AT16567U1 - DEVICE FOR CONTACTLESS REFLECTING AND DRYING OF A FIBER TRAIN - Google Patents

Abstract

Device for contactless deflection and drying of a fiber web (W), with a housing (2) around which the fiber web (W) is guided at least in sections and the outer surface of which forms a deflection element (3) for deflecting the fiber web (W), and with a drying device (4) acting on one side of the fiber web (W), the housing (2) having at least two separate chambers (5, 6), the at least two chambers (5, 6) each having separate accesses (7, 8 ) for a drying medium, and at least in the first chamber (5), which first acts on the fiber web (W), there is a temperature of at least 200 ° C.

Description

The invention relates to a device for contactless deflection and drying of a fiber web, with a housing, around which the fiber web is guided at least in sections and whose outer surface forms a deflection element for deflecting the fiber web, and with one acting on one side of the fiber web drying device.

A generic device is known from DE 39 42 029 B4. In the case of such devices, it is necessary to use respective additional drying devices immediately before and partly also after the same, in order to achieve adequate drying of the fiber web, since this is the prerequisite for good quality of a coating which is carried out in a subsequent step. These additional drying devices represent a considerable effort, both in terms of acquisition and energy costs.

It is therefore an object of the present invention to provide a device for deflecting and drying a fiber web, which ensures reliable drying of the fiber web with simple means.

According to the invention this object is achieved by the features mentioned in claim 1.

The inventive division of the housing, on which the fiber web is guided at least in sections around and the outer surface of which in this way also forms the deflecting element for deflecting the fiber web, in at least two chambers makes it possible to set different temperatures in the two chambers. This is simplified according to the invention in that both chambers have separate accesses for a drying medium.

Due to the inventive temperature of at least 200 ° C in the first chamber, that is, in the chamber in which the drying medium acting first on the fibrous web is located or to which the fibrous web is first passed, there is a substantially increased drying capacity , which means that additional drying facilities can be dispensed with. This not only results in a shorter dwell time of the fiber web between a coating device and the start of drying, but also results in a very simple construction and a compact structure of the device according to the invention.

In a very advantageous development of the invention it can be provided that in the first chamber there is a higher temperature than in a second chamber, which acts on the fiber web after the first chamber. This results in a gradual drying of the fiber web, which significantly increases the effectiveness of the device according to the invention.

It has been found to be particularly advantageous with regard to a good drying result for the fibrous web if a temperature in the first chamber of 200 ° C to 500 ° C, preferably 250 ° C to 350 ° C, and a temperature in the second chamber from 100 ° C to 350 ° C, preferably 100 ° C to 200 ° C.

Another very advantageous embodiment of the invention may consist in that an outlet for the drying medium from the first chamber is connected to the access for the drying medium in the second chamber. In this way, considerable energy savings can be achieved since the thermal energy of the drying medium discharged from the first chamber can still be used for a subsequent drying process for the fiber web.

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Kterreichiiitiei palpriar.i [0010] This connection can be implemented in a very simple and reliable manner if the outlet for the drying medium from the first chamber is connected to the access for the drying medium into the second chamber by means of a connecting line.

In order to ensure the desired flow of the drying medium, an exhaust fan can also be arranged in the connecting line.

The high temperatures prevailing in the device according to the invention can be achieved in a particularly simple manner if the drying device has at least one gas burner and / or at least one electric heating element and / or at least one steam heating element.

It can be provided that a separate gas burner and / or a separate electrical heating element is assigned to each of the at least two chambers. This enables the desired temperatures in the at least two chambers to be set very precisely.

In order to reduce the costs for the device according to the invention, it can further be provided that the two chambers are assigned a common gas burner and / or a common electric heating element.

A particularly high effectiveness with regard to drying the fiber web is obtained when the drying medium is a gas, in particular air.

[0016] In the following, exemplary embodiments of the invention are shown in principle with reference to the drawing.

[0017] It shows:

1, 2, 3, 4, 5, a first embodiment of the device according to the invention; a second embodiment of the device according to the invention; a third embodiment of the device according to the invention;

a fourth embodiment of the device according to the invention; and a fifth embodiment of the device according to the invention.

Figures 1-5 show different embodiments of a device 1 for deflecting and drying a fibrous web W, in particular a paper or cardboard web. The running direction of the fiber web W through the device 1 is indicated in FIGS. 1 to 5 by an arrowhead at the end of the fiber web W.

The device 1 has a housing 2, around which the fiber web W is guided at least in sections. The outer surface of the housing 2 thus forms a deflecting element 3 for deflecting the fibrous web W. In the present case, deflecting means a change in direction of the fibrous web W from a direction perpendicular upward to a direction perpendicular downward. Of course, the deflection element 3 could also be designed such that it causes another change in direction of the fiber web W, for example also such that a change in direction is effected by an angle different from 180 °. Furthermore, the device 1 has a drying device 4, which acts on the section of the fiber web W which extends around the housing 2 and thus causes the fiber web W to dry on one side. The drying device 4 has an air supply device 4a, which supplies a drying medium, preferably heated air, into the interior of the housing 2. This air, which is fed into the interior of the housing 2, is then discharged through openings (not shown) in the surface or the curved wall of the housing 2 to the outside in the direction of the fiber web W. The fibrous web W therefore moves on a type of air cushion around the housing 2 and is deflected and dried by this air cushion without contact.

The housing 2 has at least two separate chambers 5 and 6, which are connected to the air supply device 4a, so that the air or generally the drying medium is introduced into the respective chamber of the housing 2 and optionally discharged from the same

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Kterreichiiitiei palpriar.i can be tet. In all of the exemplary embodiments described herein, the housing 2 has exactly two chambers 5 and 6, but it is fundamentally possible to use a larger number of chambers. The chamber to which the fibrous web W is first passed is referred to below as the first chamber 5, and the chamber to which the fibrous web W is guided past the first chamber 5 is referred to as the second chamber 6. The drying medium flowing out of the first chamber 5 thus comes into contact with the fiber web W before the drying medium flowing out of the second chamber 6.

The two chambers 5 and 6 each have separate accesses for the drying medium used by the drying device 4, not shown, for example air. The access to the first chamber 5 is provided with the reference number 7 and the access to the second chamber 6 with the reference number 8.

In the first chamber 5 there is a temperature of at least 200 ° C. It is particularly preferable if the temperature in the first chamber 5 is higher than in the second chamber 6. It has turned out to be particularly advantageous for effective drying of the fibrous web W if a temperature in the first chamber 5 of 200 ° C. to 500 ° C., preferably 250 ° C. to 350 ° C., and in the second chamber 6 a temperature of 100 ° C to 350 ° C, preferably 100 ° C to 200 ° C. It can be seen that the two temperature ranges in the two chambers 5 and 6 partially overlap. However, the above statement applies to these temperature ranges, according to which there is preferably a higher temperature in the first chamber 5 than in the second chamber 6.

The different embodiments of Figures 1 to 5 differ essentially in the design of the drying device 4, in particular the air supply device 4a. The different embodiments of the drying device 4 and the air supply device 4a are described in detail below. In all the embodiments, the drying device 4 or the air supply device 4a can have a gas burner 9 and / or an electric heating element (not shown). All descriptions for the gas burner 9 thus also include the use of an electric heating element.

In the embodiment of the device 1 shown in FIG. 1, each of the two chambers 5 and 6 is each assigned a separate gas burner 9. The drying device 4 or the air supply device 4a is in principle identical for each of the two chambers 5 and 6. The gas burner 9 introduces the drying medium into the respective chamber 5 or 6 via a line 10 leading to the access 7 or 8. A gas supply line 11, a combustion air blower 12 and a circulating air blower 13 are connected to each of the gas burners 9.

While the combustion air blower 12 is supplied by a preheater or heat exchanger 14, the circulating air blower 13 sucks the air through an outlet 15 from the respective chamber 5 or 6 in order to supply it to the gas burner 9 and, appropriately heated, back in to manage the respective chamber 5 or 6. A combustion air line 16 and a supply air line 17 each lead to the heat exchanger 14. Furthermore, an exhaust air blower 18 and a silencer 19 are connected to the heat exchanger 14.

The two chambers 5 and 6 are thus heated completely independently of one another in the embodiment of FIG. 1, the gas burner 9 being supplied with fresh air and with air taken from the respective chamber 5 and 6, respectively.

In the embodiment of the device 1 according to FIG. 2, the two gas burners 9 are also provided, which are connected via respective lines 10 to the accesses 7 and 8 to the chambers 5 and 6, respectively. A separate gas burner 9 is therefore again provided for each of the chambers 5 and 6. The gas supply line 11 leading to the gas burner 9, the combustion air blower 12 and the circulating air blower 13 are also provided for the two chambers 5, 6. In contrast to the embodiment of FIG. 1, however, the output 15 is for

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Kterreichiiitiei palpriar.i the drying medium from the first chamber 5 is connected to the access 8 for the drying medium into the second chamber 6 by means of a connecting line 20. For this purpose, an additional exhaust air blower 21 is provided in the connecting line 20, which extracts the air from the first chamber 5 and guides it into the second chamber 6 via the gas burner 9, the line 10 and the access 8. As a result, the exhaust air from the first chamber 5 can be reused. In this way, energy can be saved and no disadvantages with regard to drying the fibrous web W are to be expected, since the temperature in the second chamber 6 is lower than that in the first chamber 5.

As in the embodiment of FIG. 1, the heat exchanger 14 is provided with the exhaust air blower 18 connected to the same and the muffler 19 following in the flow direction of the air. In contrast to the embodiment of Fig. 1, however, the heat exchanger 14 supplies the two chambers 5 and 6, i. H. only one heat exchanger 14 is provided.

In the embodiment of FIG. 3, in contrast to that of FIG. 2, a gas burner 9 is only provided for the first chamber 5, whereas the second chamber 6 is supplied with the drying medium exclusively by the exhaust air from the first chamber 5. Therefore, the heat exchanger 14 can be made simpler and, in addition to the second gas burner 9, the combustion air blower 12 can also be dispensed with. Similar to FIG. 2, the exhaust air blower 21 is again provided in the connecting line 20 connecting the two chambers 5 and 6, which sucks the drying medium out of the first chamber 5 and via the circulating air blower 13 also provided here and via the access 8 of the second Feeds chamber 6.

The embodiment of the device 1 according to FIG. 4 is very similar to that according to FIG. 3, i. H. here too, only one gas burner 9 is provided, namely that for the first chamber 5. The second chamber 6 is in turn supplied exclusively with the drying medium by the exhaust air from the first chamber 5. In contrast to the embodiment of FIG. 3, similar to the embodiment of FIG. 2, part of the drying medium or the air is fed through the heat exchanger 14 to the second chamber 6. Therefore, the heat exchanger 14 is in principle identical to that of the embodiment according to FIG. 2. In contrast to the embodiment in FIG. 2, however, it is not the combustion air blower 12, which is not present at all in the embodiment of FIG. 4, but the circulating air blower 13 is connected to the heat exchanger 14.

In the embodiment of Fig. 5 only the gas burner 9 is provided for the first chamber 5, i.e. here too, the second chamber 6 is supplied with the drying medium exclusively by the exhaust air from the first chamber 5. In addition, the drying medium is also removed from the first chamber 5 via the outlet 15 by means of the exhaust air blower 21 and fed into the second chamber 6 via the inlet 8. However, a return of the drying medium from the second chamber 6 into the second chamber 6, as is the case with the embodiments of FIGS. 1-4, is not provided, i. H. the outlet 15 from the second chamber 6 leads directly to the heat exchanger 14.

Claims (10)

1. Device for contactless deflection and drying of a fiber web (W), with a housing (2) around which the fiber web (W) is guided at least in sections and the outer surface of which forms a deflection element (3) for deflecting the fiber web (W) , and with a drying device (4) acting on one side of the fiber web (W), characterized in that the housing (2) has at least two separate chambers (5, 6), the at least two chambers (5, 6) each being separate Have accesses (7,8) for a drying medium, and at least in the first chamber (5), which first acts on the fiber web (W), there is a temperature of at least 200 ° C. 2. Device according to claim 1, characterized in that in the first chamber (5) there is a higher temperature than in a second chamber (6), which acts on the fiber web (W) after the first chamber (5). 3. Device according to claim 2, characterized in that in the first chamber (5) a temperature of 200 ° C to 500 ° C, preferably 250 ° C to 350 ° C, and in the second chamber (6) a temperature of 100 ° C to 350 ° C, preferably 100 ° C to 200 ° C. 4. Apparatus according to claim 1, 2 or 3, characterized in that an outlet (15) for the drying medium from the first chamber (5) is connected to the access (7) for the drying medium into the second chamber (6). 5. The device according to claim 4, characterized in that the outlet (15) for the drying medium from the first chamber (5) by means of a connecting line (20) with the access (7) for the drying medium in the second chamber (6) is connected , 6. The device according to claim 5, characterized in that an exhaust fan (21) is arranged in the connecting line (20). 7. Device according to one of claims 1 to 6, characterized in that the drying device (4) has at least one gas burner (9) and / or at least one electric heating element and / or at least one steam heating element. 8. The device according to claim 7, characterized in that each of the at least two chambers (5,6) is assigned a separate gas burner (9) and / or a separate electric heating element. 9. The device according to claim 7, characterized in that the two chambers (5, 6) are assigned a common gas burner (9) and / or a common electrical heating element. 10. Device according to one of claims 1 to 9, characterized in that the drying medium is a gas, in particular air.