FI120980B - A system and method for removing fluid from a moving web - Google Patents

Description

A SYSTEM AND METHOD FOR REMOVING LIQUID FROM A MOVING RAIN

Field of the Invention

The invention relates to a system for removing fluid from a moving web. The invention relates to a method for removing fluid from a moving web.

Background of the Invention

For example, papermaking machines have a circulating endless wire having a pulp on it, which is composed of a liquid and fibers required for papermaking, also referred to in this application as web. The web is dewatered in several stages by means of devices placed underneath the wire, such as various rotating rolls whose perforated jacket is permeable to air. The roll is placed in a box provided with a vacuum, which can be called a suction roll. One suction roller is disclosed in EP-0639667-A1, which also discloses the use of overpressure to enhance fluid removal.

"... A particularly effective suction roller is disclosed in WO-2006 / 090012-, * ··, A1. Such equipment is capable of supporting a moving wire. An aperture on the upper surface of the apparatus, against the moving wire, is provided with a perforated rotating roll, <<* 25, through which a negative pressure acts on the wire. The apparatus provides sufficient suction effect and high capacity fluid removal, so it can also be applied to high speed wires.

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SUMMARY OF THE INVENTION ut ί. * 30 tic ““ i Requirements for fluid removal efficiency are constantly increasing. The object of the invention is to improve the function of the prior art equipment. It is a further object of the invention to provide an efficient unit with various suction rolls i, 1 'and in particular with the equipment vv 35 of WO-2006/090012-A1.

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The system according to the invention is set forth in claim 1. The method according to the invention is set forth in claim 7. Other embodiments disclose certain embodiments of the invention.

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The solution of the invention for enhancing the operation of the fluid removal apparatus comprises an apparatus wherein the overpressure acts on the opposite side of the wire and the web as compared to the action of the underpressure. The overpressure, for example, enhances the drainage of the fluid from the wire and web and improves the operation of the apparatus 10. The overpressure moves the fluid from the web to the affected area of the underpressure and the underpressure further moves the fluid away from the web and the wire. Overpressure affects the area, which is also affected by the vacuum created by the suction system.

The solution can be used in particular when using a single wire having a web over it. The overpressure apparatus is not directly against the web, but another wire runs between the overpressure apparatus and the web, which also mechanically acts on the web. The wire included in the overpressure apparatus, preferably forming an endless loop, is air permeable so that the air fed to the overpressure apparatus passes through the wire and web under pressure and further through the suction roll, carrying fluid and moisture. On one side of the web over the wire, i.e. below the wire, there is a suction device and on the other side: \> t, i.e. on the web, there is an overpressure device implemented e.g. by means of a <<< box. In addition, over a "" "moving wire of pressure equipment is fed between the web and the pressure box.

<<<. ··: 25 <<«: If necessary, the wire of the overpressure equipment also mechanically acts on the web, thus allowing the web to be flattened or pressed to the desired strength. The apparatus for transporting the wire; Y is preferably arranged to be adjustable so that its distance relative to the web and the skew in the plane 30 in the direction of travel of the web are adjustable. Compression enhances the removal of liquid, but above all, the contact between the wire and the web affects the quality of the surface of the web and Υ («the composition of the web. In particular, the web surface can be smoothed with a wire, which has beneficial effects e.g.

('Y: 35 The cleaning of the fabric of the overpressure equipment is efficient because of the pressure exerted through the fabric, which transfers the material or liquid adhered from the web back to the web. Therefore, it is not necessary to use separate wire washing equipment and structure. with respect to air permeability, they remain constant as the wire is continuously cleaned and consequently the quality of the web can be kept constant, the property of which is that of air permeability and preferably is as dense as possible 5 Preferably, the wire is of monolayer and flat wire type.

Brief Description of the Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings.

Figure 1 shows a system according to the invention, viewed from the end.

Figure 2 is a side view of the system of Figure 1.

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Detailed Description of the Invention

Figure 1 illustrates a system for removing fluid from a web of material according to the invention in simplified form and only in substantial parts. The apparatus 20 1 is shown viewed from the end. In Figure 1, the apparatus is horizontal and the wire 4 preferably forms a horizontal plane. Hardware 1 is «*. shown front end 2 (see figure 2) removed by other structures, ·· *. uncovering. Figure 1 shows the rear end 3. The ends 2 and 3 are, for example, vertical plate structures, and may have a shape that may vary from about <25 cm.

• c <• C <C cct • "In addition, as part of the entire system and as a fluid removal device, the following is used: .. c *, for example, a device according to WO-2006/090012-A1 which applies vacuum to the wire and web. The pressure apparatus 5 is shown only partially and in cross-section in Figure 1. The under pressure apparatus 5 comprises a box-shaped, basin-operable and sealed chamber 6 with a rotatable roll 7. The upper surface 6a of the chamber 6 against which the wire 4 rests is substantially flat.The chamber 6 is longitudinally conical and extends beneath the wire 4 substantially throughout its width, V t 35. The chamber 6 is transverse to the direction of travel of the wire 4, preferably perpendicular to it. as well as the opening 6b in the upper surface 6a of the chamber 6. The opening 6b is continuous and continuous and extends over the entire width of the wire 4.

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The chamber 6 is closed by end portions through which the axis of the roll 7 passes. The shaft is bearing and connected to the motor of the rotation equipment.

Inside the chamber 6 is placed a roll 7 which can rotate the mu 4 of the wire 4. The opening 6b exposes at least a portion of the outer sheath 7a of the roll 7 so that the movable wire 4 which touches the chamber 6 can rest against the outer sheath 7a. The wire 4 runs along the upper surface 6a and the vacuum acting on the wire 4 draws, for example, liquid out of the wire 4. The roll 7 is perforated, provided with openings or metal fabric, and the internal vacuum draws the outer 10 of the wire 4 against the jacket 7a. inside and into chamber 6. The beams 8 and 9 of the upper surface 6a define the suction area at the opening 6b, i.e. they define the area where the vacuum is applied. The sealing between the roll 7 and the wire 4 and the sealing and suction of the suction area to prevent air leakage at the ends of the roll 7 are carried out in an appropriate manner and e.g. dimensioning the equipment to fit -15. For example, the solution according to WO-2006/090012-A1 is used.

In the example of Figure 1, the pressure equipment 10 is mounted as a pair of vacuum equipment 5, on the opposite side of the wire 4 and centrally to the opening 6b. The overpressure apparatus 10 comprises a box or structure, also referred to herein as a pressure box 11, wherein the wire 4 and the web "... 12 on top thereof are disposed between the pressure box 11 and the roll 7. Distance of pressure box 11. · * ·. with respect to the web 12 is adjustable by means of adjusting means, for example threaded rods, which are fixed on one hand to the chamber 6 and on the other hand to the body of the overpressure device 10 (e.g. pressure box 11) or to the ends 2 and 3 of the device 1.

The pressure box 11 and at the same time the apparatus 1 can also be attached to other structures of the vacuum apparatus 5 as desired. It is also possible to use: ·· · 1 controlled actuators or motors.

c c j 30 The angular position of the pressure box 11 with respect to the web 12 is also adjustable, e.g., by means of a joint and an arm mechanism, using a suitable adjusting member, ψ, for example a threaded rod. Controlled actuators or motors can also be used for control. By means of the inclination adjustment, the distance of the pressure box 11 from the inlet side of the web 12 is made greater or less than that of the outlet side 35. The pressure box 11 may also be supported, for example, on top of the pressure apparatus 5 and the wire 4, or on structures located on either side of the wire. Attachments and constructions of the details of the apparatus may be applied in accordance with principles which are conventional or known per se to those skilled in the art.

The pressure box 11 is located at the suction area 5 (corresponding to the opening 6b) defined by the vacuum apparatus 5 and the size of the pressure box 11 is selected so that the suction area is affected by the overpressure. The pressure box 11 is connected by means of one or more connections 13 to a separate pressure system which provides a pressure effect and air flow to the pressure box 11. The pressure box can be constructed, for example, of metal or plastic. In the example of Figure 1, the pressure box 11 10 is formed within a semicircular body extending over the web 12 while supporting the apparatus 1. The body is open downward. The pressure box 11 is attached to the ends 2 and 3 of the apparatus 1 which close the ends of the pressure box 11.

The pressure box 11 comprises at least one overpressure chamber 14 located at the intake area and extending transversely across the web 12. The overpressure chamber 14 is a narrowing gap or throat in cross-section. Preferably, warm or hot air is sought to be accelerated by a tapered shape. The overpressure chamber 14 is open toward the web 12 and narrows along the conveyor 20 toward the web 12. The opening of the overpressure chamber 14 between the parts 15 and 16 substantially corresponds to the suction area.

c · · c. · **. According to one embodiment, the overpressure chamber 14 is formed by two opposed portions 15 and 16, which are plate-like, extend ≤ c ≤ 25 transverse to the web 12 and are folded, e.g., at an acute angle I "such that one side is with the web 12. one side and another: the side forms one side of the slot or throat. The overpressure chamber 14 is bounded between the parts 15 and 16 and under the body of the aforementioned pressure box 11. The parts 15 and 16 are also bounded to the said body. * ·· 30 a background smoothing member 17 which is e.g. a perforated plate or mesh extending over the web 12 and uniformly distributing the airflow from the connection 13 to the entire area of the web 12. The overpressure chamber 14 is also accessible through the connection 18, through which, for example, water is supplied for washing.

The apparatus 1 further comprises a web 19 moving between the web 12 and the pressure box 11 having the same speed as the wire 4 supporting the web 12. The wire 19 is fed between the web 12 and the pressure box 11 and pulled off the web 12 by the pressure box 11. after, essentially immediately. Most preferably, the wire 19 extends across the web 12 in the transverse direction of the web 12. The wire 19 passes as an endless loop, e.g. through the pivot rolls 20 and 21 and the rotation roll 22. Rotating roll 22 moves the wire 19 through friction.

The pivoting rollers 20 and 21 are disposed adjacent the web 12 on both sides of the pressure box 11. The spinning roll 22 is located above the pressure box 11 and the pressure box 11 is located inside the loop of the wire 19. The pressure box 11 is disposed near the web 12, from which it is separated by a wire 19. The beam box 11 may be provided with bearing members against which the wire 19 may press 10 as it moves past the pressure box 11 and when the web 12 presses the wire 19. preferably located centrally with respect to the suction area and the pivoting rollers 20 and 21. A motor 23 is connected to the rotation roller 22 which, by means of transmission, rotates the rotation roller 22. The rotation roller 22 and the pivot rollers 20, 21 are principles known per se can be applied. The distance of the at least one pivoting roll relative to the second pivoting roll is adjustable, whereby the tension of the wire 19 can be adjusted by changing that distance.

The apparatus 1 forms an integral structure, comprising an overpressure apparatus 10 and a wire 19. When the position of the wire 19 is changed, e.g. the position of pressure box 11 changes. Swivel rolls 20 and 21 and rotary roller 22 are the same. and move with the wire 19. The design allows easy adjustment, since the overpressure apparatus 10 and the wire 19 are in the same apparatus 1, and furthermore easy installation.

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In the embodiment shown, the wire 19 extends evenly over the entire suction area and C t also extends to the area of both beams 8 and 9, covering at least a portion of the upper surface 6a both on the inlet side and the outlet side of the web 12. The contract; The 30 virm wire 19 is straight between the rollers 20 and 21, as well as the web "c" 12 which runs along the planar upper surface 6a of the vacuum apparatus 5.

<- <i t <. The rotating rolls 20, 21 and in particular the wire 19 act mechanically on the web 12, squeezing and sealing it as needed. Due to mechanical compression, the removal of L 35 fluid from web 12 can be enhanced. The liquid is transferred, for example. to the wire 4 underneath the web '' '12 from which it is transferred under vacuum to the chamber 6. At the same time, the overpressure acting through the wire 19 transfers the fluid from the web 7 12 through the wire 4 to the chamber 6. The overpressure also affects the wire 19 from which the material adhered to the web 12 and at the same time from the web 12 to the wire 19 is transferred back to the web 12. The overpressure thus affects the wire 19 and continuously cleans it.

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Suitable fabrics typically have an air permeability of about 5500-7500 m3 / m2h (permeability, 317-475 CFM). According to a suitable embodiment of the invention, a low air permeability wire with an air permeability of about 5000-5500 m3 / m2h is particularly used.

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The invention can be applied to a wide variety of material webs. The invention can be applied not only to a paper mill but also to other types of process plants. With the help of wire and rollers, the web of material can be mechanically compressed and at the same time liquid removed. At the same time, the materi-15 can be affected by suction and pressure, which enhances the removal of fluid from the material.

The apparatus and system are suitable for removing liquid as well as solids, such as dust, from wire, felt, or other types of tissue used in, for example, a paper machine. More generally, the apparatus and system may be used as a purification apparatus or a dewatering device (i. E., A liquid or solid material that is removed from a moving mass, (a web or tissue having sufficient air or liquid permeability).

e c c c tea c c c 25 The invention is not limited to the above examples but the invention may: vary within the scope of the appended claims.

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Claims (8)

A system for removing liquid from a movable web having at least: - an overpressure device (10) located on one side of the web (12) and through which the overpressure affects the web (12) which moves past said overpressure device and which is located on a wire (4), a surface (6a, 7a) which is on the opposite side of the web relative to said overpressure device and against which the wire (4) presses under the influence of the vacuum, and through which the vacuum can affect the wire (4) moving past said surface (6a, 7a), and further the web, - a movable wire (19) forming an endless loop within which the overpressure device is located, the wire is between said web and said overpressure device and by which the overpressure of the overpressure device can affect the web, said movable wires (19) being further positioned against the moving web (12), characterized in that the system further comprises: a rotatable roller (7) which is located transversely of the movable web and comprising a surface (7a) through which a fluid flow can be transmitted within the roller, and - a chamber (6) in which said roller is located and comprising an opening (6b) arranged to expose at least a portion of said surface (7a) such that the wire (4) which tangles the chamber may support said surface 10. c c ICC (CC (CC c 2. A system according to claim 1, characterized in that the distance of the movable wire (19) and the overpressure device to the web can be controlled, and that the c c c obliquity of the movable wire (19) and the overpressure device relative to the web 30 can be controlled. C (c c c) (CU 3. A system according to claim 1 or 2, characterized in that the movable wire (19) permeates air and is flat and single layered type. , v, 35 System according to any one of claims 1-3, characterized in that the wire (19):: has been passed through two turning rollers (20, 21) located on the bed sides of the 11 pressure device and by means of which the movable wire (19) ) can be pressed against the web. System according to claim 4, characterized in that the web (12) can be pressed and densified by means of said turning rollers (20, 21). System according to any of claims 1-5, characterized in that the web is on a second wire (4), the web being placed at said overpressure device between said second wire (4) and the moving wire (19). 10 7. A method for removing liquid from a wire running in a paper machine and from a web placed on this path, characterized in that the liquid is removed by means of a system according to any of claims 1-8. Use of the system according to any of claims 1-6 for cleaning a movable wire, blanket or other fabric. <«« · · «*« «·« C «« «<<<<i <t <<« <c cc * c «* {E (t (« CC * cc * cc * cc C i * * cc 1 (1) (* * «c etet ttttttttttttt an UI tttc tee