AT508471B1 - DEVICE FOR PRODUCING A FIBROUS WEB - Google Patents

Description

Austrian Patent Office AT 508 471 B1 2012-01-15

description

DEVICE FOR PRODUCING A FIBROUS WEB

The invention relates to a device for producing a fibrous web, such. a paper, cardboard or tissue web.

In the production of fibrous webs, there is generally the problem that the sometimes very moist fibrous web during manufacture must be dried gently to achieve the desired paper quality. Therefore, one uses dryer sections with a plurality of single-row or double-row, heated drying cylinders, on which the paper web rests, wherein the water present in the paper web evaporates slowly through the hot drying cylinder surfaces. However, there is the one problem that the still very wet paper web sticks easily to the drying cylinder surface, especially when desired fast machine running; and also the entire length of the manufacturing device or the manufacturing machine is greatly increased by the many successive arranged in a row drying cylinder.

In view of this problem field, impact-drying devices have been proposed in the prior art (see, for example, WO 2004/099495 A1, US Pat. No. 6004430 A, DE 102004056320 A1, DE 19944266 A1, EP 1156155 A2, DE 102007038133 A1 or DE 102007026931 A1) which an impact dryer is provided with a blast hood for applying the fibrous web with a dry medium, eg Hot air to thereby temporarily remove more moisture from the wet fibrous web.

The invention provides a device for producing a fibrous web is created, which allows for a reduced required space efficient fibrous web drying.

This is achieved by a device having the features of claim 1. Further developments of the invention are described in the dependent claims.

By according to the invention, the two impingement drying units are adjacent to each other, with their front portions adjacent to each other and facing each other, their longitudinal axes - either e.g. extend substantially parallel or substantially at an angle of 90 ° to each other -with about 45 ° to the horizontal plane, the space usually present vertically above and below the device and the horizontally available space evenly in the vertical upward and downward and exploited in the horizontal. Furthermore, in the variant with the mutually parallel longitudinal axes, the band transfer between the first and the second drying unit can be done very gently. In addition, the tape take-up can also be made very gentle by the front impact drying unit in the transport path (in which the impact drying device is located), by placing this front impact drying unit in the transport path, e.g. in the direction of the transport path (= to the rear) inclined provides; The fibrous web is in this case usually fed horizontally by a device preceding the transport path of the impact drying device, so that due to the substantially 45 ° inclination whose longitudinal axis to the rear an obtuse angle of 135 ° between the horizontally zoom fibrous web and the longitudinal axis of the transport path front impingement drying unit is present, which brings no strong deflection for the fibrous web with it. In this case, the rear impact-drying unit in the transport path is correspondingly inclined by 45 ° counter to the transport path (forward) or by 45 ° in the direction of the transport path (to the rear); in the first mentioned case, the tape delivery can be done very gently; The fibrous web is generally continued substantially horizontally by the impact drying device, so that there is also an obtuse angle of approximately 135 ° between the longitudinal axis of the rear impact drying unit in the transport path, insofar as it is inclined forwards, and the horizontally continued fibrous web. The first and the second inclined impact drying unit or their inclined longitudinal axes lie substantially in a vertical plane; The same applies to any further inclined accordingly arranged and the first and the second impingement drying unit downstream T rocknungseinheiten.

According to the invention, the fibrous web in the area of the impact surfaces is further supported on one side or only from one side by the associated support cloth of the respective impact drying unit, whereby an effective drying can be achieved since the impact medium strikes directly on the fibrous web. Here, e.g. for each impingement drying unit, the impingement dryer is directed to the side of each of the two impingement surfaces which faces away from the supporting cloth in each case.

The impact dryer of the respective impact drying unit can, as described above, have a hood arranged above the respective impact surface, in which shielding an impact medium, in particular hot air, is blown onto the fibrous web supported by the support cloth. Such hoods can be present per impact surface on both sides of the fibrous web in order to be able to act on these on both sides with the impact medium. The impingement dryer is preferably designed such that at least the side of all the impact surfaces not covered by the support cloth is exposed to the impact medium, because the direct impact of the impact medium on the fibrous web has a higher efficiency than if a support cloth is still therebetween.

According to the impact dryer of the at least first impingement drying unit is designed such that the impact medium is also applied to the covered by the backing cloth side of the fibrous web on the impact surface; when the support cloth is completely closed, the effect is then practically the same as that of a drying cylinder (only heat transfer to the fibrous web); if the support cloth is provided with holes or perforations, then there are convection effects on the side of the impact surface covered by the support cloth.

The impingement-drying device according to the invention may comprise a plurality of pairs of first and second impingement-drying units, which are arranged in the direction of the transport path of the fibrous web successive and adjacent to each other. In addition to the first and the second impact drying device, the impact drying device preferably also has one to three impact drying units, wherein the longitudinal axes of all the impact drying units are substantially parallel to one another or the longitudinal axes of the upper impact drying units are substantially parallel to one another the longitudinal axes of the lower impact drying units substantially parallel to each other at an angle of about 90 ° between the longitudinal axes of the upper and lower longitudinal axis (= nested arrow pairs). If the first impingement-drying unit in this case is the front of the impingement-drying units in the transport path, then the respective odd (that is for example the third and / or the fifth) impact-drying unit also extends again corresponding to the first one; that is, the front portions of the first and each further odd impact drying unit face in the same direction with respect to their respective longitudinal axis. Preferably, the front portions of all odd impingement drying units are arranged substantially at the same vertical level; The same applies preferably to the front sections of all straight impact T rocknungseinheiten.

The impact surfaces of the impact drying units preferably extend symmetrically to the associated longitudinal axis. The impact surfaces may be flat; but they can also be curved, in particular convex curved. Furthermore, the impact surfaces may extend parallel to the longitudinal axis of the associated impingement drying unit; in the case of a curved impact surface, for example, the tangent at the apex of the impact surface may be parallel to the longitudinal axis. The impact surfaces or their vertex tangents extend at an angle of less than 90 °, advantageously less than 45 °, preferably less than 30 °, particularly preferably less than 15 °, relative to their associated longitudinal axis. 2.13

The impact drying device is particularly preferably arranged immediately after a press of the device, because the fibrous web immediately after passing through the press has a high water content, so that there used the impact drying particularly effective can be. Accordingly, the impingement-drying device or an additional impingement-drying device, which is constructed according to the invention, arranged immediately after a commissioned work, with which the paper with any media, such as glue, impregnating material, treated and therefore also again has an increased degree of wetness.

In the apparatus according to the invention the respective impingement-drying device are preferably followed immediately drying cylinder, which are arranged in a horizontal row one behind the other (single-row design) or in two superimposed rows, each horizontally arranged one behind the other (double-row design).

Suction devices, including combined suction / blowing devices, may be provided on the sides of the scrim to hold the fibrous web adjacent the scrim, with the aspirator / blower device e.g. Seen in fibrous web longitudinal direction suction devices and blowing devices can be arranged alternately.

The respective impact drying unit may also be equipped with fibrous web deflection rollers having a perforated roll shell and which are evacuated. The suction of these rolls can be done either indirectly via a suction box or directly over the roll shaft.

The invention will be explained below with reference to embodiments with reference to the figures. 1 shows a schematic side view of an apparatus for producing a fibrous web according to one embodiment of the invention, [0018] FIG. 2 shows a schematic side view of an apparatus for producing a fibrous web according to another embodiment of the invention, [0019] FIG 3 shows a schematic side view of an apparatus for producing a fiber web according to yet another embodiment of the invention, and [0020] FIG. 4 shows a schematic side view of an apparatus for producing a fiber web according to yet another embodiment of the invention.

In the figures, the same reference numerals are used for the same components.

In the apparatus 1 according to the invention for producing a fibrous web 3 shown in Figure 1, the fibrous web 3 along a transport path (arrow Tw) is transported substantially from left to right, wherein the transport path, i. the course or course of the web of fibrous web 3 in the device 1, as such is partially guided around meandering around rollers, wherein the transport path also has sections which extend a piece opposite to the general transport path Tw. Further, e.g. the expression " device in the forward transport route " or " device in the rear transport route " Also to be understood that the fibrous web 3 passes through the front in the transport device before and the rear in the transport way, however, only later. The device is designed to be elongate in accordance with the general transport path Tw, with its device longitudinal axis VL extending substantially horizontally.

The apparatus 1 has an impact drying device 5 located in the transport path Tw, which in turn comprises a first elongate impact drying unit 7 and a second elongated impact drying unit 9 adjacent thereto. Each of the impact drying units 7, 9 has two impact surfaces 11 , 13 and 15, 17, which are arranged on opposite sides of the longitudinal axis L of the associated impingement drying unit 7, 9, and each of which has its own support cloth 19, 21, from which the fibrous web 3 is supported only from one side , The support cloth 19, 21 of the respective impact drying unit 7, 9 is guided over four respective guide rollers 23 ', 23, 25 and 27', 27, 29 each in a quadrangular shape, this quadrangle is formed by two triangles, the 3/13 Austrian Patent Office AT 508 471 B1 2012-01-15 have the same basic side and their tips pointing in opposite directions (dragon shape).

Both impingement drying units 7, 9 have seen in their longitudinal direction L each have a front (end) portion 31 and 33 and a rear (end) portion 35, 37, wherein the front portions 31, 33 facing each other or each other are arranged adjacent and are arranged approximately at the same height, which corresponds approximately to the height of the horizontal extension or longitudinal extent (longitudinal axis VL) of the device 1. In the lower impact drying device in FIG. 1, its deflection rollers 23 are arranged symmetrically with respect to their longitudinal axis L; i.e. the foremost deflection roller 23 'with respect to the longitudinal axis L and the rearmost deflection roller 25 define the longitudinal axis L and the two remaining deflection rollers 23 lie diametrically opposite one another perpendicular to the longitudinal axis L. In the upper impact drying unit 9 in FIG. 1, the foremost deflection roller 27 'is arranged at a distance offset downwards relative to the longitudinal axis L; The triangle formed by the rearmost deflection roller 29 and the two middle deflection rollers 27 is arranged symmetrically to the longitudinal axis L of the upper impact drying unit 9.

In this formed by the pulleys 23 ', 23, 25 and 27', 27, 29 respectively dragon form the support cloth 19 and 21 of the first and the second impingement drying unit 5, 7 therefore substantially convexly circulating, i. There are, except for the between the pulleys 23 ', 23, 25, 27', 27, 29 present straight sections only convex deflection and no concave sections.

Further, each of the impingement drying units 7, 9 has an impingement dryer 39, 41 each having four sub-dryers 39 ', 39 ", 39", 39IV and 4T, 41 ", 4T", 41lv, respectively. Here, in each case directly opposite the side facing away from the respective support cloth 19 or 21, each impact surface 11, 13 or 15, 17 is one of the sub-dryers 39 ', 39 ". or 4T, 41 " arranged, which has a hood, within which the fibrous web 3 in the region of the impact surface 11, 13, 15, 17 directly with a collision medium (hot air) can be acted upon.

On the side of each impact surface 11, 13, 15, 17 facing the support cloth 19 and 21, respectively, one of the sub-dryers 39 '", 39ιν, 4T", 41IV is also arranged, which has a hood within which the fibrous web 3 in the region of the impact surface 11, 13, 15, 17 can be acted upon indirectly by the support cloth 19, 31 through the impact medium. If the support cloth is formed closed, e.g. in the form of an imperforate plastic strip or an unperforated metal strip, the impact medium only causes heating of the support cloth 19, 31, so that in this way drying of the fibrous web 3 takes place only by heat conduction. Preferably, the respective support cloth 19, 31 formed perforated, so that the impact medium can also act through the support cloth 19, 31 through partially directly to the fibrous web 3; However, this partial direct action is to be understood in the context of the invention as being indirect through the support cloth.

The longitudinal axis L of the first impingement drying unit 7 and the longitudinal axis of the second impingement drying unit 9 are substantially parallel to each other and at an inclination angle α of 35 ° -55 °, preferably 40 ° -50 °, preferably about 45 °, with respect to a horizontal plane HE arranged inclined. The first and second impingement drying units 7, 9 are, as explained above, with their front portions 31, 33 facing each other in their longitudinal direction L facing each other, extending from their respective front portion 31, 33 into their respective longitudinal direction extend opposite directions (both vertically and horizontally). In this case, the lower, first impingement drying unit 7, which is arranged in the transport path Tw in front of the upper, second impingement drying unit 9, extends obliquely downwardly and rearwardly with respect to the horizontal plane HE from its front section 31 in its longitudinal direction L. with respect to the transport path Tw). Accordingly, the second impingement drying unit 9 extends obliquely upward and forward with respect to the horizontal plane HE from its front portion 33 (with respect to the transporting path Tw).

Seen in the longitudinal direction L of the respective impact drying unit 7, 9 rear 4/13 Austrian Patent Office AT 508 471 B1 2012-01-15

Guide pulley 25 or 29 is formed as a suction roll, the interior of which is sucked via an external suction box 25 ', 29'. The suction roll can also be vacuumed directly via a suction roll hollow shaft. The respective support cloth 19 or 21 of the first or the second impact drying unit 7, 9 runs convexly in the transport path between the respective two impact surfaces.

The apparatus 1 further comprises a press section 43 with a nip press 45, which has two opposing, a press nip 47 between them forming press rolls 49, 51. The moist fibrous web 3 is guided through the press nip 47 and thereby pressed. Immediately thereafter, the paper web 3 is fed to the first impact drying unit 7 of the impact drying device 5. The transfer point to or the receiving point 53 of the first impingement drying unit 7 is located in the front section 31, and here exactly at the front guide roller 23, which is provided at the transfer point 53 with a suction device to the fibrous web 3 securely to the pulley 23 to suck.

The fibrous web 3 then successively passes through the impact surfaces of the first impingement drying unit 7 and reaches a delivery point 55 of the first impact drying unit 7, where the fibrous web 3 is discharged from the first impingement drying unit 7; This discharge point 55 is also located in the front portion of the first impingement drying unit 7.

The receiving point 57, at which the fibrous web 3 enters the second impingement drying unit 9, is immediately adjacent to the discharge point 55 of the first impact drying unit 7, in the front portion 33, in this case formed on the front guide roller 27 ', which this is equipped at the receiving point 57 with a suction device. The fibrous web 3 then successively passes through the impact surfaces 17, 15 of the second impingement drying unit 7, in order then to be transferred to a delivery section 59 of the apparatus 1 arranged immediately following it at a delivery point 59 also arranged in the front section 33 of the second impingement drying unit 7.

In the area between the front guide roller 27 'and the following in the web running direction, middle guide roller 27 is on the side facing away from the fibrous web 3 of the respective support cloth 19, 21 each have a suction device in the form of a suction box 63, 65, by means of which the fibrous web 3 is sucked in the direction of the respectively associated support cloth 19 or 21, in order to stabilize the web run.

The drying section 61 has a plurality of single-row in the horizontal along the longitudinal axis of the device VL successively arranged drying cylinders 67, between which, in an underlying, parallel to the row of drying cylinders row, pulleys 69 are arranged. The fibrous web 3 is guided in an alternating manner, meandering around the drying cylinder 67 and the deflection rollers 69. The drying section 61 is e.g. divided into several drying groups, of which in Figure 1, only the impact drying device 5 nearest drying group is shown. Each drying group comprises a number of drying cylinders. In the present case, the drying group shown in Figure 1 is equipped with a single support cloth 71 which is brought from above to the fibrous web 3, wherein it supports the fibrous web 3 in the wrap around the drying cylinder 67 from the outside, so that the fibrous web 3 directly is applied to the drying cylinder 67, and wherein the support cloth 71 is in the looping of the fibrous web 3 to the guide rollers 69 between the guide rollers 69 and the fibrous web 3.

It is also possible to provide groups with two superposed, parallel rows of drying cylinders mixed with single-row drying groups.

The impingement drying device according to the invention, such as e.g. that impact-drying device 5 as described above with reference to Figure 1, is preferably arranged immediately after the press unit 43 and immediately before the drying section 61 of the device 1; However, it can also be used between drying groups of drying cylinders or between drying sections AT 508 471 B1 2012-01-15

Cylinders are arranged within dryer groups. For example, It is also conceivable to replace one or the other dryer group in existing devices by the impingement-drying device according to the invention, whereby even more drying groups can be omitted, because the drying performance of an impingement-drying unit is greater than that of a number of drying cylinders. Preferably, the impact-drying device according to the invention or an impact-drying device additionally constructed according to the invention is also arranged immediately after a commissioned work, which is often arranged in the dryer section between dryer groups.

In the embodiment of a device 1 according to the invention for producing a fibrous web 3 shown in Figure 2, the impingement-drying device 5 in addition to the first and the second impingement drying unit 7, 9 still a third and a fourth impingement drying unit 73 and 75 on.

The third impact drying unit 73 is arranged adjacent to the second impact drying unit 9 in the web running direction; it is elongate, its longitudinal axis L being parallel to the longitudinal axes L of the first and second impingement drying units 7, 9; it extends from a front (end) portion 77 obliquely downwards and (in the direction of the transport path Tw) to the rear; its front portion 77 is approximately at the same height level as the front portions 31, 33 of the first and second impingement drying units 7, 9.

The fourth impingement drying unit 75 is disposed adjacent to the third impingement drying unit 73 in the transport path Tw; it is elongate, with its longitudinal axis L parallel to the longitudinal axes L of the first to third impingement drying units 7, 9, 73; it extends from a front (end) portion 79 obliquely upward and (in the direction of the transport path Tw) forward; its front portion 79 is approximately at the same height level as the front portions 31, 33, 77 of the first to third impingement drying units 7, 9, 73.

The third and the fourth impingement drying units 73, 75 have the same individual constituents as the first and the second impingement drying units 7, 9, ie they each have their own support cloth 81, 83 which extends along one of deflecting rollers 85 ', 85, 87 and 89 ', 89, 91 each defined dragon-shaped quadrangular circumferential ring rotates; they furthermore each have two impact surfaces 93, 95 or 97, 99 and an impingement dryer 101, 103, both on the sides facing away from the respective support cloth 81, 83 sides and on the respective support cloth 81, 83 facing sides of the impact surfaces 93, 95 and 97, 99 acts by a respective hood is arranged, within which an impact medium on the associated side of the impact surfaces 93, 95, 97, 99 is applied.

The third impingement drying unit 73 has in its front portion 77 both a receiving point 105 and a discharge point 107 at which the fibrous web 3 is transferred from the delivery point 59 of the second impingement drying unit 9 directly to the third impingement drying unit 73 or the fibrous web 3 of the third impingement drying unit 73 is transferred directly to the fourth impingement drying unit 75, which is provided for this purpose in its front portion 79 with a receiving point 109. The fourth impingement drying unit 79 is further provided in its front portion 79 with a discharge point 111, at which the fibrous web 3 from the fourth impingement drying unit 75 and thus from the impact drying device 5 to the subsequently arranged drying section 61 is transferred.

The receiving points 105 and 109 of the third and the fourth impingement drying unit 73, 75 are also located exactly on the front guide rollers 85, 89, which are equipped at the respective receiving point 105, 109 with a suction device.

In all of the impact drying units 7, 9, 73, 75 shown in FIGS. 1 and 2, the impact surfaces 11, 13 or 15, 17 or 93, 95 and 97, 99 are symmetrical to the longitudinal axis L of the associated impact drying unit 7, 9, 73, 75 arranged; However, it is also possible to arrange the respective pair of impact surfaces 11, 13 or 15, 17 or 93, 95 or 97, 99 asymmetrically with respect to the associated longitudinal axis L ,

In Figures 1 and 2, the longitudinal axes L are defined as by the rear guide pulley 25, 29, 87, 91 and the middle of the distance between the two middle pulleys 23, 27, 85, 89 extending; However, the longitudinal axes could also be defined as by the respective front and rear pulley 23 ', 25 and 27', 29 and 85 ', 87 and 89', 91 extending; in the latter case, the impact surfaces 11, 13 would then be arranged symmetrically to the associated longitudinal axis L only in the first impact drying device 7, whereas in the second to fourth impact drying devices 9, 73, 75, the impact surfaces 15, 17 and 93, 95 and 97, 99 are then arranged asymmetrically to then present there longitudinal axis L '.

In the embodiment of a device 1 according to the invention for producing a fibrous web 3 shown in Figure 3, the impact drying device 5, a first and a second impingement drying unit 7, 9, whose longitudinal axes L at an angle α of 45 ° relative to the horizontal plane HE extend and from their (seen in their longitudinal direction) front end portion 31 and 33 are both inclined in the transport direction Tw to the rear, so that their longitudinal axes L extend at an angle of 90 ° relative to each other (arrow shape against the transport direction Tw directed). In other words, the first and second impingement drying units 7, 9 extend horizontally in their respective longitudinal direction from their respective front portions 31, 33 in the same direction (here backwards) and vertically in opposite directions (viz. up).

The first impingement drying unit 7 is arranged in the web running direction (fibrous web path) immediately after a press section 43 and immediately before a dryer section 61.

With regard to their structural details, the impact drying units 7, 9 are otherwise designed like those of the previously described embodiments according to Figures 1 and 2, so reference is made in this regard to the preceding description.

In the embodiment of a device 1 according to the invention shown in Figure 4, the impingement drying unit 5, which is also arranged here between a press section 43 and a drying section 61, four impingement drying units 7, 9, 73, 75, which in terms of their structural Details according to the four impact drying units 7, 9, 73, 75 are formed according to the embodiment of Figure 2. In this case, however, not all longitudinal axes L of the impact drying units 7, 9, 73, 75 run parallel to each other, but only the longitudinal axes L of the two above-arranged impingement drying units 9, 75 and the longitudinal axes L of the two lower impingement drying units 7, 73 Longitudinal axes L of the two upper impingement drying units 9, 75 inclined relative to the horizontal plane HE by an angle a 'of 55 ° in the transport direction Tw backwards, and the longitudinal axes L of the two lower impingement drying units 7, 73 are relative to the horizontal plane HE by an angle α of 45 ° tilted backwards. Thus, the longitudinal axes L of the two upper impact drying units 9, 75 extend with respect to the longitudinal axes L of the two lower impingement drying units 7, 73 at an angle of 100 ° relative to each other (arrow shape of the longitudinal axes L against the transport direction Tw directed). In other words, the first, second, third and fourth impingement drying units 7, 9, 73 and 75 extend horizontally in the same direction from their respective front portions 31, 33, 77 and 79, respectively, in their respective longitudinal directions (FIG. here to the rear) and vertically in opposite directions (namely, the lower impingement drying units 7, 73 downwards and the upper impingement drying units 9, 75 upwards).

Preferably, the impingement-drying device 5 has an even number of impingement-drying units.

Further advantages of the invention are for example as follows: in that the front section of the respective impact drying unit seen in the longitudinal direction is preferably tapered towards its longitudinal end, the impact drying unit facing towards its front sections can be arranged compactly against each other at the front. Also 7/13

Claims (14)

Austrian Patent Office AT 508 471 B1 2012-01-15 the longitudinal section of the respective impact drying unit is preferably designed to be tapered, so that it can be accommodated in space to save space. 1. Device (1) for producing a fibrous web (3), which is transported by the device (1) along a transport path (Tw), with an impingement drying device (5), comprising: a first elongated impact drying unit (7) and a second elongate impact drying unit (9) adjacent thereto, each having two impact surfaces (11,13; 15,17) disposed on opposite sides of the longitudinal axis (L) of the associated impingement drying unit (5; 7) and each of which has its own support cloth (19; 21) from which the fibrous web (3) is unilaterally supported from one side and each of which has an impingement dryer (39; 41) disposed on at least one of the respective two impact surfaces (19; 11, 13, 15, 17) is directed in order to be able to act directly on the support cloth (19, 21) facing away from the fibrous web (3), wherein the first and the second Aufpra drying unit (5, 7) having its respective longitudinal portion (L) seen front portion (31; 33) are arranged facing each other, characterized in that the longitudinal axis (L) of the first and the second impingement drying unit (7, 9) at an inclination angle of 35 ° -55 °, preferably 40 ° -50 °, preferably about 45 °, with respect a horizontal plane (HE) is arranged inclined, and that the first and the second impact drying unit (7, 9) extend from their respective front portion (31; 33) in their respective longitudinal direction (L) vertically and horizontally in opposite directions or extending from their respective front portion (31; 33) in their respective longitudinal direction (L) vertically in opposite direction and horizontally in the same direction, the impact dryer (39) of at least the first impingement drying unit (7) on both sides of the respective two Impact surfaces (11, 13) is directed to act on the support cloth (19) facing away from the fibrous web (3) directly and on the support cloth (19) Covered side of the fibrous web (3) indirectly through the support cloth (19) to act through. 2. Device (1) according to claim 1, wherein the longitudinal axis (L) of the first impingement drying unit (7) and the longitudinal axis of the second impingement drying unit (9) are arranged substantially parallel to each other. A device (1) according to claim 1 or 2, wherein the respective support cloth (19; 21) of the first and second impingement drying units (7; 9) is convex in the transport path between the respective two impact surfaces (11,13; 15,17) , 4. Device (1) according to one of claims 1 or 2, wherein the respective support cloth (19; 21) of the first and the second impingement drying unit (7; 9) rotates in a substantially convex annular form. 5. Device (1) according to one of claims 1 to 4, further comprising a press section (43), wherein the impact drying device (5) in the transport path (Tw) immediately after the press section (43) is arranged. 6. Device (1) according to one of claims 1 to 5, further comprising a drying section (61) with a plurality of single-row and / or double-row drying cylinders (67), wherein the impact drying device (5) or an additional such impact Drying device (5) in the transport path (Tw) immediately before the drying section (61) or in the drying section (61) between drying cylinders (67) is arranged. 7. Device (1) according to one of claims 1 to 6, further comprising a commissioned work for applying and / or introducing an agent, such as an impregnation and / or a glue on / in the fibrous web (3), wherein the impact Drying device (5) or an additional such impact drying device (5) in the transport path (Tw) is arranged immediately after the commissioned work. 8/13 Austrian Patent Office AT 508 471 B1 2012-01-15 8. Device (1) according to one of claims 1 to 7, wherein the first impingement drying unit (7) in the transport path in front of the second impingement drying unit (9) is arranged and wherein the first impingement drying unit (7) with respect to the horizontal plane (HE) of its front Section extends in its longitudinal direction (L) obliquely downwards and backwards or obliquely upwards and backwards. 9. Device (1) according to one of claims 1 to 8, wherein the support cloth (19; 21) is designed as a sieve with perforations or with other openings. 10. Device (1) according to one of claims 1 to 9, wherein the fibrous web (3) in the respective impact drying unit (7; 9) is supported continuously by the associated support cloth (19; 21). 11. Device (1) according to one of claims 1 to 10, wherein in the transport path (Tw) in addition to the impingement drying device (5) a plurality of such, preferably corresponding impact drying devices (5) are arranged one behind the other, wherein the longitudinal axes (L ) of all impact drying units (7, 9, 73, 73) are preferably arranged substantially parallel to one another. 12. Device (1) according to one of claims 1 to 11, wherein the first and the second impact drying unit (7; 9) each have a fibrous web receiving point (53; 57) at which the fibrous web (3) on the respective associated fibrous web receiving station (53; 57) in the front portion (31; 33) of the respective impact drying unit (7; 9) arranged is. 13. Device (1) according to one of claims 1 to 12, wherein the first and the second impact drying unit (7, 9) each have a fibrous web discharge point (55; 59), on which the fibrous web (3) of the respective the fibrous web discharge point (55; 59) is arranged in the front section (31; 33) of the respective impact drying unit (7; 9) , 14. The apparatus according to claim 1, wherein the front portion (31; 75) is tapered towards its end. 4 sheets of drawings 9/13