Pocket space end sealing system

Abstract

The invention relates to a pocket space end sealing system, which is an independent end sealing system (20) arranged at each longitudinal end of a pocket space (T). The independent end sealing system (10) is located at the respective end area of the pocket space and the independent end sealing system comprises at least one end seal (21) substantially covering cross-sectional area of the pocket space (T). The at least one end seal (21) is movably supported on a support shaft (45) or an outlet pipe (42) or an inlet pipe (41) by a bracket support (50) and transversal location of the end seal (20) is independently adjustable.

Description

Technical field

[0001] The invention relates generally to production of fiber webs and to drying sections of fiber web production lines. Especially, the invention relates to a pocket space end sealing system according to the preamble of the independent pocket space end sealing system claim.Background

[0002] It is known that fiber webs, e.g., paper and board webs, are manufactured in devices and machines which together constitute a fiber web production line, which can be hundreds of meters long. As known from the prior art in fiber web production lines typically comprise an assembly formed by a number of the devices and the machines arranged consecutively in a process line. A typical production line for fiber web comprises a forming section comprising a head box and a wire section, a press section and a drying section and a reel-up. The production line can further comprise other sections and devices for treatment and / or finishing the fiber web, for example a sizer, a coating device, a calender. The production and treatment line also typically comprises at least one slitter-winder for forming customer rolls as well as a roll packaging apparatus.

[0003] As known from the prior art, drying groups of drying sections based on cylinder drying in a fiber web production line employ twin wire draw and / or single wire draw, i.e. twin or single tier drying groups. In single wire draw, i.e. in single tier drying groups, each group of drying cylinders comprises only one drying wire on whose support the fiber web runs through the entire group so that the drying wire presses the fiber web against the heated cylinder surfaces of the drying cylinders and the fiber web remains at the side of the outside curve of the turning rolls situated between the drying cylinders. Thus, in single wire draw in single tier drying groups, the drying cylinders are arranged outside the drying wire loop, and the turning rolls are arranged inside the loop. In the following description, by the term 'turning roll' is also meant a reversing cylinder or a reversing roll alternatively placed in a corresponding position, and these terms are to be understood as synonyms in this description and the claims. In the single tier drying groups of drying sections based on cylinder drying in fiber web production lines, a pocket space defined by a wire is formed between two adjacent drying cylinders and a turning roll situated between them in a lower row. In cross-direction the pocket space is typically limited by end seals located at respective ends of the pocket space. Further, in the prior art arrangements a pocket space is typically fitted with a box like runnability component contouring said wire, roll & cylinders. There are several seals attached to said box in cross direction and in the end walls. So the pocket space is filled with box structures and closed with seals extending from the box structure towards wire, roll & cylinders for bordering the web wide transverse vacuum areas. In connection with the pocket space, we speak of 'opening nips' and 'closing nips', i.e. 'opening gaps' and 'closing gaps', by which opening nip, or opening gap, is meant an area where the drying wire separates from the drying cylinder and, correspondingly, a closing nip, or a closing gap, is formed on the side of the pocket space when the drying wire runs to the turning roll. In a similar manner, when the drying wire leaves the turning roll, an opening nip, i.e. an opening gap, is formed on the outgoing side of the pocket space and, correspondingly, when the drying wire runs to the next drying cylinder, a closing nip, i.e. a closing gap, is formed between the drying wire and the drying cylinder.

[0004] As known from the prior art, by using different runnability components, such as blow and vacuum boxes, located in pocket spaces of drying groups runnablility of the drying section has been improved. These solutions comprise also drying groups of a drying section of a fiber web production line, in which in drying groups based on cylinder drying in the drying section, the run between a drying cylinder and a turning roll in the area of an opening gap has been arranged to be short. Traditional runnability components have seals in cross machine direction, against the drying wire and / or the cylinder for focusing the vacuum effect to at least some important fiber web wide parts of the pocket space for keeping the fiber web attached to the drying wire. The seals are prone to wear due moving surfaces, thermal elongation, changing underpressure and wire tension. This means that accurate and skilled assembly, control and maintenance of the seals is needed regularly. Sometimes, maintenance of the runnability component requires, it to be removed from its location in the pocket space.

[0005] In patent application publication EP1979534A1 is disclosed a drying section of a fiber web machine, in which drying section of the fiber web machine at least one drying group is a drying group which applies single wire draw and comprises at least two drying cylinders, at least one reversing cylinder and a wire supporting the run of a web, in which drying group the paper web that is being dried is arranged to run on support of the drying wire such that the drying wire presses the web on the drying cylinder against heated cylinder surfaces, and the web remains at the side of the outside curve of the reversing cylinders situated between the drying cylinders, and in which drying group a runnability component is placed in a pocket space confined by two adjacent drying cylinders and the reversing cylinder situated between them and by the drying wire, the drying cylinder and the reversing cylinder of the drying group are placed with respect to each other in such a way that the transfer of the web from the drying cylinder to the reversing cylinder is short, length of the transfer is 80 - 400 mm, and during said short transfer, a negative pressure effect is arranged to be applied by means of the runnability component to the web and to the drying wire supporting it, and for the purpose of confining an area of the negative pressure effect, seals of the runnability component are placed so as to be directed against the surface of the drying cylinder and against the surface of the reversing cylinder.

[0006] In patent application publication EP1979535A1 a drying section of a fiber web machine, in which dryer section of the fiber web machine at least one drying group is a drying group which applies single wire draw and comprises at least two drying cylinders, at least one reversing cylinder and a drying wire supporting the run of the web, in which drying group a paper web that is being dried is arranged to run on support of the drying wire such that the drying wire presses the web on a drying cylinder against heated cylinder surfaces, and the web remains at the side of the outside curve of the reversing cylinders situated between the drying cylinders, and in which drying group a pocket space is confined between two adjacent drying cylinders and the reversing cylinder situated between them, and the drying wire, and in which a negative pressure component is placed in at least one pocket space of the drying group to produce a negative pressure effect in the pocket space such that a pressure difference is effective over the drying wire and the web, and the drying cylinders and the reversing cylinder of the drying group are placed with respect to one another in such a way that the transfer of the web from the drying cylinder to the reversing cylinder and from the reversing cylinder to the next drying cylinder is short, whose length is 100 - 500 mm, and for the purpose of confining an area of the negative pressure effect, seals of the negative pressure component are placed so as to be directed against the surface of the drying cylinders, and the tension of the drying wire is at least 3 kN / m.

[0007] In the above examples known from the prior art the drying group has a so-called compact geometry, in which the wire draw limiting the pocket space has been made short by placing the respective drying cylinder close to the turning roll and a runnability component or a vacuum component has been located in the pocket space to confine an area of negative pressure effect. The runnability component or the vacuum component located in the pocket space increase the length of the drying section in machine direction. Even as the required space in the machine direction for one runnability or vacuum component is not big, the drying section typically has several drying groups, each typically provided with several runnability and / or vacuum components, and thus, the overall length requirement for these components in machine direction is signification. The runnability and vacuum components also require for example air systems and other equipment for operating, which also require space. It should also be noted that the runnability and vacuum components and their equipment also have a significant effect on overall manufacturing and operating costs of a drying section, as well as in investment and energy costs.

[0008] An object of the invention is to provide a pocket space end sealing system to eliminate and / or minimize the above-noted problems and disadvantages associated with the drying groups known from prior art, in particular relating to problems and disadvantages of a runnability component placed in a pocket space of a drying group of a drying section.

[0009] A particular object of the invention is to provide a pocket space end sealing system, by which cost savings, especially investment-wise, are achieved.

[0010] A particular object of the invention is to decrease in production of runnability components and / or the systems amount, and number of elements and materials needed.Summary

[0011] To achieve the above-mentioned objects and those which come out later, the pocket space end sealing system according to the invention is mainly characterized by what is presented in the characterizing part of the independent pocket space end sealing system claim. Advantageous features and embodiments of the invention are defined in dependent claims.

[0012] In this description and the claims by the term machine direction is meant the general process direction i.e., main running direction of the fiber web in the fiber web production line, as generally used in connection with fiber web production technology. By the term cross direction is meant the direction perpendicular to the machine direction. Further, it should be noted that by distances mentioned are meant the shortest distance between the mentioned objects, i.e. it is question of the distance measured between the closest points of the mentioned objects.

[0013] According to the invention the pocket space end sealing system is an independent end sealing system arranged at each longitudinal end of a pocket space, the independent end sealing system is located at the respective end area of the pocket space, the independent end sealing system comprises at least one end seal substantially covering cross-sectional area of the pocket space, the at least one end seal is movably supported on a support shaft or an outlet pipe or an inlet pipe by a bracket support, and transversal location of the end seal is independently adjustable.

[0014] According to an advantageous feature of the invention the end seal comprises three concave end seals formed in a seal body.

[0015] According to an advantageous feature of the invention the independent end sealing system comprises an end seal and an additional sealing element spaced apart in the longitudinal direction of the pocket space.

[0016] According to an advantageous feature of the invention the end seal and the additional sealing element a chamber is formed to provide air flows to effect the sealing.

[0017] According to an advantageous feature of the invention the pocket space is confined by two adjacent drying cylinders and a turning roll situated between and below the drying cylinders and by a drying wire of a drying group for drying a fiber web.

[0018] According to an advantageous feature of the invention the pocket space is free of runnability or vacuum components between the independent end sealing systems.

[0019] According to an advantageous feature of the invention the independent end sealing system further comprises an outside seal element located just outside the end of the pocket space.

[0020] According to an advantageous aspect of the invention an independent, separate end sealing system comprising two end seals is located at each longitudinal end area of the pocket space, wherein the end seal substantially covers cross-sectional area of the pocket space.

[0021] According to an advantageous aspect of the invention inside of the pocket space between the independent end sealing systems is empty i.e. free of runnability components extending through the pocket space, i.e. in cross direction in view of the main running direction extending structures or like are not located in the pocket space. This provides that no runnability or vacuum components are needed to be mounted or aligned inside the pocket space between the independent end sealing systems, as the in the pocket space extending runnability or vacuum components can be omitted.

[0022] According to an advantageous aspect of the invention no air is supplied into the pocket space to effect the runnablility of the cross directional center areas of the fiber web.

[0023] According to an advantageous aspect of the invention the pocket space is closed at its longitudinal ends by independent end sealing systems, i.e. by the end seals, which substantially cover cross-sectional area of the pocket space and which are located at the edge area of the drying wire such, that air leakage from outside the fiber web area through the drying wire is prevented to the by the end seals closed pocket space. Preferably the end seals are each supported at its own side and thus, the locations of the end seals are independently adjustable. Advantageously, the end seal comprises three concave end seals and three triangular gap end seals formed in a seal body such, that they form end seals contouring the surface of the respective cylinder. The seal body has advantageously a substantially triangular form and the end seals extend on the sides of the triangular form into the respective gap area of the pocket space.

[0024] By the invention and its advantageous features several advantages are achieved: A significantly improved and simplified runnability is achieved. Further, the investment costs and the energy consumption is decreased as no runnability or vacuum components are needed in the pocket space. In production of runnability components and / or the systems amount and number of materials needed is significantly decreased and also energy, raw materials consumption is significantly decreased. Thus, the runnablity system is sustainable and environmentally friendly.Brief description of the drawings

[0025] Aspects of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of some example embodiments when read in connection with the accompanying drawings and in the following the invention is described in more detail referring to the accompanying drawing, in which In figure 1 is schematically shown an example of a drying group known from prior art. In figure 2 is schematically shown an advantageous example of a drying group. In figure 3 is schematically shown an advantageous example of one pocket space of a drying group comprising an advantageous example of a runnability system of the drying group. In figure 4 is schematically shown an advantageous example of an end seal system of the runnability system of the drying group. In figures 5A-5D is schematically shown advantageous examples of runnability systems of the drying group. Detailed description

[0026] In the following description same reference signs designate for similar components unless otherwise mentioned and it should be understood that the examples are susceptible of modification in order to adapt to different usages and conditions within the frames of the invention. Repetition of some reference signs may have been omitted in figures for clarity reasons.

[0027] In figure 1 shown an example known from prior art of a single tier drying group applying single wire draw for a drying section of a fiber web production line, drying cylinders 12 are located in an upper row and turning rolls 11 are placed in a lower row. A fiber web to be dried is arranged to run on support of a drying wire 10 from the drying cylinders 12 to the turning rolls 11 in a manner of single wire draw. Runnability or vacuum components 14 are placed in a pocket space T remaining between two adjacent drying cylinders 12 and a turning roll 11 and the drying wire F, which runnability or vacuum component 14 produces a negative pressure that is used for enhancing the runnability of the fiber web W in cylinder drying, in particular in an area of a gap opening from the drying cylinder 12. The runnability component 14 produces a negative pressure area on the run of the web and the wire 10 from the drying cylinder 12 to the turning roll 11, Said negative pressure area is confined by seals 25, 26 sealing the operating area of the runnability component 14 to the run of the wire 10 in the area between the surface of the drying cylinder 12 and the surface of the turning roll 11. The runnability component 14 is typically provided with seals, for example mechanical or air flow seals. In drying groups according to prior art the cross-sectional (in view of the machine direction area of the pocket space T is typically about 0,25 m 2< , as shown in figure 3.

[0028] In figure 2 shown advantageous example of a single tier drying group, i.e. applying single wire draw for a drying section of a fiber web production line, drying cylinders 12 are located in an upper row and turning rolls 11 are placed in a lower row. Rotating direction of the drying cylinders 12 is indicated by arrows R12 and rotating direction of the turning roll 11 is indicated by arrow R11. A fiber web to be dried is arranged to run on support of a drying wire 10 from the drying cylinders 12 to the turning rolls 11 in a manner of single wire draw. In the drying group applying the single tier drying, geometry is fully compact such that distances between the two adjacent drying cylinders 12 and the turning roll 11, which together limit the pocket space T, are short 10-50 mm, advantageously 10-25 mm. Preferably, the distance between the two adjacent drying cylinders 12 is 15-25 mm and the distance between the drying cylinder 12 and the turning roll 11 is 10-25 mm. Thus, the cross-sectional area of the pocket space T in view of the prior art drying groups is significantly decreased, to even only 0,12 m 2< and thus, a more compact, fully compact, geometry of the single tier drying group is achieved. The fully compact geometry of the single tier drying group can be formed by locating the drying cylinders 12 close to each other and locating the turning roll in vertical direction close to both of the drying cylinders 12. The fully compact geometry fits to various dimensioning of drying cylinders 12 and turning rolls 11. The inside of the pocket space T is free, i.e. empty of components, i.e. no cross-structures or like are located in the pocket space T. The pocket space T is underpressurized only using as the turning roll 11 a perforated vacuum turning roll comprising vacuum connections, by which the underpressure of the pocket space T is operated. Further, preferably the vacuum is provided around the circumference of the vacuum turning roll 11 such, that in addition to the pocket space T also underpressure at the circumferential surface of the vacuum turning roll 11 is operated. Advantageously, in addition to the perforation the mantle of the vacuum turning roll 11 comprises circumferential grooves, which assists in distribution of the underpressure at the circumferential surface of the vacuum turning roll. In the gap between the two adjacent drying cylinders 12 the opposite directional boundary layer air flows of the circumferential surfaces of the two adjacent rotating R12 drying cylinder 12 provide a sealing effect in the gap and thus, underpressure generated by the vacuum turning roll 11 provides desired underpressure in the pocket space T, as the opposite directional boundary layer air flows prevent leakage of air to the pocket space. The direction of the boundary layer air flow corresponds the rotating direction R12 of the respective drying cylinder 12. The pocket space T is closed at its longitudinal ends by end sealing 20 by end seals 21, which substantially cover cross-sectional area of the pocket space T. Preferably the end seals 21 are each supported only at its own side and thus, the end seals 21 are independently adjustable. Advantageously, the end seal 21 comprises an end seal body 22 (fig. 3-4) with three curved concave end seals and three triangular gap end seals 23 (fig. 3-4). The seal body 22 has a substantially triangular form and the concave end seals extend between respective gap end seals 23, i.e. on the sides of the triangular form. In the drying group in connection with the drying cylinder 12 a doctor beam15 is arranged and in connection of the doctor beam 15 preferably doctor ventilator 16 is provided to blow replacement air in vicinity of the fiber web to enhance drying of the fiber web and to support the fiber web against the drying wire 10.

[0029] In the example of figure 3 is shown one pocket space T of a single tier drying group, i.e. applying single wire draw for a drying section of a fiber web production line. The drying cylinders 12 are located in an upper row and the turning rolls 11 are placed in a lower row. Rotating direction of the drying cylinders 12 is indicated by arrows R12 and rotating direction of the turning roll 11 is indicated by arrow R11. A fiber web to be dried is arranged to run on support of a drying wire 10 (fig. 2) from the drying cylinders 12 to the turning roll 11 in a manner of single wire draw. In the drying group applying the single tier drying a runnability system is arranged by forming the geometry fully compact such that distances between the two adjacent drying cylinders 12 and the turning roll 11, which together limit the pocket space T, are short 10-50 mm, advantageously 10-25 mm. Preferably, the distance between the two adjacent drying cylinders 12 is 15-25 mm and the distance between the drying cylinder 12 and the turning roll 11 is 10-25 mm. Thus, the cross-sectional area of the pocket space T in view of the prior art drying groups is significantly decreased, to even only 0,12 m 2< and thus, a more compact, fully compact, geometry of the single tier drying group is achieved and runnability is enhanced. The fully compact geometry of the single tier drying group can be formed by locating the drying cylinders 12 close to each other and locating the turning roll in vertical direction close to both of the drying cylinders 12. The fully compact geometry fits to various dimensioning of drying cylinders 12 and turning rolls 11. The runnablity system further comprises independent, advantageously separate, end sealing system 20 formed at each longitudinal end area of the pocket space T.

[0030] The independent end sealing system 20 comprises two end seals 21 located at each longitudinal end area of the pocket space T. The end seal 21 substantially covers cross-sectional area of the pocket space T. The pocket space T is closed at its longitudinal ends the independent end sealing system 20 by the end seals 21, which substantially cover cross-sectional area A of the pocket space T. Preferably the end seals 21 are each supported only at its own side and thus, the end seals 20 are independently adjustable. Advantageously, the end seal 21 comprises an end seal body 22 with three concave end seals and three gap end seals 23. Thus, the end seal 21 comprises three curved concave end seals formed in a seal body 22 and three gap end seals 23. The seal body 22 has a substantially triangular form and the end sealing extends between respective gap end seals, i.e. on the sides of the triangular form. The end seals 23, thus form three triangular-shaped concave gap end seals contouring the surface of the respective cylinders 12, 11. The seal body 22 has a substantially triangular form and the end seals 23 extend on the sides of the triangular form to the gap area of the pocket space T. The end seals 23 advantageously also comprises blow openings 26 (fig. 4) to create sealing blowing BS, BC to side and gap areas of the pocket space T, i.e. at the vicinity of surfaces of the drying cylinders 12 and of the turning roll 11 to prevent leakage of air to the pocket space T and thus, to improve the runnability. In the drying group in connection with the drying cylinder 12 a doctor beam 15 is arranged and in connection of the doctor beam 15 preferably doctor ventilator 16 is provided to blow replacement air in vicinity of the fiber web to enhance drying of the fiber web and to support the fiber web against the drying wire 10 and thus, to improve the runnability.The inside of the pocket space T is free, i.e. empty of components, i.e. no cross-structures or like are located in the pocket space T between the end seals 21. The pocket space T is underpressurized using as the turning roll 11 a perforated vacuum turning roll comprising vacuum connections, by which the underpressure of the pocket space T is operated. Further, preferably the vacuum is provided around the circumference of the vacuum turning roll 11 such, that in addition to the pocket space T also underpressure at the circumferential surface of the vacuum turning roll 11 is operated. Advantageously, in addition to the perforation the mantle of the vacuum turning roll 11 comprises circumferential grooves, which assists in distribution of the underpressure at the circumferential surface of the vacuum turning roll. In the gap between the two adjacent drying cylinders 12 the opposite directional boundary layer air flows of the circumferential surfaces of the two adjacent rotating R12 drying cylinder 12 provide a sealing effect in the gap and thus, underpressure generated by the vacuum turning roll 11 provides desired underpressure in the pocket space T, as the opposite directional boundary layer air flows prevent leakage of air to the pocket space.

[0031] The direction of the boundary layer air flow corresponds the rotating direction R12 of the respective drying cylinder 12.

[0032] As can also be seen from the example of figure 4 The independent end sealing system 20 comprises two end seals 21 located at each longitudinal end area of the pocket space T. The end seal 21 substantially covers cross-sectional area of the pocket space T. The pocket space T is closed at its longitudinal ends the independent end sealing system 20 by the end seals 21, which substantially cover cross-sectional area A of the pocket space T. Preferably the end seals 21 are each supported only at its own side and thus, the end seals 20 are independently adjustable. Advantageously, the end seal 21 comprises an end seal body 22 with three end seals and three gap end seals 23. Thus, the end seal 21 comprises three curved concave end seals formed in a seal body 22 and three gap end seals 23. The seal body 22 has a substantially triangular form and the end sealing extends between respective gap end seals, i.e. on the sides of the triangular form. The end seals 23, thus form three triangular-shaped concave gap end seals contouring the surface of the respective cylinders 12, 11. The seal body 22 has a substantially triangular form and the end seals 23 extend on the sides of the triangular form to the gap area of the pocket space T. The end seals 23 advantageously also comprises blow openings 26 (fig. 4) to create sealing blowing BS, BC to side areas of the pocket space T, i.e. at the vicinity of surfaces of the drying cylinders 12 and of the turning roll 1 to prevent leakage of air to the pocket space T and thus, to improve the runnability. Air IA is provided for the sealing blowing BS, BC by an air inlet 41, also forming a support structure for the end seal body 22. In the example of figure 4 the independent end sealing system 20 further comprises an additional end sealing element 32 for providing an edge chamber and / or a labyrinth sealing.

[0033] As shown in the example of figure 5A the independent end sealing system 20 is located at the end area of the pocket space T in the longitudinal direction thereof. Advantageously, the end seal 21 is located over the edge of the fiber web W and on the area of the drying wire 10. In this example the end seal 21 is supported by a support shaft 45, which is movably supported by bracket support 50 comprising two brackets 51, 52 spaced apart in longitudinal direction of the support shaft 45. Thus, the location of the end seal 21 can be adjusted by moving the support shaft 45 in the bracket support 50 and the two spaced apart brackets 51, 52 provide that the support direction is steady. The pocket space T is underpressurized using as the turning roll 11 a perforated vacuum turning roll comprising vacuum connections, by which the underpressure of the pocket space T is operated, as indicated by suction arrows S11.

[0034] The example of figure 5B corresponds to the example of the figure 5A and the independent end sealing system 20 is located at the end area of the pocket space T in the longitudinal direction thereof. Advantageously, the end seal 21 is located over the edge of the fiber web W and on the area of the drying wire 10. The end sealing 20 in this example further comprises an additional sealing element 32 located space apart from the end seal 21 and inner in the pocket space T in longitudinal direction and on the edge area of the fiber web W. The end seal 21 is supported by a support shaft 45, which is movably supported by bracket support 50 comprising two brackets 51, 52 spaced apart in longitudinal direction of the support shaft 45. Thus, the location of the end seal 21 can be adjusted by moving the support shaft 45 in the bracket support 50 and the two spaced apart brackets 51, 52 provide that the support direction is steady. The pocket space T is underpressurized using as the turning roll 11 a perforated vacuum turning roll comprising vacuum connections, by which the underpressure of the pocket space T is operated, as indicated by suction arrows S11. The suction is provided by arranging an outlet flow O11 through the end of the turning roll. The additional sealing element 32 provides that the suction effect of the turning roll 11 can be increased in the edge area of the fiber web W to improve runnability of the edge areas of the fiber web W.

[0035] The example of figure 5C corresponds to the examples of figs 5A-5B but in this example a suction chamber 34 is arranged between the end seal 21 and the additional sealing element 32. The suction chamber 34 has openings 36 through which air is removed from the edge area of the fiber web W, as indicated by arrows O34. In this example as the support shaft is arranged an outlet pipe 42 for the removal of the air flow O21 from the suction chamber 34. This outlet pipe 42 advantageously is connected to an outlet pipe 43 for removal of the air flow O11 from the turning roll 11. The end sealing 20 can further be provided with an outside seal element 33 located just outside the end of the pocket space 11 and the respective cylinders 11, 12. The outside seal element 33 prevents side flows to disturb the sealing and thus, further improves the runnability.

[0036] The example of figure 5D corresponds to the examples of figs 5A-5C but in this example an air chamber 37 is arranged between the end seal 21 and the additional sealing element 32. The air chamber 37 provides air flow for the sealing blowing BS, BC. In this example as the support shaft is arranged inlet pipe 41 for inlet air to the air chamber 37 as the inlet air flow IA from the air chamber 37.

[0037] In the description in the foregoing, although some functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain embodiments or examples, those features may also be present in other embodiments or examples whether described or not. Above the invention has been described by referring to some advantageous examples only to which the invention is not to be narrowly limited. Many modifications and alterations are possible within the invention as defined in the following claims.

Examples

Embodiment Construction

[0026]In the following description same reference signs designate for similar components unless otherwise mentioned and it should be understood that the examples are susceptible of modification in order to adapt to different usages and conditions within the frames of the invention. Repetition of some reference signs may have been omitted in figures for clarity reasons.

[0027]In figure 1 shown an example known from prior art of a single tier drying group applying single wire draw for a drying section of a fiber web production line, drying cylinders 12 are located in an upper row and turning rolls 11 are placed in a lower row. A fiber web to be dried is arranged to run on support of a drying wire 10 from the drying cylinders 12 to the turning rolls 11 in a manner of single wire draw. Runnability or vacuum components 14 are placed in a pocket space T remaining between two adjacent drying cylinders 12 and a turning roll 11 and the drying wire F, which runnability or vacuum component 14 p...

Technical field

[0001] The invention relates generally to production of fiber webs and to drying sections of fiber web production lines. Especially, the invention relates to a pocket space end sealing system according to the preamble of the independent pocket space end sealing system claim.Background

[0002] It is known that fiber webs, e.g., paper and board webs, are manufactured in devices and machines which together constitute a fiber web production line, which can be hundreds of meters long. As known from the prior art in fiber web production lines typically comprise an assembly formed by a number of the devices and the machines arranged consecutively in a process line. A typical production line for fiber web comprises a forming section comprising a head box and a wire section, a press section and a drying section and a reel-up. The production line can further comprise other sections and devices for treatment and / or finishing the fiber web, for example a sizer, a coating device, a calender. The production and treatment line also typically comprises at least one slitter-winder for forming customer rolls as well as a roll packaging apparatus.

[0003] As known from the prior art, drying groups of drying sections based on cylinder drying in a fiber web production line employ twin wire draw and / or single wire draw, i.e. twin or single tier drying groups. In single wire draw, i.e. in single tier drying groups, each group of drying cylinders comprises only one drying wire on whose support the fiber web runs through the entire group so that the drying wire presses the fiber web against the heated cylinder surfaces of the drying cylinders and the fiber web remains at the side of the outside curve of the turning rolls situated between the drying cylinders. Thus, in single wire draw in single tier drying groups, the drying cylinders are arranged outside the drying wire loop, and the turning rolls are arranged inside the loop. In the following description, by the term 'turning roll' is also meant a reversing cylinder or a reversing roll alternatively placed in a corresponding position, and these terms are to be understood as synonyms in this description and the claims. In the single tier drying groups of drying sections based on cylinder drying in fiber web production lines, a pocket space defined by a wire is formed between two adjacent drying cylinders and a turning roll situated between them in a lower row. In cross-direction the pocket space is typically limited by end seals located at respective ends of the pocket space. Further, in the prior art arrangements a pocket space is typically fitted with a box like runnability component contouring said wire, roll & cylinders. There are several seals attached to said box in cross direction and in the end walls. So the pocket space is filled with box structures and closed with seals extending from the box structure towards wire, roll & cylinders for bordering the web wide transverse vacuum areas. In connection with the pocket space, we speak of 'opening nips' and 'closing nips', i.e. 'opening gaps' and 'closing gaps', by which opening nip, or opening gap, is meant an area where the drying wire separates from the drying cylinder and, correspondingly, a closing nip, or a closing gap, is formed on the side of the pocket space when the drying wire runs to the turning roll. In a similar manner, when the drying wire leaves the turning roll, an opening nip, i.e. an opening gap, is formed on the outgoing side of the pocket space and, correspondingly, when the drying wire runs to the next drying cylinder, a closing nip, i.e. a closing gap, is formed between the drying wire and the drying cylinder.

[0004] As known from the prior art, by using different runnability components, such as blow and vacuum boxes, located in pocket spaces of drying groups runnablility of the drying section has been improved. These solutions comprise also drying groups of a drying section of a fiber web production line, in which in drying groups based on cylinder drying in the drying section, the run between a drying cylinder and a turning roll in the area of an opening gap has been arranged to be short. Traditional runnability components have seals in cross machine direction, against the drying wire and / or the cylinder for focusing the vacuum effect to at least some important fiber web wide parts of the pocket space for keeping the fiber web attached to the drying wire. The seals are prone to wear due moving surfaces, thermal elongation, changing underpressure and wire tension. This means that accurate and skilled assembly, control and maintenance of the seals is needed regularly. Sometimes, maintenance of the runnability component requires, it to be removed from its location in the pocket space.

[0005] In patent application publication EP1979534A1 is disclosed a drying section of a fiber web machine, in which drying section of the fiber web machine at least one drying group is a drying group which applies single wire draw and comprises at least two drying cylinders, at least one reversing cylinder and a wire supporting the run of a web, in which drying group the paper web that is being dried is arranged to run on support of the drying wire such that the drying wire presses the web on the drying cylinder against heated cylinder surfaces, and the web remains at the side of the outside curve of the reversing cylinders situated between the drying cylinders, and in which drying group a runnability component is placed in a pocket space confined by two adjacent drying cylinders and the reversing cylinder situated between them and by the drying wire, the drying cylinder and the reversing cylinder of the drying group are placed with respect to each other in such a way that the transfer of the web from the drying cylinder to the reversing cylinder is short, length of the transfer is 80 - 400 mm, and during said short transfer, a negative pressure effect is arranged to be applied by means of the runnability component to the web and to the drying wire supporting it, and for the purpose of confining an area of the negative pressure effect, seals of the runnability component are placed so as to be directed against the surface of the drying cylinder and against the surface of the reversing cylinder.

[0006] In patent application publication EP1979535A1 a drying section of a fiber web machine, in which dryer section of the fiber web machine at least one drying group is a drying group which applies single wire draw and comprises at least two drying cylinders, at least one reversing cylinder and a drying wire supporting the run of the web, in which drying group a paper web that is being dried is arranged to run on support of the drying wire such that the drying wire presses the web on a drying cylinder against heated cylinder surfaces, and the web remains at the side of the outside curve of the reversing cylinders situated between the drying cylinders, and in which drying group a pocket space is confined between two adjacent drying cylinders and the reversing cylinder situated between them, and the drying wire, and in which a negative pressure component is placed in at least one pocket space of the drying group to produce a negative pressure effect in the pocket space such that a pressure difference is effective over the drying wire and the web, and the drying cylinders and the reversing cylinder of the drying group are placed with respect to one another in such a way that the transfer of the web from the drying cylinder to the reversing cylinder and from the reversing cylinder to the next drying cylinder is short, whose length is 100 - 500 mm, and for the purpose of confining an area of the negative pressure effect, seals of the negative pressure component are placed so as to be directed against the surface of the drying cylinders, and the tension of the drying wire is at least 3 kN / m.

[0007] In the above examples known from the prior art the drying group has a so-called compact geometry, in which the wire draw limiting the pocket space has been made short by placing the respective drying cylinder close to the turning roll and a runnability component or a vacuum component has been located in the pocket space to confine an area of negative pressure effect. The runnability component or the vacuum component located in the pocket space increase the length of the drying section in machine direction. Even as the required space in the machine direction for one runnability or vacuum component is not big, the drying section typically has several drying groups, each typically provided with several runnability and / or vacuum components, and thus, the overall length requirement for these components in machine direction is signification. The runnability and vacuum components also require for example air systems and other equipment for operating, which also require space. It should also be noted that the runnability and vacuum components and their equipment also have a significant effect on overall manufacturing and operating costs of a drying section, as well as in investment and energy costs.

[0008] An object of the invention is to provide a pocket space end sealing system to eliminate and / or minimize the above-noted problems and disadvantages associated with the drying groups known from prior art, in particular relating to problems and disadvantages of a runnability component placed in a pocket space of a drying group of a drying section.

[0009] A particular object of the invention is to provide a pocket space end sealing system, by which cost savings, especially investment-wise, are achieved.

[0010] A particular object of the invention is to decrease in production of runnability components and / or the systems amount, and number of elements and materials needed.Summary

[0011] To achieve the above-mentioned objects and those which come out later, the pocket space end sealing system according to the invention is mainly characterized by what is presented in the characterizing part of the independent pocket space end sealing system claim. Advantageous features and embodiments of the invention are defined in dependent claims.

[0012] In this description and the claims by the term machine direction is meant the general process direction i.e., main running direction of the fiber web in the fiber web production line, as generally used in connection with fiber web production technology. By the term cross direction is meant the direction perpendicular to the machine direction. Further, it should be noted that by distances mentioned are meant the shortest distance between the mentioned objects, i.e. it is question of the distance measured between the closest points of the mentioned objects.

[0013] According to the invention the pocket space end sealing system is an independent end sealing system arranged at each longitudinal end of a pocket space, the independent end sealing system is located at the respective end area of the pocket space, the independent end sealing system comprises at least one end seal substantially covering cross-sectional area of the pocket space, the at least one end seal is movably supported on a support shaft or an outlet pipe or an inlet pipe by a bracket support, and transversal location of the end seal is independently adjustable.

[0014] According to an advantageous feature of the invention the end seal comprises three concave end seals formed in a seal body.

[0015] According to an advantageous feature of the invention the independent end sealing system comprises an end seal and an additional sealing element spaced apart in the longitudinal direction of the pocket space.

[0016] According to an advantageous feature of the invention the end seal and the additional sealing element a chamber is formed to provide air flows to effect the sealing.

[0017] According to an advantageous feature of the invention the pocket space is confined by two adjacent drying cylinders and a turning roll situated between and below the drying cylinders and by a drying wire of a drying group for drying a fiber web.

[0018] According to an advantageous feature of the invention the pocket space is free of runnability or vacuum components between the independent end sealing systems.

[0019] According to an advantageous feature of the invention the independent end sealing system further comprises an outside seal element located just outside the end of the pocket space.

[0020] According to an advantageous aspect of the invention an independent, separate end sealing system comprising two end seals is located at each longitudinal end area of the pocket space, wherein the end seal substantially covers cross-sectional area of the pocket space.

[0021] According to an advantageous aspect of the invention inside of the pocket space between the independent end sealing systems is empty i.e. free of runnability components extending through the pocket space, i.e. in cross direction in view of the main running direction extending structures or like are not located in the pocket space. This provides that no runnability or vacuum components are needed to be mounted or aligned inside the pocket space between the independent end sealing systems, as the in the pocket space extending runnability or vacuum components can be omitted.

[0022] According to an advantageous aspect of the invention no air is supplied into the pocket space to effect the runnablility of the cross directional center areas of the fiber web.

[0023] According to an advantageous aspect of the invention the pocket space is closed at its longitudinal ends by independent end sealing systems, i.e. by the end seals, which substantially cover cross-sectional area of the pocket space and which are located at the edge area of the drying wire such, that air leakage from outside the fiber web area through the drying wire is prevented to the by the end seals closed pocket space. Preferably the end seals are each supported at its own side and thus, the locations of the end seals are independently adjustable. Advantageously, the end seal comprises three concave end seals and three triangular gap end seals formed in a seal body such, that they form end seals contouring the surface of the respective cylinder. The seal body has advantageously a substantially triangular form and the end seals extend on the sides of the triangular form into the respective gap area of the pocket space.

[0024] By the invention and its advantageous features several advantages are achieved: A significantly improved and simplified runnability is achieved. Further, the investment costs and the energy consumption is decreased as no runnability or vacuum components are needed in the pocket space. In production of runnability components and / or the systems amount and number of materials needed is significantly decreased and also energy, raw materials consumption is significantly decreased. Thus, the runnablity system is sustainable and environmentally friendly.Brief description of the drawings

[0025] Aspects of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of some example embodiments when read in connection with the accompanying drawings and in the following the invention is described in more detail referring to the accompanying drawing, in which In figure 1 is schematically shown an example of a drying group known from prior art. In figure 2 is schematically shown an advantageous example of a drying group. In figure 3 is schematically shown an advantageous example of one pocket space of a drying group comprising an advantageous example of a runnability system of the drying group. In figure 4 is schematically shown an advantageous example of an end seal system of the runnability system of the drying group. In figures 5A-5D is schematically shown advantageous examples of runnability systems of the drying group. Detailed description

[0026] In the following description same reference signs designate for similar components unless otherwise mentioned and it should be understood that the examples are susceptible of modification in order to adapt to different usages and conditions within the frames of the invention. Repetition of some reference signs may have been omitted in figures for clarity reasons.

[0027] In figure 1 shown an example known from prior art of a single tier drying group applying single wire draw for a drying section of a fiber web production line, drying cylinders 12 are located in an upper row and turning rolls 11 are placed in a lower row. A fiber web to be dried is arranged to run on support of a drying wire 10 from the drying cylinders 12 to the turning rolls 11 in a manner of single wire draw. Runnability or vacuum components 14 are placed in a pocket space T remaining between two adjacent drying cylinders 12 and a turning roll 11 and the drying wire F, which runnability or vacuum component 14 produces a negative pressure that is used for enhancing the runnability of the fiber web W in cylinder drying, in particular in an area of a gap opening from the drying cylinder 12. The runnability component 14 produces a negative pressure area on the run of the web and the wire 10 from the drying cylinder 12 to the turning roll 11, Said negative pressure area is confined by seals 25, 26 sealing the operating area of the runnability component 14 to the run of the wire 10 in the area between the surface of the drying cylinder 12 and the surface of the turning roll 11. The runnability component 14 is typically provided with seals, for example mechanical or air flow seals. In drying groups according to prior art the cross-sectional (in view of the machine direction area of the pocket space T is typically about 0,25 m 2< , as shown in figure 3.

[0028] In figure 2 shown advantageous example of a single tier drying group, i.e. applying single wire draw for a drying section of a fiber web production line, drying cylinders 12 are located in an upper row and turning rolls 11 are placed in a lower row. Rotating direction of the drying cylinders 12 is indicated by arrows R12 and rotating direction of the turning roll 11 is indicated by arrow R11. A fiber web to be dried is arranged to run on support of a drying wire 10 from the drying cylinders 12 to the turning rolls 11 in a manner of single wire draw. In the drying group applying the single tier drying, geometry is fully compact such that distances between the two adjacent drying cylinders 12 and the turning roll 11, which together limit the pocket space T, are short 10-50 mm, advantageously 10-25 mm. Preferably, the distance between the two adjacent drying cylinders 12 is 15-25 mm and the distance between the drying cylinder 12 and the turning roll 11 is 10-25 mm. Thus, the cross-sectional area of the pocket space T in view of the prior art drying groups is significantly decreased, to even only 0,12 m 2< and thus, a more compact, fully compact, geometry of the single tier drying group is achieved. The fully compact geometry of the single tier drying group can be formed by locating the drying cylinders 12 close to each other and locating the turning roll in vertical direction close to both of the drying cylinders 12. The fully compact geometry fits to various dimensioning of drying cylinders 12 and turning rolls 11. The inside of the pocket space T is free, i.e. empty of components, i.e. no cross-structures or like are located in the pocket space T. The pocket space T is underpressurized only using as the turning roll 11 a perforated vacuum turning roll comprising vacuum connections, by which the underpressure of the pocket space T is operated. Further, preferably the vacuum is provided around the circumference of the vacuum turning roll 11 such, that in addition to the pocket space T also underpressure at the circumferential surface of the vacuum turning roll 11 is operated. Advantageously, in addition to the perforation the mantle of the vacuum turning roll 11 comprises circumferential grooves, which assists in distribution of the underpressure at the circumferential surface of the vacuum turning roll. In the gap between the two adjacent drying cylinders 12 the opposite directional boundary layer air flows of the circumferential surfaces of the two adjacent rotating R12 drying cylinder 12 provide a sealing effect in the gap and thus, underpressure generated by the vacuum turning roll 11 provides desired underpressure in the pocket space T, as the opposite directional boundary layer air flows prevent leakage of air to the pocket space. The direction of the boundary layer air flow corresponds the rotating direction R12 of the respective drying cylinder 12. The pocket space T is closed at its longitudinal ends by end sealing 20 by end seals 21, which substantially cover cross-sectional area of the pocket space T. Preferably the end seals 21 are each supported only at its own side and thus, the end seals 21 are independently adjustable. Advantageously, the end seal 21 comprises an end seal body 22 (fig. 3-4) with three curved concave end seals and three triangular gap end seals 23 (fig. 3-4). The seal body 22 has a substantially triangular form and the concave end seals extend between respective gap end seals 23, i.e. on the sides of the triangular form. In the drying group in connection with the drying cylinder 12 a doctor beam15 is arranged and in connection of the doctor beam 15 preferably doctor ventilator 16 is provided to blow replacement air in vicinity of the fiber web to enhance drying of the fiber web and to support the fiber web against the drying wire 10.

[0029] In the example of figure 3 is shown one pocket space T of a single tier drying group, i.e. applying single wire draw for a drying section of a fiber web production line. The drying cylinders 12 are located in an upper row and the turning rolls 11 are placed in a lower row. Rotating direction of the drying cylinders 12 is indicated by arrows R12 and rotating direction of the turning roll 11 is indicated by arrow R11. A fiber web to be dried is arranged to run on support of a drying wire 10 (fig. 2) from the drying cylinders 12 to the turning roll 11 in a manner of single wire draw. In the drying group applying the single tier drying a runnability system is arranged by forming the geometry fully compact such that distances between the two adjacent drying cylinders 12 and the turning roll 11, which together limit the pocket space T, are short 10-50 mm, advantageously 10-25 mm. Preferably, the distance between the two adjacent drying cylinders 12 is 15-25 mm and the distance between the drying cylinder 12 and the turning roll 11 is 10-25 mm. Thus, the cross-sectional area of the pocket space T in view of the prior art drying groups is significantly decreased, to even only 0,12 m 2< and thus, a more compact, fully compact, geometry of the single tier drying group is achieved and runnability is enhanced. The fully compact geometry of the single tier drying group can be formed by locating the drying cylinders 12 close to each other and locating the turning roll in vertical direction close to both of the drying cylinders 12. The fully compact geometry fits to various dimensioning of drying cylinders 12 and turning rolls 11. The runnablity system further comprises independent, advantageously separate, end sealing system 20 formed at each longitudinal end area of the pocket space T.

[0030] The independent end sealing system 20 comprises two end seals 21 located at each longitudinal end area of the pocket space T. The end seal 21 substantially covers cross-sectional area of the pocket space T. The pocket space T is closed at its longitudinal ends the independent end sealing system 20 by the end seals 21, which substantially cover cross-sectional area A of the pocket space T. Preferably the end seals 21 are each supported only at its own side and thus, the end seals 20 are independently adjustable. Advantageously, the end seal 21 comprises an end seal body 22 with three concave end seals and three gap end seals 23. Thus, the end seal 21 comprises three curved concave end seals formed in a seal body 22 and three gap end seals 23. The seal body 22 has a substantially triangular form and the end sealing extends between respective gap end seals, i.e. on the sides of the triangular form. The end seals 23, thus form three triangular-shaped concave gap end seals contouring the surface of the respective cylinders 12, 11. The seal body 22 has a substantially triangular form and the end seals 23 extend on the sides of the triangular form to the gap area of the pocket space T. The end seals 23 advantageously also comprises blow openings 26 (fig. 4) to create sealing blowing BS, BC to side and gap areas of the pocket space T, i.e. at the vicinity of surfaces of the drying cylinders 12 and of the turning roll 11 to prevent leakage of air to the pocket space T and thus, to improve the runnability. In the drying group in connection with the drying cylinder 12 a doctor beam 15 is arranged and in connection of the doctor beam 15 preferably doctor ventilator 16 is provided to blow replacement air in vicinity of the fiber web to enhance drying of the fiber web and to support the fiber web against the drying wire 10 and thus, to improve the runnability.The inside of the pocket space T is free, i.e. empty of components, i.e. no cross-structures or like are located in the pocket space T between the end seals 21. The pocket space T is underpressurized using as the turning roll 11 a perforated vacuum turning roll comprising vacuum connections, by which the underpressure of the pocket space T is operated. Further, preferably the vacuum is provided around the circumference of the vacuum turning roll 11 such, that in addition to the pocket space T also underpressure at the circumferential surface of the vacuum turning roll 11 is operated. Advantageously, in addition to the perforation the mantle of the vacuum turning roll 11 comprises circumferential grooves, which assists in distribution of the underpressure at the circumferential surface of the vacuum turning roll. In the gap between the two adjacent drying cylinders 12 the opposite directional boundary layer air flows of the circumferential surfaces of the two adjacent rotating R12 drying cylinder 12 provide a sealing effect in the gap and thus, underpressure generated by the vacuum turning roll 11 provides desired underpressure in the pocket space T, as the opposite directional boundary layer air flows prevent leakage of air to the pocket space.

[0031] The direction of the boundary layer air flow corresponds the rotating direction R12 of the respective drying cylinder 12.

[0032] As can also be seen from the example of figure 4 The independent end sealing system 20 comprises two end seals 21 located at each longitudinal end area of the pocket space T. The end seal 21 substantially covers cross-sectional area of the pocket space T. The pocket space T is closed at its longitudinal ends the independent end sealing system 20 by the end seals 21, which substantially cover cross-sectional area A of the pocket space T. Preferably the end seals 21 are each supported only at its own side and thus, the end seals 20 are independently adjustable. Advantageously, the end seal 21 comprises an end seal body 22 with three end seals and three gap end seals 23. Thus, the end seal 21 comprises three curved concave end seals formed in a seal body 22 and three gap end seals 23. The seal body 22 has a substantially triangular form and the end sealing extends between respective gap end seals, i.e. on the sides of the triangular form. The end seals 23, thus form three triangular-shaped concave gap end seals contouring the surface of the respective cylinders 12, 11. The seal body 22 has a substantially triangular form and the end seals 23 extend on the sides of the triangular form to the gap area of the pocket space T. The end seals 23 advantageously also comprises blow openings 26 (fig. 4) to create sealing blowing BS, BC to side areas of the pocket space T, i.e. at the vicinity of surfaces of the drying cylinders 12 and of the turning roll 1 to prevent leakage of air to the pocket space T and thus, to improve the runnability. Air IA is provided for the sealing blowing BS, BC by an air inlet 41, also forming a support structure for the end seal body 22. In the example of figure 4 the independent end sealing system 20 further comprises an additional end sealing element 32 for providing an edge chamber and / or a labyrinth sealing.

[0033] As shown in the example of figure 5A the independent end sealing system 20 is located at the end area of the pocket space T in the longitudinal direction thereof. Advantageously, the end seal 21 is located over the edge of the fiber web W and on the area of the drying wire 10. In this example the end seal 21 is supported by a support shaft 45, which is movably supported by bracket support 50 comprising two brackets 51, 52 spaced apart in longitudinal direction of the support shaft 45. Thus, the location of the end seal 21 can be adjusted by moving the support shaft 45 in the bracket support 50 and the two spaced apart brackets 51, 52 provide that the support direction is steady. The pocket space T is underpressurized using as the turning roll 11 a perforated vacuum turning roll comprising vacuum connections, by which the underpressure of the pocket space T is operated, as indicated by suction arrows S11.

[0034] The example of figure 5B corresponds to the example of the figure 5A and the independent end sealing system 20 is located at the end area of the pocket space T in the longitudinal direction thereof. Advantageously, the end seal 21 is located over the edge of the fiber web W and on the area of the drying wire 10. The end sealing 20 in this example further comprises an additional sealing element 32 located space apart from the end seal 21 and inner in the pocket space T in longitudinal direction and on the edge area of the fiber web W. The end seal 21 is supported by a support shaft 45, which is movably supported by bracket support 50 comprising two brackets 51, 52 spaced apart in longitudinal direction of the support shaft 45. Thus, the location of the end seal 21 can be adjusted by moving the support shaft 45 in the bracket support 50 and the two spaced apart brackets 51, 52 provide that the support direction is steady. The pocket space T is underpressurized using as the turning roll 11 a perforated vacuum turning roll comprising vacuum connections, by which the underpressure of the pocket space T is operated, as indicated by suction arrows S11. The suction is provided by arranging an outlet flow O11 through the end of the turning roll. The additional sealing element 32 provides that the suction effect of the turning roll 11 can be increased in the edge area of the fiber web W to improve runnability of the edge areas of the fiber web W.

[0035] The example of figure 5C corresponds to the examples of figs 5A-5B but in this example a suction chamber 34 is arranged between the end seal 21 and the additional sealing element 32. The suction chamber 34 has openings 36 through which air is removed from the edge area of the fiber web W, as indicated by arrows O34. In this example as the support shaft is arranged an outlet pipe 42 for the removal of the air flow O21 from the suction chamber 34. This outlet pipe 42 advantageously is connected to an outlet pipe 43 for removal of the air flow O11 from the turning roll 11. The end sealing 20 can further be provided with an outside seal element 33 located just outside the end of the pocket space 11 and the respective cylinders 11, 12. The outside seal element 33 prevents side flows to disturb the sealing and thus, further improves the runnability.

[0036] The example of figure 5D corresponds to the examples of figs 5A-5C but in this example an air chamber 37 is arranged between the end seal 21 and the additional sealing element 32. The air chamber 37 provides air flow for the sealing blowing BS, BC. In this example as the support shaft is arranged inlet pipe 41 for inlet air to the air chamber 37 as the inlet air flow IA from the air chamber 37.

[0037] In the description in the foregoing, although some functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain embodiments or examples, those features may also be present in other embodiments or examples whether described or not. Above the invention has been described by referring to some advantageous examples only to which the invention is not to be narrowly limited. Many modifications and alterations are possible within the invention as defined in the following claims.

Examples

Embodiment Construction

[0026]In the following description same reference signs designate for similar components unless otherwise mentioned and it should be understood that the examples are susceptible of modification in order to adapt to different usages and conditions within the frames of the invention. Repetition of some reference signs may have been omitted in figures for clarity reasons.

[0027]In figure 1 shown an example known from prior art of a single tier drying group applying single wire draw for a drying section of a fiber web production line, drying cylinders 12 are located in an upper row and turning rolls 11 are placed in a lower row. A fiber web to be dried is arranged to run on support of a drying wire 10 from the drying cylinders 12 to the turning rolls 11 in a manner of single wire draw. Runnability or vacuum components 14 are placed in a pocket space T remaining between two adjacent drying cylinders 12 and a turning roll 11 and the drying wire F, which runnability or vacuum component 14 p...

Claims

1. Pocket space end sealing system, characterized in, that the pocket space end sealing system is an independent end sealing system (20) arranged at each longitudinal end of a pocket space (T), that the independent end sealing system (10) is located at the respective end area of the pocket space, that the independent end sealing system comprises at least one end seal (21) substantially covering cross-sectional area of the pocket space (T), that the at least one end seal (21) is movably supported on a support shaft (45) or an outlet pipe (42) or an inlet pipe (41) by a bracket support (50), and that transversal location of the end seal (20) is independently adjustable.

2. Pocket space end sealing system according to claim 1, characterized in, that the end seal (21) comprises three concave end seals formed in a seal body (22).

3. Pocket space end sealing system according to claim 1 or 2, characterized in, that the independent end sealing system (20) comprises an end seal (21) and an additional sealing element (32) spaced apart in the longitudinal direction of the pocket space (T).

4. Pocket space end sealing system according to claim 3, characterized in, that between the end seal (21) and the additional sealing element (32) a chamber (34; 37) is formed to provide air flows (O34; BS, DC) to effect the sealing.

5. Pocket space end sealing system according to any of previous claims, characterized in, that the pocket space (T) is confined by two adjacent drying cylinders (12) and a turning roll (11) situated between and below the drying cylinders (12) and by a drying wire (10) of a drying group for drying a fiber web.

6. Pocket space end sealing system according to any of previous claims, characterized in, that the pocket space (T) is free of runnability or vacuum components between the independent end sealing systems (20).

7. Pocket space end sealing system according to any of previous claims, characterized in, that the independent end sealing system (20) further comprises an outside seal element (33) located just outside the end of the pocket space (11).

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