FI81402C - MAONGCYLINDERTORK. - Google Patents

Description

81 402 1 Multi-cylinder dryer Game cylinder cylinder

The invention relates to a multi-cylinder dryer comprising a plurality of successive cylinder groups, of which in the former group a single-wire or two-wire outlet is used and in the latter group a two-wire outlet is used.

10

The multi-cylinder dryer of a paper machine is known to comprise two overlapping rows of drying cylinders over which the web is guided on its knees. The multi-cylinder dryer uses various groups, such as wire groups and drive groups, in which in the latter the rotational force of the cylinders is applied to all the cylinders belonging to the group on the same drive shaft via a gear transmission.

It is known that multi-cylinder dryers use the so-called a two-wire export in which the paper web has free gaps as it moves from one cylinder-2q blade row to another. In addition, in the initial part of the multi-cylinder dryer, the so-called a single wire outlet, wherein the drying wire is arranged to support the web also as it moves from one cylinder row to another. In this case, in the second row of cylinders, the drying cylinders remain inside the loop of the drying wire and in the second row outside the loop.

25

The export of the paper web in the group spacing of the multi-cylinder dryer has become problematic when using previously known arrangements. If free web export is applied between groups, it causes flutter in the web and a consequent risk of web breakage and deterioration.

In addition, it has previously been necessary to use a fairly large speed difference between groups, which adversely stretches the web.

2g. The above-mentioned web export problems in the group slots of a multi-cylinder dryer have been known to be solved by various means, such as by overlapping the wire guide rollers, with the aim of closing the free export of the web in the group slots. In addition, various blow boxes have been used. However, these solutions have not been able to avoid all problems. An additional drawback has been the difficulty of exporting the head of the web.

5

One previously known solution is presented in FI patent application 871493. In this previously known solution, the web is led from one group to another by means of a special group intermediate cylinder. However, such a group spacer cylinder is large in size and has no heating effect, so that passing the web through the group spacer cylinder does not promote drying of the web. In addition, when such a large-diameter group-intermediate cylinder is used, the group spacing becomes narrow.

The object of the invention is to provide such a group intermediate export that there are no previously common problems in the export of the web.

It is a further object of the invention to provide such an intermediate connection so that a narrow space with several rollers does not form between the cylinders and which makes it difficult to remove the wreck.

20

It is a particular object of the invention to provide such an inter-group export that large diameter inter-group cylinders are not required between the cylinders.

It is a further object of the invention to provide such an inter-group export that there are no previously common problems with the web head export.

In order to achieve the above objects and the advantages which will become apparent later, the invention is mainly characterized in that in the group 30 is driven onto the wire of the next drying group 35, that the paper web is held in the transfer wire / receiving wire by means of a suction box / blow box during export, and that a small diameter piece roll is attached to the end of the suction box / blow box and supported and bearing using said suction box / blow box as a support frame, the suction / blow zone starting as close as possible to the receiving cylinder / delivery s upper surface.

5

In addition, other advantageous features of the invention are set out in claims 2-9.

In principle, the group intermediate export according to the invention can also be performed in such a way that, in group spaces, the export of the paper web from one drying group to another takes place between the cylinders in a tangential plane outside the lower cylinders. However, this makes it difficult to remove the wreck, so the export in the tangential plane between the upper cylinders described above is the most advantageous solution.

15

When using a group intermediate according to the invention, it is possible to remove the first drying cylinder of each group, e.g. a UNO-VAC roll or a UNO-ROLL roll, depending on where the paper machine is used. In this way, a saving of about 5-6 drying cycles-20 blades / roll is achieved with a conventional machine.

Another advantage of the group spacing according to the invention is that web end-export ropes are not required, but the group spacing is run without head-export ropes.

25

When using the group spacer according to the invention, the group spacers also become open, whereby an advantage is achieved in interruption situations and wreck removal.

Another advantage of the group intermediate export according to the invention is that the web can be retrieved very close to the last roll of the previous group, whereby no long free space is formed. In this case, it is an almost closed export, which eliminates the problems caused by flutter.

The group intermediate export according to the invention is applicable to both single and double wire areas and also to the exports between them.

In addition, by using the piece roll according to the invention in the group intermediate export of the paper web, the deflections of the rolls can be better controlled.

In the following, the invention will be described in more detail with reference to some application examples of the invention shown in the figures of the accompanying drawing, to the details of which the invention is in no way narrowly limited.

Figure A schematically shows a previously known solution for the drying section of a paper-10 machine.

Figure 1 shows a solution according to the invention as a drying section of a paper machine.

Fig. 2 schematically shows a group intermediate export according to the invention, feeding a paper web, provided with a suction box.

Figure 3 schematically shows a group intermediate export according to the invention, searching for a paper web, provided with a suction box.

20

Figure 4 shows a piece roll according to the invention.

Figure 5 shows a group intermediate export according to the invention, fed to a paper web, equipped with a blow box.

25

According to Fig. 1, by using the group intermediate outlet 1 according to the invention in the drying section of the paper machine, a considerable overall length saving is achieved compared to the previously known solution A shown in Fig. A. In the solution 1 according to the invention, one cylinder 30 is removed from each group R, whereby the total length Lj formed by the groups R according to the invention is shorter than that of the groups according to the previously known solution.

The total length L formed by R. However, the achievable wire coverage is A A

at least exceed the good as in the previously known solution. In the solution according to the invention, the saving in the drying section of the paper machine is about 5-6 35 cylinders.

II

5 81402 ^ In Fig. 2, the group spacing is illustrated by the line RV. The group spacing RV is formed between the groups and. From the previous group R 1, the upper cylinders 10 and 12 and the lower cylinder 11 are shown. In the group R 1, a single-wire output is used. The wire is indicated in the figure by reference numeral 13.

In the group R 1, the web W passes from above the upper cylinder 10 below the lower cylinder 11 and further to the upper cylinder 12. The paper web W is supported by the wire 13, the upper cylinders 10 and 12 by the wire 13 and the cylinder 10, respectively. 12, between and on the lower cylinder 11 outside the wire 13 and the cylinder il.

10 In the latter group R 2, a two-wire export is used. The upper wire is indicated by reference numeral 35 and the lower wire by reference numeral 34. The group R 1 shows upper cylinders 31 and 33 and lower cylinder 32. In addition, the guide roller 36 and transfer apparatus 37 of the upper wire 35 are shown. 35 and the upper cylinder 31, moving further between the lower wire 34 and the lower cylinder 32 and further between the upper wire 35 and the upper cylinder 33. In the two-wire outlet, the wire transfer apparatus 37,38 comprises a suction box 60, in which the air flows are directed into the suction box 60 through holes made in the side walls 20 of the suction box 60 according to the arrows shown in the figure. Attached to the suction box 60 are wire guide rollers 61. Each transfer apparatus 37,38 includes two wire guide rollers 61 formed of a piece roll type structure in a manner similar to the piece roll 25 used in group intermediate export, which will be described in more detail later.

25

According to the invention, in the group gap RV, the export of the paper web W from the drying group R 1 to the second R 1 takes place from the last cylinder 12 of the previous group R 1 to the first cylinder 31 of the next group R 1 in the outer tangential plane between the cylinders 12,31. Most preferably, the export of the pape-30 path W in the group spacing RV takes place between the upper cylinders 12 and 31 in the tangential plane outside the upper cylinders 12,31. The paper web W from the group Rj is driven onto the wire 35 of the next drying group. The paper web W is held in the donating wire 13 during export by means of a suction box 20. Attached to the end of the suction box 20 is a slit roll 25 instead of a small diameter 35 so that the suction zone continues as close as possible to the surface of the receiving cylinder 31, whereby the free portion of the paper web W, i.e. the portion of the paper web W not supported by the wire 6 81402, is as short as possible. The airflows produced by the suction box 20, indicated by arrows S in the figure, support the paper web supported on the wire during group insertion. The free part Wq of the paper web W is only about 50 mm. A vacuum is applied in the suction box 20 and the suction openings 5 are placed on the side of the suction box 20 according to the arrows S, whereby a suction surface is formed on the side of the suction box which is planar and located in the outer tangential plane between the upper cylinders 12,13. The suction surface provides support for the wire 13 and the paper web W.

Fig. 3 shows another application example of a group intermediate export according to the invention, in which in the group space RV the change of the paper web W from the drying group Rj to another takes place between the upper cylinders 12 and 31 in a horizontal plane. The paper web W from the group R 1 is driven onto the wire 35 of the next drying group. The paper web W is held on the new wire 35 by means of a suction box 20 during the exchange. Attached to the end of the suction box 20 is a small diameter piece roll 25 to make the suction zone start as close as possible to the surface of the delivery cylinder 12.

In the application example 20 of the piece roll 25 according to the invention according to Fig. 4, the piece roll 25 consists of two sub-rolls 25 and 25. At one end, the part roll 25 is supported on the flange 40 by means of a shaft 41 and its bearings 42. By means of the flange 40, the piece roll is supported on a suction box 20 (Figures 2 and 3). Correspondingly, the second sub-roll 25 ^ of the piece roll 25 is supported at one end by means of a shaft 44 and its bearings 45 on a flange 43, which is respectively supported on a suction box 20. The sub-rolls 25 ^ and 252 are connected to each other via a shaft 47. The shaft 47 is mounted 48 on a flange 46. The flange 46 is supported on a suction box 20 (Figures 2 and 3). A small gap 49 is formed between the sub-rollers 251 and 252. However, the wire is sufficiently rigid, 30 so that the spacing of the piece roll 49 leaves no marking on the wire.

The section roll 25 according to the invention has at least two section rolls 25, 252, it is also possible to use section rolls consisting of several roller-like parts. Preferably, the piece roll 25 comprises 3-5 part rolls.

The ratio of the diameter D of the sub-roll 25, 252 of the section roll 25 to the diameter of the drying cylinder is in the range 0.2 to 0.7, preferably in the range 0.18 to 0.10.

35 7 81402 ^ The diameter D of the part roll 25 ^, 252 is 150-300 mm, preferably 200-270 mm. Such a small-diameter roll can be taken to a more difficult place than the group intermediate cylinders of the previously known solutions, which have been even more than 700 mm in diameter. In addition, such a small-diameter 5-piece roll is cheaper in manufacturing cost.

The rigidity of the piece roll 25 is provided by attachment to the body of the suction box 20 via flanges 40, 43, 46.

10 Figure 5 is shown in Figure 2, corresponding to the embodiment of the invention group in the export, in which instead of the suction box 20 (Figure 2), a blow box 50, in which the air flows directed according to the arrow P, the overpressure generated 31 from which nip a piece of the roll 55 and the drying cylinder is removed. Such a blow plate 15, in which the blows provide a vacuum carrying the paper web W, is disclosed, for example, in F1 patent publication 67 107.

In the two-wire export of the latter group, the closed export of the wires takes place by means of the wire transfer devices 70. The wire transfer apparatus 70 20 comprises a blow box 72 in which air flows Pj are provided through the blow openings. The blow box 72 is also supported by piece-roll type wire guide rollers 71.

The following claims set forth within the scope of the inventive idea as defined by the various details of the invention.

30 35

Claims (10)

A multi-cylinder dryer comprising several consecutive cylinder groups, of which cylinder groups (R 2, R 2) are used in the preceding group 5 (R 2) using single wire pull (13) or double wire pull (34,35) and in the latter group (R2) uses double wire pull (34,35), in which wire pull (13; 34,35) the wires Mr are arranged to control the paper web (W) to be dried via drying cylinders and which wires are controlled by articulated rolls, can be drawn therefrom; that between the (RV) Ί0 groups, the paper web (W) is pulled from one drying group (Rj) to another (R2) between the last cylinder (12) of the preceding (Rj) and the first cylinder (31) of the latter group (R2) in a tangential plane outside the cylinders (12, 31), most preferably in an outer tangential plane between the upper cylinders in such a way that the paper web (W) coming from the previous group (R the wire (35) of the following drying group (R2), that the paper web (W) during the drawing is pcs at the transferring wire (13) / receiving wire (35) by means of a suction drawer (20) / blower (50), and attaching a truncated roller (25) to the end of the suction drawer (20) / blowing drawer (50) having a small diameter supported and stored by using said suction (20) / blower (50) as the support body, the suction / blowing zone beginning to say near the surface of the receiving cylinder (31) / transferring cylinder ( 12) as possible. 1 Patent claim Manganese cylinder dryer according to claim 1, characterized in that the small diameter truncated roller (25) which is pushed against the end of the suction drum (20) / blowing drum (50) and which is used in the draw between the groups of the manganese dryer consists of at least two partial rollers (25). ^, 252) »most preferably 3-5 part rolls. 30 Manganese cylinder dryer according to claim 1 or 2, characterized in that the small diameter truncated roller (25) used in the draw between the groups of the manganese dryer is supported by and stored by at least three flanges (40,43,46). by mediating bearings (42,45,48) to the body of the suction drawer (20) / blower drawer (50). 11 81402 1 4. A multi-cylinder dryer according to claims 1 to 3, characterized in that the small diameter truncated roller (25) used in the draw between the groups of the multi-cylinder dryer consists of partial rollers (25 25, 252) which are connected to each other by the mediation of an axis ( 47) and a bearing (48), leaving a small gap (49) between the sub rolls (25 ^, 252) to allow bends of the roll (25). 5. A multi-cylinder dryer according to any one of claims 1-4, characterized in that the ratio between the diameter (D) of the truncated roll (25) used in the double winding of the manganese dryer and the drying cylinders (10, 11, 12, 13, 14). 15.16) diameter is in the range of 0.2 ... 0.07, most preferably 0.18 ... 0.10. 6. A multi-cylinder dryer according to any one of claims 1 to 5, characterized in that the diameter (D) of the truncated roll (25) used in the double winding of the manganese dryer is 150-300 mm, most preferably 200-270 mm. 7. A multi-cylinder dryer according to any one of claims 1-6, characterized in that a flat suction surface is formed in the outer tangential plane of the last cylinder (12) of the preceding cylinder with the suction vane (20) used in the draw between the groups of the multi-cylinder dryer. the group (R 2) and the first cylinder (31) of the latter group (R 2) 8. A multi-cylinder dryer according to any one of claims 1-7, characterized in that a flat suction surface is formed in the outer tangential plane between the last cylinder (12) of the preceding group with the blowing carriage (50) used in the draw between the groups of the multi-cylinder dryer. (R 2) and the first cylinder (31) of the latter group 30 (R 2). 9. A multi-cylinder dryer according to any one of claims 1-8, characterized in that in the drying group (R2) of the multi-cylinder dryer using double wire pull, a closed draw is made between the wire (34) and the wire (35) using transfer means (37, 38) which comprise a suction sleeve (60) and / or a blowing sleeve (70) and wire guide rollers (61; 71) of the truncated type.