Rotatingly Drivable Grinding Media Mill for Obtaining Polyisoprene and/or Other Apolar Materials

Abstract

The present invention relates to a grinding media mill (2) for obtaining polyisoprene and/or other apolar materials from raw plant materials, having a drum (4) which is peripherally closed and has a milling chamber (10) that is peripherally closed and located in the interior of the drum (4). The aim of the invention is to create a grinding media mill that enables careful processing of the raw plant materials, on the one hand, but is also variable in processing intensity and throughput time, on the other hand. This aim is achieved, according to the invention, in that the milling chamber (10) is divided into a plurality of sections along the rotation axis (6) by partitions arranged crosswise to the rotation axis (6), the partitions have passage openings through which the ground product mixture can pass from one section into an adjacent section, wherein the passage openings are sized such that they retain the grinding media located in a section, and the motor (8) is provided with an apparatus (38) by means of which the rotational speed of the drum (4) is variably adjustable.

Claims

1-20. (canceled)

21. A grinding media mill for obtaining polyisoprene and/or other apolar materials from plant raw materials, the grinding media mill comprising: a motor; a peripherally closed drum, configured to be driven in rotation about an axis of rotation by the motor; the peripherally closed drum comprising a peripherally closed milling chamber located in an interior of the peripherally closed drum and configured to receive grinding media; a feed device arranged at a first end of the peripherally closed drum and configured to feed a material mixture to be ground, comprised of solids and a liquid, into the peripherally closed drum through a rotary feedthrough; a discharge device arranged at a second end of the peripherally closed drum opposite the first end, the discharge device configured to discharge the material mixture to be ground that has been processed in the peripherally closed milling chamber from the peripherally closed drum; the peripherally closed milling chamber divided along the axis of rotation into sections by partitions arranged transversely to the axis of rotation in the interior of the peripherally closed drum, wherein the partitions comprise passage openings through which the material mixture to be ground can pass from one of the sections into a neighboring one of the sections, respectively; wherein the passage openings are dimensioned to retain the grinding media in the sections, respectively; and wherein the motor comprises a device configured to variably adjusted a rotational speed of the peripherally closed drum.

22. The grinding media mill according to claim 21, wherein at least one of the partitions comprises a cutout arranged in a region around the axis of rotation, wherein the cutout comprises a radius in at least one part of a circular arc covered by the cutout, wherein the radius of the cutout is larger than a radius of the axis of rotation in a region of said at least one partition.

23. The grinding media mill according to claim 21, wherein the sections of the peripherally closed drum each comprise an outer wall and wherein the outer wall of at least one of the sections comprises an opening permeable for the material mixture to be ground, wherein the opening is adjoined in a radially outward direction of said at least one section by a closed receiving chamber, wherein process tools are arranged in the receiving chamber.

24. The grinding media mill according to claim 21, wherein the sections among each other are furnished with a different quantity of grinding media and/or with grinding media of different sizes.

25. The grinding media mill according to claim 21, wherein at least one of the sections comprises feed and removal openings configured to supply grinding media and/or to remove grinding media.

26. The grinding media mill according to claim 21, wherein the feed device comprises a drivable forced feed action arranged in front of the rotary feedthrough and/or in the rotary feedthrough.

27. The grinding media mill according to claim 26, wherein the forced feed action is arranged coaxially to the axis of rotation of the peripherally closed drum.

28. The grinding media mill according to claim 21, wherein the axis of rotation of the peripherally closed drum is angularly positioned relative to the horizontal.

29. The grinding media mill according to claim 21, wherein an inner surface of at least one of the sections comprises no cylindrical basic shape.

30. The grinding media mill according to claim 21, wherein the peripherally closed drum comprises pipe segments connected to each other along the axis of rotation of the peripherally closed drum.

31. The grinding media mill according to claim 30, wherein the pipe segments comprise flange surfaces, wherein the flange surfaces are congruent to each other and are connected to each other by connection elements.

32. The grinding media mill according to claim 21, further comprising four or more rollers, wherein at least one of the four or more rollers is motor-driven, wherein the peripherally closed drum is supported on the four or more rollers.

33. The grinding media mill according to claim 21, further comprising a feed container, wherein the feed container is configured to meter the material mixture to be ground or a part of the material mixture to be ground to the feed device.

34. The grinding media mill according to claim 33, further comprising a feed conduit connected to the feed device and/or connected to the feed container, wherein the feed conduit is configured to meter liquid and/or gaseous substances into the feed device and/or into the feed container.

35. The grinding media mill according to claim 21, further comprising: an electronic control unit connected to the device configured to variably adjusted a rotational speed of the peripherally closed drum; sensors connected to the electronic control unit and configured to detect process-technological parameters of the grinding media mill and transmit sensor signals of the process-technological parameters to the electronic control unit; actors configured to change the process-technological parameters of the grinding media mill; wherein the electronic control unit comprises software configured to evaluate the sensor signals and wherein the electronic control unit is configured to control the actors as a function of the evaluation of the sensor signals by the software and/or by manual operating inputs of an operator.

36. The grinding media mill according to claim 35, wherein the sensors include at least one sensor arranged in the peripherally closed milling chamber for process monitoring.

37. The grinding media mill according to claim 36, wherein said at least one sensor is arranged in the peripherally closed milling chamber adjacent to the axis of rotation.

38. The grinding media mill according to claim 21, wherein an end wall of the peripherally closed drum arranged at the second end of the peripherally closed drum comprises control ports.

39. The grinding media mill according to claim 21, wherein the peripherally closed milling chamber comprises a conically tapering constriction at the second end of the peripherally closed drum.

40. A method for obtaining natural rubber from biological raw materials, wherein the method comprises: extracting the natural rubber in the grinding media mill according to claim 1 and agglomerating the natural rubber in the peripherally closed drum by driving the peripherally closed drum in rotation.

Description

[0037] The invention will now be explained with the aid of a preferred embodiment as well as with reference to the attached drawings in more detail.

[0038] It is shown in:

[0039] FIG. 1: a side view of a grinding media mill;

[0040] FIG. 2: a section view of the drum illustrated in FIG. 1;

[0041] FIG. 3: an enlarged detail view of a feed device;

[0042] FIG. 4: a view of a drum with an ascending axis of rotation;

[0043] FIG. 5: a view of a partition;

[0044] FIG. 6: a view of the feed side of the grinding media mill;

[0045] FIG. 7: a view of the discharge side of the grinding media mill; and

[0046] FIG. 8: a cross section view of the drum with a receiving chamber.

[0047] In FIG. 1, a side view of a grinding media mill 2 is illustrated. The grinding media mill 2 comprises a drum 4 through which a material mixture to be ground is conveyed in order to remove the natural rubber contained in a plant raw material and to agglomerate the natural rubber so that it can be removed as an agglomerate easily from the material mixture to be ground and separated therefrom.

[0048] The drum 4 is rotatably supported about an axis of rotation 6. Axis of rotation 6 can be designed as a real shaft but it can also be provided only by the type and manner of the support of the drum 4. The drum 4 is caused to rotate by the two motors 8 shown in the illustrated embodiment. Within the drum 4, there is a milling chamber 10 in which the material mixture to be ground is worked on by grinding media that are located in the milling chamber 10. The grinding media are not illustrated in the Figures.

[0049] The drum 4 comprises a first end face 12 from where the material mixture to be ground is fed into the milling chamber 10. After passing through, the material mixture to be ground exits again from the milling chamber 10 via the discharge device 18 which is located in the region of the second end face 14. The material mixture to be ground is supplied by a separate feed device 16 to the milling chamber 10 through a rotary feedthrough 20. A rotary feedthrough can also be provided in the region of the discharge device 18.

[0050] In order to be able to fill and remove again grinding media into the milling chamber 10, a number of openings 22 are provided in the wall of the drum 4. The openings 22 can be correlated with a respective section within the milling chamber 10.

[0051] In the embodiment, the drum 4 is assembled of a plurality of six pipe segments 24. Each pipe segment 24 comprises a flange surface 26 at the end face that is embodied congruent to the flange surfaces 26 of other pipe segments 24. By a simple positioning of the flange surfaces 26 against each other, arbitrary pipe segments 24 can thus be assembled to a drum 4 in an also principally arbitrary orientation. The pipe segments 24 can have different lengths along the axis of rotation 6 and diameters. The diameters of the pipe segments 24 can also vary across their length in direction of the axis of rotation 6.

[0052] In the embodiment, the drum 4 is supported at its outer circumference on rollers 28. The two rollers 28 illustrated in FIG. 1 are driven by the motors 8. In the embodiment, the rollers 28 run along the outer edges of the flange surfaces 26 so that they form a circumferential running surface.

[0053] The material mixture to be ground can be supplied to the milling chamber 10 via the feed container 30. For this purpose, the material mixture to be ground is filled from above into the feed container 30. From here, it is then supplied through the rotary feedthrough 20 to the milling chamber 10. In the embodiment, the feed container 30 comprises an additional feed conduit 32 by means of which liquids or gases can be added to the material mixture to be ground. Due to the arrangement of the feed conduit at the feed side of the drum 4, it is possible to additionally liquefy the material mixture to be ground, to loosen it, or to additionally decompose the biological raw materials when the medium conveyed through the feed conduits 32 is introduced at high pressure or at a high temperature into the feed device 16. Thus, the feed conduits 32 can supply, for example a liquid, which decomposes the cell structures of the plant raw materials by mechanical action and/or thermally, through a steam nozzle or a spray valve.

[0054] The discharge device 18 can be provided with an end wall 34 that delimits the discharge device 18.

[0055] The working processes that are performed by the grinding media mill 2 can be adjusted and controlled by a control unit 36. The control unit 36 is connected to the devices 38 by means of which the rotational speed of the drum 4 can be variably adjusted. The device 38 can be an output regulator for the motor 8. However, also other configurations for the device 38 are possible, for example, a planetary transmission or stepless transmission with which the rotational speed of the drum 4 is variably adjustable.

[0056] The control unit 36 is connected by means of corresponding connection lines 40 to the devices 38 as an example of a rotational speed control, the actor 44 as an on-off switch or rotational speed regulator for the feed device 16 as well as a camera 42 as an example of a sensor. The connection lines 40 can be realized as connection cables but there are also other connection types possible, for example, a wireless connection by radio communication, by optical waveguides, or other media for transmitting data.

[0057] In the embodiment illustrated in FIG. 1, the drum 4 is supported by a total of four rollers 28 of which the two rollers 28 illustrated in the front are driven by a motor 8, respectively. Depending on the length and weight of the drum 4, additional rollers 28 can be provided also. It is also possible to drive more or only a single roller 28 by a motor.

[0058] In FIG. 2, a section view of the drum 4 illustrated in FIG. 1 is shown. In the section view a total of six partitions 46 can be seen that divide the milling chamber 10 into seven sections 48. In each of the sections 48, grinding media can be arranged wherein the number, the weight, the shape, and the size of the grinding media can vary between the individual sections 48. The selection of the grinding media to be respectively introduced into a section 48 has an effect on the decomposition of the biological raw materials, the dissociation of the natural rubber from the biological raw materials as well as on the agglomeration of this natural rubber.

[0059] The section illustration illustrated in FIG. 2 shows that the inner surfaces 50 of the outer walls 52 are not embodied plane-parallel to the axis of rotation 6 but comprise a conical basic shape. In deviation from the embodiment, the inner surfaces can be designed, of course, also cylindrical or in other ways. By means of the setting angle of the outer walls 52 or of the inner surfaces 50 relative to the axis of rotation 6, it is possible to affect as a whole the flow rate of the material mixture to be ground through the sections 48 and the milling chamber 10. While the wall with the inner surface 50 of the first pipe segment 24, comprises a setting angle relative to the axis of rotation 6 of 85 degrees, the inner surface 50 of the second pipe segment 24 is positioned at a setting angle of 79.5 degrees. Of course, also setting angles deviating therefrom can be selected. Also other non-cylindrical basic shapes of the pipe segments 24 can be selected. The pipe segments 24 have in this context a suitable length in order to be able to perform a suitable processing of the plant raw materials in the corresponding section 48. The number, the length, the diameter, the shape of the pipe segments that are assembled to a drum 4 can be suitably designed and selected by a person of skill in the art.

[0060] The flange surfaces 26 of the pipe segments 24 can be connected to each other by connection elements such as, for example, a number of screws with lock nuts or stud bolts.

[0061] In the section illustration of FIG. 2, it can be seen well that the milling chamber 10 comprises a conically tapering constriction toward the discharge device 18 in the region of the second end face 14 and thus at its end positioned downstream. The illustrated constriction is well suited to skim off the flakes of agglomerated natural rubber floating up to the surface of the material mixture to be ground. The discharge can be realized in that either a material mixture to be ground is increasingly supplied to the milling chamber 10 whereby a flushing impulse in the milling chamber 10 is generated and/or the axis of rotation 6 of the drum 4 at the feed side end is lifted and/or lowered at the discharge-side end, whereby then the flakes are flushed out of the milling chamber 10 without in this context higher proportions of the remainder of the plant raw materials being flushed out. The fraction of the material mixture to be ground that no longer contains noteworthy quantities of natural rubber can subsequently be discharged from the last section 48, wherein then the respective fractions can be separated by the discharge device 18 in that they are conveyed into different discharge containers. It is of course also possible to discharge the material mixture to be ground as a whole from the milling chamber 10 without separately skimming off the agglomerated natural rubber by means of the grinding media mill 2.

[0062] FIG. 3 shows an enlarged section view of the feed device 16. For supplying the material mixture to be ground, the feed device 16 comprises a connection socket 54 to which the feed container 30 can be connected. In the region of the connection socket 54, there is also the feed conduit 32. In the feed device 16, there is a screw conveyor as a drivable forced feed action 56 which passes through the rotary feedthrough 20 and conveys material mixture to be ground supplied by the connection socket 54 into the milling chamber 10. The augers of the screw conveyor force the plant raw materials reliably into the milling chamber 10. They prevent at the same time that grinding media that are moved upon rotation of the drum 4 in the milling chamber 10 can pass into the feed device 16. Also, a return flow of the material mixture to be ground into the feed device 16 is prevented by the forced feed action 56. The forced feed action 56 is arranged coaxial to the axis of rotation 6 of the drum 4.

[0063] FIG. 4 shows a grinding media mill 2 in which the axis of rotation 6 of the drum 4 is lifted relative to the horizontal W. Since in this way also the inner surfaces 50 of the pipe segments 24 ascend in the conveying direction along the axis of rotation 6 toward the right relative to the horizontal W, the conveying speed with which the material mixture to be ground flows through the milling chamber 10 is naturally reduced in such an angle position of the drum 4. In reverse, it is conceivable that, for an angle position of the axis of rotation 6 in which the latter descends in conveying direction relative to the horizontal, the conveying speed of the material mixture to be ground through the milling chamber 10 is increased. In the embodiment, the drum 4 is held on a frame that, in turn, is supported by rotary bearings on the ground. For changing the spatial position of the axis of rotation 6, mechanical adjusting means can be provided but it is also possible to lift or lower the frame at one or both sides by motor-driven actuators such as, for example, a lifting cylinder.

[0064] In FIG. 5, an end face view of a partition 46 is illustrated. The partition 46 comprises a number of passage openings 58 through which the material mixture to be ground can flow from one section 48 to the neighboring downstream section 48. In the embodiment illustrated in FIG. 5, the passage openings 58a, 58b, and 58c have different shapes and sizes. While the passage openings 58a in regard to their shape and size are sized such that they retain the grinding media contained in a section, the passage openings 58b are sized in regard to their shape and size such that through them grinding media can also pass into a neighboring section.

[0065] The partition 46 illustrated in FIG. 5 has the passage opening 58c embodied as a cutout 60 whose radius R.sub.1 in at least one part of the circular arc covered by the cutout 60 is larger than the outer circumference of the axis of rotation 6 determined by the radius R.sub.2 in the region of the corresponding partition 46. In the embodiment illustrated in FIG. 5 of a partition 45, the cutout 60 is provided with a grid in order to avoid passage of grinding media. When however the grid illustrated in FIG. 5, in deviation from the embodiment, is omitted, it is possible to move sensors 42 along the axis of rotation 6 through one or a plurality of sections 48. In FIG. 5, it can be seen that the camera as sensor 42 is arranged adjacent to the axis of rotation 6 in the milling chamber 10. In case of a fill of the milling chamber 10 with material mixture to be ground 64, indicated by the wavy line 62, the sensor 42 is arranged at a distance to the material mixture to be ground 64 at which damage or soiling of the sensor 42 is hardly probable.

[0066] In FIG. 6, a view of the feed side of the grinding media mill 2 is illustrated. In this view, the round circumferential shape of the drum 4 can be seen well. Also, the feed device 16 with the funnel-shaped feed container 30, the connection socket 54 arranged underneath, as well as the plurality of feed conduits 32 can be seen. In the end view, the axis of rotation 6 can be seen also wherein the axis of rotation 6 here illustrates the rotary bearing of the forced feed action 56 that is driven by a separate motor 8. In this view, it can also be seen well that the drum 4 is held by the rollers on the frame 66.

[0067] In FIG. 7, a view of the discharge side of the grinding media mill 2 is illustrated. In this view, the control ports 68 can be seen that are provided in the end wall 34 in order to be able to visually check through the control ports whether the natural rubber contained in the biological raw materials has agglomerated to flakes in the last section 48 of the milling chamber 10.

[0068] The material mixture to be ground 64 discharged through the discharge device 18 from the milling chamber 10 can be further conveyed via a discharge socket 70 to downstream separating and cleaning devices.

[0069] In FIG. 8, a cross section view of a drum 4 with a receiving chamber 72 is illustrated. The outer wall 52 of the drum 4 in the embodiment is designed as a perforated metal plate so that the material mixture to be ground 64 can pass from the milling chamber 10 in the interior of the drum 4 through the openings 74 in the perforated metal plate outwardly into the receiving chamber 72. The openings 74 can be designed such that grinding media from the milling chamber 10 can pass through them into the receiving chamber 72, or they are designed such that this is prevented. The receiving chamber 72 can be utilized to wash, to boil the plant raw material contained in the material mixture to be ground 64 and/or to separate and discharge components of the material mixture to be ground 64. For this purpose, corresponding process tools can be arranged in the receiving chamber 72. In the embodiment, a screw conveyor 76 is illustrated with which the sediment that collects at the bottom of the receiving chamber 72 can be discharged. Furthermore, heaters 78 are illustrated with which the material mixture to be ground 64 can be heated, for example, in order to boil it.

[0070] Above the drum 4, there is furthermore a jacket 80 illustrated in FIG. 8 which surrounds the circumference of the drum 4 partially and at which nozzles 82 are arranged. By means of the nozzles 82, a liquid, a gas or hot steam can be injected into the milling chamber 10 from the exterior through the openings 74 in the outer wall 52 of the drum 4. In the jacket 80, also metering means for adding solids into the milling chamber can be provided, which solids are added to the material mixture to be ground in order to assist in dissociation and separation of the polyisoprenes and other apolar materials that are released upon processing.

[0071] The invention is not limited to the afore described embodiments. A person of skill in the art will have no difficulties in modifying the embodiments in a manner appearing suitable to him in order to adapt it to a concrete application case.