DE2104630A1 - Carrying and supporting device for a paper web in its raw state on a paper machine - Google Patents

Description

January 29, 1971 Appleton Mills, Appleton, Wisconsin, USA f

Carrying and supporting device for a paper web in the raw state on a paper machine

The invention relates to a porous carrying and supporting device for a web or such a covering made of saser with a liquid soaking the web or the covering and in particular a carrying and supporting device for carrying and advancing a paper web through a paper machine.

In a paper machine, dilution water that is used to is to use cellulosic fibers for web formation, are removed and that entrained by the web formed Water must be drawn out. In addition, it is necessary that most of the water that is subjected to pressure treatment Coating is absorbed, expelled by heat, v, to create a paper product. While these processes, which have the purpose of dehydration, take place, the paper web must or the paper covering is supported and conveyed further by means of a device that meets all the requirements with the removal of the Waesera. Because gravity, negative pressure, Pressure and absorption and evaporation are applied sequentially to provide an appropriate level of maximum water removal to reach and bring about and also to all with the

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The facilities control the quality properties or requirements related to the smoothness of the covering and the paper that carry, support and transport the paper web, the success and quality of the paper manufacturing process.

The paper machine comprises three departments: forming, pressing and drying. Jfcde department has special bearing and support as well Transport devices with which different amounts of water are removed and different the smoothness and quality of the paper surface relevant; Ί iInfluences can be reached at the same time for the requirements of the process and the product, as described above. The facilities * used to carry and convey the paper web in each of these departments are Fourdrinier wires or screens or molded fabrics, wet and dry felts.

Each of these particular devices has functional and practical drawbacks. Metal wires are subject to a considerable Wear or are easily damaged as a result of their fragile structure, causing frequent and significant Cost replacement will be required. Wet felts are easily clogged with foreign particles and drain the water poorly is expressed in considerable quantities from the formed path, which also requires frequent and costly replacement measures are. Drying felts are generally not very effective because the evaporated water is absorbed by the fabric itself as a result of which the released water vapor returns to the web.

In each of these facilities are both in the direction of rotation The machine has horizontal elements or warp threads as well as transverse elements, which increase the effectiveness of the facilities limit in their primary function, which is the dehydration. If you remove the transversely directed elements, an unlimited amount of removed water can be achieved, since neither the water nor the steam obstructs it or would be held back or caught, since there is always an unimpeded flow between the in the direction of rotation of the mas * lying elements is possible. In addition, the

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Wear on the wires is reduced, since the elements running in the transverse direction give rise to the elements lying in the direction of rotation Elements generally zigzag-shaped or wave-shaped, and weüVftie nodes ° vfr * connection points of the elements opposite in the transverse direction Hitting running components of the paper machine, causing considerable wear and tear at the junctions. the Removal of the transverse elements would also reduce clogging of the wet felts, so there would be no holes or There are pockets that can become clogged. In addition, this would increase the efficiency of the drying felts because the water vapor would not be caught in the tissue because exit channels are always available.

As a result, the invention is directed to a carrying and supporting device directed for a paper web or for a paper overlay in which the transverse elements are removed and are a single endless strand in the form of a number of loops or turns running in the direction of travel is arranged and serves to carry and support the paper web during each portion of the papermaking process. Since the individual strand in terms of composition, structure, Size and spacing can be varied, it is possible to allow any of the three basic bearing and support devices to be added replace and improve decisively that were previously common in paper machines.

In detail, there is the carrying and Stutζeinrichtung after Invention from a single endless element or strand, which is arranged so that it over a number of rollers an endless path. The trajectory is designed so that parts of adjacent loops or turns of the strand are moved in the conveying or direction of rotation of the machine and are arranged in parallel at a close distance from one another and form a moving support and support surface or a moving support table which serves to feed the paper web and carry them through the various departments of the paper machine. According to a feature of the invention every second turn can be separated from the adjacent turns after leaving the support and wing

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and then passes through an intersection area in which the winding is in contact with and in an angular position opposite one another the adjacent turns. The intersection area is used for multiple punctures, in which it is not only used for this there is to control the correct running of successive turns, but rather as a result of the contact between adjacent turns also brings about a self-cleaning effect and automatically spacing the individual windings apart.

The use of a single endless strand to form a web support surface offers significant advantages over this the normal carrying and supporting devices as compared to the conventional Fourdrinier wires, wet or dry felts. Since the elements or threads running in the transverse direction have been removed, an almost unlimited amount of water is removed, for the water or the water vapor can freely move between the elements lying in the direction of rotation of the machine without Get in contact with or obstruction by transverse elements.

Another advantage is that the lateral distance between loops lying in the direction of circulation of the machine is easily adjustable and adjustable within the support and support surface to meet the respective requirements the desired paper quality.

In addition, by increasing the lateral distance between loops in a non-operative area, a cleaning effect is achieved that serves to remove foreign particles dissipate that have deposited between adjacent loops.

Conventional felt or fabric can be destroyed and if, for example, a hole is poked in the fabric, the fabric is practically worthless and must be replaced. This results in considerable downtime on the ^Ai aschine. Similarly, when a shaping wire is bent or dented, excessive wear is usually created in the bent area,

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which reduces the life of the forming wire and requires the machine to be shut down to remove and replace the forming wire. The use of a single endless strand overcomes these problems because the strand can be replaced if it is damaged or subjected to significant wear without significantly disrupting the continuity of the papermaking process. The """machine can be stopped momentarily, the strand cut and a new strand connected to the cut end that the new strand can be put in the place of the old train, without that one has to interrupt the operation of the machine in any significant way. λ As an alternative method, it is possible in some cases to separate a portion of the strand that is not located in a operational position is while the machine is in operation and to connect a new strand to the severed end when the strand traverses its Bwwegungsbahn.

As a further advantage, it is possible to carry out desired work on the strand outside of the surface supporting the web. The strand can, for example, in a non-operative zone, treatments such as size divisions, as well as lubrication and cleaning measures or the like. be subjected. This allows the strand to be handled during normal operation without downtime for the machine. i

The application and use of a single endless strand has another significant advantage in that the web-bearing and supporting device can be manufactured in situ rather than prefabricated and transported to the paper mill. Sin Fourdrinier wire is particularly fragile and must be Exercise extreme caution during loading and transport to avoid damage. The strand according to the invention is brought to the shipping in the form of coils or in some other way folded turns, and at the location of the paper machine, the strand laid in turns

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only in the desired trajectory through the machine guided. It is clear that these facilities make shipping and all related requirements critical be simplified.

The invention also simplifies the construction of the paper machine itself. In the conventional form and In the spinning departments, the side of the paper machine must be designed in such a way that it can be opened to accommodate the endless forming wire or to be able to pull on and remove felt. The present invention eliminates the need for a construction that the machine side can be opened because the strand is easily guided through the rollers in the desired path pattern can be.

Further features and advantages according to the invention emerge from the following description, in which a preferred exemplary embodiment the invention is explained in more detail with reference to the drawings. In the drawings show:

Fig. 1 is a perspective view of a Fourdrinier paper machine, at which a Bahnstutζeinrichtung after the invention is applied;

2 shows a schematic representation of the printing department of the paper machine in side view;

3 shows a schematic view of the representation of the movement path of the strand in the spinning department;

Figure 4 is a partial view of a rake or comb used in the apparatus of Figure 2;

5 shows a perspective illustration of the intersection of the straig elements or the windings in an intersection area.

Fig. 1 shows schematically a paper machine with a Fourdrinier department 1 _r a printing department 2 and a dry

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division 3. The Fourdrinier department contains a container 4, which guides or discharges a sludge or a mass of pulp through a slot 5 onto a web support surface 6, around a paper web or to form a paper covering 7. The web support surface 6 is formed from a single endless strand 8, which is looped around a roller arrangement in such a way that adjacent turns lying in the direction of conveyance or circulation of the strand are closely spaced and parallel to one another and the moving web support surface 6 form.

During the molding process, a thin-layered fiber suspension is applied to the support surface 6, which drains away fluid unhindered discharged, which acts as a filter, itadem the fibers into one wet mat are summarized or collected and a free passage of water between the lying in the direction of rotation Allow elements or turns. Therefore, the web seat surface must filter out fibers from the suspension and excess Dissipate amounts of water while at the same time supporting and transporting the web of loose fibers that are on its surface is formed. In order to carry out these operations effectively, the web support surface 6 should be relatively open with a uniform one Space between adjacent turns of the strand. A free and unimpeded drainage of fluids to achieve, and the strands used are preferably impermeable and can be formed from metal wire, or from a monofilament plastic such as nylon, polyester or polyacrylic or from a textile yarn or a strand that is impregnated with a plastic coating or a non-impregnated fabric, which consists of natural or synthetic fibers or a mixture of both.

The roller arrangement which carries the strand 8 has a chest tree or a breast roll 9 which is arranged below the slot. The one through the slot onto the web support surface discharged sludge is carried over a plurality of table rollers 10. When the paper web 7 runs over the table rollers 10, some of the water contained in the web is removed and through the spaces between adjacent turns of the

Strand 8 listed.

When the web is continued from the web support surface 6 of the endless strand 8, you will be subjected to the action of a number of water drainage sheets 11, followed by a number of suction boxes 12, which also serve a part to remove the water from the web. A third process for removing the water can also be provided, namely using a driven couch roller 13 which has a suction cap or similar, which extends over the length of the roller extends. A negative pressure, which is brought to act on the suction cap, also serves to draw water from the web.

The roller assembly of the Fourdrinier department also includes a number of guide rollers 14, which are in levels below the Table rollers 10 are arranged.

In order to achieve an endless path of movement for the strand 8, the turn of the located at a side corner moves The strand pattern from the breast roll 9 upwards over a guide or guide roller 15, then starts running in the horizontal direction the opposite side of the machine, where it is moved down around a guide or guide roller 16 and back into the Strand pattern occurs.

Following the molding department, the web 7 is transferred to the printing department 2 and the invention will now be described in detail with respect to the push station. Press is that The act of wringing or driving water from the wet fibrous web by moving the web through a set with one another cooperating pressure rollers is performed. The web 7 is transported on a support device which, firstly, serves to to support the weak web within the nip zone, which secondly compresses the wet fibrous web uniformly in order to Thirdly, to achieve the highest possible printing efficiency and surface smoothness, absorbs water squeezed out of the web and fourthly, the water pushes mush out of the pressure zone.

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As can best be seen from Fig. 2, the spinning department 2 a pair of pressure rollers 17 on and a single endless strand 18, similar to strand 8, is arranged to pass over a roller assembly to run, the turns of the strand are moved in the direction of rotation and at a small distance from each other are arranged in parallel to form a web support structure provided between the pressure rollers 17 and denoted by 19 is.

The turns of the strand 18 should lie close together on the support surface 19 or be arranged relatively close to one another to achieve the highest possible level of even, uniform support and pressure application. aside from that should the strand be penetrable in order to come out of the paper web | to absorb or treat squeezed water, compressible, in order to be able to respond to the pressure zone and to apply a uniform pressure, as well as resilient elastic in order to be able to expand again after leaving the pressure zone and to have continuous openings for receiving of the squeezed out water to keep ready. When pressure is applied, it is found that the surface 19 is close to one another Has lying strand elements, which under the pressure in the area of the roller gap zone with the geometry of the roller gap to match. E§ has been shown that textile yarns that. either from natural or synthetic fibers or from Mixtures of the two exist, in the form of endless yarn strands or strands or twisted strand formations the desired " Have properties and are particularly well suited as a strand 18 in the pressure roller department 2.

As shown in FIG. 2, every other or second turn or loop of the strand 18 is separated from the neighboring ones Windings separated when leaving the nip zone and runs downwards around a roller 20 to a roller 21 while the possible turns run around rollers 22 and with the second turns meet again on the roller 21. The turns are in turn every other turn separated by running around the rollers 23 up and back into the roll nip zone between the pressure rollers 17, while the

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adjacent turns moved over the roll 20 and at the nip zone reunited with the second turns. The group winds the from the pressure roller 17 downwards too the roller 20, crosses the group of turns or runs under contact and at an angle sin this group of turns over, which run from the roller 20 up to the pressure roller 17. This encounter takes place at one labeled 24 Crossing point instead. Similarly, the group of turns running from roller 20 to roller 21 crosses that one Group of turns running from roller 21 to roller 20. This encounter takes place at an intersection area 24a instead of. The action between adjacent turns at intersection areas 24 and 24a serves a number of purposes. Through this is not just the order of consecutive turns controlled and controlled, but rather in a mutual pole Action or as a result of mutual stripping creates a self-cleaning effect for the strand, and moreover the individual turns are automatically spaced from one another.

TJm in the area of the bearing and support surface 19 in the waizen gap zone A number of ridges are required to achieve a precisely aligned arrangement of the windings with regard to the lateral spacing or rake 25 is used. Each comb 25 has a number of slots or teeth 26 for receiving individual turns and is used to separate turns exactly from one another with regard to their distance. The different groups of turns, namely both the incoming as well as the turns running behind the area of the support and bearing surface 19 the teeth 26 of the combs 25, so that adjacent windings in the area of the support surface 19 are precisely spaced or aligned are. In order to be able to change the lateral spacing of the turns in the area of the support surface 19, the combs can be used 25 either pivotable or adjustable or designed as combs with different tooth spacing. If you have the side The distance between the turns in the area of the support surface 19 varies, so that the quality properties of the paper can be influenced.

In addition, the adjustment of the device in one can not

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operative zone help to remove foreign particles that have settled between the turns. For example can be an increase in the lateral distance between the adjacent turns in a single plane or separation adjacent turns in different levels is very important be useful if you want to remove dirt between adjacent turns.

The combs 25 also serve the purpose of preventing lateral displacement of the turns as a result of the fact that the strand is laterally displaced by the width of a turn each time the strand completes one revolution around the roller assembly. This function can also be performed by the fact that, by providing a free schweiMbare roller in the whale, etc. zenanördnung so that the pivoting action automatically tends to divert the wrap laterally in a direction opposite the normal direction VersetzungsrüLtung.

FIG. 3 shows in a schematic representation the path of movement which the strand follows in the arrangement shown in FIG. 2. As 3 is shown in Fig., The strand of a path running from roll ¹ 23 to the platen 17 along 13a and when the train passes over the platen roller 17, it forms a part of the web support device 19 runs From there, the Then strand down, as indicated at 18b, around the roller 22 to the roller 21 on the path 18c. The strand then runs around the roller 21 on the path 18b upwards, runs I over the roller 20 and back to the pressure roller upwards on the path designated by 18e. The part of the winding which is arranged on the pressure roller 17 also forms part of the arrangement 19 supporting the web the way 18g. After its revolution around the roller 21, the strand moves up the path 18h around the roller 23 and runs back towards the pressure roller 17 on the path 18i which runs parallel to the path 18a and also as part of the path ^ supporting arrangement 19 acts. The strand then passes from the pressure roller 17 to the roller 22 on a path 18jnid the roller 22 and from

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there along the path 18a down to the roller 21. After the he has passed underneath the roller 21, the strand runs around the guide rollers 27 and 28 and re-enters the web pattern on the way 18a.

While Pig. 3 the turns in the support area 19a to a considerable extent Distance from each other shows, these turns are close together in practice. While Fig. 3 only three turns shows, which are used as part of the supporting "surface 19, are in practice compared to possibly hundreds or thousands of adjacent turns used, closely spaced and parallel to each other are arranged and so form the supporting and bearing surface of the web.

While the web support surface 6 in the molding department 1, the paper web or carries the paper covering 7 over a considerable distance, the web supporting surface 19 in the Pressing department 2 only in the area of the roller gap zone between the pressure rollers 17 are in contact with the mat or the covering or the web 7.

The winding pattern of the strand 18 as shown in FIGS. 2 and 3 is not critical to the invention, and different winding patterns can be used for the endless strand may be used, including patterns with or without crossing points and with or without separation of the second Turns from the adjacent turns during different parts of the trajectory.

The ^ principle of using a single strand is also applied to the drying section of the three. The drying process is used in the wet web or the wet surface 7 to expel existing moisture by means of added thermal energy. The drying compartment 3 comprises, as can be seen from Fig. 1, a number of heated upper drying rolls 29 and lower drying rolls 30, and the paper web 7 runs one after the other over rollers 29 and 30. A single endless strand 31, similar to strand 18, runs over a number of rollers

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32, and neighboring ones running in the direction of rotation of the machine Windings of the strand serve as a support and support arrangement for the paper web and exert a uniform pressure on the upper drying rollers 29 in order to ensure the transfer of heat from the drying rollers to increase the paper web.

To use the endless strand pattern for strand 31, the turn runs on one side corner of the support arrangement over a guide roller 33, then lays a horizontal path to the opposite side corner of the support assembly back, where it runs over a guide roller 34 and back into the web pattern in the manner described for Yor entry.

In this application, the turns of the strand should be proportionate lie close together in order to achieve the greatest possible heat transfer, and the strand itself can be permeable or impermeable, depending on the volume is treated or what type and size the mat to be treated is.

In addition to the strand 31, a second endless strand 35 is wound over a number of rollers 36 to provide a second support arrangement for the paper web. The belts lying next to each other in the circumferential direction or turns of the strand 351efi.nden in closely spaced from each other and serve to apply a uniform pressure to the surface of the \ lower dryer rolls 30, to bring the heat transfer to the highest possible value.

In order to create an endless band pattern for the strand 35 as well, the winding runs on one side corner of the support arrangement via guide or guide rollers 37, then runs horizontally to the opposite® side of the machine, where they over a second guide roller, not shown, runs and re-enters the pattern in the manner previously described.

The removal of transverse elements in dry fabrics

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has the advantage of drying that you can reduce the air pumping that occurs in drying compartments that are open-meshed Working dry fabrics. Large volumes of air trapped within the mesh can cause fluttering of the web or cause unstable behavior when the machine is operated at high speed.

The use of a single endless strand to form a moving support surface for the paper web forms a new and unique principle. The waiver of transversely directed elements in the production of support surfaces leads to the significant advantage that the water separation and also the vapor separation is improved. In addition, a more uniform quality of the paper is achieved. Finally, this also makes it easy to clean the device without having to turn off the machine.

Patent claims:

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Claims (22)

104630 M 02 78T February 1, 1971 K / am Claims 1. Carrying and supporting device for a paper web in the raw state on a paper machine, the paper web soaked with a flowable medium and a guide arrangement being provided, characterized by a first guide member (e.g. 9) and a second guide member (e.g. 13), one on the guide assembly in Form of a number of turns for an endless path of movement arranged endless strand (8), with parts extending from the first to the second guide member in a substantially parallel arrangement and forming a web support surface (6), an arrangement (4) for feeding one with a flowable medium soaked web (7) to the web support surface (6), devices (eg 11, 12) for removing the
flowable medium from the web (7) during its arrangement on the support surface (6) and by drive devices for advancing the strand (8) on the endless path for a forward movement of the web (7) on the support surface (6). 2. Device according to claim 1, characterized in that the supporting surface (6) forming
Parts of the turns are arranged at a distance from each other and are pilot adjacent to the support surface means (zB24,25) g view to a uniform lateral gap to be maintained between the parts of the turns. 3. Device according to claim 1 or 2, characterized in that cleaning devices (24-26) are arranged in engagement with the strand (18) for cleaning the same as it rotates on the endless path. 4. Device according to claim 3, characterized in that the cleaning devices (24-26) opposite the support surface (19) at a remote location
are arranged. - _A ", - ~ - 16 - InQOOC / Γιΐ Ο Q I U υ U · * ·· '' '' ** J 5. Device according to one or more of the preceding claims 1-4, characterized in that the web (7) made of cellulose fibers and the flowable Medium consists of water. 6. Device according to one or more of the preceding claims 1-5, characterized in that the support surface is solely made in the direction of rotation of the machine running elements. 7. Device according to one or more of the preceding claims 3-6, characterized in that the cleaning device (24-26) one of the support surface (19) includes remote means for increasing the lateral spacing between the turns to thereby Remove foreign particles between adjacent turns. 8. Device according to claim 7 »characterized that the means located away from the support surface (19) also comprises a device with which the lateral distance between the turns can be reduced to its original value. 9. Device according to one or more of the preceding claims 1-8, characterized in that devices (20-23) for separating the movement paths every second Winding from the trajectory of the adjacent windings and devices are provided with which one the second Rotate turns in an angular position as well as in mutual contact with neighboring turns to clean the strand can leave. 10. Device according to claim 9, characterized in that a device for reuniting the movement paths of the respective second turns with the movement path of the adjacent turns are present. - 17 - 10983S / 0189 11. Device according to one or more of the preceding claims 1-10, characterized by a roller arrangement with a first roller (e.g. 9) and a second roller (e.g. 13) »which is arranged essentially parallel to the first roller (9), an endless strand (8), which is arranged for an endless movement path on the roller device in a number of gradually recovering turns, parts of these turns extending in a parallel position from the first roller (9) to the second roller (13) and a support surface (6 ), which consists exclusively of elements running in the direction of rotation of the machine, a device (4,5) for feeding a paper web (7) soaked with water to the web support surface (6), a device for removing the water from the web (7) when this is in contact with the support surface 6, and by a g drive device for the advancement of the strand (8) on an endless path of movement, in order to thereby the web support surface (6) and d To convey the web (7) in a direction leading from the first roller (9) to the second roller (13). 12. Device according to claim 11, characterized that an arrangement (24-26) is provided, which allows a lateral displacement of the turns with respect to the Roller arrangement reduces. 13. Device according to claim 11, characterized that outside the support surface (19) located devices (17.21-23 and 27.28) for separating the | Movement path of every second turn is provided from the movement path of adjacent turns, with parts of each second turns in a first plane and parts of the adjacent turns in a second plane, the the first plane intersects, and that parts of the respective second turns are in alternating order as well as in Contact with parts of the neighboring turns to clean the strand. - 18 - 109835/0189 14. Device according to claim 11, characterized in that the cleaning device in one . handle stands with the strand and is arranged for cleaning the strand outside the support surface, the cleaning takes place when this is on its endless path. 15. Device according to claim 11, characterized in that the roller arrangement is part of a Forming department (1) of a paper machine, the strand (8) consists of a water-impermeable material and the the support surface (6) forming parts of the turns are spaced apart. 16. The device according to claim 15, characterized in that the strand of metal, a thread Plastic or a textile yarn impregnated with plastic. 17. Device according to claim 11, characterized that the roller arrangement forms part of a spinning section (2) of a paper machine, the strand made of a compressible, resilient and water-permeable Material is formed and the turns forming the support surface are generally close together. 18. Device according to claim 17, characterized in that the strand consists of a twisted or yarn twisted in another way. 19. Device according to one or more of the preceding claims 1-18, characterized by a roller arrangement, an endless strand, which for an endless Movement path in a roller arrangement in the form of repetitive turns with adjacent parallel to each other in Direction of rotation of the machine parts of the strand, which form a support surface for a paper web, is provided, cooperating pressure members (17), which for Act on part of the paper web (7) that - 19 109835/0189 is transported on the support surface to thereby draw water out of the paper tap (7), and by a drive device for a feed of the strand on its endless path to thereby the support surface and the paper web to move forward in relation to the pressure members. 20. Device according to claim 19, characterized in that the strand consists of a compressible and resiliently elastic and water-permeable material is formed and. the parts forming the support surface of the turns are essentially in close proximity to one another. 21. Device according to claim 11, characterized in that that the roller arrangement forms part of a drying section (3) of a paper machine, the first and the second roll consists of heated dryer rolls, and the parts of the turns the paper web against the dryer rolls (29,30) and water vapor coming out of the web between the parts of the turns to the outside got. 22. Device according to one or more of the preceding claims 1-21, characterized in that a carrying and supporting device is provided for a paper web is, wherein the support device consists exclusively of one Number of mutually parallel and extending in the direction of rotation of the machine elements, and the elements a number repeating turns of an endless strand. 109835 ^ 0189