CN107130460B

CN107130460B - Dewatering device for a fiber web machine

Info

Publication number: CN107130460B
Application number: CN201710103139.2A
Authority: CN
Inventors: M·J·萨尔米宁; R·佩利卡; 桑帕·J·萨尔米宁; J·T·马基宁; V·佩索宁; A·金斯伯格
Original assignee: Metso Paper Oy
Current assignee: Valmet Technologies Oy
Priority date: 2016-02-29
Filing date: 2017-02-24
Publication date: 2020-02-18
Anticipated expiration: 2037-02-24
Also published as: EP3211134A1; FI20165152A; FI127081B; EP3211134B1; CN107130460A

Abstract

The invention relates to a dewatering device of a fiber web machine, comprising: a body (22) having a length greater than a width; a plurality of brackets (22.4) attached to the body (22) at intervals along the longitudinal direction (L) of the body; and at least one panel attachment rail (28) parallel to the body (22) and fixed to the body (22) by means of a bracket (22.4) for supporting the panel (26) in the device. The dewatering device further comprises a plurality of support ribs (30) parallel to the brackets (22.4), to which the sheet attachment rails (28) are attached, and wherein the support ribs (30) are fixed to the brackets (22.4) such that one or more support ribs (30) abut against and partially overlap one or more of said brackets (22.4), and the attachment between the support ribs (30) and the brackets (22.4) is provided in the overlap area (a).

Description

Dewatering device for a fiber web machine

Technical Field

The invention relates to a dewatering device for a fiber web machine, comprising: a body having a length greater than a width, and a plurality of support ribs attached to the body transverse to a longitudinal direction of the body; and at least one sheet attachment rail parallel to the body and adapted to the support ribs for supporting a sheet (foilblade) in the dewatering device according to the invention.

Background

Dewatering devices are used in particular in so-called web forming sections of fiber web machines, where water is mechanically removed from a fiber suspension spread on a fabric to form a web. This web forming section is also called wire section. The web forming section is provided with a number of dewatering devices in succession, which are usually located on the side of the fabric opposite to the web. The dewatering devices of the web forming section are based on dewatering blades (which are also called plates). The dewatering tables (dewatering forms) are supported to the box frame structure of the dewatering device, in which case such a dewatering device is called a plate box (form box). Each of the plate boxes typically has a plurality of dewatering plates, although separate dewatering plates may also be fitted in the forming section. The dewatering plates are in contact with the fabric and form gaps between successive dewatering plates. Thus, the web is subjected to successive pulses that promote the removal of water from the web. A vacuum may also be created in the crate to enhance dewatering.

Both ends of the crate are attached to the fiber web machine. It is known to produce a flat box from a plurality of sheet metal parts by welding. In order to achieve sufficient rigidity, a plurality of support portions and reinforcing portions are additionally used. As a result, the crate becomes heavy and its manufacture slows down. Furthermore, local stress peaks occur in the plate box during use and it is difficult to install the dewatering plates in the correct position with sufficient accuracy. The dewatering plates wear during use and may also break, in which case it is sometimes necessary to replace the dewatering plates.

US 20040238142a1 discloses a dewatering apparatus in which the frame structure is formed by large support beams to which transverse intermediate supports are fastened. Each intermediate support has two parts and is provided with profiled slot-like openings for fastening the dewatering plates. Furthermore, each dewatering plate comprises profiled support blades which form a form-lock against the gap in the intermediate support.

The above-described dewatering device is above all very heavy and bulky, because the frame structure consists of beam-shaped structures and thick and heavy parts. Furthermore, the manufacture of these components requires extensive machining. The frame structure must also be designed and manufactured separately for different applications. It is often desirable that the dewatering plates form as flat a surface as possible. With the above solution, it is difficult to achieve planarity, since the dewatering plates are bent following the bending of the frame structure. On the other hand, off-flat surface implementations are not feasible, or at least require the use of a custom intermediate support.

WO 2009101243a1 discloses a dewatering device of a fiber web machine, which dewatering device comprises: a frame structure having a length greater than a width; a plurality of intermediate supports secured to the frame structure at intervals from one another and disposed in a transverse direction relative to a longitudinal direction of the frame structure; and at least one panel attachment rail extending longitudinally relative to the frame structure and supported to an opening provided in the intermediate support. The opening has a bottom, and a panel attachment rail is installed in each intermediate support at a desired distance from the bottom of the opening, and there is a welded connection between the panel attachment rail and the intermediate support. Although this arrangement is advantageous in many respects, there is still a need to provide a more advantageous dewatering apparatus.

The object of the invention is to provide a dewatering device of a fiber web machine, by means of which the desired shape is accurately obtained, and which is lighter but sufficiently stiff than previous devices.

Disclosure of Invention

The objects of the invention can be substantially achieved according to the technical solutions disclosed in the various embodiments of the invention.

The dewatering device of a fiber web machine of the invention comprises: a body having a length greater than a width, and a plurality of brackets attached to the body at intervals in a longitudinal direction of the body; and at least one panel attachment rail parallel to the body and secured to the body by a bracket for supporting the panel in the apparatus. The dewatering device further comprises: a plurality of support ribs parallel to the above-mentioned brackets, to which support ribs the sheet attachment rails are attached, and wherein the support ribs are fixed to the brackets such that one or more support ribs partially overlap and abut one or more brackets, the attachment between the support ribs and the brackets being provided in the region of the overlap, and the support ribs being provided with at least one coupling groove into which a holding part is fitted, wherein the holding part is provided to extend via the grooves of at least two support ribs.

According to an embodiment of the invention, each support rib is provided with at least one coupling groove into which a holding part with an internally threaded hole is releasably fitted, and the sheet attachment rail is releasably attached to the support rib by screwing (screwing) with the holding part.

According to an embodiment of the invention, the groove is an open groove or a recess.

According to another embodiment of the invention, the slot is a closed hole.

According to an embodiment of the invention, the holding part is form-locked to the support rib at least in the direction of the plane of the support rib.

According to an embodiment of the invention, the support rib is of plate-like construction, while the coupling groove is provided at the edge of the support rib, which groove has a first width of the groove at the edge (rim) of the support rib and a second width of the groove at a distance from the edge of the support rib, wherein the second width is larger than the first width.

According to an embodiment of the invention, the holding part is a rod arranged to extend via the grooves of at least two support ribs in succession.

According to an embodiment of the invention, the rod is provided with a plurality of holes with internal thread, wherein the pitch of the holes is equal to the pitch of the support ribs.

According to an embodiment of the invention, the rod is provided with: an internally threaded bore is located at a position between two support ribs and the distance between the successive support ribs is less than 500 mm.

According to an embodiment of the invention, the holding part is a rod arranged to extend via the grooves of all successive support ribs. In this way, each sheet attachment rail can be attached using only one rod, which makes the mounting operation simple and easy.

According to an embodiment of the invention, the sheet attachment rail may be attached using more than one bar arranged to extend via the grooves of at least two, but not necessarily all, successive support ribs.

According to an embodiment of the present invention, a dehydration apparatus includes: a plurality of panel attachment rails arranged parallel to and at a distance from each other, and each support rib is provided with a number of coupling grooves equal to the number of panel attachment rails, and a retaining member is arranged to extend via each successively aligned groove.

According to an embodiment of the invention, the body is made of sheet metal parts by welding and comprises a bottom part and a cover part, the opposite longer edges of which are joined together, and the body is provided with a plurality of transverse brackets to which the support ribs are attached.

The dewatering device of a fiber web machine according to an embodiment of the invention is manufactured in such a way that: setting a welding line plan (plan) for a dewatering device, wherein the welding line plan defines the position of a welding seam in the device during the process, subsequently manufacturing a first dewatering device for a fiber web machine by assembling parts forming the body of the dewatering device and welding the parts together using the set welding line plan, and wherein manufacturing a second dewatering device for a fiber web machine by assembling parts forming the body of the second dewatering device and joining the parts together by performing welding according to the set welding line plan.

According to an embodiment of the invention, more than one dewatering device is manufactured, which dewatering devices are adapted to operate at different positions of the same fiber web machine, whereby the welding of each device is performed according to the same welding line scheme.

According to an embodiment of the invention, the body is formed with a length greater than a width, the support ribs are provided with at least one coupling groove into which a holding part with an internally threaded hole is releasably fitted, and a plurality of support ribs are attached to the body at a distance from one another and transversely to the longitudinal direction of the body, and at least one sheet attachment rail is also attached to the support ribs by being screwed with the holding part.

According to an embodiment of the invention, before attaching the support ribs to the body, the support ribs are aligned so that the coupling grooves are oriented according to the requirements of the direction of the plate.

With these coupling slots properly aligned, the orientation of the plates will also be correct.

The dewatering device according to the invention does not require machining and is easy to manufacture, which makes the required dimensions accurate.

The exemplary embodiments of the invention presented in this patent application should not be interpreted as limitations to the applicability of the appended claims. The verb "to comprise" is used in this patent application as an open limitation that does not exclude the presence of other features not mentioned. The features recited in the dependent claims may be freely combined with each other, unless otherwise specified. The novel features believed characteristic of the invention are set forth with particularity in the appended claims.

Drawings

The invention will be described hereinafter with reference to the accompanying exemplary schematic drawings, in which:

figure 1 shows a fiber web machine according to an embodiment of the invention,

figure 2 shows a dewatering apparatus according to an embodiment of the invention,

figure 3 shows a cross-sectional view taken along the line III-III in figure 2 according to an embodiment of the invention,

figure 4 shows a cross-sectional view taken along the line III-III in figure 2 according to another embodiment of the invention,

figures 5A to 5E show cross-sectional views of a dewatering apparatus according to an embodiment of the invention,

figure 6 shows a dewatering device according to the invention when the sheets are oriented flat, an

Fig. 7A to 7C show different embodiments of the dewatering device according to the invention.

Detailed Description

As an example of a practical application of the dewatering device according to the invention, fig. 1 schematically depicts a web forming section 10 of a per se conventional fiber web machine. In the forming section, the fibre suspension is led from the headbox 12 to a so-called bottom fabric 14. The term "fiber web machine" is used in particular to refer to machines for drying paper, board, toilet paper and pulp. A plurality of

dewatering devices

20, 20', 20 "are arranged one after the other below the bottom fabric. The dewatering devices of the web forming section are based on dewatering blades (which are also called plates). These dewatering plates are supported to the box frame structure of the dewatering device, in which case such a dewatering device is called a plate box.

In fact, at the moment of reaching the bottom fabric, the fibre suspension is subjected to an impulse action which assists in removing water from the fibre suspension and thus in assisting in web formation. It is also known that such dewatering devices can be connected to a vacuum system to withstand the suction (water absorption) of the web.

In fig. 2, a partial view a shows a cross-sectional view of a dehydration engine 20 according to an embodiment of the present invention. The part B diagram shows the circled part in the part a diagram in a more detailed manner, and the part C diagram shows the circled part in the part B diagram in a more detailed manner. In fig. 3, a cross-sectional view taken along line III-III of the partial C diagram of fig. 2 is shown, according to an embodiment of the invention.

Referring now to fig. 2, 3 and 6, the dehydration engine 20 includes a body 22 and a pallet (foil table) 24. The length of the body 22 (and hence the dewatering device) is greater than the width. The body 22 is a beam structure with a longitudinal direction, which is made by welding from suitably cut and shaped sheet metal parts. When the dewatering device is installed in a fiber web machine, the longitudinal direction of the dewatering device usually coincides with the transverse direction of the fiber web machine. The platform 24 is formed by a plurality of dewatering plates 26, which dewatering plates 26 are arranged at a distance from each other forming a substantially continuous plane which is straight or curved in a direction transverse to the longitudinal direction L of the body 22.

In accordance with the first aspect of the invention, in addition to the dewatering plates 26, the pallet 24 also includes a board attachment rail 28 associated with each plate 26 for attaching each plate 26 to the dewatering apparatus. It is envisaged within the scope of the invention that a dewatering apparatus comprising only one plate may be provided using the concepts of the present invention. The panel attachment rails 28 and the panels 26 are provided with form locking means to form a releasable coupling between the panel attachment rails 28 and the panels 26. Advantageously, the panel attachment rail 28 is a rail generally in the form of a T, and the panel 26 is provided with a mating cavity (mating cavity) disposed along one face of the panel 26. In this way, the panel can slide on the panel attachment rail from the end of the panel attachment rail. The mating cavity may also be a T-cavity. When the pallet 24 or the board 26 is mounted to the body 22 of the dewatering device 20, the board attachment rails are parallel to the body 22.

The apparatus 20, and in particular the pallet 24, includes a plurality of support ribs 30 arranged to support and attach the panel attachment rails 28 and the panel 26 to the body 22. The support ribs 30 are generally disposed transverse to the plate 26. Advantageously, the support ribs 30 are arranged substantially perpendicular to the longitudinal direction of the plate. The support ribs 30 are plate-like structures, advantageously made of cut sheet metal. To attach the panel attachment rail 28 to the body 22, the apparatus 20 includes a plurality of support ribs 30 disposed parallel and spaced apart from one another along the entire length of the pallet 24, as shown in fig. 3. A suitable distance D between successive support ribs 30 is, for example, 100 and 500mm, depending on the design of the particular application.

A plurality of coupling grooves 32 are provided at one edge of the support rib 30, and this edge of the support rib 30 is disposed at the top of the body when the support rib is mounted to the body. Advantageously, the number of slots 32 is equal to the number of plates belonging to the pallet 24. In the pallet, coupling grooves for one blade are arranged in a straight line in successive support ribs 30. Of course, additional slots without attachment plates may be present if desired. Thus, in case the dewatering device has only one plate, the support ribs 30 will have only one coupling groove 32, respectively.

In fig. 2, the circumferential edge of the coupling groove 32 is provided to one edge of the support rib 30. A holding member 34 is provided in the coupling groove 32 of the rib 30. The retaining member 34 is provided with one or more internally threaded bores. The retaining member and the groove are formed such that the retaining member 34 does not come out of the coupling groove 32 in its attachment position. Thus, the holding part 34 is form-locked to the support rib at least in the planar direction of the support rib.

The coupling slot 32 is formed to have a first width W1 of the slot at the edge of the support rib and a second width W2 of the slot at a distance from the edge of the support rib 30, wherein the second width W2 is greater than the first width W1. In the embodiment of fig. 2, the slot is an open slot, i.e. not a closed hole. As can be seen in fig. 3, a threaded rod, screw 38 or the like is provided in a substantially middle region of the width or thickness of the support rib 30. This provides the function of a coupling between the retaining member 34 and the panel attachment rail 28, wherein the coupling force acts in the region of the support ribs 30. In this way, the attachment of the sheet attachment rail 28 is such that the support portion and the sheet 26 are not bent. The actual attachment of the sheet attachment rail 28 to the support rib 30 is produced by screwing with the retaining member 34. A projection of the support rib 30 is pressed between the panel attachment rail 28 and the holding member 34 fastened to each other and tensioned toward each other by a screw that is disposed in a hole of the panel support rib and is screwed into an internal thread in the holding member 34.

As can be seen in fig. 3, the retaining member 34 is here an elongated flat rod. The flat bar 34 is provided with a plurality of internally threaded holes, while the panel attachment rail 28 is provided with a plurality of openings through which screws or the like can be mounted for attachment to the threads of the flat bar 34. The holes in the flat bar 34 and the openings in the panel attachment rails 28 are equally spaced in the longitudinal direction. The flat bars extend through all the support ribs 30 in the dewatering device.

The support ribs 30 are provided with an outwardly extending portion adjacent the slot. Which extends towards the panel attachment rail 28. More specifically, the support rib 30 has a flat surface on which the coupling groove 32 is formed, and the groove edges provided to the flat surface and opened in the longitudinal direction of the support rib 30 are spaced apart by a certain distance. The extension forms a shoulder 40 against which the panel attachment rail 28 is positioned and supported when installed. The shoulder may also be referred to as a claw (claw). The shoulder 40 defines the actual position of the attachment rail 28 in the dewatering device. The distance from the edge of the notch (notch) to the groove is such that the panel attachment rail 28 abuts the notch when mounted to the support rib 30. The shoulder 40 and the groove 32 together form an attachment for the panel attachment rail 28. The flat bar 34 and the panel attachment rail 28 can be adjusted together with respect to their positions so that the panel attachment rail 28 can be positioned against the shoulder 40.

Referring now in particular to figures 3 and 6, it can be seen that the body is provided with a plurality of transverse supports 22.4. These brackets extend outwardly from the surface of the body 22. The bracket 22.4 is fitted to the support rib 30 and serves to attach the support rib 30 to the body 22. The brackets 22.4 are attached to the body 22 in a spaced apart manner. Advantageously, the brackets are spaced the same distance from the support rib 30 to the body 22 over the length of the body. The bracket 22.4 and the support rib 30 overlap each other in the shadow area a so that they can be attached to each other by means of the bolted connection 44, the bracket 22.4 and the support rib 30 abutting each other in the shadow area a.

The support ribs 30 in a dewatering device are similar to each other. The operating direction relative to the machine direction can be easily changed by simply mounting the dewatering device to the fibre web machine so that the shoulder 40 is downstream or after the panel attachment rail 28 in the running direction of the fabric of the paper machine. The orientation of the support ribs 30 during manufacture can be easily selected so that the same basic components are available in either operating orientation.

In fig. 4, a cross-sectional view taken along line III-III of the partial C diagram of fig. 2 according to another embodiment of the invention is shown. It can be seen that in this embodiment the body 22 is also provided with a plurality of transverse brackets 22.4. These brackets extend outwardly from the surface of the body 22. The bracket 22.4 is fitted to the support rib 30 and serves to attach the support rib 30 to the body 22. These brackets 22.4 are spaced on the body at the same spacing as the support ribs 30. The bracket 22.4 and the support rib 30 overlap each other so that they are attached to each other by means of, for example, a bolt connection 44.

Here, the sheet attachment rail 28 is supported on two adjacent support ribs 30. As can be seen in fig. 3, a bolt 38 is provided substantially midway between the two support ribs 30. This provides the function of a coupling between the retention member 34 and the panel attachment rail 28, wherein the coupling force is distributed between the two support ribs 30 and the attachment of the panel attachment rail 28 does not tend to over-bend the support and the panel 26. The actual attachment of the sheet attachment rail 28 to the support rib 30 is formed by screwing with the holding member 34. Although not shown, in particular in the present embodiment, the coupling slot 32 may be a closed hole, since a symmetrical distribution of the attachment forces is obtained by the position of the bolts 38 between the support ribs 30.

Fig. 5A to 5E show cross-sectional views of the dehydration engine 20 according to an embodiment of the present invention, which shows the structure in a more detailed manner. Fig. 5A to 5E show certain portions of the device 20 in solid lines, while other portions are shown in dashed lines. The plate 26, the plate attachment rail 28, the retaining member 34 and the bolt 38 are not shown here for clarity. Advantageously, the body 22 is welded from sheet metal parts. The body 22 comprises a base 22.1 which is longer than it is wide. The bottom 22.1 is formed by a rectangular sheet metal piece bent in the form of a groove, i.e. having a concave or curved shape with an upper side open when the body is in the position shown in fig. 5A to 5E. During the manufacturing process, two opposite long edges of the rectangular plate member are bent toward each other to form a groove shape. This stage is shown in fig. 5D. The bend may be comprised of a plurality of bend segments as shown in the figures, or the bend may be a continuous curve (not shown) having a predetermined radius or radii. The body 22 further comprises a cover portion 22.2 as shown in fig. 5C. The length of the cover part 22.2 is equal to the length of the base part 22.1. This lid portion is also formed of a rectangular metal plate formed into a curved shape. In the body 22, the opposite long edges 22.5 of the bottom and the cover are joined together by welding continuously or intermittently in the longitudinal direction of the body, the body 22 comprising an end portion 22.3, the end portion 22.3 being attached to the ends of the bottom 22.1 and the cover 22.2. This is shown in fig. 5E. Furthermore, the body 22 is provided with a plurality of transverse brackets 22.4. These brackets are arranged transversely with respect to the longitudinal direction of the body 22, which is perpendicular to the plane of the cross section in the figure. Here the bracket is attached to the cover part 22.2, but it is conceivable that the bracket will extend from the edge of the bottom part over the cover part and further to the edge of the bottom part. This is shown in fig. 5B. In fig. 5A, the support rib 30 is shown attached to the transverse bracket 22.4 by means of a bolted connection.

According to one aspect of the invention, during the process of manufacturing a dewatering device of a fiber web machine, a so-called weld line solution is set for a dewatering device. The weld line profile defines the weld locations of the device during the process. Thereafter, the first dewatering device 20 of the fiber web machine is manufactured by assembling the bottom part 22.1, the cover part 22.2, the end part 22.3 and the transverse brackets 22.4 to form a first dewatering device and welding the parts together using the set welding line scheme. Next, a second dewatering device 20' of the fiber web machine is manufactured by assembling the bottom part 22.1, the cover part 22.2, the end parts 22.3 and the transverse brackets 22.4 to form a second dewatering device and joining the parts together by performing welding according to the set welding line scheme. Thus, according to the invention, more than one

dewatering device

20, 20', 20 "is manufactured: the welding of each device is thus performed according to the same welding line scheme, wherein the

dewatering devices

20, 20', 20 "are mounted at different locations of the same fiber web machine 10.

According to another aspect of the invention, the dehydration engine is fabricated to form the body 22 with a length greater than a width. The body is formed by preparing a rectangular sheet metal part and shaping it into the shape of a recess (rough) constituting the bottom 22.1. Secondly, the recess is closed by the cover 22.2, so that together they substantially enclose a space. The body is also provided with a plurality of transverse supports 22.4 which are arranged in spaced relation from one end of the body to the other end of the body. Next, one (or two, as shown in fig. 4) support rib 30 is disposed next to or against each lateral bracket 22.4 in an overlapping manner as shown, but this is such that the rib 30 is not bolted or otherwise substantially fastened to the bracket 22.4. The overlap area a serves to provide attachment between the support rib 30 and the bracket 22.4. At this time, the support ribs 30 are in the correct position in the longitudinal direction. Each support rib 30 is still movable in the plane of the support 22.4 as indicated by arrow 25 in fig. 6. This enables accurate positioning of each support rib before it is attached to the bracket 22.4. At this point, these support ribs 30 are movable against the brackets 22.4 but still at least along their plane (transverse to the longitudinal direction of the body 22) and set or adjust the final orientation of the sheet relative to the body 22. In other words, the distance of the plate to the body is adjusted according to the desired requirements, so that before attaching the support rib 30 to the body, the support rib is placed so that the coupling groove and the plate are oriented according to the requirements of the direction of the plate. When the support rib 30 is in the desired position, the support rib 30 is fixed to the transverse bracket 22.4 in the overlap region a. This attachment is preferably provided by a bolted connection, by which the bracket 22.4 and the support rib 30 are pressed against each other.

As can be seen in fig. 3, locking pins 47 or similar elements can be used with the bolted connections 44 to ensure correct positioning of the support ribs 30 relative to the brackets 22.4. In addition, or instead of the use of locking pins 47, the support ribs 30 and the brackets may be spot welded to each other, for example, to achieve the same effect.

After the support ribs 30 are placed and fixed to the bracket 22.4, the sheet attachment rail 27 and the corresponding holding part 34 or rod are mounted in connection with the coupling groove 32 and joined together by means of mounting screws. The pallet 24 is formed at this stage.

Because the parallel slats 26 are coupled to the support ribs 30, the curvature of the pallet may be minimized (or controlled, if desired). For example, the arcuate panels are provided very simply by individually adjusting the fixing position of each support rib 30 to the transverse bracket 22.4, as required. This can be simplified by using an assembly jig suitably designed for this purpose. Figure 6 shows a dewatering apparatus according to the invention in which the plates are in a flat orientation.

Even though the basic components of the dewatering device may have some differences at different locations of the fiber web machine, these basic components, i.e. the bottom part 22.1, the cover part 22.2, the end part 22.3 and the transverse brackets 22.4 have the same cross-sectional shape as shown in fig. 5 and are weld-assembled according to the set weld line scheme. In fig. 7A-7C, several variations of the dewatering device 20 according to the invention are shown. In fig. 7A dewatering device 10 is shown which operates solely on the basis of the natural pressure pulses caused by the plates. In other words, the bottom part 22.1 and the cover part 22.2 form a closed surface in its entirety. In fig. 7B, a so-called vacuum box is shown, in which the cover part 22.2 has the same cross-sectional profile as in fig. 7A, but has a plurality of openings 42 therein. The body 22 is also provided with auxiliary recesses 45, i.e. the bottom 22.1 and the cover 22.2 define a vacuum space with the plate 24. The auxiliary groove 45 is connected to the vacuum system through a vacuum system opening 48 at the end 22.3 of the device 20. One or more water scavenging channels 46 are also provided in fluid communication with the vacuum space. A modification is shown in fig. 7C in which the vacuum system opening 48 and the water scavenging passage 40 are combined into a single connection at the end of the body 22. In all variants, the basic components, namely the base part 22.1, the cover part 22.2, the end part 22.3 and the transverse support 22.4, have the same cross-sectional shape and are produced in the following manner: the welding of each individual device including the same weld line scheme is performed.

As an example of a set welding line scheme, it may comprise setting a weld to connect all components along a line coinciding with the contact surfaces of the components 22.1, 22.2, 22.3, 22.4 with each other.

The dewatering device 20 is attached to the fiber web machine 10 by means of a suitable bracket (not shown), which may be attached to the end 22.3 of the device 20.

It is advantageous to cut these parts from a metal sheet using laser cutting, by means of which high dimensional and shape accuracy of the parts is obtained. Accordingly, by laser welding, a narrow and deep weld is achieved, whereby also parts of different thicknesses can be connected. Due to the low thermal conductivity, detrimental deformations can be avoided. Laser welds are ready made without subsequent machining and welds have high welding speeds but are reliable.

While the invention has been described herein by way of examples in connection with what are at present considered to be the most preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various combinations or modifications of its features and several other applications falling within the scope of the invention, as defined in the appended claims. The device may be made of, for example, a composite material (e.g., a carbon fiber composite sheet) rather than a metal sheet. Details described in connection with any of the embodiments above may be used in connection with another embodiment, if such a combination is technically feasible.

Claims

1. A dewatering device of a fiber web machine, comprising: a body (22) having a length greater than a width, and a plurality of brackets (22.4) attached to the body (22) at intervals along a longitudinal direction (L) of the body; and at least one sheet attachment rail (28) parallel to the body (22) and fixed to the body (22) by the bracket (22.4) for supporting a sheet (26) in the dewatering device, characterized in that it further comprises: -a plurality of support ribs (30) parallel to the brackets (22.4), -the sheet attachment rails (28) are attached to the support ribs (30), and wherein the support ribs (30) are fixed to the brackets (22.4) such that one or more support ribs (30) partly overlap and abut one or more brackets (22.4), the attachment between the support ribs (30) and the brackets (22.4) being provided in the overlapping area (a), and-the support ribs (30) are provided with at least one coupling groove (32) into which a holding part (34) fits, wherein the holding part (34) is provided to extend via the coupling grooves (32) of at least two support ribs (30).

2. A dewatering apparatus of a fiber web machine according to claim 1, characterized in that each support rib (30) is provided with at least one coupling groove (32) into which the holding part (34) with an internally threaded hole is releasably fitted, and the sheet attachment rail (28) is releasably attached to the support rib (30) by screwing with the holding part (34).

3. A dewatering arrangement for a fiber web machine according to claim 2, characterized in that the holding part (34) is form-locked to the support rib at least in the direction of the plane of the support rib (30).

4. A dewatering arrangement for a fiber web machine according to claim 2 or 3, characterized in that the support rib (30) is a plate-like structure and the coupling slot (32) is arranged at the edge of the support rib, the coupling slot (32) having a first width (W1) of the coupling slot at the edge of the support rib (30) and a second width (W2) of the coupling slot at a distance from the edge of the support rib (30), wherein the second width (W2) is larger than the first width (W1).

5. A dewatering arrangement for a fiber web machine according to claim 1, characterized in that the holding part (34) is a bar arranged to extend via the grooves of at least two of the support ribs (30) in succession.

6. A dewatering arrangement for a fiber web machine according to claim 5, characterized in that the rod is provided with a number of holes with internal thread, where the pitch of the holes equals the pitch of the support ribs (30).

7. A dewatering apparatus of a fiber web machine, according to claim 5, characterized in that the bar is provided with: an internally threaded hole is located at a position between two support ribs (30) and the distance between successive ones of said support ribs is less than 500 mm.

8. A dewatering arrangement for a fiber web machine according to claim 4, characterized in that the holding part (34) is a bar arranged to extend via the coupling slots (32) of all successive support ribs (30).

9. A dewatering apparatus of a fiber web machine according to claim 1, characterized in that the dewatering apparatus comprises: -a plurality of sheet attachment rails (28) arranged parallel to and at a distance from each other, and wherein each support rib (30) is provided with a number of coupling grooves (32) equal to the number of sheet attachment rails (28), and-the retention means (34) is arranged to extend via each successively aligned coupling groove (32).

10. A dewatering device of a fiber web machine according to claim 1, characterized in that the body (22) is made of sheet metal parts by welding and comprises a bottom part (22.1) and a cover part (22.2), and that the opposite long edges (22.5) of the bottom part (22.1) and the cover part (22.2) are joined together.