FI117402B - Method and arrangement for cooling the fibrous web - Google Patents

Description

117402

Method and arrangement for cooling the fibrous web

The invention relates, for example, to a method for cooling a fibrous web according to the preamble of claim 1.

The invention also relates to an arrangement according to the preamble of claim 8 for cooling the fibrous web.

For calendering of a paper web, prior to winding the web of fiber onto the machine reel, the final moisture of the web should be about 5%. In addition, in terms of rollability, the temperature of the fibrous web should be below 50 ° C. Excessively high winding temperature and low humidity cause winding problems that appear as irregularities in the tension profile of the machine roll in the width direction (CD direction, machine direction) and longitudinal direction (MD direction, machine direction) of the fibrous web. An uneven / poor tension profile of a rolled machine roll causes, among other things, folding of the web taken from the machine roll, web instability, web breaks, uneven edges, etc.

High caliper temperatures are often used in calendering to achieve the desired paper quality. Particularly in multi-roll calendars, the fiber web dries easily below the 5% moisture level ideal for machine winding due to the high temperature of the thermo rolls and the open track inlets between the roll nipples.

• *

The temperature of the fibrous web leaving the multi-roll calender is often 80-90 ° C after the last 20 roll rolls of the calendar, which is significantly higher than winding v: would be desirable (below 50 ° C). Therefore, the fiber web must be cooled before it is rolled into a machine roll. It is known that the paper web can be cooled by cooling cylinders. However, the cooling capacity of the cooling cylinders is relatively low, which is why more cooling cylinders are generally used, which necessitates long journeys of fibrous webs in open exports. In an experiment conducted at different web speeds, it was found that the fiber web dries about 1-1.5 percentage points in free web exports after the last calendering nip before entering the rewind station. Due to the drying of the fibrous web, it has been necessary to increase the calendering moisture, especially in multi-roll calenders. However, high calendering humidity 30 causes so-called calendering black.

*

An attempt has been made to prevent drying of the fibrous web leaving the calendar in the prior art DE 102 17 910 and in the arrangement used therein by adding steam to the surface of the fibrous web before and during cooling. The surface of the fibrous web is cooled in the process by cooling cylinders. Li-2 117402 is used to export the fibrous web. in a method known in the art, partially supported by wires between cooling cylinders, which aims to reduce evaporation of water vapor from the surface of the fibrous web. However, such cooling of the fibrous web is relatively ineffective due to the fact that the contact 5 between the fibrous web and the surface of the cooling cylinder is relatively weak even if the web is tightened, for example, by a support wire against the cooling surface. Further, in the arrangement shown, the fibrous web has to be wetted due to the fact that the fibrous web is still drying too much.

The present invention is intended to eliminate the problems encountered in the prior art. Accordingly, it is a first object of the invention to provide a cooling 10 method and a cooling arrangement used therein that are capable of effectively preventing the drying of the fibrous web between the calendering unit and the winding station. Another object of the invention is to provide a cooling method and an arrangement used therein to efficiently cool the fibrous web to the desired final moisture.

The above objects are achieved, for example, by the method of claim 1 and, for example, by the arrangement of claim 8.

The invention is based on preventing the evaporation of moisture from the surface of the fibrous web by one or more preferably two vapor-tight supporting surfaces and simultaneously creating an adequate compression pressure between the fibrous web and the supporting surface which in turn contributes to preventing evaporation of water vapor from the fibrous surface. Compressive pressure is provided between the cooling apparatus and the fiber web, which improves the heat transfer between the hard surface and the fibrous web by conducting ♦ by increasing the heat transfer surface at their interface. The fibrous web is cooled either by a conventional cooling cylinder cylinder or by using as a cooling apparatus both fiber * y /. 25 as a support surface of the web, a heat-conductive material that is cooled by an external *****.

In the method of cooling the fibrous web according to the invention, in the contact region K between the fibrous web and: ***: the fibrous web being supported on at least one of the supporting surfaces in said contact area, the fibrous web is cooled by: . In the method, at least one support surface and a fiber web surface and at least one cooling surface, and: T: the fiber web surface is arranged in mutual contact with at least a portion of the contact area by compressing the support surface (s) and fiber web and cooling fiber and web against one another; that the vaporization temperature of the water 35 in the fibrous web increases and that the effective contact area between the fibrous web and the surface 3 117402 intended for cooling thereof is sufficient for cooling power.

Here, the contact area is defined as the interface between the surface of the fibrous web and the surface cooling the fibrous web, where heat can be transferred from one surface to another.

The advantage of such a method over, for example, the previously mentioned method known from DE-10217910 is that a sufficiently large effective contact area is formed between the fibrous web and the hard cooling surface of the cooling medium, which has a sufficient heat transfer surface and good cooling efficiency. Preferably, the support surface and the fibrous web are pressed towards each other with a force such that the compression pressure (P) between them is at least 0.1 MPa to 15 MPa, preferably 0.5 MPa to 15 MPa. The compression pressure (P) is preferably further dimensioned such that the effective contact area between the fibrous web and the surface intended to cool it is at least 15% of the total contact area therebetween.

The arrangement according to the invention, in turn, comprises a pressing apparatus whereby at least one support surface and the fibrous web and the fibrous web and the surface of the cooling means can be arranged in such mutual contact in at least a part of the contact area that a cooling surface and a fibrous web can be provided between the supporting the compression pressure by which the water vaporization temperature of the fiber web (W) rises and the effective contact surface area of the fibrous web: * "· nan (W) with the surface of the cooling medium for cooling it is sufficient for cooling efficiency.

· # *

Sufficient compression pressure (P) is preferably achieved by a compression apparatus consisting of two roll means between which a compression nip can be formed.

In a preferred embodiment of the invention, the fibrous web is provided on both sides with the support surfaces in the contact area and cooling of the fibrous web is accomplished by cooling each support surface with the same or different cooling power. In this way, the fiber web is provided with cooling as well as a supported outlet between the sealed surfaces, whereby no moisture is evaporated from the fiber web and a contact surface between the fiber web and the cooled support surface is formed.

v: In another preferred embodiment of the invention, the fibrous web cooling support surface is cooled by spraying a fluid or gas onto the support surface. The support surface is preferably a liquid impervious, flexible, inelastic, heat-conducting endless belt such as a metal belt. When the support surface is highly conductive and not permeable to water vapor, the advantage is obtained that the passage of steam through it is effectively prevented and at the same time the support surfaces can be cooled from one side by a suitable cooler. If desired, the support surfaces located on different sides of the fibrous web can also be cooled by radiators of different cooling power. 5 Other advantages of the invention include:

The calendering process can be better dimensioned from the point of view of the nip process without having to worry about the drying effect of the post-calming cooling process on the quality of the web being wound. The fiber web does not evaporate water during the cooling process, so lower si-10 weathering moisture of the fiber web can be used for calendering, which, among other things, avoids calendering blackening. The advantage is noted, for example, with smooth printing papers (SC), which are finished with multi-roll calendars. Post-roughening may also decrease. In calendering, the temperature of the thermo rolls can be lowered, since no energy is spent on heating and evaporating the excess water. Supported export of web from calendering to the reel 15 step improves / ensures runnability. By using this method, the energy balance of the cooling process and calendering is improved, since energy is not wasted and it does not burden the ventilation of the factory hall.

Other advantages and features of the invention will be apparent from the following detailed description of the invention, and from the dependent claims.

·· «• · · · ·

The invention will now be described in more detail with reference to the accompanying drawings.

• ·· • *

• I

*: * Figure 1 shows the arrangement according to the invention directly in the cooling arrangement * * * *. * · *. viewed at the other end when the arrangement is applied to cooling the paper web after the multi-roll calender.

Fig. 2 shows an alternative embodiment of the cooling system according to the invention, also looking directly at the other end of the arrangement.

• * ♦

Figure 3 shows in more detail a portion of the contact area K in the cooling arrangement of Figure 1.

* ·· • · · V l 30 The following is a first overview of the structures and functions shown in Figures 1-3 * * * * ·.

5, 117402

Fig. 1 shows a cooling arrangement 1 according to the invention immediately adjacent to the last roll nip of the multi-roll calender 7; Nt after, but before the roller machine 3, which rolls the paper web W into machine rolls. The cooling arrangement 1 comprises two cooling means 4; 4a and 4; 4b for cooling the lower and upper surfaces of the fibrous web W in the contact region K. The cooling means 4 comprise a metal belt for rotations 2; 22, 21 metal belts M supporting the fibrous web; M1, M2, and the respective surface of each belt are cooled by respective fluld coolers 41b and 41a. The outer surface of the strap M is that side of the strap which has turned away from the fibrous web supported by the strap. The metal straps M are supported on both sides of the fiber webs of the metal strap turns 10; M2 and M; M1 passes the fibrous web W both, enclosing the fibrous web W in its contact region K between them.

In the contact area K, the fibrous web W passes through its opposed load 5 used as a press assembly 5; 51 and 5; 52 of the roll nip (press nip) between 52; Np1 through which the loading rolls raise the pressing pressure P provided by the pressing force F between the metal belts M and the fibrous web W passing between them to the desired level (the force effects are shown in more detail in Figure 3).

Fig. 2 shows a cooling arrangement 1 according to the invention, which may be located immediately after the multi-roll calender or any other calendar. In this cooling-to-20 arrangement, 1 fiber web W is also cooled on each side. The first or upper side W1 of the fiber web W is cooled by the cooling means 4; 4c having a cooling cylinder 4; 43 and the second or lower side W2 of the fibrous web is cooled by ··· V · * cooling means 4; 4d having a metal belt loop 2; 23 metal belts M; M3, O which is cooled by a gas cooler 41c. Opposite the cooling cylinder 43: * 25 divides the loading roll 5 and the fiber web W passes the roll nip Np between the cooling cylinder 43 and the loading roll 5; Np2, whereby a sufficiently high compression pressure P. can be created between the fibrous web W and the cooling ** cylinder (roll for cooling) 43 and the fibrous web W and the metal belt M3. Compression - ***! pressure is the total compression force F on the roll nip times the sum of the contact surface area of rolls 51 and 52 30 with the upper and lower surface W1, W2 of the fibrous web at Np2 (press nip).

• * * *

Figure 3 illustrates a portion of the fibrous web W of the cooling arrangement of Figure 1

* ·:: And metal belts M; M1, M2 in the contact area K. In the contact area K between the fibrous web * · V *: and the metal belts M which cools it, the fibrous web and 35 chilled metal belts running on each side thereof are pressed against each other by loading rollers 5; 51 and 5; 52, Np with the force £ F = Fa + Fb, providing a pressure of P = £ F * (area of the X nip).

In the following, the invention will be described in more detail with reference to Figures 1-3 and the above general description of the figures.

Embodiments of the invention illustrated in Figures 1 and 2 illustrate a cooling arrangement 1 according to the invention, wherein the fibrous web W is provided with cooling in the contact area K and supported by a metal strap M used as one or two closed support surfaces M. is prevented from entering steam. The evaporation of water vapor 10 from the upper or lower surface of the fibrous web W is also prevented by creating an overpressure between the fibrous web W and the metal belt M by a pressing device 5 consisting of two opposing rolls with a compressed snip (roll nip) Np. In the roll nip, the fibrous web and the metal belt are pressed towards each other at a pressure P greater than 0.5 MPa (cf. Figure 3, where the total pressure in the roll nip is 15 P = Pa + Pb). The Applicant has found by contact area measurements that the effective contact area between a hard cooling surface such as a metal surface 43a of the roll and a surface W1 of the fibrous web W printed against it is strongly dependent on the compression pressure between the cooling surface and the fibrous web. ) only about 5-15% of the surface area of the fibrous web in contact region K is in effective contact with the cooling surface.

··· • · • ♦ «« «. ···. In Figure 1, the paper web W enters the cooling arrangement 1 from the multi-roll calender 7 on the left of Figure 7. The multi-roll calender 7 is schematically illustrated with δ rolls, some of which are heated metal surface thermo rolls and **: * some of the rolls.

*;:! 25 The roller has a so-called pivoting nipple with two polymer rolls 71b and 71c facing each other * ··· *, which allows both sides of the paper web to be calendered in the same way. The passage of the fiber web from the roll nip to the roll nip is controlled by the take-out rollers 73.

«... T Reference is made to the state of the art with regard to the detailed structure and operation of the multi-roll calender. From the last roll nip N; Eg the temperature of the output paper web W. 30 is 80-90 ° C and must therefore be cooled prior to the roll of paper web W * * * backing machine rolls with the far right winding station 3. Paper web W is cooled by cooling systems 1 according to the invention to below 50 ° C, preferably to about room temperature. . The paper web W passes through the contact area K of the cooling arrangement shown in Fig. 1 with its upper and lower surfaces W1, W2 supported by cooled metal belts M; M2, M1.

I 117402 7

The contact area is the calculated contact area between the surface of the fibrous web and the cooling surface in contact with it. In Figure 1, the metal belts M2 and M1 of the metal belt loops 22 and 21 meet at about the same point A on the upper and lower surfaces W1 and W2 of the fibrous web W coming from the multi-calender calender 7.

5 The metal straps M extend from the upper and lower surfaces of the fibrous web at approximately the same point B. Then, the upper surface of the rotating metal belt M2 and the upper surface W1 of the fibrous web and the lower surface of the lower web

10 Metal belts M have good thermal conductivity and are impermeable to liquid. Because of their construction, the metal belts M are rigid, inelastic, yet sufficiently flexible to control their rotation in and out of the contact area via guide rollers 24. Due to its impermeable structure, the surface of the metal belt M can be cooled by a suitable fluid cooler, such as a water cooler, without the risk of wetting the fibrous web beneath it. In this connection, it is noted that the invention specifically aims to avoid wetting the fibrous web after calendering, in contrast to the method described in DE 102 17 910. In Figure 1, the coolers 41; 41a, 41b are located in the immediate vicinity of the outer surface of the metal belts M, at a vertical distance 20 above and below the contact area. The outer surface of the metal belts here refers to the side of the metal belts M which has turned away from the fibrous web W in the contact region K1 ". The cooling surface of each radiator 41; 41a, 41b is approximately parallel to the plane passing through the metal belts M and: 25 opposed above and below the beginning of the contact region K. The metal belts M; M2, M1 passing above the fiber web W and below the ... T are pressed towards the fiber web.

an upper and lower surface W1, W2 with a pair of rollers 5 used as a press device 5 approximately above and below the center of the contact area, consisting of two ··· press rolls 51, 52. In this case, the paper web W of each metal belt M2 or M1

····. A compression pressure P is formed between the inverted surface 30 and the surface W1 or W2 of the paper web opposite it; Pb or P; Pa greater than 0.1 MPa, preferably greater than * · * · * 0.5 MPa (Figure 3). The metal belts are of a dense structure, whereby the fiber web W and the metal belts M; The compression pressure Pb or Pa formed between M1, M2 increases the water evaporation heat from the fibrous web, thus preventing the water from evaporating from the surface of the fibrous web. Preferably, the metal belts M are slightly wider than the paper web W, whereby their edges extend slightly outside the paper web edges, whereby the upper and lower surfaces W2 and W1 of the paper web W extend in the contact area around the periphery to create the desired pressure P. the pressure P also increases the effective contact area between the surfaces W1 and W2 of the fibrous web W and the surfaces of the metal belts M2 and M1 passing above and below the fibrous web, and thus also the heat transfer area therebetween. at the surface boundary. 5, the heat is effectively transferred from the fibrous web W to the cooled metal strap M of the cooling means 4 to provide a sufficient clamping pressure P between the fibrous web W and the metal straps M in an enclosed periphery but open at its ends. As described above, cooling systems 1 in which the fibrous web W is supported above and below by metal 10 belts M can be cooled on different sides of the web with the same or different cooling power. If the average compression pressure P in the contact area K is provided in the range of 0.1 to 15 MPa, the cooling time should be at least 50 ms, preferably at least 150 ms, in order to ensure sufficient cooling power.

The cooling systems 15 1 connected to the multi-roll calender 7 shown in Fig. 1 provide a great advantage, for example, with smooth printing papers (SC), since the fiber web W

the moisture in the calendering step can be dimensioned purely by calendering techniques without having to worry about drying the fiber web before winding the fiber web. In this case, the temperature of the thermo rolls in the multi-roll calender 7 can be set lower than usual, since during the calendering, the fiber web does not have to evaporate excess moisture.

• * *

A slightly different cooling arrangement 1, however, using the same basic idea as in the embodiment of Figure 1, is shown in Figure 2. The cooling arrangement 1 shown in Figure: T: 2 can be used, for example, in a multi roll calender, ·· '·· soft, shoe or metal belt calender. The arrangement comprises two cooling means 4, the surfaces of which are cooled on different sides of the fibrous web. To the first] ···. cooling arrangement 4; 4c includes a cooling drum or a cooling cylinder 43 having a · · cooling surface 43a. The construction of the cooling cylinder 43 is conventional in the art and cools the top W1 of the fibrous web. The underside of the fiber web W2 cooling • ll \ tämiseen is used to turn a second cooling device 4; 4d, which means consists of 30 metal straps M; M3 and metal belt surface cooling condenser: 41c, which uses a gas such as air as the cooling medium. Cooling means 4; 4d the cooling surface is formed in the contact region K of the metal belt; K2 from the surface Mb of the fibrous web facing the Mb, which is cooled just before the metal belt ^ | M3 entry into contact area K; K2. If the fibrous web were cooled by a fluid-cooled cooler, it would be more advantageous to cool the metal side M3 away from the fibrous web in the contact area K2 with its pivoting side Ma. The functional properties of the metal 9117402 belt are M; M1 and M; Like M2.

The fibrous web W arrives at arrangement 1 from a calendar (not shown) and passes through an endless metal belt M; M3 supported through contact area K. Contact area K 5 consists of two separate parts of the contact area. The first portion of the contact region is a metal belt M; M3 is the contact area K between the surface Mb and the lower surface W2 of the fibrous web W; K2, starting at C, where the metal belt is guided by the metal belt cycle 2; 23 with a guide roll 24 to support the fiber web W from the calendering from below and the contact area K2 ends at point D where the metal belt is guided by the guide roll 24 24 of the metal belt cycle 2 to not support the fiber web. The second part K1 of the contact region K comprises an interface between a hard metal sheath 43a of a rotatable cooling cylinder 43 and an upper surface W1 of the fibrous web W. In the metallic belt cycle 2, the metal belts 23 are conveyed clockwise by the guide rollers 24.

Opposite the cooling cylinder 43 is a counter-clockwise rotating load roll 5, whereby a clamping nip Np is located between the clockwise rotating cooling cylinder 43 and the loading roll; Np2 through which the fibrous web W passes along with a metal belt M3 supporting it from below. The upper side W1 of the fibrous web W is pressed by a loading roll 5 used as a press device 5, behind the cooling cylinder pin 20; 43a. By compressing the fibrous web W in the contact area K towards the surface 43a of the cooling cylinder 43, a sufficient effective contact area is ensured on the one hand: [[: K1 on the contact area K between the cooling cylinder surface 43a and the upper surface W1 of the paper web; M3 against the fibrous web · ·. a portion K2 of the contact area K between the surface Mb and the lower surface W2 of the fibrous web. On the purge, 25 nip Np2 is formed on the one hand as a cooling medium for cooling the upper surface of the fiber web 1; 4c between the used cooling cylinder 43 and the fibrous web W and on the one hand a cooling means 4 for cooling the fibrous web W and the lower surface of the fibrous web; 4d, a compression pressure between the included metal belt M3 which increases the heat transfer surface area between the paper web and the surface of the cooling cylinder 43a and the paper web and the metal belt surface. Thus, both the surface of the cooling cylinder surface 43a and the metal belt:. The cooling capacity of the upper and lower surfaces W1, W2 of the nanofiber M3 fiber web W is sufficient. * ··. use in. Said increase in compression pressure also increases the water vaporization temperature, reducing water evaporation from the surface of the fibrous web W. Due to the dense metal belt M3, which manually supports the fiber web from below V * j, the water vapor el is able to evaporate: Λ: 35 from below the fiber web and the cooling cylinder 43 prevents the water vapor from evaporating from above the fiber web.

10 117402

In a preferred embodiment of the invention, the upper surface W1 of the fibrous web, after the cooling cylinder 3, is supported from above by a belt twist, for example a wire or a metal belt. This also prevents water vapor from escaping from above the fibrous web.

In another preferred embodiment of the invention, the fiber web cooling arrangement 1 is integrated with the calender, for example with a multi-roll calender, at the last roll nip.

Only certain embodiments of the method according to the invention and the cooling arrangement used therein are described above, and it will be apparent to one skilled in the art that the invention may be practiced in many other ways within the scope of the inventive idea set forth in the claims.

Thus, the process according to the invention as well as cooling refining can be used in conjunction with other unit processes where the fibrous web should not be over-dried when cooled. Such a unit process is, among other things, dry coating of the fibrous web 15.

The support surface M used in the process may be, for example, a coated metal belt, a coated or coated dense polymeric belt, a layered metal belt or the like. The wire can also be used as a support surface.

· »« • · • e * ·· 444 • · • · ee · «et * · · • et • i ·· e * •« «·« • tee e • »« e • · «e ··· · · »· * · * • i • 4 • 44 * 4 4» · • 4 «44 4« 44 4 4 «4 444 4 444 4 4 4 4 4 4 4 4 4 • 4 4 4 44 4 4

Claims (16)

A method of cooling a fiber web (W) within the contact area (K) between the fiber web and the cooling surface, wherein the fiber web is supported with at least one support surface (M) within said contact area (K), the fiber web being cooled so that the text is transmitted on the fiber web mainly by conductivity, whereby at least one supporting surface (M) and the fiber web (W) surface and at least one cooling surface and the fiber web (W) surface are arranged in mutual contact at least on a part of the contact area (K), characterized in that the support surface (s) (M) and the fiber web (W) as well as the cooling surface and the fiber web (W) are pressed against each other with such force (F) that the compression pressure (P) between the fiber web (W) and the support surface (M) and / or the surface designed to cool the fiber web at least 0.1-15 MPa, preferably 0.5-15 MPa, to raise the water's temperature of change in the fiber web, and to provide an effective contact surface between the fiber web (W) and the surface intended to cool the fiber web which is at least 15% of the total area between them to provide a sufficient cooling effect. : [[[: 2. Method according to claim 1, characterized in that evaporation of meadow / water via the support surface (M) of the fiber web (W) is also substantially prevented within the contact surface (K). 3. Method according to any of the preceding claims, characterized in that the effective contact time between the support surface (M) and the surface of the fiber web (W) within the contact area is at least 50 ms, preferably at least 50 ms. 150 ms. ,. ·. Method according to any of the preceding claims, characterized in that the cooling of the full web (W) is carried out via one or more cooling support surfaces (M). • · • » 5. A method according to claim 5, characterized in that the fiber web (W) is used. Arranged on contact of the bed sides with the support surfaces (M; M1, M2) at the contact area (K) and that the surfaces (W1, W2) of the fiber web (W) are cooled with the same or different cooling effect on said support surfaces. «4 1 · · • 44 4 4 117402 Method according to claim 5 or 6, characterized in that the support surface (M) is cooled by spraying fluid or gas on its surface. An arrangement (1) for cooling the fiber web (W) within a contact area K between the fiber web and the cooling surface, the fiber web being supported by at least one supporting surface (M) within said contact area (K), wherein the fiber web is cooled by the cooling element ( 4) so that the cooling effect is transmitted on the fiber web mainly by conductivity, the arrangement comprising a pressing device (5) comprising at least one supporting surface (M) and a fiber web (W), and the fiber web (W) and the cooling element (4) can be arranged in the mutual contact at least in part of the contact area, characterized in that at least one supporting surface (M) and the fiber web (W) and the fiber web (W) and the cooling means (4) can be arranged with the pressing device (5) in such a mutual contact in a part of the contact area that a compressive pressure (P) can be created between the support surface (s) (M) and the fiber web (W) and the surface of the cooling means (4) to be cooled and the fiber web (W) which is 0.1 to 15 MPa preferably , 5-15 MPa for raising the water displacement temperature in the fibrous web and that the effective contact surface between the fibrous web (W) and the surface of the cooling means (4) intended to cool the fibrous web is at least 15% of the total contact surface between them, to provide a sufficient cooling effect. Arrangement (1) according to claim 7, characterized in that the surface 20 of the cooling means (4) is a support surface which can be cooled, such as a belt (M) or a sheath (43a) for a cooling rolling means such as a cooling cylinder (43). . Arrangement (1) according to claim 8, characterized in that the surface of the cooling means (4) is an endless band (M) which is liquid impervious, flexible, inelastic and heat conductive. . ***** * * "j. 25 Arrangement (1) according to any of claims 7-9, characterized in that both sides (W1, W2) of the fiber web (W) in the arrangement are supported within the contact ***** area (K) with a cooling support surface (M ; M1, M2). Arrangement (1) according to claim 10, characterized in that the support surfaces (M; ***: M1, M2) consist of a material which is substantially impermeable to water vapor *. And their tension and the transverse width of the fiber web are such that they form a space closed at the edges around the fiber web, whereby it is possible to produce pressure with the pressing device (5) above 0.1, preferably above 0.5 MPa in space. * · ♦ ♦ · Arrangement (1) according to claim 11, characterized in that at least the one support surface (M; M1, M2) is wider than the fiber web (W). 117402 Arrangement (1) according to any one of claims 11 - 12, characterized in that the tension of the support surfaces (M; M1, M2) can be controlled. Arrangement (1) according to any of claims 7-13, characterized in that the support surface (M) is a metal band. Arrangement (1) according to any of claims 7-14, characterized in that the cooling means (4) comprise one or more metal strips (M) which are cooled by a cooler (41) outside the metal strips. Arrangement (1) according to any of claims 7-15, characterized in that the cooling means (4) further comprise one or more machine cloths used as a supporting surface. * ♦ · P · p ft ft · ft ft ft ft • • ft ft ft • ft # ft * · ft ft ft ft ft ft ft «« · ft ft ft ft ft · ft ft ft ·· • ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft «ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ·· ft ft ft ft ft ft ft ft ft ft ft