A paper machine equipped with a device for dewatering or washing the fabric.

Abstract

The present invention relates to an apparatus for dewatering or cleaning a fabric in a paper machine, the apparatus (1) comprising: a contact portion (2) arranged on a first side of the apparatus (1) for contacting the fabric within the paper machine; an air device (4) for transporting air to or from the fabric, the air device (4) being operatively connected to at least one opening (3) in the first side for supplying or removing air through the at least one opening; a vibrator (5) operatively connected to the contact portion and configured to cause vibration of the contact portion during operation of the apparatus; and The present invention also relates to a paper machine (100, 100') comprising at least one such apparatus.

Description

Technical Field

[0001] The present invention relates to an apparatus for dewatering or washing a fabric in a paper machine and a paper machine equipped with such an apparatus. In particular, the paper machine may be a machine for manufacturing tissue paper.

Background Art

[0002] A paper machine typically operates by injecting a base paper into the forming gap of a forming section to create a paper web that is formed, dewatered, dried, and optionally structured through various sections to form a finished paper. The paper web is transported on a series of wires or fabrics, such as felts, that are arranged in an endless loop and serve to form and protect the paper web and optionally generate a structure on the paper web.

[0003] Since the base paper usually has a water content of about 97%, the main purpose in manufacturing paper is to remove water, which is achieved by a combination of pressing, suction, and heating. In some sections of the paper machine, water and air are transported through wires or felts to suck water from the paper web or to allow air currents or hot air to reach the paper web. Some pulp fibers from the paper web may be trapped on the felt or wire or remain on the surface after the paper web is transferred to further sections of the paper machine, and for this reason, a cleaning device is provided to help clean and dry them while they return to the point where they pick up the paper web again.

[0004] Current cleaning devices for wires and felts have problems such as high energy consumption for removing water in order to sufficiently dry the wires and felts so that they can accept the paper web. Also, it is difficult to completely clean the wires and felts in a short time until the paper web is picked up to remove all the remaining pulp fibers.

[0005] Dewatering and drying paper webs is also cumbersome, and due to the high cost and energy consumption of heating steam and air, it is highly desirable to remove as much water as possible before the drying stage, which involves hot air or heated rolls.

[0006] Therefore, improvements are needed in both the cleaning of the wires and felt, and the dewatering of the paper web. [Overview of the Initiative]

[0007] The object of the present invention is to resolve, or at least minimize, the above-mentioned problems. This is achieved by an apparatus for dewatering or washing a fabric in a paper machine, and a paper machine equipped with such an apparatus, according to the appended independent claims.

[0008] The apparatus of the present invention comprises a contact portion positioned on a first side of the apparatus to contact a fabric in a paper machine; an air device for transporting air to or from the fabric, which is operatively connected to at least one opening on the first side to supply or remove air through at least one opening; and a vibration generator operatively connected to the contact portion and configured to cause vibration of the contact portion during operation of the apparatus.

[0009] By causing vibrations at the contact points, water and remaining pulp fibers are loosened from the fabric and more easily removed by an air device supplying pressurized air or vacuum, thus enabling more efficient washing or dewatering. This significantly improves the efficiency of fabric washing, as it allows for more thorough cleaning and removal of remaining pulp fibers. At the same time, using this device for dewatering fabrics that transport paper webs results in a significant improvement in dewatering, leading to substantial savings in both cost and energy consumption. This is because the degree of dryness of the paper webs can be increased with the use of less dewatering equipment, and the amount of residual moisture that must be removed by hot air or steam is reduced.

[0010] At least one opening is preferably located at the downstream end of the first side, and the contact portion is preferably located at the upstream end of the first side. This allows for air suction or blowing immediately after the fabric is vibrated, so that water and optionally paper fibers loosened by the vibration are immediately removed.

[0011] Alternatively, at least one opening is located at the upstream end, and the contact portion is located at the downstream end of the first side. This makes the suction or blowing highly efficient at removing water and optionally pulp fibers, as the suction or blowing affects the fabric just before it vibrates, and the vibration of the fabric propagates from the contact point with the contact portion, loosening the water and optionally pulp fibers.

[0012] In another alternative configuration, at least one opening is positioned at the contact point so that air is supplied to or removed from the fabric through the contact point. This allows suction or blowing to occur precisely where vibrations are transmitted to the fabric, making it highly efficient in removing water and optionally any residue attached to or trapped in the fabric.

[0013] In some embodiments, the device is provided with only one opening, while in other embodiments, multiple openings may be provided, located not only within the contact portion itself but also upstream and / or downstream of the contact portion. It is highly advantageous to provide one or more openings near the contact portion so that water and optionally residue can be removed in areas where the amplitude of vibration is large.

[0014] In some embodiments for dewatering or washing, the air device is a suction device for drawing air from the fabric into the opening. This is also advantageous when the fabric is transporting a paper web, as it provides efficient suction combined with vibration without damaging the paper web. This helps to increase the amount of water removed compared to conventional suction devices such as Uhle boxes.

[0015] In other embodiments for cleaning fabrics, the air device is an air knife for blowing air onto the fabric through an opening. This is advantageous for thoroughly cleaning the fabric because any remaining residue is blown away with the water, and the combination of the air knife and vibration is significantly better than known air knives.

[0016] The vibration generator is appropriately configured to operate at a frequency of at least 10 kHz, preferably at least 15 kHz, and more preferably at least 20 kHz. This ensures that the contact area vibrates at a frequency suitable for transmission to the fabric.

[0017] The vibration generator may be configured to produce a contact amplitude of at least 10 μm, preferably at least 15 μm, and more preferably at least 20 μm during the operation of the device. In some embodiments, the amplitude may be as large as 50 μm. This causes the fabric to vibrate, efficiently removing water. A larger amplitude is advantageous because it improves the removal of water from the fabric.

[0018] The device may also have at least two contact points, and vibration generators may be operationally connected to each of the contact points and configured to vibrate them independently of each other. This is advantageous in providing a more robust device with a longer lifespan, as vibration can be generated at one contact point even if the vibration of other contact points malfunctions or fails. The frequency and / or amplitude of the contact points can also be varied to increase the efficiency of removing water from the fabric. A further advantage is that multiple contact points and multiple openings can remove water more efficiently than a single contact point with a single opening.

[0019] In some embodiments, the contact portion is a cylinder, preferably a TAD cylinder for a paper machine, and multiple openings are arranged in the contact portion to allow air to be transported through it. Thus, the advantages of the present invention are achieved by vibrating the surface of the TAD cylinder.

[0020] The present invention also relates to a paper machine equipped with the apparatus as defined above. This makes it possible to remove water from the fabric more efficiently with higher energy and cost efficiency compared to known prior art solutions. The paper machine of the present invention is equipped with at least one apparatus according to the present invention, but may optionally be equipped with a plurality of apparatus used for dewatering, washing, or both.

[0021] It is preferable that at least one device be positioned in the forming section of the paper machine and configured to dewater the first fabric that transports the paper web. This improves dewatering in the forming section and reduces the moisture content of the paper web when it is transported to subsequent sections.

[0022] At least one device may be positioned in the press section of the paper machine and configured to dewater a second fabric that carries the paper web. This improves dewatering in the press section, as well as subsequent washing and optionally drying.

[0023] It is preferable that at least one device be located in the structured section of the paper machine and configured to dewater a third fabric that carries the paper web. This improves dewatering in the structured section and reduces the moisture content by the final drying stage.

[0024] In some embodiments, the structured section is a ventilated drying section, or TAD. This improves the combination of structuring and drying and can reduce the need for heated air.

[0025] It is preferable that at least one device be placed in the drying section of the paper machine and configured to dewater the fabric that carries the paper web. This makes the removal of residual moisture from the paper web more efficient and reduces the consumption of steam or hot air.

[0026] At least one device is suitably arranged in a cleaning section for cleaning the fabric. Thereby, the cleaning of the fabric is improved as compared to the cleaning sections of the prior art.

[0027] Many further benefits and advantages of the present invention will be readily understood by those skilled in the art upon consideration of the following detailed description.

[0028] Next, the present invention will be described in more detail with reference to the accompanying drawings.

Brief Description of the Drawings

[0029] [Figure 1] The device according to the present invention is schematically disclosed. [Figure 2a] A perspective view from above of the device according to the first embodiment is disclosed. [Figure 2b] A perspective view from below of the device of FIG. 2a is disclosed. [Figure 3a] A perspective view from the side of the device according to the second embodiment is disclosed. [Figure 3b] A plan view from the side of the device of FIG. 3a is disclosed. [Figure 3c] An enlarged cross-sectional view of the upper part of the device of FIG. 3b is disclosed. [Figure 4] A papermaking machine according to the first embodiment of the present invention is schematically disclosed. [Figure 5] A papermaking machine according to the second embodiment of the present invention is schematically disclosed.

Modes for Carrying Out the Invention

[0030] All the figures are schematic and not necessarily to scale. Generally, only the parts necessary to clarify each embodiment are shown, and other parts may be omitted or merely suggested. Any reference numerals appearing in multiple drawings refer to the same object or feature throughout the drawings unless otherwise indicated.

[0031] In the context of this invention, the term “fabric” is used to refer to any wire, band, structured fabric or belt used in a paper machine to form or convey a paper web. Such bands or belts include wires such as forming wires and structuring wires, as well as felt and other fabrics used in a paper machine.

[0032] In this specification, the term "paper machine" is used to refer to any machine suitable for producing paper from pulp. Such machines include, but are not limited to, machines for producing tissue paper, paper, and cardboard.

[0033] In this specification, when it is stated that two components are operationally connected to each other, this should be understood as the components being connected to each other in such a way that signals, motion, or forces can be transmitted from one to the other. Therefore, the fact that a vibration generator is operationally connected to a contact should be understood as the vibration generator being able to vibrate the contact.

[0034] The terms “upstream” and “downstream” are used herein in relation to the direction of movement of the fabric or paper web in a paper machine. Thus, a location upstream of another location is a location that any given point on the fabric or paper web passes before reaching the other. The terms “before” and “after” are used to indicate that any given point on the fabric or paper web passes a location “before” another location at an earlier time than a location “after” the other.

[0035] A paper web is defined as the pulp fibers that move together on the fabric to form a continuous web, from the forming nip where the paper web is formed by the pulp suspension to the roll section where the paper web arrives as finished paper. "Captured residue" or simply "residue" is used to refer to any material or particles of the paper web that remain in or on the fabric after the paper web has been transferred to the subsequent section of the paper machine. Such material or particles include, among other things, adhesives, coatings, dirt, and pulp fibers.

[0036] The present invention will be described below, starting with one embodiment of the apparatus schematically shown in Figure 1, and then a preferred embodiment shown in Figures 2a and 2b. Next, the paper machine according to the present invention will be described with reference to two embodiments illustrating different methods for manufacturing paper, particularly tissue paper. It should be noted that the present invention can be used in any type of paper machine.

[0037] Figure 1 discloses an apparatus 1 for dewatering or washing a fabric according to the present invention. The apparatus 1 comprises a contact portion 2 located on a first side A of the apparatus 1, the first side A being a surface intended to face a fabric F in a paper machine. The fabric F is schematically disclosed in Figure 2, and the direction of movement D of the fabric F is indicated by an arrow pointing to the left side of the figure.

[0038] The contact portion 2 is operationally connected to a vibration generator 5 configured to cause vibration of the contact portion 2 when the device 1 is in use. The vibration generator 5 is shown to be connected to the contact portion 2 by a connector 5', but in some embodiments, the vibration generator 5 may be integrated with the contact portion 2 or may be positioned to contact the contact portion 2 without a connector 5'. The vibration generator 5 is appropriately connected to a power source (not shown). The device 1 also appropriately comprises a housing 6 in which at least some of the components of the device 1 are housed.

[0039] The contact portion 2 may extend along the entire length l of the device 1 on the first side A of the device 1, but in other embodiments, it may consist of only a portion of the length l. Also, in some embodiments, the contact portion 2 extends across the entire width w of the device 1, but in other embodiments, it may consist of only a portion of the width w. The length l is defined as the extension of the device 1 on the first side A in the direction of movement of the fabric F, and the width w is the extension of the device 1 on the first side A in a direction perpendicular to the length l. Figure 1 discloses the length l of the device 1, while Figure 2a shows both the length l and the width w.

[0040] In some embodiments, the contact portion 2 is a single part of the device 1, but in other embodiments, the device 1 may have multiple contact portions 2 that are individually or collectively connected to the vibration generator 5.

[0041] The apparatus 1 also comprises an air device 4 for transporting air to or from the fabric F, and further comprises at least one opening 3 on the first side A for supplying or removing air. The at least one opening 3 may be an opening in the contact portion 2, upstream of the contact portion 2, downstream of the contact portion 2, or a combination of these options. In some embodiments, there may be at least one opening 3 lateral to the contact portion 2, parallel to the contact portion 2, i.e., in a direction traversing the direction of movement D of the fabric F. Note that in most embodiments, multiple openings 3 are arranged on the first side A, but a single opening 3 is also possible within the scope of the invention.

[0042] If at least one opening 3 is located upstream US of the contact portion 2, then the contact portion 2 is located downstream DS of at least one opening 3, and vice versa.

[0043] The first side A of the device 1 may include both the housing 6 and the contact portion 2, and at least one opening 3 is provided in the first side A by extending into the device 1 through the housing 6 or through the contact portion 2. If there are multiple openings 3, these may be openings 3 provided in the housing 6, openings 3 provided in the contact portion 2, or both.

[0044] In some embodiments (see Figures 2a to 2b), the first side A of the device may consist only of the contact portion 2, and at least one opening 3 is provided in the first side A by extending through the contact portion 2 into the device 1.

[0045] The air device 4 is connected to at least one opening 3 by an air connection 4', preferably a tube or conduit, so that air can pass between the air device 4 and the opening 3. The device 1 may also have a transport connection 4'', which may be a tube or conduit for transporting air between the air device 4 and a separate unit (not shown).

[0046] In some embodiments, the air device 4 is a suction device such as a Uhle box that operates by generating a negative pressure (usually called a vacuum) and thereby drawing air into the opening 3 to the air device 4. In such embodiments, the transport connection 4” may lead to a receiving container for receiving air along with water, residue, and optionally other substances such as dirt or particles from the fabric F. The air device 4 generates a negative pressure of at least 10 kPa, more preferably at least 30 kPa, and even more preferably at least 65 kPa.

[0047] In other embodiments, the air device 4 is instead an air knife that operates by blowing pressurized air through at least one opening 3. In such embodiments, the transport connection 4” may be connected to a source of pressurized air. The pressurized air is supplied at a pressure of at least 0.5 bar, more preferably at least 5 bar, and even more preferably at least 10 bar. Higher pressures are advantageous for better removal of water and optionally residue from the fabric.

[0048] The vibration generator 5 is configured to vibrate the contact portion 2, thereby generating vibrations in the fabric F as the fabric F passes through the device 1 during operation. In some embodiments of the paper machine, the device 1 is configured to contact the fabric F, but in other embodiments, the device 1 may instead be positioned closer to the fabric F so that the vibration of the contact portion 2 contacts the fabric F, or so that the vibration of the contact portion 2 closer to the fabric F also vibrates the fabric F. The vibration generator 5 is preferably configured to actuate the contact portion 2 at a frequency of at least 10 kHz, preferably at least 15 kHz, and more preferably at least 20 kHz. Higher frequencies cause the fabric F to vibrate more violently, thereby facilitating the release of trapped water and residue. In some embodiments, the vibration generator 5 is configured to produce an amplitude of at least 10 μm, preferably at least 15 μm, and more preferably at least 20 μm. In some embodiments, the amplitude may be 50 μm or more. In both low-frequency and high-frequency embodiments, larger amplitudes are advantageous as they further increase the release of water and residue from the fabric F.

[0049] Figures 2a to 2b disclose a first embodiment of the apparatus 1 having a plurality of openings 3 arranged along a contact portion 2. The apparatus 1 is held by a holder 7 which also includes a transport connection portion 4" and connections such as a power supply. Providing a plurality of openings 3 is advantageous for uniform suction or blowing so that the entire width of the fabric F is cleaned or dewatered. Also, providing the contact portion 2 along the entire width of the fabric F is advantageous for generating vibrations throughout the fabric F and releasing trapped water and residue. The preferred embodiment of Figures 2a to 2b is suitable for use both when the air apparatus is a suction device and when it is configured to supply pressurized air to the openings 3. The apparatus 1 also comprises a housing 6.

[0050] Figures 3a to 3c disclose a second embodiment of the apparatus 1 having two contact portions 2a, 2b and a plurality of vibrators 5 that function as a vibration generator 5. In the second embodiment, the vibrators 5a in the first row are arranged in a mechanically intersecting direction with respect to the first contact portion 2a, i.e., perpendicular to the direction of movement D of the fabric F, and the vibrators 5b in the second row are arranged in a mechanically intersecting direction with respect to the second contact portion 2b. In this way, the vibrators 5a, 5b in each row are configured to vibrate one of the contact portions 2a, 2b. The apparatus 1 is connected to an air device 4 (not shown) that supplies suction or pressurized air to the opening 3. In the embodiments of Figures 3a to 3c, air is transported inside the housing 6 to or from the opening 3 so that the inside of the housing 6 becomes negative pressure and air is drawn into the apparatus 1 through the opening 3, or so that it becomes high pressure and air is blown out of the apparatus 1 through the opening 3.

[0051] The contact portions 2a and 2b are preferably made of sheet metal that can be easily vibrated by the vibrator 5.

[0052] The vibration generator 5 is operationally connected to each of the contact portions 2a and 2b, allowing them to vibrate independently of each other. This may be caused by separate transducers for each of the contact portions 2a and 2b, as shown in Figures 3a to 3c, or by a single vibration generator 5 being operationally connected to both of the contact portions 2a and 2b, enabling individual vibrations. The vibration generator 5 may be in the form of a sonotrode or a plate-shaped ultrasonic transducer (e.g., a sonoplate).

[0053] In some embodiments, the contact portions 2a and 2b are configured to vibrate at different frequencies and / or different amplitudes, but in other embodiments, they may instead be configured to vibrate at the same frequency and / or amplitude.

[0054] In some embodiments, the contact portions 2a and 2b are instead connected to a vibration generator 5 so that they vibrate together.

[0055] In the third embodiment, the contact portion 2 is in the form of a part of the cylinder, and the first side A is the outside of the cylinder. At least one opening 3 is a plurality of openings 3 arranged in the contact portion 2 so as to allow air to be transported through the contact portion 2, i.e., from the inside to the outside of the cylinder (blowing) or from the outside to the inside of the cylinder (suction). The apparatus 1 of this embodiment preferably forms a TAD (through air drying) cylinder configured to provide improved drying of paper webs by a combination of vibration of the contact portion 2 and airflow through the plurality of openings 3.

[0056] In all embodiments disclosed herein that disclose an air device 4 as a suction device, the device 1 may be modified to have the air device 4 as an air knife instead. Similarly, where an embodiment is described using an air knife, this can be modified to a suction device without substantially modifying the device 1 itself. In some embodiments, the air device 4 may also have a dual function and be configured to switch between a suction function and a blowing function.

[0057] Next, the paper machines 100, 100' according to the present invention will be described with reference to Figures 4 and 5. In particular, it should be noted that the present invention includes any type of paper machine as long as at least one apparatus 1 according to the present invention is installed. However, the present invention is particularly advantageous in paper machines for producing tissue paper, since washing and dewatering structured fabrics used in tissue paper machines is particularly difficult.

[0058] Figure 4 discloses a paper machine 100 according to a first embodiment of the present invention in a ventilated drying (TAD) design. The paper machine 100 comprises at least one, preferably more than one, device 1 according to the present invention in any or all of the press section 20, the structuring section 30, and the washing section 60. In other embodiments, at least one device 1 may also be included in any other section of the paper machine 100, where appropriate.

[0059] The paper machine 100 includes a forming section 10 into which a base paper containing diluted pulp is injected into a forming nip between a first fabric 71, which may be called a forming fabric, and a second fabric 72, which may be called an inner wire. This produces a paper web P which is transported onto the second fabric 72 through a pressing section 20 for pressing and dewatering. The paper web P is then transported onto a third fabric 73, which may be called a structuring fabric, through a structuring section 30, and structured and dried on at least one, preferably two, dryer rolls 31, 32. The paper web P is then transported to a drying section 40, which is appropriately equipped with a Yankee dryer for removing residual moisture, from which the finished paper is transported to a roll section 50 for rolling. This operation of a ventilated dryer TAD is well known in the art.

[0060] The first, second, and third fabrics 71, 72, and 73 each form an endless loop, moving in the machine direction M when conveying the paper web P, and returning in the opposite direction when the paper web P is transferred to the subsequent section. During the return, each fabric 71, 72, and 73 is washed. A washing section 60 is provided for the third fabric 73 to allow for complete washing and drying.

[0061] In the press section 20, at least one device 1 can be positioned to dewater the second fabric 72 and, consequently, the paper web P, by combining the vibration of the contact portion 2 with the negative pressure from the air device 4, which functions as a suction device. This has the advantage of making the paper web P adhere more firmly to the second fabric 72 and efficiently dewatering the second fabric 72 and, consequently, the paper web P.

[0062] In the structured section 30, at least one device 1 can be positioned either before, between, or after the dryer rolls 31, 32 to dewater the third fabric 73. Similar to the use of device 1 in the press section 20, the air device 4 is configured to function as a suction device by providing negative pressure for dewatering the third fabric 73. This has the same advantages as when used in the press section 20, by combining efficient dewatering with improved adhesion to the third fabric 73.

[0063] In the washing section 60, at least one device 1 may be placed within a washing station (not shown) where the third fabric 73 is washed by supplying a washing solution such as water and dried by dewatering.

[0064] Conventional techniques typically involve spraying a cleaning solution onto a fabric under high pressure and using at least one Uhle box or air knife to suck or blow the liquid away from the fabric.

[0065] In the paper machine 100 of the present invention, at least one such Uhle box or air knife can be replaced with the apparatus 1 according to the present invention. When washing the third fabric 73, it is advantageous to provide the apparatus 1 with an air device 5 that functions as a suction device because it improves the efficiency of removing liquid compared to a conventional Uhle box. However, it is also advantageous to provide the apparatus 1 with an air device 5 configured to blow pressurized air onto the third fabric 73, in which case the liquid is removed efficiently and the paper web P is not transported while the third fabric 73 is in the washing section 60.

[0066] It is particularly advantageous to combine at least one device 1 that functions as a suction device for the washing section 60 with at least one device 1 that functions as an air knife to supply pressurized air to the third fabric 73, as this results in both complete washing and drying of the third fabric 73. The device 1 of the present invention may be provided before the third fabric 73 enters the washing station 61, inside the washing station 61, or after the washing station 61, or any combination thereof.

[0067] In the forming section 10, at least one apparatus 1 according to the present invention may be arranged to dewater or wash the first fabric 71 while the first fabric 71 is returning to the forming nip FN. The apparatus 1 may be configured as a suction device or a blowing device, and if one or more apparatus 1 are provided, they may be configured in the same way or in different ways.

[0068] The drying section 40 may also optionally include the apparatus 1 according to the present invention, which is positioned before drying in the Yankee dryer 41.

[0069] Among the many possible arrangements of the apparatus 1 according to the present invention, it may be particularly advantageous to configure the apparatus 1 in relation to a first roll downstream of the forming nip FN. It may also be particularly advantageous to configure the apparatus 1 in relation to a roll that transfers the paper web to a third fabric 73, or downstream of these rolls and upstream of the TAD cylinder.

[0070] Figure 5 discloses a paper machine 100' according to a second embodiment of the present invention. This paper machine 100' is a DCT (dry crepe tissue) paper machine equipped with a crescent-shaped forming body suitable for the manufacture of tissue paper, and the paper machine 100' in Figure 5 differs from the paper machine 100 of the first embodiment mainly in that it does not have a structured section 30. In the paper machine 100' of the second embodiment, parts and components that are similar or identical to those of the paper machine 100 of the first embodiment are indicated by the same reference numeral followed by a prime "'".

[0071] Accordingly, the paper machine 100' of the second embodiment includes a forming section 10' into which a base paper is injected to produce a paper web P', and which is formed between a first fabric 71' (which may be called a forming fabric) and a second fabric 72' (which may be called a felt). In the pressing section 20', the paper web P' is conveyed onto the second fabric 72' and pressed and dewatered before reaching the drying section 40', where it is transferred to a Yankee dryer 41' to remove any remaining moisture before being transferred to the rolling section 50' for rolling. Similar to the first embodiment, the first fabric 71' and the second fabric 72' are washed while they are returning, and in the case of the second fabric 72', a washing station 61' is provided in the washing section 60'.

[0072] The apparatus 1 of the present invention may be provided in any of the forming section 10', the pressing section 20', and the washing section 60'. If the drying section 40' is configured to have components in front of the Yankee dryer 41', at least one apparatus 1 may be placed in the drying section 40'.

[0073] In the first embodiment, the apparatus 1 is preferably used to dewater a paper web P' conveyed by a second fabric 72', and the air apparatus 5 is configured as a suction device to protect the paper web P' and improve its adhesion to the second fabric 72'.

[0074] When the device 1 is positioned in the washing station 60' in relation to the first fabric 71' or the second fabric 72', or when the second fabric 72' does not transport the paper web P', the air device 5 is preferably configured as either a suction device similar to a Uhle box or a blowing device similar to an air knife. The combination of vibration and suction is very advantageous in washing and dewatering the first fabric 71' or the second fabric 72', and the combination of vibration and blowing of pressurized air is very advantageous in washing and drying the first fabric 71' or the second fabric 72'.

[0075] Apparatus 1 of the present invention can be attached to paper machines 100, 100' during the manufacture of paper machines 100, 100', but it can also be used to modify an existing paper machine to form the paper machines 100, 100' of the present invention by adding at least one apparatus 1 according to any embodiment of the present invention disclosed herein.

[0076] It should be noted that the features from the various embodiments described herein can be freely combined unless such combination is explicitly stated to be inappropriate.

Claims

1. A paper machine comprising at least one device for dewatering or washing a fabric, The aforementioned device is A contact portion (2) is positioned on the first side surface (A) of the device (1) to contact the fabric inside the paper machine, An air device (4) for transporting air to or from the fabric, the air device (4) being operatively connected to the at least one opening (3) of the first side (A) to supply or remove air through the at least one opening (3), A vibration generator (5) is operatively connected to the contact portion (2) and configured to cause vibration of the contact portion (2) during the operation of the device (1), Equipped with, A paper machine in which at least one device (1) is located in the forming section (10, 10') of the paper machine (100, 100') and is configured to dewater a first fabric (71, 71') that conveys a paper web.

2. A paper machine comprising at least one device for dewatering or washing a fabric, The aforementioned device is A contact portion (2) is positioned on the first side surface (A) of the device (1) to contact the fabric inside the paper machine, An air device (4) for transporting air to or from the fabric, the air device (4) being operatively connected to the at least one opening (3) of the first side (A) to supply or remove air through the at least one opening (3), A vibration generator (5) is operatively connected to the contact portion (2) and configured to cause vibration of the contact portion (2) during the operation of the device (1), Equipped with, A paper machine in which at least one device (1) is located in the press section (20, 20') of the paper machine (100, 100') and is configured to dewater a second fabric (72, 72') that conveys a paper web.

3. A paper machine comprising at least one device for dewatering or washing a fabric, The aforementioned device is A contact portion (2) is positioned on the first side surface (A) of the device (1) to contact the fabric inside the paper machine, An air device (4) for transporting air to or from the fabric, the air device (4) being operatively connected to the at least one opening (3) of the first side (A) to supply or remove air through the at least one opening (3), A vibration generator (5) is operatively connected to the contact portion (2) and configured to cause vibration of the contact portion (2) during the operation of the device (1), Equipped with, A paper machine, wherein at least one device (1) is located in a structured section (30) of the paper machine (100, 100') and is configured to dewater a third fabric (73) that conveys a paper web.

4. A paper machine comprising at least one device for dewatering or washing a fabric, The aforementioned device is A contact portion (2) is positioned on the first side surface (A) of the device (1) to contact the fabric inside the paper machine, An air device (4) for transporting air to or from the fabric, the air device (4) being operatively connected to the at least one opening (3) of the first side (A) to supply or remove air through the at least one opening (3), A vibration generator (5) is operatively connected to the contact portion (2) and configured to cause vibration of the contact portion (2) during the operation of the device (1), Equipped with, A paper machine in which at least one device (1) is located in the drying section (40, 40') of the paper machine (100, 100') and is configured to dewater the fabric that carries the paper web.

5. A paper machine comprising at least one device for dewatering or washing a fabric, The aforementioned device is A contact portion (2) is positioned on the first side surface (A) of the device (1) to contact the fabric inside the paper machine, An air device (4) for transporting air to or from the fabric, the air device (4) being operatively connected to the at least one opening (3) of the first side (A) to supply or remove air through the at least one opening (3), A vibration generator (5) is operatively connected to the contact portion (2) and configured to cause vibration of the contact portion (2) during the operation of the device (1), Equipped with, A paper machine, wherein at least one device (1) is located in a washing section (60, 60') for washing the fabric.

6. The paper machine according to any one of claims 1 to 5, wherein the at least one opening (3) is located at the downstream end (DS) of the first side surface (A), and the contact portion (2) is located at the upstream end (US) of the first side surface (A).

7. The paper machine according to any one of claims 1 to 5, wherein the at least one opening (3) is located at the upstream end (US) and the contact portion (2) is located at the downstream end (DS) of the first side surface (A).

8. The paper machine according to any one of claims 1 to 5, wherein at least one opening (3) is positioned in the contact portion (2) such that air is supplied to or removed from the fabric through the contact portion (2).

9. The paper machine according to any one of claims 1 to 5, wherein the air device (4) is a suction device for drawing air from the fabric into the opening.

10. The paper machine according to any one of claims 1 to 5, wherein the air device is an air knife for blowing air onto the fabric from the opening.

11. The paper machine according to any one of claims 1 to 5, wherein the vibration generator (5) is configured to operate at a frequency of 10 kHz or higher.

12. The paper machine according to any one of claims 1 to 5, wherein the vibration generator (5) is configured to cause an amplitude of 10 μm or more in the contact portion during operation of the device.

13. The paper machine according to any one of claims 1 to 5, further comprising at least two contact portions (2a, 2b), wherein the vibration generator (5) is operatively connected to each of the contact portions (2a, 2b) and configured to vibrate them independently of each other.

14. The paper machine according to claim 8, wherein the contact portion (2) is a cylinder, and a plurality of openings (3) are arranged in the contact portion (2) to allow air to be transported through the contact portion (2).

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