FI123681B - Arrangement in the drying portion of a fiber web machine and method for improving the drivability of the dryer portion of a fiber web machine - Google Patents

Description

CONVENTION WITH THE DRYING PART OF THE FIBER MACHINE AND A METHOD FOR IMPROVING THE RUNNING OF THE DRYING PART OF THE FIBER MACHINE

The invention relates to an arrangement on a dryer section 5 of a fiber web machine comprising a press section comprising at least one press nip and a subsequent drying section, wherein the dryer section is adapted to pass through a plurality of successive drying cylinders. from the upper half of the solids-temperature adhesion curve. Furthermore, the invention also relates to a method for improving the runnability of the drying section of a fiber web machine.

Known in the art are fiber web machines with a drying section based solely on multicylinder drying technology. Such a drying section consists exclusively of successive drying groups. They each have two rows of hot drying cylinders and unheated rotating rollers arranged alternately and in which the web is introduced into the drying tissue as a supported slalom export from one row to the other.

Increasing the speeds of fiber web machines cause serious runnability problems, for example in the drying section and especially in the initial section. Machine speeds are already reaching 2000 m / min 25 and development work continues to achieve ever higher speeds. At the beginning of the drying section, large adhesive forces are formed between the wet web and the drying cylinder. The web would rather stick to the hot drying cylinder than to continue its desired course with the fabric supported. Also? The opening opening formed by the ir drying fabric which separates from the drying cylinder causes an under pressure pressure ridge in connection with the drying cylinder. Increasing the speed of the machine merely enhances the vacuum peak caused by the opening rt [35] and thus facilitates the adhesion of the web r-o to the drying cylinder.

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Attempts have been made to solve the above problem with runner components 2 fitted to the pocket formed by the drying fabric and the pivot roll, such as vacuum box devices. They use a high level of vacuum to transfer and secure the web to the drying fabric. However, the operating limits of vacuum devices, such as economically manageable vacuum levels, limit their use as speeds increase.

An attempt has been made to solve the runnability problem discussed above with a multi-cylinder drying section in which drying cylinders which are substantially hotter than the rest of the drying section are used at the beginning of the drying section 10, i.e. immediately after the pressing section. Such is disclosed in Applicant FI Patent Application No. 20041697 (PCT Publication No. WO 2006/070063 A1). However, this solution does not shorten the length of the drying section, but still remains a rather long and thus cost intensive entity. In addition, the initial drying performed on the "super hot" drying cylinders fitted at the beginning of the drying section does not yield the desired drying effect, since these drying cylinders are in any case followed by a multi-cylinder dryer at normal temperature levels known per se.

In addition, reference is made to FI 20041697 A, DE 19958867 A1, FI 20045148 A and FI 103999 B as prior art.

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T-It is an object of the present invention to provide an arrangement for the drying section of a fiber web machine, by which the machine runnability? with respect to the state of the art and with the result that drying 0 is also more efficient. Characteristic features of the arrangement according to the invention are set forth in claim 1. The invention also relates to a method for improving the runnability of the drying section of a fiber web machine S, the characteristic features of which are set out in claim 8.

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In the arrangement according to the invention, immediately after at least one drying cylinder following the press section, the temperature of the 3 drying cylinders being adapted to be selected from the upper half of the dry-temperature adhesion curve of the web, is fitted with an blow-drying unit. The concept improves the runnability of the drying section and shortens the size, such as the length of the dry section, in the machine direction. In addition, the drying efficiency of the drying section is improved.

According to one embodiment, at least one drying cylinder adapted to be selected from the upper half of the dry solids -10 temperature adherence curve of the web is immediately at the beginning of the cylinder drying, followed by a blow-drying. In addition, after the at least one drying cylinder, the on-blow drying unit may have one, two or three drying cylinders, the temperature of which is also adapted to be selected from the upper half of the dry solids-temperature adhesion curve of the web. According to one embodiment, there may be even several successive drying cylinders before and / or after the blow-up, the temperature of which is adapted to be substantially higher than the other drying cylinders of the subsequent drying section 20. For example, there may be two to five such drying cylinders. The blowing unit, which can blow directly into the web, can be, for example, vertical or realized with a high vacuum roller.

At least one drying cylinder prior to the blow-drying unit having a drying cylinder temperature adapted to lie above the dry solids-temperature adhesion curve? tilt, enables efficient overflow at an already surprisingly early stage of the drying section. The drying cylinder-impingement

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With the £ 30 hallus, the adhesion of the web to the drying cylinders is minimized and thus the machine runnability is substantially improved. With the invention, higher temperatures can also be used in the blow-drying itself itself right from the beginning of the drying section.

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In addition to the problems associated with the runnability of a fiber web machine, the concept of the invention increases the drying capacity of the machine, shortens the machine direction of the dryer section, increases the production of the fiber web machine, and reduces the machine manufacturing and operating costs. The approach of the invention is applicable both to new machines and to machine operations. Other additional advantages achieved by the invention will be apparent from the description and the features of the appended claims.

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The invention, which is not limited to the following embodiments, will be further described with reference to the accompanying drawings, in which Figure 1 shows a first embodiment, seen from the beginning of the dryer section,

Figure 2 shows an embodiment of Figure 1 at the beginning of the dryer section, Figure 3 shows another embodiment seen from the beginning of the dryer section, Figure 4 shows a rough example of a dry solids-temperature adhesion curve and

Figure 5 shows simulation results of the arrangement of Figure 1.

Figures 1-3 show some examples as schematic drawings

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viewed from the side ^ of the drying ends 10 of the dryer parts of the fiber web machine. Is the arrangement according to the invention suitable for such new ones? machines as well as rebuilding old machines. The web W of material passing through the drying section 10 is dried in the drying section

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£ 30 Sat 10 by evaporating moisture from it. Typically, the drying section 10 is preceded by a press section (reference numerals 23 in Figs. 2 and 3) in which moisture is removed from the web W by squeezing it at least r ».

o in one press nip P.

From the press section 23, the web W is introduced into the drying section 10 with the aid of a pick-up roll 50 and a vacuum box 46. With the drying section 10 following the press section 23 5, drying continues by evaporating moisture from the web W with heat energy applied to the web W. The drying section 10 may be followed, for example, by a roller or after-treatment device (not shown). An example of such a post-treatment device is a coating device such as a Sizer and subsequent post-drying section. 1-3 of the corresponding functional units have the same reference numerals.

As shown in Figures 1-3, the dryer section 10 contacts the web W with a plurality of drying cylinders, 30.1-30.3, 31, 32.1-32.3, 33.1-33.3, 34. The cylinders 30.1 to 30.3, 31, 32.1 to 32.3, 33.1 to 33.3, 34 alternate with the rotating rollers 15, 15 ', 36. The temperature of the at least one drying cylinder 30.1 to 30.3, 32.1 to 32.3, 33.1 to 33.3 in the first half of the drying section 10 is adapted to be selected from the upper half 40 of the dry solids-temperature adhesion curve W of web 40. This graph is well known to those skilled in the art. It is to be understood that in reality the curve in question may be very nonlinear or even substantially different from the curve shown in Figure 4.

The graph 38 shown in Figure 4 shows that at a 25 W dry content of paper web (horizontal axis of the coordinate system) and at what temperature of the cylinder (vertical axis of the coordinate system)?

The paper web W tends to stick to the drying cylinder.

The area 39 bounded by the vertical coordinate axis o to the left of graph 38 shows combinations of drying temperatures x x 30 of the cylinder surface and dry solids content of the web W which causes the web W to adhere to the surface of the drying cylinder o ιλ. The areas 40 and 44 o to the right of the graph 38 show combinations of dryer cylinder surface temperatures and dry solids content of web W that do not cause web W to adhere to the drying cylinder.

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For example, region 40 may be referred to as the upper half of the dry solids-temperature adhesion curve W of web 38 and lower half of the dry solids-temperature adhesion curve W of web 44 respectively. Although the dotted boundary line 38 is shown here as a sharp and accurate boundary with a slightly curved boundary, in reality, the boundary 38 between the areas 39 and 40, 44 may be quite inaccurate and may exhibit certain irregularities. Such a graph 38 or, more generally, a map, can be formed by one skilled in the art, for example, by experiment and exemplified in the prior art section of WO 2006/070063 Ai. It will be appreciated that the position and also the shape of the curve in the coordinate system may vary both horizontally and vertically between different pulp and / or paper types and / or machines 15, but the basic form of the curves is substantially as shown in Figure 4.

The arrow 41 illustrates an example of forming a drying strategy depression according to the invention on a dryer section 10 of a board machine.

The web W is introduced into the dryer section 10 from the starting point 42, whereby its dry solids content is D1 (for example 45% for that board grade). To prevent the web W from sticking to the drying cylinder, the surface temperature of at least the first drying cylinder 30.1, 25 32.1 of the drying section 10 is maintained at a temperature T4 (e.g. 160 ° C) higher than the temperature T3 ^ (e.g. 155 ° C). If the first drying cylinder 30.1,? 32.1 temperature slightly lower than T3, adhesion of web W to first drying cylinder 30.1, x

£ 30 32.1. After the first drying cylinder 30.1, 32.1, the web W

has dried up a bit. Thus, the surface temperature of the cylinders of the next drying cylinder group LO may be slightly lower than the surface temperature T4 of the first drying cylinder, if so

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desired.

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As the dry matter content of the paper web W rises to the peak solids content D2 (for example 55%) of the gripping area 38, the surface temperatures of the drying cylinders can be reduced if desired. In this case, following the drying cylinders 31, 34, more generally 5 minutes the dryer section 10 of the rest 29 may be a conventional steam heated drying cylinders, the temperature of which follows the 43 basic traveling direction of the arrow, for example, in Figure 4, or the web W, the dry matter - the temperature -tarttumiskäyrän 38 of the lower side-halves below 44 (Tl , T2 can be, for example, 60-80 ° C).

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In the context of the invention, the beginning of the drying section 10 is particularly meant the drying cylinders 30.1 to 30.3, 32.1 to 32.3, 33.1 to 33.3 which are located with respect to the press section 23 substantially before the middle of the drying section 10. More particularly, the first half of the drying section 10 includes 1/4 of the drying cylinders of the first half of the drying section 10 read from the beginning of the drying section 10, and even more particularly from the beginning of the drying section 10 are 1-7 drying cylinders 30.1-30.3.32.1-32.3, 33.1-33.3. at the beginning of.

Figures 1 and 2 show a first embodiment of an arrangement according to the invention. The temperature of the first drying cylinder 30.1 at the beginning of the drying section 10 may be, for example, 140-180 ° C, preferably 150-170 ° C. In other words, the temperature of the first drying cylinder 30.1 can be selected to be a temperature above the curve 38 of FIG. dirty 40. In this embodiment, immediately after the first drying cylinder 30.1, the drying section 10 has directly

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A £ 30 blowing drying unit 12 blowing into the web W which is vertically vertical. Thus, before the unit 12, there is at least one drying cylinder 30.1 which is immediately at the beginning of the cylinder drying section 10 and thus after the pressing section 23 and which is

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The temperature of the one or more drying cylinders 30.2, 30.3 immediately following the blow-drying unit 12, and further, or thereafter, up to the end of the drying section 10, may be lower than the first cylinder 30.1, i.e. they may thus correspond to the normal drying strategy of the drying section 10 5. The temperature of these cylinders 30.2, 30.3, 31 following the blow-drying unit 12 may be at the lower half 44 of the curve 38 shown in Fig. 4, whereby the corresponding vapor pressures may be, for example, 3 -4 bar.

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According to another embodiment, at least two drying cylinders 30.1, 30.2 may be provided at the beginning of the drying section 10, the operating temperature of which is adapted to be selected from the upper half 40 and 15 of the dry solids-temperature adhesion curve W application form. The surface temperature of the drying cylinders 30.1, 30.2 may be, for example, 140-180 ° C, preferably 150-170 ° C. In this case, the vapor temperatures may be, for example, from 140 ° C to 250 ° C and the corresponding vapor pressure of 20 to 10 bar, for example. For example, high pressure steam or oil can be used as a medium in the drying cylinders. In this case, the drying power is higher than normal. Due to the wet web W, the high temperature causes a vapor film between the web W and the cylinder 30.1, 30.2, which in turn reduces

25, and block web W

”From grasping the cylinder 30.1, 30.2, which makes cleaning of the cylinder 30.1, 30.2 easier.

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The embodiment shown in Figs. 1 and 2 may also exhibit an exceptionally high surface temperature v of the drying cylinder 30.1, 30.2. use of the dip on both sides of the blow-drying unit S 12. Now, at least one super-hot drying cylinder 30.2 is I "· - § placed immediately after the vertical unit 12 and

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the surface temperature can be adjusted to be, for example, 160 ° C, more generally 140-180 ° C and preferably 150-170 ° C. At least one drying cylinder 30.2 9 after the vertical unit 12, the temperature of which is also selected from the upper half 40 of the web-dry solids-temperature adhesion curve 38, can ensure that the solids content of the web W rises to a safe level, e.g. preferably more than 60%. 5 The solution provides a solution to current and faster paper machine runnability problems, and can achieve speeds of up to 2500 m / min.

The initial cylinders 30.1 to 30.3 of the drying section 10, which may be up to three as shown in Figure 2, have a surface temperature set at the upper half 40 of the dry solids-temperature adhesion curve 38 of the web and associated with the blowing 12 to solve runnability problems 15 as described above. With the high surface temperatures of one or more drying cylinders at the beginning of the drying section 10, the adhesion of the web W and the forces caused by the opening of the opening following the drying cylinders are reduced. At the same time, the adhesion of the web W to the drying cylinders later in the drying section 10 20 is reduced and the temperature of the web W can be raised to over 100 degrees.

The high temperature W of the web W provided by the one or more cylinders 30.1 provided prior to the blowing 12 further enhances the evaporation in the vertical unit 12 and can

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£ achieves an instantaneous value of more than 200 kg / m2h and thus significantly increases the dry solids content of web W. Despite the use- N-? However, from the evaporation values, the web W is not columned because the formed steam cannot escape from the web W and its vicinity.

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The evaporation provided by the cylinder is typically only 20-40 kg / m2h, the evaporation caused by the blasting can be, for example, 100-120 kg / m2h with normal drying cylinders and the co-evaporation provided by the hot cylinders and the blasting C 120 - 150 35 kg / m2h, preferably up to 200 kg / m2h.

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Images in the embodiment 1 and 2, the vertical impingement-drying unit 12 of the inlet and outlet side reversing roll 15 'of the web W in the running direction in common with the first dryer group of the turning roll 47.1. In addition, the blowing of the vertical blow blast drying unit 12 is arranged to apply on the same side of the web W as the drying effect of the upstream and downstream drying cylinders 30.1 to 30.3. In this case already begun the drying of one side can be continued immediately after the first group of drying cylinders 47.1 hot 30.2, 30.3, ίο wherein the drying of a particularly effective. Further, when the thermal effect of the drying cylinder 30.2, 30.3 and the blowing 12 is applied to one side of the web W, the risk of the web W sticking to the drying cylinders 31 is subsequently reduced.

According to the third embodiment shown in Figure 3, the drying section 10 may have at the beginning of up to a plurality of drying cylinders 32.1 to 32.3, 33.1 prior to vertical blow drying 12 having a surface temperature set from the upper half 40 of the web therefore, 140-180 ° C, preferably 150-170 ° C. In this case there are four such drying cylinders. The first three drying cylinders 32.1 to 32.3 with their turning rolls 15 are in a conventional multicylinder drying arrangement and form the first drying group 48.1. The fourth dryer cy-25 cylinder 33.1 is on the inlet side of the blow-drying unit 12

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1 roll and belongs to the second drying group 48.2.

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1 ^ ·? Since this embodiment is a rebuild of the drying section 10, based on prior art multi-cylinder dry-x 30 ink technology and an initial blow-drying unit 12 fitted thereto, the beginning of the drying section 10 before the blow-m dryer unit 12 is set to dry matter of web W -

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a temperature-35 condition selected from the upper half 40 of the temperature grip curve 38, such as 140-180 ° C, preferably 150-170 ° C. In part, the number of drying cylinders 32.1 to 32.3 prior to the injection 11 blowing unit 12 may also be affected by the mouth 37 of the pulper 36, according to which the multicylinder dryer assembly fits between the three clamping portions 23 and the overflow 12. Here, too, cylinders 32.1 to 32.3, 33.1 having a surface temperature 5 set at the upper half 40 of the dry solids-temperature gripping curve 38 of the web W and blowing 12 can similarly solve runnability problems while increasing the temperature W and the solids content of the web. In addition, in order to increase the evaporation intensity and efficiency of the drying section 10, the web W is further dried by vertical blow drying 12.

In the embodiment shown in Fig. 3, after the blowing 12, there may additionally be at least one, in this case two drying cylinders 33.2, 33.3, whose surface temperature is set at the temperature selected from the upper half 40 of the dry-temperature adherence curve 38, such as 140-180 ° C. 150-170 ° C. Since, after the blowing 12, high temperature drying cylinders 33.2, 33.3 are provided instead of the conventional drying cylinders 20, drying is particularly effective. Now, the web W does not have time to cool at all, as would be the case, for example, if after drying blow 12 there were normal drying cylinders.

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δ c \ j ^ The export of Rain W is arranged in each embodiment? such that the web W is dried by the blow-drying unit o 12, with drying cylinders 30 and 30.3, 32.1 to 32.3, 33.1 to 33.3 on the same side before and after.

cn ιλ The drying section 10 further comprises a blow-drying unit o 12 and optionally the at least one drying cylinder 30.2, 33.2, 33.3 having a surface temperature set at the upper half 40 of the 35 W dry-temperature adhesion curve 38, e.g. 29. The dryer 29 has one or more cylinder drying groups 47.2, 48.3. Each group 47.2, 48.3 has a plurality of drying cylinders 31, 34 and pivot rolls 15 known per se, such as 1 to 15. The cylinders 5 31, 34 and rollers 15 alternate in groups 47.2, 48.3 in a manner known per se. For example, there may be 2 to 10 drying groups.

In the embodiment of Fig. 2, the drying cylinder 30.1, 30.2, 30.3, 10 of which is set to a surface temperature of at least 40 selected from the upper half 40 of the dry-temperature adhesion curve 38 of the web W and the blowing unit 12 with rotating rollers 15, 15 'and the first blowing unit 12. The next drying group 47.2 may be constituted by a drying group known per se, comprising at least the visible drying cylinders 31 and the turning rolls 15. The wire 21.2 passes through the drying cylinders 31.

In the embodiment of Figure 3, the first drying group 48.1 is formed by three drying cylinders 32.1 to 32.3 having a surface temperature set at the upper half 40 of the dry solids-temperature gripping curve 38 of the web W, with rotating rollers 15. Wire 21.1 passes through them. The second drying group 48.2 is formed by the drying cylinder 33.1 with rollers 36, the blow-blast drying unit 12 and subsequent drying cylinders 33.3,

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f-33.3 with rotating rollers 36, 15. Wire 21.2 passes through these, o ^ The following drying group 48.3 may consist of a known drying group r-- 9, comprising at least the visible drying cylinders 34 with rotating rollers 15. Wire 21.3 passes through drying-x £ 30 through cylinders 34 and pivot rolls 15.

S The drying section 10 may terminate on a multi-cylinder unit 12 known per se or on subsequent drying rollers 30.2, 30.3, 33.2, 33.3, at least a part of which is set at a surface temperature of the dry solids-temperature adhering temperature of the web W. directly to the vertical drying unit

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13 selected curve 38 from upper half 40, such as 140-180 ° C, preferably 150-170 ° C. Surprisingly 5, the blow-drying unit 12 and the drying cylinders 30.1 to 30.3, 33.1 to 33.3 on both sides thereof may have a common drying fabric 21.1, 21.2, as in the embodiment of Figures 2 and 3. This simplifies the arrangement of fabrics on the dryer section 10. From the last dryer cylinder (not shown) of the dryer section 10 (not shown), the web W is fed to either the reel or to a pre-treatment device (not shown).

For example, the blow-drying unit 12 may be of a type known per se. The vertical inflatable drying unit 12 may include at least two known infusion devices 13, a plurality of rolls 15 ', 17, 18 known per se and arranged in a straight-line or high-curvature arrangement, and further possible runner devices 49 known per se. The blowing device 12 may be, for example, a gas blowing unit which circulates air in a manner known per se. 20 In Figure 1, the outlet side of the impingement device 13 is shown pulled apart the web W..

Alternatively, the small rollers 18 shown in Figures 1 and 2 may be replaced by a single large diameter suction roll 35 of Figure 3 being a VAC roll type vacuum roller with a surface

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^ the blowing units 13 follow. The export of the paper web W is supported on the rollers 18, 35 through the wire 21.1, 21.2, whereby at least one blow surface or plane is formed. With respect to wire 21.1, 21.2, on the opposite side of the export there is

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£ 30 device 13, thus acting directly on the r - web W traveling on export.

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1 · "· § To the vertical blow-drying unit shown in Figure 1

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12 includes at least one auxiliary pivot-rolls 15 ', 17 fitted at both ends and support rolls 18 between them. Support rolls 18, which may be deep-grooved non-pressurized rolls, may have 14-16 on each side, as in the case of Figures 1 and 2. . The support rolls 18 and the auxiliary pivoting rollers 15 ', 17 may be non-doctored and of small diameter, such as 400 mm to 1000 mm. In this case, their rotation is 5 light. In the embodiment of Figures 1 and 2, the auxiliary turning rolls 15 ', 17 are, for example, VAC rolls. Vacuum boxes 45 in the pockets can be vacuum-pressed or provide vacuum in the space they delimit by means of fabric 21.2 and deep-grooved rollers 18.

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Figure 5 shows simulation results of the drying concept of the invention at the beginning of the drying section. The arrangement corresponds to the embodiment of Figure 1. 5 is a graphical representation of the situation in the machine direction corresponding to the concept diagram above.

15 The vertical axis corresponds to the dry matter content, temperatures and evaporation. The horizontal axis corresponds to the simulation time, which is basically proportional to the machine-directed distance. The curves in Figure 5 depict evaporation, temperatures, and solids. As can be seen from the graph, the drying cylinders 30.1, 30.2 20 have temperatures above 100 ° C, evaporation above 150 kg / m2h, instantaneous evaporation unit 12 instantaneous evaporation above 200 kg / m2h and web W temperature of about 75 ° C. Even the average evaporation becomes quite high. High evaporation in the blasting reduces the heat of the web, whereupon the hot cylinders 25 can then again effectively increase the temperature of the web W,

g In addition, the increased solids content contributes to the reduction of web W

c \ j ^ the risk of contagion. In the coordinate system of Fig. 5, the evaporation intervals of the cylinders 30.1, 30.2 and of the blow-blanket covers 13 o are denoted by the abbreviation o fd. It can be seen from the graph that the first x 30 interval has a greater evaporation than the subsequent free evaporation intervals after the blowing 13.

σ> m o The arrangement according to the invention, irrespective of the dry content of the web W, avoids the tendency of the web W to adhere, minimizes the adhesion and forces exerted by the opening rod and improves runnability. With the invention, the runnability of the paper machine, which is no longer dependent on the wet end or the press section, can be better controlled, thus minimizing fluttering and bonding problems. Due to the reduced adhesion and the forces exerted by the opening rod, the dryer section 10 is also capable of operating at lower power pocket space runners 49 also at the beginning of the dryer section 10.

It is to be understood that the foregoing description and the accompanying drawings are intended only to illustrate the present invention. Thus, the invention is not limited to the embodiments set forth above or as defined in the claims, but many variations and modifications of the invention which are possible within the scope of the inventive concept defined in the appended claims will be apparent to those skilled in the art.

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Claims (9)

An arrangement with a drying section of a fiber web machine, the fiber web machine comprising 5 press sections (23) having at least one press nip (P) and a subsequent drying section (10), wherein the web (W) is arranged to be inserted into a plurality of steam heated drying cylinders , 31, 32.1 to 32.3, 33.1 to 33.3, 34), of which the temperature of at least one steam heated drying cylinder (30.1, 32.1 to 32.3, 33.1) fitted at the top of the drying section (10) is adapted to be selected from the material-temperature-gripping curve (38) from the upper half (40), characterized in that: - immediately after said drying cylinder (30.1, 32.1 - 32.3, 33.1) is fitted a blow-drying unit (12), - immediately after the blow-drying unit (12) at least one steam-heated drying cylinder (30.2, 33.2) having a temperature adapted to be selected from the dry solids-temperature adhesion of the web (W); from the upper half (40) of the curve 20 (38), - the blow-drying unit (12) and said steam-heated drying cylinders (30.1, 30.2, 32.1 to 32.3, 33.1, 33.2) being arranged to belong to the same drying group (47.1, 48.2). 25 CO An arrangement according to claim 1, characterized in that the drying cylinder (30.1, 32.1 to 32.3, 33.1), the temperature of which is adapted to be selected from the upper half (38) of the dry-temperature-adherence curve (38). 40), immediately after the press section x £ 30 (23), and the blow-drying unit (12) is arranged to blow directly into the web (W). o m o Arrangement according to Claim 1 or 2, characterized in that the temperature of the at least one drying cylinder (30.2, 33.2) fitted immediately after the blow-drying unit (12) 35 is between 140 and 180 ° C. Arrangement according to one of Claims 1 to 3, characterized in that a number of drying cylinders (30.1, 32.1 to 32.3, 33.1) having a temperature of 140 to 180 ° C are arranged in front of the blow drying unit (12). 5 Arrangement according to one of Claims 1 to 4, characterized in that the temperature of the drying cylinders (30.1, 30.2, 32.1 to 32.3, 33.1 to 33.3) is preferably 150 to 170 ° C. Drying section according to one of Claims 1 to 5, characterized in that the spray drying unit (12) and said drying cylinders (30.1 to 30.3, 32.1 to 32.3) are arranged to form a drying group (47.1, 48.2). Drying section according to one of Claims 1 to 6, characterized in that the blow-drying unit (12) is arranged on the drying section (10) such that the turning roll of the multi-cylinder dryer (29) is arranged as the top turning roll (15 ') of the blow drying unit (12). A method for improving runnability in a dryer section of a fiber web machine, the fiber web machine comprising a press section (23) comprising at least one press nip (P), wherein moisture is removed from the web (W) and with a plurality of steam heated drying cylinders (30.1 to 30.3, 31, 32.1 to 32.3, 33.1 to 33.3, 34) and wherein the drying section (10)? initially, the temperature of the at least one steam-heated drying cylinder (30.1, no. 32.1 to 32.3, 33.1) is selected from the upper half (40) of the dry (X) 30 adhesion curve (38) of the web (W), characterized in that (30.1, 32.1 to 32.3, 33.1), the web (W) is dried by an air blast (12), 35. immediately after the air blast drying unit (12), the web (W) is dried by at least one steam heated drying cylinder (30.2, 33.2) from the upper half (40) of the dry-temperature adhesion curve (38) of the web (W), and wherein the blow-drying unit (12) and said non-steam drying cylinders (30.1, 30.2, 32.1 to 32.3, 33.1, 33.2) belong to the same drying group ( 47.1, 48.2). Method according to Claim 8, characterized in that the drying cylinder (30.1, 32.1 to 32.3, 33.1), the temperature of which is selected from the upper half (40) of the dry-temperature adhesion curve (38) of the web (W), is immediately After (23) and the blow drying unit (12) is blown directly into the web (W). co δ CvJ i ^. cp o X X Q. 1 ^^ · σ> LO o o CVJ