DEVICE AND PROCESS FOR THE PRODUCTION OF NANOCELLULOSE

Abstract

The invention pertains to a device and a process for the production of nanofibers, in particular, nanocellulose from a fiber-containing mixture of substances, whereby the device is formed including at least one discharge element with a discharge opening for the passage of a fiber-containing mixture of substances, at least one feeding device for the supply of the fiber-containing mixture of substances to the discharge element with a predeterminable process pressure, at least one positioning device for the positioning of the discharge element and whereby, for the disintegrating of the fiber-containing mixture of substances, a moveable processing body is arranged opposite relative to at least one discharge element whereby on the passage of the fiber-containing mixture of substances through the discharge element a slit-like processing area is formed between the discharge element and the substance mixture-affected partial surface of the moveable processing body.

Claims

1. A device for the production of nanofibers from a fiber-containing substance mixture, the device including: at least one discharge element with a discharge opening, for the outlet of a fiber-containing substance mixture; at least one feeding device for the supply of the fiber-containing substance mixture at the discharge element with a predeterminable process pressure; at least one positioning device for the positioning of the at least one discharge element; and a moveable processing body for disintegrating of the fiber-containing substance mixture is arranged opposite relative to at least one discharge element, wherein on the outlet of the fiber-containing substance mixture through the discharge element a slit-like processing area between the discharge element and a substance mixture-affected partial area of the moveable processing body is formed.

2. The device according to claim 1, wherein the moveable processing body is formed to be driveable, by means of a drive unit, in a direction of movement, primarily sideways to one of the discharge element axes of the discharge element.

3. (canceled)

4. The device according to claim 1, wherein the moveable processing body is formed as a disc rotatable sideways to the discharge element.

5. The device according to claim 4, wherein the at least one positioning device is formed moveable parallel to a rotation axis of the disc, for the setting of a predeterminable radial distance of the discharge element axis from the rotation axis.

6. The device according to claim 1, wherein the discharge element is formed with at least in part a functional surface surrounding the discharge opening for the formation of a hydrodynamic bearing in the processing area.

7. The device according to claim 6, wherein the functional surface is formed with a larger longitudinal extension in the direction of movement than in the cross section and/or against the direction of movement.

8. The device according to claim 6, wherein the functional surface is formed essentially complementary in shape to the substance mixture-affected partial surface of the moveable processing body.

9. The device according to claim 1, wherein the at least one discharge element is formed adjustable to a predeterminable solid angle of the discharge element axis relative to the surface area of the moveable processing body.

10. The device according to claim 1, wherein the at least one positioning device is formed adjustable for the setting of an operating distance and/or a solid angle (26) between the at least one discharge element and the substance mixture-affected partial surface of the moveable processing body.

11. The device according to claim 1, wherein an end section of at least one discharge element is mounted at least partially moveable relative to the opposite lying substance mixture-affected partial surface.

12. The device according to claim 1, wherein at least two discharge elements are arranged symmetrically in the circumferential direction and/or the radial direction relative to the moveable processing body.

13. The device according to claim 1, wherein at least one second discharge element is arranged essentially opposite a first discharge element, wherein the first discharge element is allocated to a first surface area of the moveable processing body, and the corresponding, second discharge element is allocated to the second surface area lying opposite the first surface area.

14. The device according to claim 1, wherein at least two discharge elements are arranged along the direction of movement and/or normal to the direction of movement of the moveable processing body.

15. The device according to claim 2, wherein at least the moveable processing body is sealed off from the drive unit by a housing by means of a contacting and/or contact-free sealing component.

16. A process for the production of nanofibers from a fiber-containing substance mixture, the process including: moving a moveable processing body relative to at least one discharge element at a predeterminable relative speed; pressing a substance mixture through the at least one discharge element at a predeterminable process pressure, wherein the substance mixture includes at least one liquid component and fibers; processing the substance mixture through a formation of a slit-like processing area for disintegrating of fibers between the discharge element and a substance mixture-affected partial surface of the moveable processing body through the positioning of the discharge element relative to the moveable processing body.

17. The process according to claim 16, wherein the moveable processing body is moved, by means of a drive unit, in a direction of movement, primarily sideways to one of the discharge element axes of the discharge element.

18. The process according to claim 16, wherein at least one discharge element with a discharge opening formed with at least in part a functional surface is used for the formation of a hydrodynamic bearing between the discharge element and a substance mixture-affected partial surface.

19. The process according to claim 16, wherein the relative speed of the processing body moved for the setting of the shear forces formed in the slit-like processing area is controlled.

20. The process according to claim 16, wherein an operating distance between the at least one discharge element and the corresponding substance mixture-affected partial surface for the setting of compressive forces on the moving processing body is controlled by means of at least one positioning device.

21. The process according to claim 16, wherein a solid angle of a discharge element axis of at least one discharge element is controlled by means of at least one positioning device.

22. (canceled)

23. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0066] For better understanding of the invention, it is explained in more detail by means of the following figures:

[0067] There is shown in a highly simplified, schematic representation in:

[0068] FIG. 1 is a schematic cross-section representation through a discharge element and a processing body for explanation of the operating principle;

[0069] FIG. 2 is a schematic cross-section representation through a discharge element with a functional surface and a processing body for explanation of the operating principle;

[0070] FIGS. 3a-3b are schematic cross-section representation of possible design shapes of the device with two discharge elements that are allocated spaced in the circumferential direction to a first surface (a) and allocated to a first and second surface lying opposite (b);

[0071] FIGS. 4a-4c are schematic cross-section representation of processing bodies as cylinders (a), cones (b) and band (c) with several discharge elements;

[0072] FIGS. 5a-5d are schematic representation of a discharge element in cross-section tilted at a solid angle (a), with a flexible end section (b), with a form-matching functional surface (c), and in a bottom view (d);

[0073] FIG. 6 is a schematic overview presentation of a possible arrangement of a device for the production of nanofibers.

DETAILED DESCRIPTION

[0074] To begin with, it should be noted that in the differently described configurations the same components are given the same reference characters and/or the same component designations, whereby the disclosures contained in the complete description can be logically transferred to the same parts with the same reference characters and/or the same component designations. Also, the position specifications chosen in the description, such as, for example, up, down sideways, etc., refer to the directly described and illustrated figure and these position specifications must be transferred logically to the new positions in the event of a change of position.

[0075] In FIG. 1, a device 1 for the production of nanofibers 5, especially of nanocellulose 6, from a fiber-containing 3, especially pulp 4, substance mixture 2 is schematically represented. The principle of the disintegrating of the fiber-containing substance mixture 2 can be seen from the cross-section illustration. In accordance with the invention, a moveable processing body 7 is arranged relative to at least one opposite lying discharge element 11. Between the discharge element 11 and a substance mixture-affected partial surface 10 of the moveable processing body 7, a slit-like processing area 16 is formed.

[0076] As schematically represented in FIG. 1, the substance mixture 2 includes a liquid component as well as fibers 3, which can consist especially of pulp 4 or cellulose. The substance mixture 2 is pressed through the discharge element 11 at a predeterminable process pressure 15. In the process, the moveable processing body 7 can, for example, be passively moved in a relative movement through the discharge of the processed substance mixture 2 out of the processing area 16 in a direction of movement 23. Likewise, the processing body 7 can be actively moved, for example, as shown in FIG. 6, in the direction of movement 23 by a drive unit 20. On the passage of the fiber-containing 3 substance mixture 2 through the discharge element 11, the shear forces occurring in the slit-like formed processing area 16 are utilized for the disintegrating of the fibers 3, especially of the pulp 4 to nanofibers 5, especially nanocellulose 6.

[0077] The example configuration in FIG. 1 represents a processing body 7 formed as a disc 22. In this case, the processing body 7 is rotatable about a rotation axis 24 and/or flexibly mounted. The discharge element 11 has a discharge element axis 21, that essentially corresponds to an imaginary longitudinal axis through the discharge element 11 in the center of the discharge opening 12. As can be seen particularly clearly from the integrated view of FIG. 1 with FIG. 2, the relative speed 27 in the processing area 16 can be set through the radial distance 25 between the discharge element axis 21 and the rotation axis 24.

[0078] It can be seen from the integrated view of FIG. 1 with FIG. 2 up to FIG. 6 that in the direction of movement 23, the moveable processing body 7 is passed by at the discharge element 11. This relative movement takes place preferably primarily sideways, especially preferred normal to a discharge element axis 21.

[0079] FIG. 2 shows a further and possibly independent design of the invention-related device. In this design, the discharge element 11 has at least in part a functional surface 13 surrounding the discharge opening 12. As shown, the functional surface 13 can be formed in one piece with the discharge element 11. It is, however, conceivable that the functional surface 13 can be attached to the discharge element 11 as a part of an end section 14 or also as a separate component in order to ensure simple exchangeability. On the passing and/or pressing of the substance mixture 2 through the discharge element 11, a hydrodynamic bearing 29 can be formed in the processing area 16. In this case, the processing area 16 includes the functional surface 13 and the corresponding opposite lying substance-affected partial surface 10. Through the formation of a fluid wedge in the hydrodynamic bearing 29, the contact of the discharge elements 11 and/or the functional surface 13 with the processing body 7 can be avoided.

[0080] It can also be seen in FIG. 2 that the discharge element 11 has an operating distance 17 from the substance mixture-affected partial surface 10. Such an operating distance 17 can likewise be set for the device schematically represented in FIG. 1.

[0081] An example of the configuration of a positioning device 18 for the positioning of the discharge element 11 is shown in FIGS. 3a-4c and FIG. 6 and is logically transferable to FIGS. 1, 2 and 5a-5d. As is especially evident in the FIGS. 3a and 3b, the positioning device 18 can be used to move the at least one discharge element 11 in the direction of the processing body 7 and/or at right-angles to this. Such a positioning device 18 can be used especially for the setting of the operating distance 17.

[0082] In FIGS. 3a, b as well as in FIGS. 4a to 4c, devices 1 are schematically represented in which two or more discharge elements 11 are arranged relative to a processing body 7. Here, FIG. 3a shows two discharge elements 11 that are spaced apart from a first surface area 8 of the processing body 7 symmetrically from the rotation axis 24. In FIG. 3b a situation is schematically represented whereby two discharge elements lying essentially opposite and symmetrical to each other are arranged on a first surface area 8 respectively a second surface area 9 of the processing body 7. Through the design of the processing body 7 as a disc 22, in the designs represented in FIGS. 3a and b any bending moments on the disc 22 and thereby on the rotation axis can be compensated.

[0083] The feeding of the at least one discharge element 11 can in each case be achieved via a separate feeding device 19 or also via a common feeding device 19 for the supply of the fiber-containing 3 substance mixtures 2. For reasons of simplicity, the representation of such a feeding device 19 is dispensed with in FIGS. 1, 2, 4a-4c and 5a-5d.

[0084] The moveable processing body 7 can be formed invention-related as a rotationally symmetrical body such as a cylinder, a drum, a cone or a disc 22, as schematically represented in FIGS. 4a, 4b and 3a-3b. As an alternative, it is possible to form the moveable processing body 7 band-shaped, for example, as a chain or a belt as schematically shown in FIG. 4c. Especially in FIGS. 3a-3b and 4a-4c, it can be seen that several discharge elements 11 can be allocated to a commonly used processing body 7. In doing so, the moveable processing body 7 can be connected to a drive unit 20, as can be seen in FIGS. 3a-3b, 4a-4c and 6. Such a drive unit 20 can, for example, be configured as a hydraulic or pneumatic motor and, especially preferable, as an electric motor and be provided with a speed control.

[0085] The positioning device 18 schematically represented in FIGS. 3a-3b, 4a-4c and 6 can be formed as adjustable and/or positionable for the setting of the operating distance 17 and/or a solid angle 26 between the at least one discharge element 11 and the substance mixture-affected partial surface 10 of the moveable processing body. It is likewise imaginable, that by means of a common positioning device 18 several discharge elements 11 can be positioned together relative to the processing body. In addition, it can be seen in FIGS. 3a-3b and 4a-4c that at least two discharge elements 11 can be arranged in the circumferential direction and/or radial direction relative to the moveable processing body 7. In doing so, the discharge elements 11 can be arranged symmetrically and/or off set to each other on a first surface 8 and/or a second surface 9.

[0086] Not illustrated is a special configuration of cylinders, cones, belts or chains in which at least one second discharge element 11 is arranged essentially opposite a first discharge element 11 whereby the first discharge element 11 is allocated to a first surface area 8 of the moveable processing body 7 and the corresponding, second discharge element 11 is allocated to the second surface area 9 lying opposite the first surface area 8. This situation is discernible from FIG. 3b for a processing body 7 formed as a disc and can be extrapolated by a specialist to other rotationally symmetrical and/or band-shaped processing bodies 7.

[0087] In FIGS. 5a to 5d, several discharge elements 11 in different possible configurations are shown.

[0088] Here, FIG. 5a shows a discharge element 11 the discharge axis 21 of which is arranged at a preferred, predeterminable solid angle relative to the perpendicular of the substance mixture-affected partial surface 10 of the processing body 7. Such a positioning of the discharge element 11 can be carried out by means of a positioning device 18 as previously explained. From this schematic representation, the formation of a hydrodynamic bearing 29 can also be clearly seen.

[0089] Another example of a discharge element 11 is shown schematically in FIG. 5b, wherein an end section 14 of the discharge element 11 facing the substance mixture-affected partial area 10 is at least partially flexibly mounted.

[0090] In this way, a type of floating bearing of the end section 14 can be formed during the formation of the hydrodynamic bearing 29 without causing the jamming or clogging of the end section 14.

[0091] FIG. 5c shows a schematic sectional view through a discharge element 11, one discharge element opening surrounding functional surface 13 and a curved surface processing body 7. The functional surface 13 is essentially formed shape-complementary to the substance mixture-affected partial surface 10 of the processing body 7. Thereby, especially concave and convex shapes of the functional surface 13 are conceivable, as is especially clearly evident in FIG. 5c.

[0092] In FIG. 5d, another possible configuration of a discharge element 11 and a functional surface 13 is suggested schematically in a bottom view. Thereby, the functional surface 13 is formed with a larger longitudinal extension in the direction of movement 23 than in the cross section and/or against the intended direction of movement 23. The motion arrows shown indicate schematically the homogenous discharge of the processed substance mixture 2. When using such a shaped functional surface 13, the shape can be optimized by a specialist for the respective application and the geometry of the processing body 7. The processing area 16 should, as previously explained, essentially be formed between the functional surface 13 and the corresponding substance mixture-affected partial surface 10.

[0093] According to the invention, the discharge elements 11 and their combination shown in FIGS. 5a to 5d can be included in the descriptions of FIGS. 2, 3a-3b, 4a-4c and 6 and for reasons of brevity are not discussed separately but are referenced to the appropriate discussions.

[0094] FIG. 6 shows a general schematic view of the invention-related device 1. Here there is simply a discharge element 11 aligned relative to the moveable processing body 7. The positioning of the discharge element 11 is done by means of a positioning device 18. The feeding of the substance mixture 2 takes place via a feeding device 19. The processing body 7 formed as a disc 22 is driven in the direction of movement 23 by a drive unit 20.

[0095] As can be seen from FIG. 6, the device 1 has a housing 28 that is shown in the open state. The housing 28 serves for substance capture during processing and can be sealed off from at least the drive unit 20 by means of one or more sealing elements 30. Examples of such sealing elements 30 can also be seen in FIGS. 3a-3b and can be formed as contact or also non-contact. The processed substance mixture 2 can be collected in a collection tank 31. It is also conceivable that the feeding device 19 can be connected to the collection tank 31 in order to create a circulation principle.

[0096] Within the scope of the present invention, the individual process steps can also be automated and preferably, be controlled by a central, not illustrated, system controller. In addition, operation by means of a control panel or also a touchscreen for the monitoring and control of the system is envisaged.

[0097] The setting of a predeterminable dispersion of fiber lengths and/or fiber cross-sections and/or their distribution can be specified by the user and be controlled by means of a system controller. The repeated throughput of at least parts of the processed substance mixture 2 can also be used for the setting of the homogeneity and/or quality of the nanofibers 5 respectively, nanocellulose 6.

[0098] The consistency of the substance mixture 2 can have an influence on the quality of the processed substance mixture 2. With the present device 1 and the corresponding processes, suspensions, that is, substance mixtures 2, with a fiber content of 0.1 to approx. 10 vol. %, preferably 1 to approx. 8 vol. %, can be reliably and easily processed. Consistencies up to 25 vol. % and over are also conceivable. Here, under certain circumstances, it may be necessary that the specialist falls back on suitable feeding devices 19 that are capable of delivering substance mixtures 2 with such high consistencies under the application of a sufficiently high process pressure 15. Especially suitable for this are, for example, high pressure feed screw configurations.

[0099] The embodiments show possible design variants, whereby at this point it is noted that the invention is not limited to the specific design variants described, in fact much more is possible, even various combinations of the individual design variants with each other, and this possibility of variation is due to the teaching of technical action through objective creation lying in the skills of the specialist active in this technical area.

[0100] The scope of protection is determined by the claims. The description and the drawings, however, must be used for the interpretation of the claims. Individual features or feature combinations from the illustrated and described various embodiments can represent stand-alone, innovative solutions. The underlying task for the stand-alone innovative solutions can be taken from the description.

[0101] All information about the value ranges in the representational description should be understood to include any and all sub-areas thereof, for example, the specification 1 to 10 must be understood to include all sub-areas starting from the lower limit 1 and the upper limit 10, this means that all sub-areas start with a lower limit, 1, or greater and end at an upper limit of 10 or less, for example, 1 to 1.7, or 3.2 to 8.1 or 5.5 to 10.

[0102] For the sake of good order, it should be noted that for better understanding of the design, some elements have been illustrated not to scale and/or enlarged and/or scaled down.

REFERENCE CHARACTER LIST

[0103] 1 Device [0104] 2 Substance mixture [0105] 3 Fiber [0106] 30 Sealing element [0107] 31 Collection tank [0108] 4 Pulp [0109] 5 Nanofiber [0110] 6 Nanocellulose [0111] 7 Processing body [0112] 8 First surface [0113] 9 Second surface [0114] 10 Substance mixture-affected partial surface [0115] 11 Discharge element [0116] 12 Discharge opening [0117] 13 Functional surface [0118] 14 End section [0119] 15 Process pressure [0120] 16 Processing area [0121] 17 Operating distance [0122] 18 Positioning device [0123] 19 Feeding device [0124] 20 Drive unit [0125] 21 Discharge element axis [0126] 22 Disc [0127] 23 Direction of movement [0128] 24 Rotation axis [0129] 25 Radial distance [0130] 26 Solid angle [0131] 27 Relative speed [0132] 28 Housing [0133] 29 Hydrodynamic bearing