

The division of a respective inlet flow, when viewed in the direction of flow, expediently takes place at the end of the chamber.

In the section of the outlet area downstream of a respective chamber, the partial flows generated from a respective inlet flow are advantageously guided in such a way that they emerge at least substantially parallel to one another from the relevant outlet of the outlet area.

The partial flows generated from a respective inlet flow can at least partially emerge from outlets of the outlet area lying in a common horizontal plane and / or at least partially from outlets of the outlet area lying in different horizontal planes. The inlets leading into the outlet area for the partial flows fed from a respective chamber are preferably arranged in corner areas provided at the downstream end of the chamber. As a result, large web widths between the inlets are achieved and faults caused by fiber accumulations are reduced or even avoided.

In the simplest case, the outlet plane of a respective chamber provided at the beginning of the inlets leading into the outlet region for the partial flows fed from a respective chamber is oriented at least essentially evenly and perpendicularly to the flow direction of the respective inlet flow.

According to an advantageous alternative embodiment of the turbulence insert according to the invention, the outlet plane of a respective chamber provided at the beginning of the inlets leading into the outlet region for the partial flows fed from a respective chamber has a shape deviating from a flat shape. In terms of flow technology, the outlet level can in particular be designed in such a way that contamination is avoided as far as possible.

It is particularly advantageous if a respective chamber is provided with radii in the area of the free edges or corners of the outlet level provided between the inlets leading into the outlet area. With such radii, flow dead spaces in particular are avoided. Alternatively or additionally, a pointed cone can be provided as a flow divider in the central area of the outlet level.

A respective chamber can have, for example, a square or rectangular cross section. In principle, however, such a chamber can take any form. A chamber with a rectangular cross-section is particularly advantageous in that it is a vertical or z-direction between outlets lying slat holder allows more space in the z direction than in the transverse direction, in which the outlet is located on the outlet.

The largest flow cross section of a respective chamber is preferably at least 1.5 times larger than the inlet cross section of a respective inlet on the inlet side of the inlet region.

A respective inlet of the inlet area can in particular have a flow cross section which is at least substantially constant over its length dimensioned in the direction of flow.

According to a preferred practical embodiment of the turbulence insert according to the invention, a respective continuous inlet of the inlet area is followed by a continuous diffuser, short diffuser or step diffuser which widens the flow cross section for the inlet flow coming from the inlet.

It is also particularly advantageous if, in the outlet area, in particular both in the horizontal plane and in the vertical plane, there is an asymmetrical flow of the partial flows generated from a respective inlet flow.

Such an asymmetrical design of the flow guide allows a relatively large web width to be maintained between the inlets arranged in a respective horizontal plane, despite the relatively small division on the outlet side on the inlet side. By means of a corresponding flow deflection, the partial flows on the outlet side can at least essentially be carried out parallel to one another again.

The division of the outlets of the outlet area, which are distributed in a respective horizontal plane in the cross-machine direction, can expediently be carried out in one range from 5 mm to 25 mm, wherein they are preferably in a range from 10 mm to 20 mm.

The division of the inlets distributed in a respective horizontal plane in the cross-machine direction is preferably greater than approximately 20 mm.

The flow speed of a respective inlet flow is advantageously greater than 5 m / s. A separating point can be provided in the flow direction between a respective inlet and the associated outlets of the outlet region, said separation point preferably being arranged directly after a respective diffuser.

The separation point can expediently be provided with a seal, which is preferably designed as an O-ring.

It is also advantageous if the turbulence insert is at least partially produced by an additive manufacturing process. Such an additive manufacturing process (AMT, Additive Manufacturing Technology) makes it possible to produce more complex components from plastics or metals in layers. In contrast to the previous manufacturing processes such as turning, milling and drilling, additive processes enable the components to be made fiery by adding material instead of cutting and removing it. In particular, smaller wall thicknesses between adjacent flow passages and, in particular, adjacent chambers and sections of the outlet area can thus be realized, which in turn permits relatively large web widths between the inlets. Correspondingly, the inlets to adjacent sections of the outlet area can also be closer together. By means of the additive manufacturing process, several flow channels or units of the turbulence insert can be manufactured together, whereby they are preferably manufactured as modules with a certain module width. According to an expedient practical embodiment of the turbulence insert according to the invention, a plurality of flow passages or units are printed as a module with the respective module width on a pressure plate, which is preferably attached to a machine-wide inlet plate. Advantageously, the smallest wall thicknesses between adjacent flow channels or units, each comprising at least one inlet, one chamber and the relevant outlets, preferably the smallest wall thickness between the chambers of adjacent units, is up to 0.2 mm small.

The smallest wall thicknesses of individual flow paths or units or modules can therefore be half as large in the direction of an adjacent flow path or unit or module, that is to say as small as 0.1 mm. In the outermost flow paths or units or modules, that is to say in those which are arranged at the edges of the turbulence insert, the outward-facing wall thicknesses are preferably of the same size as those for an adjacent flow path or for a neighboring unit or for one Show neighboring module. This means that the same cross-sectional conditions at the outlet area and thus low beam interference can be achieved. At least two individual flow channels or units or modules can be arranged next to one another for the setting of a turbulence insert. The minimum wall thickness is up to 0.2 mm. So twice as thick as the wall thickness of a single flow passage or unit or module. Such small wall thicknesses can be realized in particular with a previously mentioned additive manufacturing process.

A horizontally extending receptacle for at least one lamella or baffle is expediently provided between the outlets of the outlet region arranged in mutually adjacent horizontal planes.

The partial flows generated from different inlet flows are preferably guided in the outlet area in outlet channels which are at least partially oriented at different angles relative to the direction of flow of the inlet flow, wherein they can preferably be directed towards the nozzle end of the relevant headbox.

In this way, deflection vortices in the nozzle inflow are avoided in particular.

The inlets leading into the outlet area can in particular have a round or rectangular cross section. A rectangular cross section of these inlets leading into the outlet area again has the particular advantage that the web widths between the inlets on the inlet side can be kept relatively large.

It is also advantageous if the inlets leading into the outlet area for the partial flows fed from a respective chamber are not only offset relative to one another in the horizontal direction, but alternatively or additionally in the vertical direction.

The cross section of a respective partial flow is preferably increased by more than 10% from the inlet side of the outlet region to the outlet side thereof. It is particularly advantageous if the increase in cross-section of a respective partial flow from the outlet side of a respective chamber to the outlet side of a respective outlet channel takes place stepwise, continuously and / or by means of a diffuser.

The total length of the flow guidance of a respective partial flow in the outlet area advantageously corresponds to at least 3 times the hydraulic diameter at the end of a respective outlet or outlet channel from which the partial flow exits.

According to a further preferred practical embodiment of the turbulence insert according to the invention, a respective section or outlet channel of the outlet region that guides a partial flow each comprises an inlet region and a wake region.

It is particularly advantageous if the length of the inlet area of a respective section or outlet channel of the outlet area measured in the direction of flow is greater than 0.2 times the diameter of the inlet area.

The length of the wake of a respective section of the outlet area is preferably greater than 3 times the hydraulic diameter of the respective outlet, from which the relevant partial flow emerges.

The headbox according to the invention is characterized in that it comprises at least one turbulence insert according to the invention.

The invention is explained in more detail below on the basis of exemplary embodiments with reference to the drawing; in this show: 1 is a schematic, partial perspective view of a conventional turbulence insert,

Fig. 2 is a schematic, perspective view of a

 Inlet of an inlet area, a chamber and a part of the outlet area which contains the part of the flow area generated by dividing the inlet flow of an exemplary embodiment of a turbulence insert according to the invention.

3 shows a schematic sectional side view of different parts, each comprising an inlet of the inlet area, a chamber and a portion of the outlet area which receives the partial flows generated by dividing the respective inlet flow, of different parts of different exemplary embodiments of the inventive turbulence insert , in which a continuous diffuser, a short diffuser and / or step diffuser is arranged downstream of a respective inlet to expand the flow cross section,

Fig. 4a is a schematic plan view of the beginning of the in the

Outflow area leading inlets provided outlet planes of two chambers immediately adjacent in the transverse direction of an exemplary embodiment of a turbulence insert according to the invention, in which a respective inlet flow is divided into four partial flows, 4b shows a schematic illustration of an inlet and a chamber downstream of this, of an exemplary embodiment of a turbulence insert according to the invention, in which the inlet flow is divided into four partial flows,

4c shows a schematic representation of an inlet and a chamber downstream from it of a further exemplary embodiment of a turbulence insert according to the invention, in which the inlet flow is divided into two partial flows,

5 shows a schematic perspective illustration of two adjacent ones, in each case one inlet of the inlet area, one chamber and one by dividing the respective

Parts of an exemplary embodiment of a turbulence insert according to the invention, which part of the outlet area comprises partial flow-receiving portions and which is provided with a receptacle for fastening at least one lamella or guide plate,

6 shows a schematic sectional side view of an exemplary embodiment of a turbulence insert according to the invention, in which the partial flows generated from different inlet flows are led into outlet channels which are at least partially directed at different angles relative to the direction of flow of the inlet flows. 7 shows a schematic, sectional top view of a plurality of flow paths jointly produced by an additive manufacturing process as a module with a specific module width of a further exemplary embodiment of a turbulence insert according to the invention,

FIG. 8 is a schematic sectional view comparable to FIG. 3

 Side view of various parts of an inlet of the inlet area, a chamber and a portion of the outlet area which contains the partial flows generated by a division of the respective inlet flow of different exemplary embodiments of the inventive turbulence insert, several as modules with one flow channels or units provided for a certain module width are printed on a pressure plate, which can be attached to a machine-wide inlet plate,

Fig. 9 is a schematic plan view of the beginning of the in the

 The outlet plane of the outlet area leading to the outlet area of a chamber of an exemplary embodiment of a turbulence insert according to the invention, the chamber being provided with radii in the area of the edges or corners of the outlet plane leading between the inlet area leading to the outlet area and a pointed cone as a flow divider in the middle area of the outlet plane is provided,

FIG. 10 shows a schematic sectional illustration of the transition region between the outlet plane and the outlet plane according to FIG. 9 Chamber and the adjacent section of the outlet area, cut along the line AA in FIG. 9,

11 is a schematic plan view comparable to FIG. 9 of the outlet plane of a chamber of a further exemplary embodiment of a turbulence insert according to the invention provided at the beginning of the inlets leading into the outlet region, in which the chamber is used both in the transverse direction and in the vertical or z direction inlets offset relative to one another and arranged in two different horizontal planes each have an at least essentially rectangular cross section,

Fig. 12 is a schematic comparable with FIGS. 9 and 11

 Top view of the outlet plane of a chamber of a further exemplary embodiment of a turbulence insert according to the invention, provided at the beginning of the inlets leading into the outlet area, in which they again offset each other in the transverse direction as well as in the vertical or z direction Inlets, however, each have an at least essentially round cross section and are arranged in four different horizontal planes due to the respective offsets in the z direction, and

FIG. 13 shows a schematic sectional view comparable to FIG. 3

Side view of an inlet of the inlet area, a chamber and a section of the outlet area that receives the partial flows generated by dividing the inlet flow of a further exemplary embodiment of the invention Turbulence insert, in which the cross section of a respective partial flow increases by more than 10% from the inlet side of the outlet area to the outlet side thereof.

1 shows a schematic perspective partial representation of a conventional turbulence insert TE 'with an inlet area 10 with inlets 12 which each distribute a fiber suspension inlet flow and have an outlet area 14 with a plurality of, distributed in two horizontal planes in the cross-machine direction CD again in two horizontal planes in the cross-machine direction CD, each with a fiber suspension outlet flow leading outlets 16.

In this conventional turbulence insert TE ', the division T' of the outlets 16 of the outlet region 14 distributed in a respective horizontal plane in the cross-machine direction CD is equal to the division T of the inlets distributed in a respective horizontal plane in the cross-machine direction CD. With such a conventional turbulence insert TE ', the disadvantages mentioned at the outset result.

FIGS. 2 to 13 show different exemplary embodiments of a turbulence insert TE according to the invention for a headbox of a machine for locating a fibrous web, in particular paper or cardboard web.

A respective turbulence insert TE according to the invention comprises an inlet area 18 with inlets 22 distributed in at least one horizontal plane, each in the cross-machine direction CD, each carrying a fiber suspension inlet flow, and an outlet area 24 with a multiplicity of in at least one horizontal plane in Cross machine direction CD distributed, each a fiber suspension partial flow 28 outlets 26. A respective turbulence insert TE according to the invention is designed in such a way that the inlet flows 20 supplied via the inlets 22 of the inlet area 18 are each divided into at least two partial flows exiting via a respective outlet 26 of the outlet area 24 as outlet flows.

The division T _from the outlets 26 of the outlet area 24, which are distributed in the cross-machine direction CD and are arranged in at least one horizontal plane, is in each case smaller than the division T _E m of the inlets 22 distributed in a respective horizontal plane in the cross-machine direction CD (cf. especially Fig. 5).

As can be seen in particular from FIGS. 2, 3 and 6 to 8, a respective inlet 22 of the inlet region 24 in the flow direction SF of the fibrous suspension can be viewed in each case with a chamber 30 with a flow cross section widening in the flow direction SF for the one coming from the inlet 22 Inlet flow 20 may be arranged downstream. The partial flows 28 generated from a respective inlet flow 20 are fed from the chamber 30.

As can be seen in particular from FIGS. 2 to 4 and 6 to 13, the division at the respective inlet flow 20, viewed in the flow direction, can take place at the end of the chamber 30.

In the section of the outlet area 34 downstream of a respective chamber 30, the partial flows 28 generated from a respective inlet flow 20 can be guided in such a way that they emerge at least substantially parallel to one another from the respective outlets 26 of the outlet area 24 (cf. in particular 3 and 8).

The partial flows 28 generated from a respective inlet flow 20 can at least partially originate from outlets lying in a common horizontal plane. run 26 and / or at least partially emerge from outlets 26 of the outlet area 24 lying in different horizontal planes.

In the embodiments of a turbulence insert according to the invention shown in FIGS. 2 to 4b and 5 to 13, the inlet flows 20 are each divided into four partial flows 28, for example, which emerge from outlets 26 of the outlet region 24 lying in two horizontal planes parallel to one another.

In contrast, in the embodiment shown in FIG. 4c, a respective inlet flow 20 is divided into only two partial flows 28, which emerge from two outlets 26 of the outlet area 24 lying in a common horizontal plane.

As can be seen in particular from FIGS. 2, 4a, 4b, 9 and 11, the inlets 32 leading into the outlet area 24 can be provided for the partial flows 28 fed from a respective chamber 30 in corner regions 34 provided at the downstream end of the chamber 30 .

As can be seen in particular from FIGS. 2, 6, 7 and 13, the outlet plane AE of a respective chamber 30 provided at the beginning of the inlets 32 leading into the outlet region 24 for the outlet flows 28 fed from a respective chamber 30 can at least in the Be aligned substantially flat and perpendicular to the flow direction of the inlet flow 20 in question.

However, embodiments of the turbulence insert TE according to the invention are also conceivable in which the outlet plane AE of a respective chamber 30 provided at the beginning of the inlets 32 leading into the outlet region 24 for the partial flows 28 fed from a respective chamber 30 is one of a plane Form has a different shape (cf. in particular the in FIG. 3, 8, 9 and 10 reproduced exemplary embodiments of the turbulence insert TE) according to the invention.

The outlet plane AE of a respective chamber 30 does not necessarily have to be flat and normal to the main flow direction, as is the case, for example, in the embodiment according to FIG. 2. In terms of flow technology, this outlet level AE can also be designed to avoid contamination. Thus, as can be seen, for example, from FIGS. 9 and 10, a respective chamber 30 in the region of the free edges or corners 34 of the outlet plane AE provided between the inlets 32 leading to the outlet region 34 can be provided with radii R in order to create dead spaces in the flow avoid. In addition, a pointed cone SK can be provided as a flow divider in the central area of the outlet level AE. This has a diameter of SKD at its base and a height of SKH.

The basic shape of a respective chamber 30 can basically take all forms. However, it expediently has a square or rectangular cross section. Here, a rectangular cross section has the particular advantage that a lamella holder or the like arranged in the vertical or z-direction between the outlets 36 provided in two adjacent horizontal planes allows more space in the z-direction (cf. in FIG. 11 the dimension KH) than in the transverse or CD direction (cf. the dimension KB in FIG. 11).

The largest flow cross section of a respective chamber 30 can be at least 1.5 times larger than the inlet cross section of a respective inlet 22 on the inlet side of the inlet region 18.

As can best be seen from FIG. 2, a respective inlet 22 of the inlet region 18 can have an at least substantially constant flow cross-section over its length measured in the direction of flow. A respective diffuser DS, short diffuser DK and / or step diffuser DS, which extends the flow cross section for the inlet flow 20 coming from the inlet 22, can be arranged after a respective inlet 22 of the inlet region 18 (cf. in particular FIG. 3).

3, in particular, it can also be seen that in the outlet area 24, in particular both in the horizontal plane and in the vertical plane, asymmetrical flow guidance of the partial flows 28 generated from a respective inlet flow 20 can take place.

The division T _from the outlets 26 of the outflow region 24 (see FIG. 5, for example) distributed in a respective horizontal plane in the machine direction CD can be in a range from 5 mm to 25 mm, in particular in a range from 10 mm to 20 mm lie.

The division T _{One of} the inlets 22 distributed in a respective horizontal plane in the machine direction CD can be greater than approximately 20 mm. The flow velocity of a respective inlet flow 20 can be greater than 5 m / s.

As can be seen in particular in FIG. 8, a separation point TR can be provided in the flow direction between a respective inlet 22 and the associated outlets 26 of the outlet area 24, which can be arranged in particular directly after a respective diffuser DS, DK, DSD (cf. again Fig. 3). In this case, the separation point TR can be provided with a seal 38, in particular as an O-ring.

The turbulence insert TE can be produced at least in part by an additive manufacturing method, ie according to the so-called AM technology (Additive Manufacturing Technology). As can be seen in particular from FIG. 7, such an additive manufacturing method can be used to produce a plurality of flow channels or units 40 of the turbulence generator TE, whereby they can be manufactured in particular as modules with a certain module width TM.

In this case, a plurality of flow channels or units can be printed as a module with the respective module width TM on a pressure plate AP, which can in particular be attached to a machine-wide inlet plate EP (cf. in particular FIG. 8).

Such an inlet plate EP can optionally be machine-wide.

The use of AM technology enables very small wall thicknesses W of up to 0.2 mm between adjacent flow passages or units 40 each comprising at least one inlet 22, one chamber 30 and the respective outlets 26 (cf. Fig. 4). As can be seen from FIG. 4, such smallest wall thicknesses W of up to 0.2 mm are possible in particular between the chambers 30 of the adjacent flow passages or units 40. A maximum asymmetry and a large web between the inlets 22 can thus be realized, for example by virtue of the chambers 30 of two flow channels or units 40, which are adjacent to one another, being close together. As can be seen in particular from FIG. 5, a horizontally extending receptacle 42 for at least one lamella or guide plate 44 can be provided between the outlets 26 of the outlet area 24 arranged in adjacent horizontal planes (cf. also FIGS. 6 and 8). . As can be seen in particular from FIG. 6, in particular to avoid deflecting vortices in the nozzle inflow, the partial flows 28 generated from different inlet flows 20 can be guided in outlet area 24 in outlet channels 46, which are at least partially at different angles a relative to the direction of flow Inlet flows 20 are aligned. In particular, they can be directed towards the nozzle end 48 of the headbox in question.

The inlets 32 leading into the outlet area 24 can have a round (see FIGS. 2, 4, 9 and 12) or a rectangular (see FIG. 11) cross section. In order to obtain a maximum web height S _H and a maximum web width S _B (cf. again FIG. 9), the outlets 26 can also be rectangular, for example with the dimensions AA, AB of the inlets 32 (cf. again FIG. 11).

The inlets 32 leading into the outlet area 24 for the partial flows 28 fed from a respective chamber 30 can be offset relative to one another in the horizontal direction and / or in the vertical direction. 11, the inlets here, for example, four in the horizontal direction and in the vertical direction are offset such that two inlets 32 are arranged in an upper horizontal plane and two inlets 32 in an underlying plane, two each inlets 32 lying in different horizontal planes I are aligned with one another when viewed in the cross-machine direction CD.

In the illustration according to FIG. 12, four inlets 32 are again provided. In the present case, however, these are offset relative to one another in the horizontal direction in the vertical direction in such a way that they lie in four different horizontal planes. In the present case, however, two inlets 32 arranged in different horizontal planes in machine cross direction CD are aligned with each other. Here, as can be seen from FIG. 12, the right pair of inlets 32 are offset from the left pair of inlets 32 by the amount V _H in the z direction.

As can be seen, for example, from FIG. 13, the cross section of a respective partial flow 28 can vary from the outlet plane AE of the respective chamber 30 provided at the beginning of the inlets 32 leading into the outlet area 24 for the partial flows 28 fed from a respective chamber 30 to the outlet side Increase A of each outlet channel 46, for example, it can increase by more than 10%. The increase in cross section of a respective partial flow 28 from the outlet plane AE of a respective chamber 30 to the outlet side A of a respective outlet channel 46 can take place in steps, continuously and / or by means of a diffuser. The total length L _{QA of} the flow guidance of a respective partial flow 28 in the outlet area 24 (cf. FIG. 13) can correspond to at least 3 times the hydraulic diameter c _hy at the end of a respective outlet 26 or outlet channel 46 at which the partial flow 28 exit.

As can also be seen from FIG. 13, a respective section or outlet channel 46 of the outlet region 24 which carries a partial flow 28 can each comprise an inlet region 50 and a follower region 52. The length Li of the inflow area 50 of a respective section or outlet channel 46 of the outflow area 24, measured in the flow direction, can be greater than 0.2 times the diameter Fu of the inflow area 50. The length L ₂ + L _{3 of} the lag area 52 of a respective section or outlet channel 46 of the outlet area 24 can be greater than 3 times the hydraulic diameter _hy at the end of a respective outlet 26 or outlet channel 46, at which the relevant partial flow 28 emerges. The purely exemplary embodiments described in connection with the drawing are conceivable individually or in any combination with one another. The inventive reduction of the division on the outlet side A compared to the division on the inlet side E of the turbulence generator TE in particular improves the jet quality. In addition, the minimum web width required for a safe flow distribution on the inlet side A of the turbulence generator TE can be observed. The integration of the slat technology is at least simplified. The optional AM technology can also be used to implement more complicated flow patterns.

The headbox according to the invention is characterized in that it contains at least one turbulence insert TE according to the invention.

Reference list

10 lead-in area

 12 enema

 14 outlet area

 16 outlet

 18 inlet area

 20 inlet flow

 22 enema

 24 outlet area

 26 outlet

 28 partial flow

 30 chamber

 32 inflow

 34 corner area

 36 free margin

 38 sealing

 40 flow passage, unit

42 recording

 44 lamella, baffle

 46 outlet channel

 48 nozzle end

 50 inlet area

 52 Tracking area

 A outlet side

 A 'outlet side

 AA measure

 AB dimension

 AE outlet level

AP pressure plate CD cross machine direction

 DK short diffuser

 DS continuous diffuser

 E inlet side

 EP inlet plate

K _H measure

 LI length of the inlet area

L ₂ + L ₃ Length of the wake area

 LQA total length

 SD step diffuser

 R radius

S _B web width

S _H bridge height

 SF Flow direction of the fiber suspension

SK pointed cone

 SKD diameter

 SKH fleas

 T division on the inlet side

r division on the outlet side

 TAUS division on the outlet side

TA division on the inlet side

 TE turbulence generator

 TE 'conventional turbulence generator

 TM module width

 TR separation point

 W wall thickness

z vertical direction

a angle

 ®hy hydraulic diameter at the end of an outlet

®L1 diameter of an inlet area

Claims

claims 1 turbulence insert (TE) for a headbox of a machine for producing a fibrous web, in particular paper or cardboard web, with an inlet area (18) with a large number of fibrous suspension suspensions distributed in at least one horizontal plane in the cross-machine direction (CD). Inlets (22) guiding inlet flow (20) and an outlet area (24) with a plurality of outlets (26) distributed in at least one horizontal plane in the cross-machine direction (CD), each carrying a fiber suspension outlet flow, the Turbulence insert (TE) is designed in such a way that the inlet flows (20) supplied via the inlets (22) of the inlet region (18) are at least partly in each case in at least two via a respective outlet (26) of the outlet region (24) as outlet flows emerging partial flows (28) are divided. 2 turbulence insert according to claim 1, characterized in that the division (T _Aus ) of the outlets (26) of the outlet region (24) which are distributed in the cross-machine direction (CD) and are arranged in at least one horizontal plane is smaller than the division (T _On ) of those in a respective horizontal plane in machines - Transverse direction (CD) distributed inlets (22). 3 turbulence insert according to claim 1 or 2, characterized in that a respective inlet (22) of the inlet region (24) in the flow direction (SF) of the fiber suspension is viewed in each case by a chamber (30) with a Direction (SF) expanding flow cross-section for the inlet flow (20) coming from the inlet (22) is arranged downstream. 4. turbulence insert according to claim 3,  thereby, the partial flows (28) generated from a respective inlet flow (20) are fed from the chamber (30) and the division of a respective inlet flow (20) preferably takes place at the end of the chamber (30). 5. Turbulence insert according to at least one of the preceding claims, characterized in that in the section of the outlet region (24) downstream of a respective chamber (30) the partial flows (28) generated from a respective inlet flow (20) are guided such that they emerge at least substantially parallel to one another from the relevant outlets (26) of the outlet area (24). 6. Turbulence insert according to at least one of the preceding claims, characterized in that the inlets (32) leading into the outlet area (24) for the partial flows (28) fed from a respective chamber (30) in at the downstream end of the chamber (30 ) provided corner areas (34) are provided. 7. Turbulence insert according to at least one of the preceding claims, characterized in that the outlet plane (AE) provided at the beginning of the inlets (32) leading into the outlet region (24) for the partial flows (28) fed from a respective chamber (30) Chamber (30) is aligned at least substantially flat and perpendicular to the flow direction of the inlet flow (20) in question. 8. Turbulence insert according to at least one of the preceding claims, characterized in that a respective chamber (30) in the region of the free edges or corners (34) of the outlet plane (AE) provided between the inlets (32) leading into the outlet region (24) ) with radii (R) and / or a pointed cone (SK) is provided as a flow divider in the central area of the outlet level (AE). 9. Turbulence insert according to at least one of the preceding claims, characterized in that a respective inlet (22) of the inlet region (18) each has a flow cross section for the inlet flow (20) coming from the inlet (22) expanding continuous diffuser (DS), short diffuser (DK) and / or step diffuser (DSD). 10. Turbulence insert according to at least one of the preceding claims, characterized in that the division (T _Aus ) of the outlets (26) of the outlet region (24) distributed in a respective horizontal plane in the machine transverse direction (CD) in a range from 5 mm to 25 mm, preferably in a range of 10 mm to 20 mm, is and / or that the spacing (T _a) in a respective horizontal plane in the cross machine direction (CD) distributed inlets (22) is greater than about 20 mm. 11. Turbulence insert according to at least one of the preceding claims, characterized in that in the flow direction between a respective inlet (22) and the associated outlets (26) of the outlet region (24), preferably immediately after a respective diffuser (DS, DK, DSD ) a separation point (TR) is provided. 12. Turbulence insert according to at least one of the preceding claims, characterized in that the turbulence insert (TE) is at least partially produced by an additive manufacturing process and preferably by the additive manufacturing process several flow channels or units (40) of the turbulence generator (TE) together, preferably as modules with a certain module width (TM), are manufactured. 13. Turbulence insert according to at least one of the preceding claims, characterized in that the partial flows (28) generated from different inlet flows (20) are guided in the outlet region (24) in outlet channels (46) which are at least partially at different angles (a) are aligned relative to the flow direction of the inlet flows (20), wherein they are preferably directed towards the nozzle end of the relevant headbox. 14. Turbulence insert according to at least one of the preceding claims, characterized in that the cross section of a respective partial flow (28) from the inlets (32) leading into the outlet area (34) for the from a respective chamber ( 30) supplied partial flows (28) provided outlet plane (AE) of a respective chamber (30) up to the outlet side (A) of a respective outlet channel (46) enlarged by more than 10% and preferably the cross-sectional increase of a respective partial flow ( 28) from the outlet level (AE) of a respective chamber (30) to the outlet side (A) of a respective outlet channel (46) in steps, continuously and / or by means of a diffuser. 15. Headbox of a machine for the production of a fibrous web, in particular a paper or cardboard web, with at least one turbulence insert (TE) according to at least one of the preceding claims.