Dilution element for headbox of web machine and headbox of fiber web machine

Abstract

A dilution element for a headbox of a fiber web machine and a headbox of a fiber web machine. A dilution element is associated with the headbox and includes: at least one mixing space formed inside the dilution element; an opening formed in the dilution element and incorporated in the mixing space, the dilution water being supplied into the mixing space through the first opening, the slurry flow being supplied into the mixing space from the manifold through the second opening by means of an inlet pipe fitted in the second opening, the slurry flow diluted with the dilution water is supplied forward in the flow direction from the mixing space through the third opening by means of an outlet tube fitted in the third opening, the outlet tube being sealed against an inner surface of the third opening. The dilution element is formed by a tube liner on a portion between the second and third openings, the mixing space is formed within the tube liner, and the first opening is formed in a housing of the tube liner. The inlet tube extends to a first opening in the tube liner in a direction of travel of the slurry flow, and the inlet tube is sealed against an inner surface of the tube liner.

Description

Technical Field

[0001] The present invention relates to a dilution element for a headbox of a fiber web machine, which is suitable for being associated with the headbox and comprises: at least one mixing space, which is suitable for being formed inside the dilution element; an opening, which is adapted in the dilution element and is suitable for merging into the mixing space, through which the following operations are realized: dilution water is suitable for being supplied into the mixing space through a first opening; a stock flow is suitable for being supplied into the mixing space from a manifold through the second opening by means of an inlet pipe adapted in the second opening; the stock flow diluted with dilution water in the mixing space is suitable for being supplied forwardly from the mixing space in a flow direction through the third opening by means of an outlet pipe adapted in the third opening, the outlet pipe being suitable for being sealed against an inner surface of the third opening; on a portion between the second opening and the third opening, the dilution element is suitable for being formed by a pipe bushing, the mixing space is suitable for being formed in the pipe bushing, the first opening being adapted in the housing of the pipe bushing.

[0002] The invention also relates to a headbox of a fiber web machine. Background Art

[0003] As a massive structural component, the dilution element of the applicant for the headbox is very expensive to manufacture. Moreover, due to the massiveness of the structural component, it is not possible to significantly change its dimensions later. The structural component is a solid plate having the same width as the entire machine, in which holes have been machined over the entire width of the machine for the stock flow and dilution water to be supplied through the plate and for the stock flow and dilution water to be mixed within the structural component.

[0004] Figure 1 An example of a prior art solution is shown, with a cross section of the headbox in the transverse direction of the machine. In the figure, the stock flow 38 is supplied from the manifold 26 through the distribution plate 17', the inlet pipe 16 fitted in the distribution plate, the dilution element 10', the outlet pipe 29 and the distribution pipe 32 onwards (through the intermediate chamber) to the turbulence generators and from there further to the wire (not shown). The dilution water supply itself is associated with the opening 15, supplied through a pipe connection 21 fitted to the dilution element 10'.

[0005] The dilution element 10' is formed by a structural member 11.1 and its cover 11.2, which are sequentially adapted and connected to each other in the machine direction MD. In this case, a mixing space 14 is formed in the dilution element 10', and the dilution water supplied to the mixing space 14 is mixed with the slurry flow supplied from the manifold 26 to the mixing area 14. In this way, a single dilution element 10' contains several independent mixing spaces 14 arranged side by side in the transverse direction of the machine. Figure 1As shown, the structural element 11.1 and its cover 11.2 are plates with a solid cross section, which are relatively high in relation to the height of the through-flow channel and the mixing space 14, and whose manufacture and support of the headbox structure 17' also involve welding. When implemented in this way, these structures become relatively expensive. Summary of the invention

[0006] The object of the invention is to achieve a dilution element for a headbox of a fiber web machine, wherein the dilution element has a light and simple structure, which is also easier to construct.The features of the dilution element according to the invention will be more fully understood from the text. The present application provides a dilution element for a headbox of a fiber web machine, the dilution element being suitable for being associated with the headbox and comprising: at least one mixing space being suitable for being formed inside the dilution element; an opening being adapted in the dilution element and being adapted to be merged into the mixing space, wherein: dilution water is suitable for being supplied into the mixing space through a first opening, a pulp flow is suitable for being supplied into the mixing space from a manifold through the second opening by means of an inlet pipe adapted in the second opening, the pulp flow diluted with dilution water in the mixing space is suitable for being supplied forwardly from the mixing space along a flow direction through the third opening by means of an outlet pipe adapted in the third opening, the outlet pipe being suitable for being sealed against an inner surface of the third opening, the dilution element being suitable for being formed by a pipe bushing on a portion located between the second opening and the third opening, the mixing space being suitable for being formed inside the pipe bushing, and the first opening being adapted in a housing of the pipe bushing, the inlet pipe extending into the pipe bushing in the traveling direction of the pulp flow, at least to the first opening in the pipe bushing, and the inlet pipe being suitable for being sealed against an inner surface of the pipe bushing. Another object of the present invention is to achieve a fiber web machine headbox that is easier to manufacture and has a lighter structure. The features of the headbox according to the present invention will be more fully understood from this article. The present application provides a fiber web machine headbox, comprising: a manifold; a dilution element, which has a mixing space suitable for being formed therein, the mixing space is suitable for being supplied with a slurry flow from the manifold through an inlet pipe, and is supplied with dilution water to dilute the slurry flow, and the slurry flow diluted with dilution water is suitable for being supplied forward from the mixing space through the outlet pipe in the flow direction of the headbox; a turbulence generator and a pipeline leading from the dilution element to the turbulence generator, the dilution element being the above-mentioned dilution element. The inlet pipe of the dilution water element extends into the pipe bushing in the direction of travel of the slurry flow, at least to the first opening in the pipe bushing, and the inlet pipe is suitable for sealing against the inner surface of the pipe bushing.

[0007] The design process of the dilution elements can be easily modified by the invention, since each dilution element in the headbox is a separate structural item and can therefore be easily replaced inside the headbox. Furthermore, the dilution elements and their manufacture are inexpensive. The manufacture of the dilution elements is also simplified when they can be realized as simple and light pipe bushings instead of large machined solid plate parts.

[0008] The manufacture of the dilution element according to the invention does not require large machine tools. Further specification of the details of the element at the design stage enables a structure that is as simple as possible in terms of both material and structure. Other additional advantages to be achieved by the invention are disclosed in the description of the invention and these features are disclosed in the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention is not limited to the embodiments given below, but is described in more detail with reference to the accompanying drawings, in which:

[0010] Figure 1 An example of a cross section of a prior art dilution element in a headbox in its machine direction is shown,

[0011] Figure 2 Two dilution elements according to the invention are shown in place,

[0012] Figure 3 Shows Figure 2 An exploded view of a dilution element is shown in FIG.

[0013] Figure 4 shows a top view of two dilution elements,

[0014] Figure 5 Shows Figure 4 A cross section of a dilution element in the machine direction is shown in

[0015] Figure 6 Shown Figure 5 a dilution element shown in cross section in FIG. 1 , which is separate from an inlet pipe and an outlet pipe to which the dilution element can be connected, and

[0016] Figure 7 An example of a headbox, in which a dilution element according to the invention can be applied, is shown, seen from the side, and the placement of the dilution element in the headbox is shown. DETAILED DESCRIPTION

[0017] Figure 2An embodiment of a dilution element 10 for a headbox 30 of a fiber web machine is shown. The figure shows two dilution elements 10 as they are mounted in parallel in the headbox 30 and without other surrounding structures in the headbox 30. The dilution element 10 according to the invention can be mounted in a replaceable manner in connection with a headbox 30 of a fiber web machine, the more detailed structure of the headbox 30 being described in detail in Figure 7 The fiber web machine may be a paper or board machine, a pulp dryer or a tissue machine, etc. The headbox 30 is used to spread and supply a stock flow 44 to the forming section of the fiber web machine in a manner known per se.

[0018] The dilution element 10 serves to adjust the concentration of the stock flow 38 coming from the manifolds 26.1, 26.2 before supplying it in the headbox 30 onwards in the flow direction F. The purpose, the operating principle and the importance of the dilution element 10 in the headbox 30 of a fiber web machine are obvious to a person skilled in the art and are therefore not described in more detail here.

[0019] The dilution element 10 comprises a mixing space 14 adapted to be formed in its interior and flow openings 15, 19 and 20 for inlet and outlet. The mixing space 14 adapted to be formed in the dilution element 10, there is currently one mixing space in the dilution element 10. Figure 5 As shown, the dilution water 37 is mixed in a set manner in the mixing space 14 with the stock flow 38 supplied in the mixing space 14, after which the diluted stock flow 44 leaves the mixing space 14 forward along the flow direction F. The stock flow 44 diluted in the mixing space 14 is further supplied along the flow direction F of the headbox 30 toward the next part of the headbox, and thus also toward the forming section.

[0020] The openings 15, 19, 20 included in the dilution element 10 are adapted to converge in the mixing space 14. The dilution water 37 is adapted to be supplied into the mixing space 14 through the first opening 15. The slurry flow 38 is adapted to be supplied into the mixing space 14 from the manifolds 26.1, 26.2 through the second opening 19. This is achieved by means of an inlet pipe 16 that can be adapted in the opening 19. The inlet pipe 16 is adapted to be sealed against the inner surface 25 of the second opening 19. The slurry flow 38 diluted with the dilution water 37 in the mixing space 14 is adapted to be supplied forwardly from the mixing space 14 in the flow direction F through the third opening 20 as a diluted slurry flow 44. This is achieved by an outlet pipe 29 that can be adapted in the opening 20. The outlet pipe 29 is adapted to be sealed against the inner surface 27 of the third opening 20.

[0021] The arrangement of the openings 15, 19, 20 is adapted in the dilution element 10 such that the second opening 19 and the third opening 20 are adapted in the dilution element 10 on opposite sides of the headbox 30 in the flow direction F of the headbox 30. The opening 15 for the dilution water and its flow direction are predominantly at right angles or acute angles to the flow direction F of the stock flow 38, 44.

[0022] The dilution element 10 is adapted to be formed by the pipe bushing 11 in its portion between the second opening 19 and the third opening 20. In other words, in this case, the dilution element 10 is a solid structure with a single component and a single material and has a tubular cross section in the flow direction F of the headbox 30, which is adapted to the pipe shape. The mixing space 14 is also adapted to be formed in the pipe bushing 11 between the second opening 19 and the third opening 20. The outer surface of the shell 12 of the pipe bushing 11 is a solid of revolution, for example a cylinder. The wall thickness of the shell 12 is relatively small in relation to, for example, the diameter of the pipe channel 13 formed in the pipe bushing 11 (or in general in relation to the outer diameter D of the pipe bushing 11).

[0023] Figure 4 Shows Figure 2 A top view of the dilution elements 10.1, 10.2 in FIG. Figure 3 Shows Figure 2 and Figure 4 An exploded view of a dilution element 10, Figure 5 Shows Figure 2-Figure 4 FIG. 1 is a cross-sectional view of a dilution element 10 in the machine direction MD. Figure 6 It also shows Figure 5 1 and 2. The dilution element 10 is shown in cross section in FIG. 1 and is separate from the inlet pipe 16 and the outlet pipe 29, which can be connected to the dilution element. According to an embodiment, the inlet pipe 16 and the outlet pipe 29 are adapted to be fastened to the dilution element 10 by means of spring pin fasteners 22. The spring pin fasteners 22 are adapted to act on the inlet pipe 16 and the outlet pipe 29 through the housing 12 of the pipe bushing 11. Figure 3 As shown, the pipe bushing 11 comprises a recess 24 for a spring pin fastener 22. During tightening, the spring pin 39 is mounted in the recess 24. In this case, according to an embodiment, the inlet pipe 16 and the outlet pipe 29 comprise grooves 43 adapted on their outer surfaces 41, 42, such as Figure 6 As shown, spring pin fasteners 22 are used to fasten the inlet tube 16 and the outlet tube 29 to the dilution element 10 .

[0024] The sealings 23.1, 23.2 are suitable for being located between the inner surface 25 of the inlet-side opening 19 and the inlet pipe 16 of the dilution element 10, and between the outlet side of the dilution element 10 (in other words, the inner surface 27 of the third opening 20) and the outlet pipe 29, as shown in FIG. Figure 5 and Figure 6 As shown. For seals 23.1, 23.2, the inlet pipe 16 and the outlet pipe 29 have Figure 6 The sealing grooves 45 are shown, in which the seals (not shown) are fixed. When the seals are located in the grooves 45, the seals are pressed against the inner surface 25 of the second opening 19 and the inner surface 27 of the third opening 20. The spring pin fastener 22 is adapted on the opposite side of the seals 23.1, 23.2 relative to the mixing chamber.

[0025] The outlet end 16' of the inlet pipe 16 of the dilution element 10 is positioned in the pipe bushing 11. The inlet pipe 16 extends into the pipe bushing 11 in the direction of travel of the slurry flow, at least to the opening 15 of the pipe nipple of the pipe bushing 11. The dilution water 37 supplied through the pipe nipple 21 of the pipe bushing 11 is advantageously guided to the outer surface of the inlet pipe 16, from which it is guided into the slurry flow through the annular opening formed between the end of the inlet pipe 16 and the end of the outlet pipe 29. The inlet end 29' of the outlet pipe 29 of the dilution element 10 is positioned in the pipe bushing 11, advantageously after the opening 15 of the pipe nipple of the pipe bushing 11 in the direction of travel of the slurry flow. The mixed slurry flow and the dilution water are supplied through the outlet pipe 29.

[0026] According to one embodiment, the pipe passage 13 (13) is formed between the second opening 19 and the third opening 20 of the pipe bushing 11. Figure 6 ) is adapted to have an inner diameter larger on the third opening 20 side than on the second opening 19 side. In this way, the cross-sectional area of ​​the chamber space formed at the end of the outlet pipe 29 can be made larger than the cross-sectional area of ​​the inlet pipe 16. As a result, an annular gap is formed between the end of the inlet pipe 16 and the end of the outlet pipe 29, and the dilution water 37 is supplied to the mixing space 14 through the annular gap on the principle of annular dilution. In other words, the dilution water 37 is brought into the mixing space 14 together with the slurry flow 38 supplied from the manifold, and is discharged therein from the inlet pipe 16 in a manner surrounding the slurry flow 38. Figure 5 The difference in size between the end of the inlet tube 16 and the end of the outlet tube 29 is well illustrated.

[0027] Figure 5It is also well shown that there is a small gap remaining between the outlet end of the inlet pipe 16 that fits in the mixing space 14 and the inlet end of the outlet pipe 29, from which gap the dilution water 37 supplied into the mixing space 14 through the pipe joint 21 can mix with the main stock flow 38 of the headbox 30 entering along the inlet pipe 16. In this way, the mixing space 14 is adapted to be formed in the pipe bushing 11 when the inlet pipe 16 and the outlet pipe 29 fit in the openings 19, 20 of the pipe bushing 11.

[0028] A first opening 15 is fitted in the housing 12 of the pipe bushing 11, through which the dilution water enters the pipe bushing 11 and further into its mixing space 14. The first opening 15 is fitted in the housing 12 of the pipe bushing 11 to connect a fitted pipe joint 21. The pipe joint 21 is arranged to connect the pipe bushing 11, for example, vertically (in the direction of travel of the slurry flow 38, 44) or at an acute angle.

[0029] according to Figure 2 and Figure 4 , the dilution element 10 or now the tube bushing 11 is adapted to be supported indirectly on the structure 17, 18 of the headbox 30 by means of the inlet pipe 16 and the outlet pipe 29. In this way, the tube bushing 11 is not in direct structural contact (e.g. via its housing 12) with the structure 17, 18 of the headbox 30. In other words, the tube bushing 11 can be arranged such that it is not directly supported on the structure 17, 18 of the headbox 30. On its inlet side, the dilution element 10 can be fastened to the manifold 26.1, 26.2 of the headbox 30 via the inlet pipe 16, e.g. via the distributor plate 17. The fluid flowing out of the manifold 26.1, 26.2 is supplied via the inlet pipe 16 into the mixing space 14 adapted to be formed in the tube bushing 11.

[0030] According to one embodiment, the outer diameter D of the pipe bushing 11 suitable for forming the dilution element 10 is as follows: Figure 2 and Figure 4 As shown, the dilution elements 10.1, 10.2 arranged in association with the headbox 30 are adapted to support each other in the cross direction CD of the headbox 30. In this way, the dilution element 10.1 is adapted to be supported by its side to the adjacent dilution element 10.2 in its installed position in view of the operating conditions of the headbox 30, in order to reduce the usually large pressure loads. Figure 4 , where the dilution elements 10 are placed side by side and in contact with each other. The dilution elements 10 are in linear contact with each other only via their sides, via their housings 12.

[0031] According to an embodiment, the dilution element 10 (in other words, the pipe bushing 11) can be made of, for example, a plastic material by using, for example, a die-casting technique. On the other hand, the dilution element 10 can also be manufactured, for example, as a 3D printed product.

[0032] In addition to the dilution element 10, the invention also relates to a headbox 30, in which Figure 7 An example of this is shown in FIG. The basic components of a headbox 30 include manifolds 26, 26.1, 26.2, a dilution element 10 and turbulence generators 33. The headbox shown in the illustrated application example is a double-layer headbox 31.

[0033] A mixing space 14 is adapted to be formed in each dilution element 10, into which a stock flow 38 is adapted to be supplied from the manifolds 26.1, 26.2 via the inlet pipe 16, and dilution water 37 is adapted to be supplied to the mixing space 14 to dilute the stock flow 38 in the mixing space 14. Furthermore, a stock flow 44 diluted with the dilution water 37 is adapted to be supplied forward from the dilution element 10 via the outlet pipe 29 in the flow direction F of the headbox 30. The outlet pipe 29 may be connected to a distribution pipe included in the conduit 32, which further supplies the diluted stock flow 44 to the turbulence generator 33, the lip channel 34, the slice 35, and further to the forming section wire 36 for web W formation.

[0034] The dilution element 10 is a dilution element according to the present invention, the portion of which between the second opening 19 and the third opening 20 is adapted to be formed by the pipe bushing 11, and the mixing space 14 is adapted to be formed inside the pipe bushing 11. Furthermore, a first opening 15 is adapted in the housing 12 of the pipe bushing 11, the first opening being used to supply dilution water 37 into the pipe bushing 11.

[0035] According to one embodiment, according to Figure 2-Figure 6 , the manifolds 26.1, 26.2 are assembled with a distribution plate 17 provided with openings 40, the height H of the distribution plate 17 being adapted to correspond to the dilution element 10. In this case, the height H of the distribution plate 17 remains moderate, requiring less material.

[0036] The solution according to the invention can also be used for headboxes with more than one tube row in a manifold tube bank. For example, in this case, in a headbox with two manifold tube banks stacked one above the other, a tube liner can be used which extends in the height direction to both tube banks. In this case, the dilution water is supplied to the tubes in both stacked tube banks via the same dilution connection.

[0037] It should be understood that the above description and the related drawings are only intended to illustrate the present invention. Therefore, the present invention is not limited to the above embodiments, and several different changes and modifications of the present invention are also obvious to those of ordinary skill in the art, and these changes and modifications are possible within the inventive concept defined by the attached claims.

Claims

1. A dilution element for a headbox of a fiber web machine, the dilution element being adapted to be associated with a headbox (30) and comprising: at least one mixing space (14) adapted to be formed inside the dilution element (10), An opening (15, 19, 20) adapted to fit in the dilution element (10) and to merge into the mixing space (14), wherein: Dilution water (37) is adapted to be supplied into the mixing space (14) through the first opening (15), A slurry flow (38) is adapted to be supplied from a manifold (26, 26.1, 26.2) into the mixing space (14) through the second opening (19) by means of an inlet pipe (16) adapted in the second opening (19), The slurry flow (44) diluted with dilution water (37) in the mixing space (14) is adapted to be supplied forwardly from the mixing space (14) through the third opening (20) in a flow direction (F) by means of an outlet pipe (29) fitted in the third opening (20), the outlet pipe (29) being adapted to seal against an inner surface (27) of the third opening (20), The dilution element (10) is adapted to be formed by a pipe bushing (11) at a portion between the second opening (19) and the third opening (20), the mixing space (14) being adapted to be formed in the pipe bushing (11), and the first opening (15) being adapted to be fitted in a housing (12) of the pipe bushing (11), It is characterized in that The inlet pipe (16) extends into the pipe liner (11) in the direction of travel of the slurry flow, at least to the first opening (15) in the pipe liner (11), and is adapted to seal against an inner surface (25) of the pipe liner (11).

2. The dilution element according to claim 1, characterized in that The inlet end (29') of the outlet pipe (29) of the dilution element (10) is positioned within the pipe liner (11), advantageously after the first opening (15) of the pipe joint of the pipe liner (11) in the direction of travel of the slurry flow.

3. The dilution element according to claim 1 or 2, characterized in that The dilution element (10) is adapted to be supported indirectly to the structure (17, 18) of the headbox (30) by means of the inlet duct (16) and the outlet duct (29).

4. The dilution element according to claim 1 or 2, characterized in that The first opening (15) is adapted to the pipe joint (21) which is arranged to be connected to the pipe bushing (11) vertically or at an acute angle.

5. The dilution element according to any one of claims 1 to 4, characterized in that The inlet pipe (16) and the outlet pipe (29) are adapted to be fastened to the dilution element (10) by means of spring pin fasteners (22) acting on the inlet pipe and the outlet pipe through the pipe bushing (11).

6. The dilution element according to any one of claims 1 to 5, characterized in that The outer diameter (D) of the tube bushing (11) is adapted to adapt adjacent dilution elements (10.1, 10.2) arranged in association with the headbox (30) to support each other in a cross direction (CD) of the headbox (30).

7. The dilution element according to claim 5 or 6, characterized in that Seals (23.1, 23.2) are adaptable between the inlet (16) and outlet (29) pipes and the inner surfaces (25, 27) of the dilution element (10), and the spring pin fastener (22) is adapted on the opposite side of the seals (23.1, 23.2) relative to the mixing space (14).

8. The dilution element according to any one of claims 5 to 7, characterized in that The pipe bushing (11) includes a recess (24) for the spring pin fastener (22).

9. The dilution element according to any one of claims 1 to 8, characterized in that The inner diameter of the pipe passage (13) formed between the second opening (19) and the third opening (20) of the pipe bushing (11) is adapted to be larger on the third opening (20) side than on the second opening (19) side.

10. A fiber web machine headbox, comprising: Manifold (26, 26.1, 26.2), a dilution element (10) having a mixing space (14) adapted to be formed therein, the mixing space (14) adapted to be supplied with a stock flow (38) from a manifold (26, 26.1, 26.2) through an inlet pipe (16) and with dilution water (37) for diluting the stock flow (38), and the stock flow (44) diluted with the dilution water (37) adapted to be supplied forward from the mixing space (14) through the outlet pipe (29) in a flow direction (F) of the headbox (30), a turbulence generator (33) and a conduit (32) leading from the dilution element (10) to the turbulence generator, Characterized in that the dilution element (10) is a dilution element according to any one of claims 1 to 9.

11. The headbox according to claim 10, characterized in that: The manifold (26) is assembled with a distribution plate (17) provided with openings (40), the height (H) of the distribution plate being adapted to correspond to the dilution element (10).

12. The headbox according to claim 10 or 11, characterized in that: The inlet pipe (16) and the outlet pipe (29) include grooves (43) fitted on their outer surfaces (41, 42) for fastening spring pin fasteners (22) of the inlet pipe (16) and the outlet pipe (29) to the dilution element (10).

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