DEVICE FOR REDUCING A MOISTURE CONTENT OF A MOIST, FIBER-CONTAINING MATERIAL

Abstract

A device for reducing a moisture content of a moist, fiber-containing material has a double-belt press with a first endless belt and a second endless belt of metal, wherein a pressing zone for pressing liquid out of the fiber-containing material is configured between the first endless belt and the second endless belt, wherein, further, a belt of a liquid-absorbing material that is guided between the two endless belts and through the pressing zone is arranged, wherein a surface of the belt liquid-absorbing material that faces the first endless belt forms a contact surface for the fiber-containing material.

Claims

1. A device (1) for reducing a moisture content of a moist, fiber-containing material (2), wherein the device has a double-belt press with a first endless belt (3) and a second endless belt (4), wherein a pressing zone (5) for pressing liquid out of the fiber-containing material (2) is configured between the first endless belt (3) and the of the second endless belt (4), wherein, further, a belt (6) of a liquid-absorbing material that is guided between the two endless belts (3, 4) and through the pressing zone (5) is arranged, wherein a surface of the belt (6) of liquid-absorbing material that faces the first endless belt (3) forms a contact surface for the fiber-containing material (2), wherein an outer side of the belt (13) of the second endless belt (3) that faces the belt (6) of liquid-absorbing material has channels (14) for discharging the liquid that run in a circumferential direction of the second endless belt (3), or diagonally to the circumferential direction of the second endless belt (3), preferably circumferential channels (14) that run in a closed loop in a circumferential direction of the second endless belt (3), wherein the channels (14) preferably have a depth between 50 ?m and 1000 ?m, in particular between 70 ?m and 300 ?m.

2. The device according to claim 1, wherein the first and the second endless belt are manufactured of metal.

3. The device according to claim 1, wherein the belt (6) of liquid-absorbing material is configured as an endless belt.

4. The device according to claim 1, wherein the first endless belt (3) and the second endless belt (4) and the belt (6) of liquid-absorbing material are driven and are each arranged circumferentially between at least two rollers (7, 8, 9, 10, 11, 12).

5. The device according to claim 4, wherein at least one of the rollers (7, 8, 9, 10, 11, 12) is heated.

6. The device according to claim 1, wherein the first endless belt (3) has a circumferential length selected from the range from 3 m to 200 m, the second endless belt (4) has a circumferential length selected from the range from 3 m to 200 m and the belt (6) of liquid-absorbing material has a circumferential length selected from the range from 5 m to 250 m.

7. The device according to claim 1, wherein the first endless belt (3) and the second endless belt (4) each have a thickness selected from the range from 0.1 mm to 3.5 mm, in particular from 0.2 mm to 1.5 mm, wherein the belt (6) of liquid-absorbing material has a thickness selected from the range from 1 mm to 10 mm, in particular from 2 mm to 4 mm.

8. The device according to claim 1, wherein a width of the first endless belt (3) and a width of the second endless belt (4) and a width of the belt (6) of liquid-absorbing material, in each case, is greater than 0.5 m, preferably greater than 1.5 m, particularly preferably greater than 4 m.

9. (canceled)

10. The device according to claim 1, wherein the bottom endless belt (3) has cups (15), in particular blind holes, on the outer side of the belt for receiving the liquid.

11. The device according to claim 10, wherein the cups (15) are arranged next to and/or between the channels (14) and end in the channels (14) and/or are connected with the channels (14) via conduits.

12. The device according to claim 1, wherein the belt (6) of liquid-absorbing material is configured as a belt of a textile fabric, in particular of a non-woven textile fabric, in particular felt or fiber web.

13. The device according to claim 1, wherein the belt (6) of liquid-absorbing material has a weight per unit area selected from the range from 500 g/m.sup.2 to 2500 g/m.sup.2 and/or a tensile strength selected from the range from 30 N/mm to 90 N/mm.

14. The device according to claim 1, wherein the belt (6) of liquid-absorbing material is also configured as permeable to liquid.

15. The device according to claim 1, wherein, in the in the pressing zone (5), a pressure between 0.1 to 20 MPa is ensured between the first endless belt (3) and the second endless belt (4).

16. The device according to claim 1, wherein the second endless belt (4) is guided downwards, away from the belt (6), by means of at least one deflection device (17), in particular by means of at least one deflection roller, in at least one liquid suction zone (16) arranged upstream and/or downstream of the pressing zone (5) in a transport direction of the material (2), which liquid suction zone (16) serves to suck off the liquid pressed out of the fiber-containing material (2) in the pressing zone (5), so that the belt (6) of liquid-absorbing material does not rest against the second endless belt (4) in the liquid suction zone (16) and a free space (18) between the belt (6) of liquid-absorbing material and the second endless belt (4) is formed in the liquid suction zone (16), wherein the device (1) has a device (19) for sucking the liquid in the region of the free space (18) off the second end-less belt (4) in particular a suction device, for example in the form of a suction pump and/or vacuum chamber with at least one inflow for the liquid, wherein the belt (6) of liquid-absorbing material rests against the second endless belt (4) in the pressing zone (5).

17. The device according to claim 1, wherein a separation zone (20) is arranged downstream of the pressing zone (5) in a transport direction of the fiber-containing material (2), wherein the second endless belt (4) is guided away from the first endless belt (3) together with the belt (6) of liquid-absorbing material by means of at least one deflection device (21), in particular by means of at least one deflection roller, in the separation zone (20), wherein a gap (22) is formed between the belt (6) of liquid-absorbing material and the first endless belt (3) in the separation zone (19).

18. The device according to claim 17, wherein at least one nozzle for generating a gas flow, in particular an air knife (23), is arranged in the gap (22) in the separation zone (20) and is directed opposite the transport direction of the material (2) and between the belt (6) of liquid-absorbing material and the first endless belt (3).

19. The device according to claim 17, wherein an impingement drying device (24) with at least one air outlet directed against a side of the fiber-containing material (2) that faces the belt (6) of liquid-absorbing material is arranged in the gap (22) in the separation zone (20).

20. The device according to claim 1, wherein, to extend the process line, the fiber-containing material (2) is guided further, from a side (3a) of the first endless belt that faces the second endless belt (4) to a side of the first endless belt (3) that faces away from the second endless belt (4).

21. An endless belt (3) for the device according to claim 1, wherein an outer side of the belt (13) of the endless belt (3) has cups (15), in particular blind holes, for receiving the liquid and/or has channels (14) for discharging the liquid that run in a circumferential direction of the endless belt (3), or diagonally to the circumferential direction of the endless belt (3), preferably channels (14) that run in a closed loop in a circumferential direction of the second endless belt (3), wherein the channels (14) preferably have a depth between 50 ?m and 1000 ?m, in particular between 70 ?m and 300 ?m.

22. The endless belt according to claim 21, wherein the cups (15) are arranged next to and/or between the channels (14) and end in the channels (14) and/or are connected with the channels (14) via conduits.

23. The endless belt according to claim 21, wherein the endless belt is manufactured of metal.

Description

[0030] FIG. 1 a device in accordance with the invention and

[0031] FIG. 2 a detailed perspective view of an outer side of a second endless belt of a double-belt press of the device from FIG. 1.

[0032] First of all, it is to be noted that, in the different embodiments described, equal parts are provided with equal reference numbers and/or equal component designations, where the disclo-sures contained in the entire description may be analogously transferred to equal parts with equal reference numbers and/or equal component designations. Moreover, the specifications of location, such as at the top, at the bottom, at the side, chosen in the description refer to the directly described and depicted figure, and in case of a change of position, these specifications of location are to be analogously transferred to the new position.

[0033] Any and all specifications of value ranges in the description at issue are to be understood to comprise any and all sub-ranges of same, for example the specification between 1 and 10 is to be understood to mean that any and all sub-ranges starting from the second limit 1 and from the first limit 10 are comprised therein, i.e. any and all sub-ranges start at a second limit of 1 or larger and end at a first limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0034] In accordance with FIG. 1, a device in accordance with the invention has a double-belt press with a first endless belt 3 and a second endless belt 4 for reducing a moisture content of a moist, fiber-containing material 2. Preferably, the two endless belts 3 and 4 are metal belts, such as, e.g., steel belts. Yet, generally, the endless belts 3 and 4 can also be made from other materials, such as plastics, composites, e.g. fiber-reinforced plastics, etc.

[0035] In the region designated with I, there is an inlet for the material 2 into the double-belt press, whereas the region designated with II represents an outlet for the material 2. Here, the material 2 is transported through the double-belt press in the direction represented with an arrow, from left to right in the drawing. The material 2 can be applied to the top endless belt 3 with a pouring device 2a, for example, such as this is represented in FIG. 1. Yet, alternatively, the material 2 can also be applied in region I, or be supplied to region I and/or the inlet already as a fiber web. It should be noted in this context that the double-belt press, as represented in FIG. 1, can be horizontally aligned, so that inlet I and outlet II are located essentially in succession, viewed in a horizontal direction, or it can also be vertically aligned, so that inlet I and outlet II are located at different heights, viewed in a vertical direction. In other words, a longitudinal center line of the double-belt press can run parallel to the horizontal line or vertical line, or it can also enclose an angle with the horizontal line or vertical line. The double-belt press can therefore have any alignment in space.

[0036] A region between a side 3a of the first endless belt 3 and a side 4a of the second endless belt 4 is configured as a pressing zone 5 for pressing liquid out of the fiber-containing material 2. The fiber-containing material 2 can be a fiber web, for example. Preferably, the fibers are cel-lulose fibers from renewable resources. The liquid can be water, for example. In this case, the device 1 serves to reduce the water content in the fiber-containing material 2.

[0037] In the pressing zone 5, the two endless belts 3, 4 can be pressed against each other with, preferably pressure-loaded, rollers, roller carpets, sliding plates and/or hydraulic and/or hydro-static pressure means, for example, which are not represented here, in order to exert a pressing force on the fiber-containing material 2. Yet, it is also possible to set the size of a pressing gap in the pressing zone 5 bounded by the two endless belts 3, 4 to a fixed value, wherein, when running through the pressing gap, the fiber-containing material 2 is compressed and liquid is pressed out of the material 2 in accordance with the distance between the side 3a of the first endless belt 3 from the side 4a of the second endless belt 4.

[0038] Preferably, a pressure between 0.1 to 20 MPa (1 to 200 bar) is exerted on the fiber-containing material 2 in the pressing zone 5. A pressure between 0.1 to 20 MPa is therefore ensured between the first endless belt 3 and the second endless belt 4 in the pressing zone 5.

[0039] Further, a belt 6 of a liquid-absorbing material is guided between the two endless belts 3, 4 and through the pressing zone 5. Particularly preferably, the material of the belt 6 is configured as not only liquid-absorbing but also permeable to liquid. A surface of the belt 6 of liq-uid-absorbing material that faces the first endless belt 3 forms a contact surface and/or a sup-porting surface for the fiber-containing material 2. The belt 6 serves to receive liquid from the material 2 and rests against the side 4a of the second endless belt 4 in the pressing zone 5.

[0040] The belt 6 can also be configured as an endless belt. Preferably, the belt 6 is configured as a belt of a textile fabric, in particular of a non-woven textile fabric, in particular felt or fiber web. A weight per unit area of the material from which the belt 6 is made can advantageously be between 500 g/m.sup.2 and 2500 g/m.sup.2. Further, the belt 6 can have a tensile strength between 30 N/mm to 90 N/mm.

[0041] As can further be gleaned from FIG. 1, the top endless belt 3, the bottom endless belt 4 and the belt 6 of liquid-absorbing material can each be arranged circumferentially between at least two rollers 7, 8, 9, 10, 11, 12. Each of the abovementioned belts can be driven separately. For example, the rollers 8, 10, 12 can be configured as drive rollers and the rollers 7, 9, 11 can be configured as deflection rollers, or vice versa. Further, one or multiple of the rollers 8-12 can be configured as heated. Preferably, the roller 8 is configured as a heated drum here.

[0042] Lengths and widths of the belts can vary. For example, the top endless belt 3 and the bottom endless belt 4 can each have a circumferential length between 3 m to 200 m and the belt 6 of liquid-absorbing material can have a circumferential length between 5 m to 250 m. Here, the belt 6 is larger in its circumferential length than the bottom endless belt 4. Also, the first end-less belt 3 can have a smaller circumferential length than the bottom endless belt 4, for example. However, this is not imperatively so: the endless belts 3 and 4 can also have the same circumferential length. Yet, it is also possible that the bottom endless belt 4 has a smaller circumferential length than the top endless belt 3.

[0043] Further, the top endless belt 3 and the bottom endless belt 4 can each have a thickness between 0.1 mm and 3.5 mm, in particular between 0.2 mm and 1.5 mm. In a dry state, the belt 6 of liquid-absorbing material preferably has a thickness between 1 mm and 10 mm, in particular between 2 mm to 4 mm.

[0044] A width of the first endless belt 3 and of the second endless belt 4, as well as of the belt 6, can be greater than 0.5 m, preferably greater than 1.5 m, particularly preferably greater than 4 m.

[0045] As can be seen from FIG. 2, an outer side of the belt 13 of the second endless belt 4 that faces the belt 6 of liquid-absorbing material can have channels 14 that run in a circumferential direction of the second endless belt 4, or diagonally to the circumferential direction of the second endless belt 4. Preferably, the channels 14 form a closed loop in a circumferential direction of the second endless belt 4. The channels 14 serve to discharge the liquid which is trans-mitted from the material 2 onto the belt 6. As the belt 6 is pressed against the outer side of the belt 13 of the endless belt 4 in the pressing zone 5, liquid can be pressed out of the belt 6 and drain into the channels 14. Preferably, the channels 14 have a depth between 50 ?m and 1000 ?m, in particular between 70 ?m and 300 ?m.

[0046] To further improve the discharge of liquid, it can be provided that the bottom endless belt 4 has cups 15, in particular blind holes, for receiving the liquid on the outer side of the belt. The cups 15 can be arranged next to and/or between the channels 14 and be connected with the channels 14. For example, the cups 15 can end in the channels or be connected with the channels 14 via conduits. A diameter of the cups 15 can be greater than a width of the channels 14, for example. Yet, it is also possible to provide only the cups 15 or only the channels 14 in the endless belt 4.

[0047] As can further be seen from FIG. 1, the side 4a of the second endless belt 4 can be guided downwards, away from the belt 6 by means of at least one deflection device 17, for example by means of deflection rollers, in a liquid suction zone 16 arranged upstream of the pressing zone 5 in a transport direction of the material 2, which liquid suction zone 16 serves to suck off the liquid pressed out of the fiber-containing material 2. In the liquid suction zone 16, therefore, the belt 6 does not rest against the side 4a, nor, therefore, against the outer side of the belt 13 of the second endless belt 4 represented in FIG. 2. Yet, alternatively to the representation in FIG. 1, the liquid suction zone 16 can also be arranged downstream of the pressing zone 5. Further, a liquid suction zone 16 can also be arranged upstream of the pressing zone 5, and a second liquid suction zone 16 downstream of the pressing zone 5.

[0048] In the free space 18 created in the liquid suction zone 16 between the belt 6 and the side 4a of the second endless belt 4, the liquid can be sucked off the outer side of the belt 13 (FIG. 2). To suck off the liquid, a device 19, in particular a suction device, for example in the form of a suction pump and/or vacuum chamber with at least one inflow for the liquid, can be provided. The device 19 can be used to create a vacuum, whereby the liquid can flow along the channels 14 on the outer side of the belt 13 in a direction towards the device 19 and be sucked off the outer side of the belt 13. In this manner, the liquid pressed out of the material 2 can be drained in a simple manner. Here, the sucking off of the liquid is done opposite the transport direction of the material 2 by the device 1 if the liquid suction zone 16 is arranged upstream of the pressing zone 5. This means that the liquid flows in the channels 14 opposite the feeding direction of the material 2 and/or the direction of circulation of the second endless belt 4 and of the belt 6. If the liquid suction zone 16 is arranged downstream of the pressing zone 5, the sucking off of the liquid is preferably done in a transport direction of the material 2.

[0049] A separation zone 20 can be arranged downstream of the pressing zone 5 in a transport direction of the material 2. In the separation zone 20, the side 4a of the second endless belt 4 is guided downwards, away from the first endless belt 3, together with the belt 6 by means of at least one deflection device 21, in particular by means of at least one deflection roller. Between the belt 6 and the side 3a of the first endless belt 3, a gap 22 is formed in the separation zone 19.

[0050] In the gap 22, an air knife 23 directed opposite the transport direction of the material 2 and between the belt 6 and the side 3a of the first endless belt 3 can be arranged. In this manner, the material 2, which adheres in part to an outer side of the side 3a can be separated from the belt 6, so that it then only adheres to the side 3a and is transported by same to the outlet II, where it can be detached from the first endless belt 3, for example by means of a scraper or of a stripping roller, not represented here in more detail. After being detached from the first end-less belt 3, the material 2 can be subjected to further processing steps.

[0051] Further, an impingement drying device 24 with at least one air outlet directed opposite a side of the side 3a of the first endless belt 3 that faces a web of fiber-containing material 2 can be arranged in the gap 22 in order to further increase the degree of dryness of the material 2 before it is detached from the first endless belt.

[0052] Further, it can be provided that, to extend the process line, the fiber-containing material 2 is guided further, from the side 3a of the first endless belt 3 that faces the second endless belt 4 to a side of the first endless belt 3 that faces away from the second endless belt 4. In the representation of FIG. 1, this means that the material 2 is guided around the roller 8 and remains on the first endless belt 3, so that the material 2 is transported to the side on which the merely op-tional pouring device 2a is marked with dashed lines. The stripping of the material 2 off the endless belt 3 can then be done by means of a stripping device, for example.

[0053] Finally, as a matter of form, it should be noted that for ease of understanding of the structure, elements are partially not depicted to scale and/or are enlarged and/or are reduced in size.

TABLE-US-00001 Table of reference numbers 1 device 2 material 2a pouring device 3 endless belt 3a side 4 endless belt 4a side 5 pressing zone 6 belt 7 roller 8 roller 9 roller 10 roller 11 roller 12 roller 13 outer side of belt 14 channels 15 cups 16 liquid suction zone 17 deflection device 18 free space 19 device 20 separation zone 21 deflection device 22 gap 23 air knife 24 impingement drying device