AT504418A2 - METHOD AND DEVICE FOR TRANSFERRING THE PAPER TRAIN FROM A SUPPORT FABRIC - Google Patents

Description

Method and device for transferring the paper web from one

Supporting Fabric (001) The present invention relates to a method and an apparatus for transferring the paper web from one support fabric to the other. The method according to the invention and the device according to the invention are thus suitable, for example, for transferring the web from the wire section onto the press felt and from the press felt into the dryer section. The method and the device are particularly advantageous when transferring the paper web from the first press of the press section of the paper, board or other corresponding machine into the second press. (002) Hereinafter, a paper web transfer method and a paper web transfer device of the prior art will be described in more detail using the example of the press section of a paper machine. At present, the press section following the wire section of the paper machine usually consists of two presses arranged one behind the other, in which the paper web is mostly transported by at least one felt, more generally supported by a fabric from one press nip to the other, the paper web also over part of the way running between two tissues. In this context, the term " tissue " also be understood a transfer belt. When transferring the paper web from the first press, i. the first press nip into the second press, i. The second press nip must first be removed from the first, for example, upper felt of the first press and adhered to the second, for example, lower felt. Thereafter, the web, carried by said second felt, is guided to the second press where it is placed on the felts of the second press. This is done by first contacting the web with the first felt of the second press and then releasing it from the second felt of the first press, holding it adhered to the first felt of the second press, and bringing it into contact with the second felt of the second press becomes. (003) Critical places in the web guide are those places where the web is detached from a felt and transferred to the next fabric. If the detachment of the web is not done carefully, there is a risk of web breaks or web breaks. The location of detachment, i. Lifting the web is usually at a felt guide roller, which rotates around a felt of the first press, while the other felt continues its way relatively straight past the roller. When the first felt circulates around the roll, the web naturally has a centrifugal force that is dependent on the roll diameter and the roll speed, but in any case it is relatively large. Of course, the aim is -3 __ ··· ·· · · · · · · · · · Remove the web from the first felt. However, it has been found that one can not rely on the centrifugal force alone, but that the separation of the web must usually be supported by any suction arrangement in front of said roller. (004) Of the said suction arrangements there are two different basic types: suction rolls and transfer suction boxes, the use of which is described for example in US 5,888,354. In principle, both types operate so that suction is applied to the web through the felt so that the web will both detach from the felt on the opposite side to the suction device and adhere to the felt located on the side of the suction device. The suction rolls are in themselves reliable devices, in the use of which there are generally no problems with the actual detachment of the web from the first felt or with the holding of the web at the second felt. However, the use of suction rolls problems of another kind in appearance: First, adjusting the Saugsektorweite designed in suction rolls consuming and complicated, and secondly, suction rollers are expensive to buy, in operation and in maintenance. (005) The transfer suction box as a second option is considerably cheaper to buy and operate. For example, in the US-4- * .. *; ν * γ · :: ·· :: · ί ·. ·: ::: * .. · ........

No. 4,113,557, the use of the transfer suction box for detaching / lifting the paper web from the wire is dealt with. In said document is set out in detail how the paper web is guided together with wire and felt around the roller, but in the vicinity of the roller, but behind this a transfer suction box is arranged, with which the web is detached from the wire. Characteristic for the operation of the transfer suction box is that the felt and with it the web is deflected by the transfer suction box opposite the sieve direction by an angle of less than 45 degrees. In other words, on the convex lid of the suction box, the felt web undergoes a curvature, which leads to increased wear of both the lid and the felt. (006) However, the transfer suction box could not be used in very fast paper machines because, as already mentioned above, the lid of the suction box and also the felt running over it wear out. The reason for this is that the felt barrel is traditionally set up so that the felt on the suction box changes its direction of travel and the felt is pressed against the suction box lid due to its tension. In other words, both the above-mentioned change in felt running direction on the suction box and the vacuum of the suction box suck the felt against the suction box lid, causing rapid wear of both the felt and the -5- ·· ♦ · · · · · ··. ·························································································

Suction box lid comes. This wear is reinforced when the felt runs at high speed over the suction box lid. For this reason, with the increasing speed of paper machines, the use of the transfer suction box has been steadily reduced. (007) The present invention seeks to remedy shortcomings of the prior art devices by providing a new type of solution for transferring the paper web from one support fabric to another. Said solution is based on the use of the transfer suction box in the form that the speed of the machine has no influence on the wear of the box lid or the felt. (008) In the solution according to the invention takes place on the transfer suction no significant change in direction of the tissue / the paper towards the lid, so so the tension of the web / tissue causes no directed towards the suction box force, but the only load that acts on the Saugkastendeckel , caused by the vacuum of the suction box. (009) Among the advantages offered by the invention are i.a. called:

Significantly less expensive to buy and operate than the current suction roll, because the suction box alone as a construction is more advantageous than the suction roll, not to mention the operation and energy consumption; Less wear of the suction box lid than with today's suction box solutions;

Less wear of the felt than in today's Saugkastenlösungen. (0010) For the method for transferring the paper web from one support fabric to the other according to a preferred embodiment of the invention, in which the paper web, located between two fabrics is brought to the suction device, the paper web with the suction device of that tissue, the is on the opposite side to the suction device of the web, detached and transported on the fabric, which is located on the side of the suction device, it is characteristic that the suction of the suction device is directed to the on the suction device opposite side of the web located guide roller and the paper web is peeled off from the leader roll side substantially at the point where the direction of movement of the leader roll side fabric, following the leader roll, begins to diverge away from the direction of movement of the fabric side fabric. (0011) For the method according to another preferred embodiment of the invention, characteristic is -7-7- ···· * ·. »··················································································································································································································································································· seeks, suction is used. (0012) For transferring the web from a backing to another serving device located on at least either side of the web W; suction means for releasing the web W from the first web, the web then being carried by the second web; on the side opposite to the suction means of the web and the fabric located felt guide roll with which the fabric from which the web has been detached, is further transported, it is characteristic that said suction means of a transfer suction box with a lid and one or more suction slots in this Cover is provided and this suction box is arranged at the felt guide roller, that one of the slots of the lid comes to lie substantially at that point of the felt guide roller at which the roller surface starts to diverge away from the direction of the transfer suction box side fabric. (0013) It is characteristic of the device according to another preferred embodiment of the invention that one of the slots of the lid is located at the inlet gusset of the felt guide roller. -8th- • · • · • · • · ·· ··

The other characteristic features of the method according to the invention and of the device according to the invention for transferring the paper web from. Are shown in FIG one support fabric to another go out from the claims. (0015) Hereinafter, the method and apparatus of the present invention will be described in detail with reference to the accompanying drawings.

Show it:

Fig. 1 shows a transfer of the paper web from a supporting fabric to another serving device according to the prior art;

Fig. 2 shows another for transferring the paper web from a backing fabric to another prior art device;

Fig. 3 is a general view of a press section of a paper machine having some preferred embodiments of the invention;

4 shows a device for transferring the paper web from one supporting fabric to another according to a first and a second preferred embodiment of the invention; -9-

, ·· ·· · · · · · ········· ··

5 shows a device for transferring the paper web from one support fabric to another according to a third and a fourth preferred embodiment of the invention, and

Fig. 6 is a more detailed illustration of the lid solution of the suction box solution to be used in the apparatus according to a preferred embodiment of the invention. Figure 1 shows a partial view of a prior art paper machine press section treated in U.S. Patent No. 5,888,354, including the apparatus for transferring the paper web from one press-forming part to the other. The press section shown in the drawing consists of a first press 10 and a second press 20. The first press is formed in the drawing by the shoe roll 12 and its counter roll 14, through the nip of the paper web lying between two felts 32 and 34 lying. The first felt 32 runs as a loop, within which the shoe roll 12 is located, around the in this case slidable felt guide roll 16 and continues its way upwards. The second felt 34, in turn, runs around the counter roll 14. The paper web W is detached from the first felt 32 by means of the transfer suction box 18 in the region between the press roll 14 and the felt guide roll 16. The suction of the suction box becomes -10- · .. · -10- · .. · · · · · · · · · · · · «« * · «♦ φ * ·· ···· ···· 18 directed toward the web W through the second felt 34 to release it from the first felt 32. Since at the same time the direction of the first felt 32 no longer leads over the lid of the suction box 18, but runs slightly higher, the detachment of the paper web W from the first felt succeeds effortlessly. At the same time, the suction of the suction box 18 also ensures that the paper web W remains reliably attached to the second felt 34. In this solution, the second felt 34 is raised by means of the suction box 18 so as to ensure that the second felt is constantly in contact with the lid of the suction box 18, which in turn ensures that a uniform suction is constantly applied to the paper web W. that reliably holds the web W on the second felt 34. Such a procedure, however, involves a relatively high load on the bag cap, as a result of which both the lid and the press felt wear out rapidly, especially at higher production speeds, e.g. over 1100 m / min. (0017) The paper web W, lying on the second felt 34, is inserted into the second part 20 of the press section, i. passed into the second press, which is represented in the drawing by the third felt 22 and the transfer suction roll 24. The transfer suction roll 24 serves to lift the paper web from the second felt 34 of the first press 10 before this second felt 34 is passed down the roll 26. In principle, the suction roll releases the paper web from the second felt 34 in the same manner as described above in connection with FIG Transfer suction box 18 has been described. Supported by the suction roll 24, the third felt 22 here representing the second press 20 continues to transport the paper web W until the fourth felt assigned to the second press is added from below, the paper web then again being sandwiched between two felts into the nip second press and, if appropriate, in further following nips is performed. (0018) In Fig. 2 there is shown a fully corresponding paper machine press section also treated in U.S. Patent 5,888,354. The only difference with respect to the solution shown in Fig. 1 is that the transfer suction box 18 shown in Fig. 1 is now replaced by the suction roll 18 ', with the completely the same function as with the suction box is achieved. In this solution, thus eliminating the problem of felt and the Saugkastendeckel wear. However, the problem has been eliminated by a solution that is costly to purchase, operate and maintain, since the suction roll as a rotating element needs both bearings and a drive in addition to the vacuum pump and piping, compared to the suction box. ·· v: ·· ·· • • ·· ·· «1 • • • ···· c ··

············································································································································································ Fig. 3 shows the general view of a device according to preferred embodiments of the invention having press section of a paper machine. The press section in Fig. 3 consists of the first press 40 built around the first press nip 42 and the second press 60 built around the second press nip 62. The web W, for example, carried by the wire 44, comes out of the wire section of the paper machine the first press 40. From the wire 44, the web, supported by the first press felt 46, is brought onto the guide roll 50 by means of the transfer suction box 48. The web supported by the first press fungus 46 is guided into the press nip 42 between the felt 46 and the press felt 52. From the nip 42, the web passes between the felt 46 and the press felt 52 to the felt guide roll 54 where the web is removed from the press felt 46 by means of the transfer suction box 56 located on the opposite side of the web from the guide roll 54. The press felt 46 continues its upward path, and the web is guided by the press felt 52 to the second press 60. In the second press 60, the web is first brought into contact with the third press felt 66 before the press nip 62, then detached from the second press felt 52 and, supported by the third press felt 66, by means of the transfer suction box 68 onto the guide roll located within the second press felt loop 52 70 brought • ♦ -13-

• • • · and brought to the first transfer belt 72. Thereafter, the web, between the third press felt 66 and the first transfer belt 72 located, passed through the second press nip 62. (0020) In the solution according to a preferred embodiment of the invention shown in FIG. 4 for transferring the paper web from the first press 40 of the paper machine into the second press 60, the paper web passes between the first press felt 46 and the second press felt 52. coming from the left to the felt guide roll 54 of the pressing devices, which may therefore consist of a shoe press or a roller press, for example. On the side of the felt 46, the web and the press felt 52 opposite to the guide roll 54, i. on the side of the second press felt 52, a transfer suction box 56 is arranged at the roller 54, the cover 80 has in the embodiment shown two slots 82 and 84. The first slot 82 viewed in the direction of web travel is preferably located exactly at the guide roller 54. However, the slot may also be at the entry gusset (left in the drawing) or, relative to the roller 54, at the location of the web where the first press felt 46 is the surface following the roller 54, a direction deviating from the direction of the second press felt, ie be arranged at the outlet gusset (right in the drawing). The first slot 82 may begin at the plane passing through the axle center line.

• · • · ·

the felt guide roller 54 and through the line at which the paper web of the felt guide roller 54 begins to follow felt 46 dissolves running. It should also be noted that the number of slots is also decisive for their placement. In other words, the more slots there are, the farther away from the guide roller location may be the outermost slots. Since the surface of the felt guide roll 54 is grooved or otherwise adapted to allow air to flow to the web lift portions, the transfer suction box 56 is adapted to peel the paper web from the first felt 46 following the surface of the guide roll 54 and to retain it on the surface of the second press felt 52. The second slot 84 in the cover 80 of the transfer suction box 56 serves the purpose of ensuring the adhesion of the web to the fabric 52 even after the actual detachment operation; In addition, in the felt guide, the web may be adhered to the fabric 52 by conventional vacuum boxes 58 to the felt guide roll 64 of the third press felt 66 of the second press 60. (0021) Essential to the placement of the transfer suction box 56 according to the first embodiment of this invention is in addition to the arrangement of the first slot 82 of the suction box lid 80 so that it at least substantially at the point where the press felt 46 and the paper web W from each other , begins, - is preferably the suction point on the previous inlet pocket -, that the lid 80 15th

The suction box 56 is flat or (in the case that the lid of the mold the roll surface follows) is preferably concave, and that the direction of the lid 80 of the suction box 56 coincides with the direction of the fabric 52. In other words, the Saugkastendeckel 80 causes no directional changes of the fabric 52, but the press felt 52 moves from the felt guide 54 from exactly in the direction determined by the felt-guide roller 64 of the second press 60 direction. On the right side in Fig. 4, as a second preferred embodiment of the invention, it is also shown how the web is detached from the second press felt 52 and brought to adhere to the third press felt 66. This is done by arranging within the second press felt loop a guide roll 70 around which the press felt 52 is guided, while at the same time the transfer suction box 68 located within the third press felt loop 66 at the guide roll 70 lifts the web from the press felt 52 and onto the press felt 66 transferred. In FIG. 5, the cover 86 of the transfer suction box 68 corresponding to this second embodiment has only one slot 88, wherein this slot 88 must be placed in the web running direction exactly at the point at which the press felt 52 separates from the press felt 66. Referring now to Fig. 5, transfer suction box solutions according to third and fourth preferred embodiments of the invention are shown in transferring the paper web from the first to the second nip of the paper machine. The paper web located between the first press felt 46 and the second fabric 52 passes from the left to the felt guide roll 54. On the side of the felts 46, 52 and the web opposite the guide roll 54, the roll 54 is on the side of the fabric 52 a transfer suction box 56 is arranged, the lid 90 is concave-shaped and in the embodiment shown four slots 92, 94, 96 and 98 has. The placement and operating principle of the last two slots 96 and 98 are substantially the same as those of the slots 82 and 82 of the previously described embodiment, i. they serve to release the web from the first press felt 46 (slot 96) and to hold the web against the fabric 52 (slot 98). Since there are overpressure in the inlet gusset, the slots located in this area serve the purpose of detaching the web from the first press felt 46 already in front of the guide roller 54. The suction prevailing in the slots 92 and 94 enhances the differential pressure exiting the web from the felt. As in the above-discussed embodiment, also in this embodiment, the lid 90 of the transfer suction box has the same direction as the fabric 52. Further, in FIG. 5, FIG Transfer the paper web from the second felt 52 to the third press felt 66 shown. This process begins when the paper web is separated from the second press felt 52. The only difference with the embodiment shown in Fig. 4 is that the lid 100 of the transfer suction box 68 is constructed differently. In the embodiment in Fig. 5, the lid 100 has two slots 102 and 104, which are placed so that the first slot 102 in the region of the Einlaufzwickeis the felt guide roll 70 (ie on the side of the incoming web) and the second slot 104 in Area the outlet gusset is located. In other words, the slits 102 and 104 serve the purpose of first releasing the web from the press felt 52 (102) and then adhering it to the third press felt 66 (104). (0025) As far as the construction of the transfer suction box is concerned, apart from the lid shape, it may be called conventional. The width of the usually one to five slots 114 and 116 in the lid 112 of the box 110 shown in Fig. 6 is on the order of 5-20 mm. It has been found that with larger slot widths than those mentioned, the felt bends into the slot, resulting in both slit and felt wear. Also, then the Sogbedarf increases significantly. The cover strips 118 are preferably made of ceramic material and are rounded at their edges to minimize wear of the strips 118 and the felt. In certain cases, plastic strips can also be considered. The strips 118 are inserted into holders 120, which are fastened by form-fitting connection to counter-profiles 122 of the suction box 110. (0026) In order to achieve an optimum mutual position of the felt-guide roller and its associated transfer suction box, either the roller or the box or possibly both are arranged adjustably. (0027) With regard to the above statements, it should be noted that the device according to the invention and the method according to the invention can be used not only for the transfer of the web within the press section described here by way of example, but also in connection with other web transfer stations of the paper machine. It is further understood that although the invention has been referred to exclusively as paper machines above, the invention is equally applicable to carton, tissue and pulp machines. So the term "paper " also cardboard as a subgroup. Generally speaking, the invention is therefore suitable for all objects in which a material web is transferred from one support fabric to another.

claims:

Claims (23)

-19- • ········································································· • • · • · Austrian & European Patent & Trademark Attorneys GIBLER & POTH Patentanwälte OEG Dorotheergasse 7 "A-1010 Vienna - patent@aon.at Tel .: +43 (1) 512 10 98 - Fax: +43 (1) 513 47 76 Claims 1. A method for transferring a paper web from a backing fabric another in which the paper web located between two fabrics is brought to a suction device, the web with the suction device is detached from the fabric located on the side of the web opposite to the suction device and transported further on the fabric side, characterized in that the suction of the suction device (48, -56, -68) to the location of the guide roll (50, 54, 70) located on the side of the paper web W opposite the suction means (48, 56, 56, 56) and the paper web W of the on the side of the guide roller (50, -54, -70) located tissue (44, -46, -52) is substantially detached at the point at which the direction of movement of the on the side of the guide roller (50 , -54, -70) located tissue (44, - 46, -52), following the guide roller (50, 54, 70), from the direction of movement of the tissue (46, 48, 56) located on the side of the suction device (48, -56, -68). 52; 66) begins to diverge. -20- A method according to claim 1, characterized in that the slot (84; 98; 104) located in the cover (80; 86; 90; 100; 112) of the suction device (48; 56; 68; passing through the axial center line of the felt guide roll (50; 54; 70) and through the line at which the paper web W begins to follow from the felt guide roll (50; 54; 70) felt (44, -46, -52). triggers, runs. 3. Method according to claim 1, characterized in that the fabric (46, -52, -66) located on the side of the suction device (48; 56; 68) passes over the cover (80; 86, · 90; 100; 112) the suction device (48, -56, -68) is guided without the running direction of the fabric (4 6, -52, -66) on said cover (80, -86, -90, -100, -112) a Change undergoes. 4. The method according to claim 1, characterized in that the suction of the suction device (56, -68) is directed to the inlet pocket of the on the suction means (56, -68) opposite side of the paper web W guide roller (54, -70) and starting the peeling of the paper web W from the guide roll side (54; 70) fabric (46, -52) already before the guide roll (54, -70). -21- • ·· 99 99 • • • • • 9 9 9 9 • • 9 99 99 • ··· • · • · · 9 9 9999 • 9 • 9 99 9 9 • ··· A method according to claim 1, characterized in that by continuing the suction of the suction means (48; 56; 68), the paper web W is provided with a second slot (84, 84, 70) further away from the guide roller (50, 54, 70). -98) is held on the fabric (46, -52, -66) located on the side of the suction device (48, -56, -68). A method according to any one of the preceding claims for transferring the paper web from the wire section into the press section of the paper machine. A method according to any one of claims 1 to 5 for transferring the paper web from the press section to the dryer section of the paper machine. 8. The method according to any one of claims 1 to 5 for transferring the paper web from the preceding press in the following press the press section of the paper machine. 9. A device for transferring the paper web from one support fabric to another, which at least on both sides of the paper web W located tissue (44,46, -46,52, -52,66, -66,72), a suction device (48, 56; 68) which removes the web W from the first web (44, 46, 52, 66) and to the second web. • • • • • • • • • • • • • • • • • • • • • • • • • · · · · · · · · · · · · · · · · · · · · and a felt-guide roll (50; 54; 70) disposed on the opposite side of the web W and the webs (44, 46, 52) from the suction means (48; 56; 68), with which the web W characterized in that the suction means consists of a transfer suction box (48, -56, -68) having a lid (80, -86, -90, -100, -112) with one or more Suction slots (82, 84, 88, 92, 94, 96, 98, 102, 104, 114, 116), and this transfer suction box is placed at the felt guide roller (50, 54, 70) so that one of the slots (82, -88 , -96, -104, -116) of the lid (80, -86, -90, -100, -112) substantially comes to lie on the position of the felt guide roll (50, -54, -70) at which the Surface of the roller (50, -54, -70) begins to diverge away from the direction of the fabric (46, -52, -66) located on the side of the transfer suction box (48, 56, 68). A device according to claim 9, characterized in that the lid (80, -86, -100) of the transfer suction box (56, -86, -100) is flat, i. is straight. 11. The device according to claim 9, characterized in that ·· 23 · · · · · · · · · ······ the cover (90; 112) of the transfer suction box (90; 110) is concave. Device according to any one of claims 9 to 11, characterized in that the cover (80) of the transfer suction box (56) has two slots (82, 84), of which the first slot (82), viewed in the fabric direction, removes the paper web W from the outer fabric (46) viewed from the transfer suction box (56) and the second slot (84) for securing the adherence of the web W to the fabric (52) located on the side of the transfer box (56). Device according to any one of claims 9 to 12, characterized in that the cover (90, -100) of the transfer suction box (56, 70) has at least two slots (92, 94, 96, 98, 102, 104), of which at least the first slot (92, 94, -102), viewed in tissue care, is located in the region of the inlet of the guide roller (54, -70). 14. The device according to claim 13, characterized in that ··· ································· The cover (90) of the transfer suction box (56) has a plurality of slots (92.) Located in the area of the feed throat of the guide roller (54) , 94). Device according to any one of claims 9 to 14, characterized in that the cover (80; 86; 90; 100; 112) of the transfer suction box (48, -56, -68) has substantially the same direction as that of the felt guide roller (80; 50, -54, -70) to the following roller (64) has running track. Device according to any one of Claims 9 to 15, characterized in that the surface of the felt guide roll (50, 54, 70) is grooved. Device according to any one of Claims 9 to 16, characterized in that the said fabrics (46, 52, 66) are felts of the press section and the transfer suction box (56, 68, 110) for transferring the web from the first press (56). 40) in the second press (60). 18. Device according to any one of claims 9 to 17, -25- -25- * * # ·· ·· ·· ·· · · · · · · · · · · · · · · · · · · · ··· Characterized in that the fabric consists of the wire (44) of the wire section and the other fabric of the felt (46) of the press section, wherein the transfer suction gas -ten (48) for transferring the web W from the wire section into the press section (40). A device according to any one of claims 9 to 18, characterized in that the one fabric consists of the transfer fabric (72) of the press section (60) and the other fabric consists of the dryer fabric of the dryer section. 20. Transfersaugkasten having a box and a lid, and the lid has in a spaced-apart strips, which are attached to the box edges, characterized in that the lid (80,86,90,100) is either flat or concave. 21. Transfersaugkasten according to claim 20, characterized in that the strips (118) of the lid (80,86,90,100) consist of ceramic material. 22. Transfer suction box according to claim 21, characterized in that -26- • · · ························· the strips (118) are fastened in special holders (120). 23. Transfersaugkasten according to claim 22, characterized in that the holders (120) by form-fitting connections to counter-profiles (122) of the suction box (110) are attached. The patent attorney: Austrian & European Patent & Trademark Attorneys Dorotheergasse 7 - A-1010 Vienna - patent@aon.at Tel .: +43 (1) 512 10 98 - Fax: +43 (1) 513 47 76 IO