Apparatus and method for rounding graphite sheets of a graphite material

Abstract

Device for rounding graphite-based material, the device having a working chamber in which the rounding takes place, a charging device for feeding graphite-based material into the working chamber, a plurality of rounding tools in the form of beaters arranged on a disc rotating around a rotation axis and in a rotation direction, located in the working chamber, preferably the device having at least one guide and a separating device for separating fines and ultrafines, the device having a product outlet and preferably having a cover ring arranged above the rounding tools, wherein the disc carries at least 40, better at least 45, preferably at least 55 beaters per meter of circumference.

Description

Technical Field

[0001] The present invention relates to an apparatus for rounding graphite sheets of graphite material according to the features of the independent claims. Background Technology

[0002] Lithium-ion batteries are currently widely used in various electronic devices, such as laptops, hand tools, and automobiles. Graphite is typically used as the negative electrode material because it has excellent electrical conductivity, making it ideal for discharging current. Furthermore, lithium ions can easily adsorb into the graphite lattice structure during battery charging.

[0003] However, one problem with using graphite as a negative electrode material is that natural graphite usually occurs as so-called flake graphite, while spherical graphite is clearly more suitable for use as a negative electrode material. The use of spherical graphite can improve the energy density of batteries and extend their service life.

[0004] For the reasons mentioned above, flake graphite must first be converted into spherical graphite before it can be used as a negative electrode material. According to... Figures 2A to 2E The morphological changes of graphite during the transformation of flake graphite into spherical graphite can be observed. Figure 2A and Figure 2B The image shows graphite in the form of flake graphite, wherein, Figure 2A The slice shown is significantly smaller than Figure 2B The image shown is a piece of paper. Figure 2C The image shows an intermediate stage in which the graphite particles have become partially rounded. Finally, in Figure 2D and Figure 2E The image shows spherical graphite. Existing technology

[0005] The conversion of flake graphite into spherical graphite or the conversion of raw coke into corresponding spherical particles is known in the prior art and is referred to as spheroidization.

[0006] First, it should be noted that whenever graphite materials and graphite particles are mentioned below, the terminology includes the corresponding precursors in the form of coke and their corresponding coke particles, as well as other graphite-based particles. Unless otherwise stated, it is preferred to interpret the terms "graphite materials" and "graphite particles" in a narrow sense, that is, in their practical sense. This clarification applies throughout the following text, even if not repeated every time.

[0007] The transformation of individual graphite particles into spherical graphite is not achieved through grinding or polishing, but rather through multiple folding processes. To achieve this, individual graphite particles are strategically moved to collide with pre-designed obstacles. The kinetic energy applied to the graphite particles is chosen such that they deform upon impact (as far as possible) without breaking apart. This deformation is called folding.

[0008] Before spheroidizing flake graphite particles, a grinding process is typically performed first. This is usually done using a sieve mill. This process step is used to reduce the size of the graphite particles and produce graphite flakes that are small enough that the subsequent spheroidizing step can produce spherical graphite of the desired quality or fineness grade.

[0009] Finally, the actual spheroidization takes place in a so-called spherical sieve. The spherical sieve consists of a chamber in which graphite particles introduced into the chamber come into contact with one or more (usually rotating) spheroidizing tools. Contact with the spheroidizing tools forces the particles toward an obstacle, also known as an impact surface. The folding process described above occurs when the particles collide with this obstacle.

[0010] To achieve the best possible spherical effect, the particles are guided by an externally introduced process airflow within the spherical screen. This causes the particles to be accelerated multiple times along the impact surface by a rounding tool, resulting in folding. Therefore, during the folding process, the particles circulate through the working chamber of the spherical screen, ensuring that all particles are accelerated multiple times along the impact surface by the rounding tool.

[0011] After specific processing times and multiple folding processes, the desired product quality is achieved and the graphite particles have a spherical shape. Since there is no pure deformation during spheroidization, but also a small amount of fragmentation, the spherical graphite particles must ultimately be separated from the resulting fine material by an integrated or external sieve.

[0012] The known problem with spherical sieves is that graphite particles are not only folded, but a relatively large portion are also unintentionally crushed, becoming waste, or if the process is set more gently, they must be circulated through the spherical sieve's chamber for a relatively long time until all the particles are folded or spherical to the desired degree. Summary of the Invention

[0013] The problem solved by the present invention

[0014] The object of the present invention is to provide an apparatus for more efficiently implementing the process for spheroidizing fine powders in a batch manner.

[0015] Solution according to the invention

[0016] According to the invention, this objective is achieved by an apparatus for rounding graphite material. The apparatus includes a chamber and a loading device in which rounding is performed, the loading device being used to typically batch-feed the graphite material into the chamber. Furthermore, the apparatus includes a plurality of rounding tools, arranged in a rotating, surrounding configuration within the chamber, said rounding tools being in the form of percussion tools.

[0017] The percussion device is arranged on a disc that rotates around a rotation axis and in the direction of rotation. Preferably, the device also includes at least one guide and a separation device for separating fine and ultrafine materials. Furthermore, the device includes a product outlet and a cover ring arranged above the rounding tool.

[0018] The device according to the invention is characterized in that the disc carries at least 40, more preferably at least 45, and most preferably at least 55 spaced-apart impactors per meter of circumference. The rotor design according to the invention allows the material to remain in the region of the radial inner edge of the impactor for a longer period and to bear stress there. This is advantageous because the collision between the particle and the impactor occurs more gently there, thus facilitating particle folding without causing significant particle breakage.

[0019] In principle, it can be said that the design of this invention provides a decisive functional difference compared to corresponding seemingly structurally similar screening mills.

[0020] In a screening mill, the desired grinding effect is largely achieved by the following method: the particles to be ground are captured by the impactor and forcefully thrown outward radially, and then impact the sharp-edged, serrated impact surface of the screening mill housing with high intensity, which surrounds the disc with the impactor on the outer periphery of the disc like a belt.

[0021] The primary point of action differs in the spherical sieve designed according to the invention. It is no longer the aforementioned impact surface, because in the spherical sieve according to the invention, the impact surface preferably has a significantly lower impact force. This is because its sole purpose is to deflect the particles colliding there substantially without cracking upwards, allowing the particles to recirculate, i.e., to collide again with the radially inner end of the impactor from a radially inward direction for further folding. Instead, the primary point of action of the spherical sieve according to the invention is the first one-sixth radially inward of the impactor, more preferably the first one-tenth radially inward, ideally the rounded portion involved therein.

[0022] Within the aforementioned defined area, the relative velocity difference between the impactor and the corresponding particle is small. Therefore, the momentum here is no longer sufficient to break the particle. Furthermore, due to the roundness of the inner side of the impactor, a velocity component is generated inward toward the screening wheel after contact. This causes the particle to remain at the inner edge of the impactor for a longer time, and due to the use of a large number of impactors according to the invention, a large number of light, ineffectively breaking contacts are generated. These contacts can also cause the particle to rotate, which is beneficial to the folding process.

[0023] Another solution according to the invention

[0024] The solution to the aforementioned problem is also achieved through a method for protecting the rounded graphite material where appropriate. Here, the graphite material is in effective contact with at least one of a plurality of rotating, surrounding rounding tools arranged very closely together in the circumferential direction, with approximately 40 to 80 rounding tools or percussioners positioned adjacent to each other along the circumferential length of the percussion wheel. Ideally, a cap ring is also arranged above the rounding tools, which restricts the movement space guiding the process airflow of the graphite material and increases the number of contacts between the graphite material and at least one rounding tool.

[0025] The method and machine used according to the invention enable the simple and cost-effective production of rounded graphite particles suitable for optimized battery manufacturing. In particular, the graphite sheet is rounded by folding the corners of the graphite sheet and winding it around the core of the graphite sheet.

[0026] Possibility of preferred design scheme

[0027] There are a number of ways to design this invention to further improve its effectiveness or usability.

[0028] Therefore, particularly preferably, some or all of the side surfaces or sides of the strikers have a tangent, either integrally or at least at their radially outer ends, with the tangent having a radial encirclement angle α at its point of tangency.

[0029] In this design, the graphite particles are not thrown radially outwards as much as possible, but rather collide obliquely with the inner surface of the housing and the impact or deflection surface formed there. This improves the return transport of graphite particles thrown radially from the impactor wheel to the working chamber.

[0030] Angle α is preferably less than 25°. However, in some cases, angles as high as 40° are also applicable.

[0031] In another preferred embodiment, the striker is composed of a plate that arches outward in an arc.

[0032] As a result, the particles are not ejected primarily radially, but rather with a component of circular motion. This imposes a greater rotational load on the particles. This rotation also improves the return transport of graphite particles ejected radially from the impactor wheel into the chamber.

[0033] Ideally, for most or all impactors, the ratio of impactor length to impactor width is greater than 5, preferably greater than 10. This ensures that the impactor has sufficient radial extension to simultaneously accelerate multiple graphite particles. This increases the processing speed of the device. At the same time, a relatively large number of impactors can be arranged on the disc without making the free space between the impactors too small, thus making it very difficult for graphite particles to circulate freely through the working chamber.

[0034] "Strike length" here refers to the extension of the striker from the end facing the axis of rotation of the disc to the end facing away from the axis of rotation of the disc.

[0035] "Strike width" here refers to the average extension of the striker from the side facing the first striker to the second striker.

[0036] Preferably, the radial length of the impactor and / or the distance to the adjacent impactor and / or the height of the impactor along the axis of rotation are selected such that most of the impact process between the particle to be rounded and the impactor occurs in the radially inward front one-sixth region of the impactor, and more preferably in the radially inward front one-ninth region of the impactor.

[0037] In the radially inner region of the impactor, impacts are primarily of insufficient intensity to break the particles. Therefore, this region is avoided as much as possible in the screening mill because it is inefficient for grinding and should never be designated as the main impact zone. Consequently, in the screening mill, the impactors are clearly spaced further apart circumferentially, because only in this way can the particles to be ground penetrate deeply into the region between the impactors, allowing them to be subjected to crushing impacts—specifically, crushing impacts from the sides of the impactors.

[0038] The spherical sieve according to the invention differs. Here, the pumping action of the disc equipped with the impactor can be easily set experimentally with the parameters described in the claims, similar to known settings for the pumping action of a centrifugal pump. With the pumping action correctly set, most of the impact between the particles to be rounded and the impactor occurs in the desired radially inward inlet region of the impactor, where the impact intensity is strong enough to cause folding, but insufficient to break most of the particles.

[0039] Preferably, the ratio of the length of the impactor, measured radially, to the outer radius of the rotatable disk carrying the impactor is between 0.1 and 0.25, and more preferably less than 0.2. Maintaining this ratio ensures that the impactor acts on the particles with sufficient force to achieve folding and good efficiency, without causing the particles to break to an intolerable degree, thus producing waste.

[0040] Ideally, the height of the impactor varies from its radially inner end to its radially outer end, preferably decreasing by 10% to 40% from the radially inner end to the radially outer end. This allows the velocity between the impactors and the typical volumetric flow rate to remain constant. Of particular interest is limiting the pumping effect between adjacent impactors to prevent excessive particle intake, thereby preventing the main impact zone from moving too far radially outward.

[0041] Preferably, the effective diameter of the screening wheel for sorting is 20% to 50% of the outer diameter of the disc, more preferably only 20% to 35%, and the impactor rotates on the disc. This ensures that the screening wheel does not make unnecessary contact with the material rings in the particles (that do not need to be screened) and does not transfer energy to the particles through impacts that are not beneficial or even harmful to folding.

[0042] In another preferred embodiment, the impact surface—preferably formed in a region of the inner side of the cylindrical structure of the housing, and which receives the impact of particles ejected from the gap between adjacent impactors—is constructed to be smooth or corrugated without sharp edges. This eliminates the risk of a large number of particles or particle fragments breaking due to impact with the edges of the impact surface. This would increase the scrap rate and reduce the efficiency of the device.

[0043] This problem is effectively solved by using a smooth or corrugated impact surface in the region of the inner surface of the shell. It should be noted that, unlike a screening mill, the impact surface in a spherical screen of the type according to the invention is not intended to break particles by impact, but rather functions as a rotary brake on the rotating flow of particles to be folded.

[0044] Preferably, the guide formed by the guiding element closes flush with the edge of the impactor internally. This prevents graphite particles from flowing past the impactor without contacting it. Instead, all particles are accelerated by the impactor each time they flow past it, causing them to fold. This implementation improves the efficiency of the device.

[0045] In another preferred embodiment, the rounded graphite material is guided to the separation device of the apparatus in a non-swirling manner. This ensures that the folded particles, as well as the fine and ultrafine particles in fragmented form, flow to the separation device in an optimal manner. Therefore, this embodiment improves the efficiency and effectiveness of the separation device.

[0046] Alternatively, it can be specified that the device operates for a limited time after it is fully filled, i.e., after the first shut-off value is reached. This limited time is, for example, determined in advance based on experience, and after this limited time, the spheroidization of all graphite sheets is reliably completed.

[0047] To further optimize process conditions, it can be specified that the speed of the rotating disk and the circulating tool can be varied during operation. For example, it can be specified that a low rotational speed is initially selected, and then increased to the maximum rotational speed during operation.

[0048] Alternatively, for a particular process, it is advantageous to start at a high speed and then reduce the speed during operation.

[0049] Preferably, the device operates at a maximum rotational speed of 60 meters per second to 120 meters per second (based on the circumference of the disk).

[0050] Overview

[0051] Although at first glance, the spherical screen according to the present invention is very similar in structure to a screening mill, it is quite different in function, which is also reflected in the different types of physical properties.

[0052] The most significant difference is that screening mills operate continuously. The coarse material to be ground is continuously fed in, and the fine material after grinding is continuously output through the screening device.

[0053] The situation is different with the spherical screen according to the invention. The spherical screen operates in batches, i.e., in a batch process, and is designed accordingly. For this purpose, at the start of the process, all the material to be sphericalized in that cycle is added. The material to be sphericalized is then processed in the spherical screen until, under any circumstances, it substantially achieves the desired sphericity. During processing, materials that have become too small due to accidental breakage rather than folding are "sorted out" by the screen. In this respect, the spherical screen according to the invention also differs from a screening mill, which removes usable material through a screen.

[0054] In principle, for the spherical sieve according to the invention, rounding must always be performed using pulses related to the product and fineness, because otherwise the particles will be broken in the process. This must be avoided. The process integration of grinding and rounding is the basis of cascaded processes, but cannot be specifically applied to batch processes.

[0055] It also shows that a targeted intensity distribution of the pulse has a positive impact on product quality. This method is most easily understood by folding a very thin book, or more intuitively by folding a single sheet of paper. On the one hand, greater stress is needed to fold multiple layers simultaneously; on the other hand, less stress is needed to smooth the surface and, if necessary, press the raised individual sheets of paper towards the sphere. Here, the stress needs to be at as little as possible, or essentially never, a 90° angle to the tool, as this usually results in breakage rather than folding. It's easy to imagine that particularly high stress produces particularly smooth spheres. Experiments also show that the final folding process requires a particularly large amount of energy. This is easily understood using the book example. Each folding process requires a slightly greater force, with the final fold being particularly difficult. Therefore, for truly three-dimensional particles, a broad stress distribution below the breakage point is ideal. Here, the number of contacts should be maximized.

[0056] In summary, the spherical screen according to the invention is designed such that the stress applied to the particles to be spheroidized is substantially lower than the stress intensity that would cause the particles to break. In most cases, compared to similar screening mills, this spherical screen is designed to increase the number of impacts experienced by the particles to be spheroidized during batch processing. Attached Figure Description

[0057] Figure 1 A schematic diagram of the device according to the present invention is shown.

[0058] Figures 2A to 2E Views are shown of graphite material before, during, and after processing within the apparatus according to the invention.

[0059] Figure 3A and Figure 3B It shows that according to Figure 1 A horizontal cross-section of the device according to the invention is shown, and the striking wheel and its partial enlarged view are also shown herein.

[0060] Figure 4 It shows Figure 1 Enlarged view of the inner shell.

[0061] Figure 5 It shows Figure 1 A magnified view of a portion of the image.

[0062] Figure 6 It shows Figure 3A and Figure 3B The illustrated alternative striking wheel has the same thickness of striking force along the circumferential direction.

[0063] Figure 7 It shows Figure 6 Side view.

[0064] Figure 8 It shows Figure 3A and Figure 3B and Figure 6 , Figure 7 An alternative to the striker wheel shown is a striker wheel in which the striker itself is straight but angled.

[0065] Figure 9 It shows Figure 8 Side view.

[0066] Figure 9a Another preferred embodiment of the striking wheel is shown.

[0067] Figure 10 It shows Figure 3A and Figure 3B , Figure 6 , Figure 7 and Figure 8 , Figure 9 The striker wheel shown is an alternative to the striker wheel (sometimes called a circular disc), whose striker itself is arched.

[0068] Figure 11 It shows Figure 10 A detailed view of a part of the image. Detailed Implementation

[0069] The following is based solely on Figures 1 to 5 Explain the working principle. Figures 6 to 11 The embodiments shown will be explained later.

[0070] First, the basic working principle of the spherical sieve according to the present invention is explained, and then the various measures according to the present invention are discussed in more detail.

[0071] Figure 1 An apparatus 1 for rounding graphite sheets GF of graphite material GM according to the present invention is shown.

[0072] The device 1 includes a housing 2 generally constructed as a vertical cylinder, with a feeding device 3 arranged on the upper side of the housing. The feeding device is used to typically batch-feed graphite material GM or raw coke. If graphite material is fed, it consists at least primarily of graphite flakes GF. In particular, in the illustrated embodiment, the feeding device 3 is constructed as a feed pipe; however, it can also be configured such that the input graphite material GM is supplied via an injector.

[0073] The graphite material GM descends to the bottom of the chamber 40. Here, the graphite material impacts a rounding tool from the radially inward side. The rounding tool consists of a striking device 5 fixed to a disc-shaped carrier or disk 74, which rotates together with the carrier plate or disk 7. This structure can be referred to as a striking wheel. When the graphite sheet impacts the striking device in the region of its radially inward end, i.e., in the region of the rounded portion at the end side of the striking device, according to the invention, the graphite sheet folds. Here, most of the graphite sheet is thrown back into the process chamber 40 in a radially inward direction, then approaches the region of the radially inward end of the striking wheel and the striking device fixed thereon again, and is folded again. Graphite particles that have crossed the radially inner region of the impactor wheel (typically approximately the innermost 1 / 5, preferably the innermost 1 / 8) in a radially outward direction are conveyed outward by the impactor, which, due to its particularly compact arrangement according to the invention, functions like a centrifugal pump, without any significant collision between the impactor 5 and the graphite particles, and the graphite particles leave the impactor wheel at the outer periphery of the impactor wheel.

[0074] At this point, the graphite particles also come into contact with the inner surface of the outer wall of the shell 2 of the spherical screen or with the impact surface 6 located therein, which is typically a separate annular component. Generally, and not limited to this embodiment, the impact surface (unlike in a screening mill) is not designed to cause collisions that break up the graphite particles. Instead, the impact surface according to the invention is designed to assist the process airflow PL (see [reference needed]) with substantially no breakage. Figure 1 (As shown on the right side of the diagram) The graphite particles tend to pass upwards through the "chimney" formed by the air guide ring 15 and the air guide element 25 and are eventually discharged radially inwards back into the process chamber 40. In the process chamber 40, the graphite particles sink to the bottom region. Here, under the action of centrifugal force, the graphite particles move outwards again. Thus, once the graphite particles have reached the bottom region of the process chamber, they come into contact with the impact wheel or its impactor, causing them to fold again.

[0075] Fragments of accidentally broken graphite particles are subjected to only a small centrifugal force, and are therefore carried into the interior of the screening wheel 11 by the process airflow PL entering the separation device 10 or its screening wheel 11, and are thus discharged through the separation device 10.

[0076] The separation device 10 is positioned above the disc 7 with the rounding tool 5. The screening wheel 11 is connected to the second drive unit 13 via the second drive shaft 12. In particular, the first drive shaft 8 and the second drive shaft 12 are arranged coaxially.

[0077] For completeness, it should also be mentioned that the above process air is guided as follows:

[0078] Process air PL is fed from bottom to top through the feed port 14 in the lower region of device 1 (particularly below the rotating disk 7 with the rounding tool 5). This process air is guided to the rounding area and then to the separation device 10 via the guide element 25. The process air PL carries fine and / or ultrafine particles FM here and is discharged from device 1 through the suction port 16, where the centrifugal force of the fine and / or ultrafine particles is insufficient to resist the transport action of the process air.

[0079] Figure 3A It shows the main basis Figure 1 and Figure 5 The horizontal longitudinal section of the embodiment described. Figure 3B A partially enlarged view of the cross-section is shown.

[0080] exist Figure 3A The disc 7 can be clearly seen in the image. The disc 7, together with the striker 5, forms a striker wheel that rotates inside the housing 2.

[0081] It is also clear that it is already in use. Figure 1 and Figure 5The guide element 25 shown is held in place by its arm-shaped bent region 27. It can also be clearly seen that the annular region between the radially inner end of the impactor 5 and the screening wheel 11, or more precisely, its axially downward protrusion, constitutes the process chamber 40.

[0082] It is evident that the impactors are arranged very densely on disk 7. It was previously believed that the impactor density along the circumferential direction in 360° must be kept significantly low, typically significantly lower than 35 impactors. This view is now considered incorrect, as the larger gaps between successive impactors lead to more violent collisions between the impactors and the graphite particles.

[0083] Within the scope of this invention, it has been found that smaller gaps between successive strikers in the circumferential direction can ensure more efficient, yet gentler, folding (with less breakage, and thus less scrap).

[0084] Based on this, the following applies to this embodiment as well as to general cases: • The minimum distance between two adjacent striking devices 5 is preferably less than the maximum width of the striking device along the circumferential direction; • Most of the strikers 5 are particularly long and thin, meaning that the maximum striker width along the circumference is at least 6 times the maximum striker length along the radial direction, and better at least 8 times. • In the circumferential direction of the striking wheel, a wider striking element 5a follows several elongated striking elements placed close together, preferably having at least one threaded hole, more preferably at least two threaded holes, for securing a cover ring 18 that covers the striking elements 5, 5a from above, see [reference]. Figure 1 The cover ring 18 is shown in the image; • The striking device 5 is designed such that the distance between the striking devices at their radially outer ends in the circumferential direction is greater than the distance between them at their radially inner ends. The striking device has a rounded, preferably substantially semi-circular, end radially inward and preferably also designed in this way at its radially outer end; The impactors each have a constant thickness along the circumferential direction; • The impactor has smooth sides, such that adjacent impactors form a radial channel that outputs graphite particles radially outward in a laminar flow manner—in the absence of significant collisions between impactors in any case. The graphite particles leave the radially inward region of the impactor suitable for folding in a radially outward direction. • The impactors are arranged close to each other in the circumferential direction and preferably also rotate rapidly, so that the particles collide mainly or substantially entirely with the aforementioned rounded radial inner end of the impactor in their path toward or into the impactor wheel. • The impactor must be designed to be thick enough in the circumferential direction so that it can form a distinct roundness at its radial end, so that the particles collide mainly or substantially entirely with the aforementioned rounded radial inner end of the impactor in their path toward or into the impactor wheel.

[0085] exist Figure 3A and Figure 3B In the embodiment shown, the striking device 5 is oriented parallel to the radial direction of the disk 7 and passes radially through the apex of the rounded portion of the striking device 5 that is opposite to the rotation axis of the disk 7.

[0086] Figure 6 and Figure 7 A variant of the striker wheel is shown, which has only the same strikers, each of which is oriented entirely radially as in Figure 3. Apart from this, the variant is identical to the embodiment just described according to Figure 3, and therefore all of the above applies here (except for the thicker strikers).

[0087] It is worth noting that, Figure 6 The radius RH and the imaginary auxiliary circumference H it points to can be seen in the figure. In the figure, with the corresponding narrower intervals of the strikers and the optional corresponding rounded portions, and optionally by the possible corresponding adaptation of the rotational speed of the striker wheel, most of the collisions, or even almost all of the collisions, occur in the area of ​​roundness at the inner end of each striker.

[0088] Figure 8 and Figure 9 A third embodiment is shown. In this striking wheel, the striking element, which is still straight, is preferably tilted radially at an angle α of 10° to 25°, more preferably only 10° to 17.5°. This tilting arrangement causes the radially inner end of the striking element to lag.

[0089] These measures can alter the impact effect and, if necessary, affect the conveying capacity of the impactor wheel, which still functions like a centrifugal pump. A particularly useful aspect here is that particles entering the area between the impactors strike the impact surface 6 in a radially outward, rotating manner, which in many cases makes it easier for the particles to return to the working chamber. See [reference needed] for more details. Figure 1 and Figure 5 The explanation in the text. For example... Figure 9a As shown, the grinding disc is specifically designed for this invention. A typical design uses a grinding disc as a turning part, with each impactor screwed onto it.

[0090] The disc 74 then participates in fixing the striker. If one were to attempt to implement this invention using a conventional design, it would quickly be discovered that the strength of the striker and the spiral connection is insufficient to achieve the tall and thin striker provided by this invention.

[0091] Furthermore, the rotating impactor presents a significant problem due to reduced strength coupled with increased force. Additionally, the impactor is a major wear component due to its high speed. Regularly replacing over 100 impactors is extremely time-consuming and labor-intensive, as each impactor is secured with two screws.

[0092] Therefore, the structure is preferably as follows: Figure 9a The design is shown. There is a universal disc 7, forming the bottom of the grinding disc, on which various impactor rings can be screwed. Pre-assembled rings are secured with screws 77. The impactor rings have discs 74. Two different impactor types are mounted on this disc. On one hand, as... Figure 9a The hammer 5 is screwed in place, while the plugged-in hammer is inserted into the grooves in the disc 74 and the cover ring 18. The whole assembly is then tightened to form a ring. If the strength used to tighten the desired hammer geometry is insufficient, it can be plugged in, and only a few fixed hammers need to be slightly reinforced to hold the structure together.

[0093] Because the continuous rings can be replaced as a whole, they are also easier to maintain.

[0094] Figure 10 and Figure 11 The embodiment of the disc 7 and the percussionist 5 shown only schematically differs from the previous embodiments in that the percussionist 5 has a curved surface. Even though not shown in the figures, as detailed in the first embodiment above, the radially inner end of the percussionist 5 always has a rounded end. The percussionist density is also according to the invention, which is... Figure 10 and Figure 11 It is not shown in the middle either.

[0095] Generally speaking, this variant is also similar to the one just mentioned. Figure 3A , Figure 3B The described embodiments are the same, therefore everything described above (except for the striker surface itself) also applies here.

[0096] Figure 11 The geometry and arrangement of the striker 5 shown are preferably described by (imaginary) straight lines r1 and r2. Line r1 represents the radius of the disk 7 originating from the axis of rotation, which is tangent to the radially inner end of the striker on its forward rotating side. Line r2 represents the tangent to the radially outer end of the striker on its forward rotating side. An angle α exists between these two lines. Angle α is approximately 10° to 25°, more preferably only 15° to 20°.

[0097] The striking device is preferably arched substantially constant along its entire length.

[0098] The advantage of this geometry of the impactor 5 is particularly that it allows for the more powerful rotational loading of graphite particles. This, in turn, facilitates the return of the particles to the chamber 40 as they impact the impact surface 6.

[0099] general

[0100] Even though no claims have been made here, it should be noted as a precaution that the spherical sieve claimed herein may also be applicable to folding or rounding particles of other materials, such as aluminum- or other metal-based particles. Therefore, it is hereby noted that the term "graphite-based particles" in the claims may be replaced by the broader term "material particles to be folded".

[0101] This instruction applies to all of the foregoing text, even if it does not appear repeatedly.

[0102] List of reference numerals 1 device 2 shells 3. Loading equipment 4 Not specified 5. 5a Rounding Tool / Strikeer 6 impact surfaces 7. Discs or carrier plates 8 First drive shaft 9 First drive unit 10 Separation Equipment 11 Screening Wheel 12 Second drive shaft 13 Second drive unit 14 feeding interfaces 15 guide rings 16 suction ports 17 Product Exports 18-ring cap 19 Second Circle Tool 20 control devices 21 Inner Surface 25 guide elements 26 guide plates 27 bending areas 30 fasteners 31 spiral connection 40 processing rooms / workshops 41 guide ring 45 gap 50 points to the side of the axis of rotation 51 impact surface 55. Side facing away from the axis of rotation 56 parts of the area 57 parts of the area 60 guide 65 absorption units 66. A cylinder that can move 66c is a cylinder that can move in the closed position. A cylinder that can move in the open position (66o) 67 Auxiliary Air Interface 70 serrated inner surface 71 Corrugated inner surface The main impact surface of the 73 impactor 74. Disc or disk-shaped carriers 75 Fasteners / Screws 76 Fasteners / Screws 77 Fasteners / Screws 78 housing components 79 gap 80 fasteners / screws 81 bolts Distance A AP absorption location B5 Rounding Tool Width D Rotation axis DR rotation direction EP final product FM fine and / or ultrafine GF graphite sheet GM Graphite Materials / Graphite-based Materials gGF large graphite sheet kGF small graphite flakes L air L5 longitudinal axis L56 length of the rear portion along the direction of rotation L57 length of the region in front along the direction of rotation RH radius H auxiliary circumference line PL process air vGT rounded graphite particles Ta tangent The radius / tangent at the inner end of the main impact surface 73 of the r1 impactor r2 tangent α angle α

Claims

1. An apparatus (1) for spheroidizing graphite-based material (GM), the apparatus (1) comprising: a working chamber (40) in which spheroidizing is performed; a loading device (3) for feeding the graphite-based material (GM) into the working chamber (40); and a plurality of spheroidizing tools (5) arranged in a rotating, circumferential configuration within the working chamber (40), the spheroidizing tools (5) being in the form of percussion instruments, the spheroidizing tools (5) being arranged on a disk (7) rotating about a rotation axis (D) and in the rotation direction (DR), characterized in that, The disc (7) carries at least 40 strikers per meter of circumference.

2. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 1, characterized in that, The device has at least one guide (60) and a separation device for separating fine and ultrafine (FM) particles, and the device has a product outlet (17).

3. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 1, characterized in that, The device has a cover ring (18) arranged above the rounding tool (5).

4. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 1, characterized in that, The disc (7) carries at least 45 strikers per meter of circumference.

5. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 4, characterized in that, The disc (7) carries at least 55 strikers (5) per meter of circumference.

6. The apparatus (1) for spheroidizing graphite-based materials (GM) according to any one of claims 1 to 5, characterized in that, The radial length of the impactor and / or the distance to the adjacent impactor and / or the height of the impactor along the axis of rotation (D) are selected such that most of the impact process between the particle to be rounded and the impactor occurs at the radially inward first sixth of the impactor.

7. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 6, characterized in that, Most of the impact process between the particle to be rounded and the impactor occurs in the inward front-ninth region of the impactor.

8. The apparatus (1) for spheroidizing graphite-based material (GM) according to any one of claims 1 to 5, characterized in that, The ratio of the length of the striker measured in the radial direction to the outer radius of the rotatable disk (7) carrying the striker is between 0.1 and 0.

25.

9. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 8, characterized in that, The ratio of the length of the striker measured in the radial direction to the outer radius of the rotatable disk (7) carrying the striker is less than 0.

2.

10. The apparatus (1) for spheroidizing graphite-based material (GM) according to any one of claims 1 to 5, characterized in that, The height of the striker varies from its radial inner end to its radial outer end.

11. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 10, characterized in that, The height of the corresponding striker decreases by 10% to 40% from the radial inner end to the radial outer end.

12. The apparatus (1) for spheroidizing graphite-based material (GM) according to any one of claims 1 to 5, characterized in that, The effective diameter of the sieve wheel (11) for sorting is 20% to 50% of the outer diameter of the disc (7), and the beater rotates on the disc.

13. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 12, characterized in that, The effective diameter of the sieve wheel (11) for sorting is 20% to 35% of the outer diameter of the disc (7).

14. The apparatus (1) for spheroidizing graphite-based material (GM) according to any one of claims 1 to 5, characterized in that, For most or all strikers: the ratio of the striker's length to its width is greater than 5.

15. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 14, characterized in that, The ratio of the length of the striking device to the width of the striking device is greater than 10.

16. The apparatus (1) for spheroidizing graphite-based material (GM) according to any one of claims 1 to 5, characterized in that, The impact surface (6) is constructed as a smooth or wavy surface without sharp edges.

17. The apparatus (1) for spheroidizing graphite-based materials (GM) according to claim 16, characterized in that, The impact surface (6) is formed by a region of the inner surface (21) of the cylindrical structure of the shell (2).

18. The apparatus (1) for spheroidizing graphite-based material (GM) according to any one of claims 1 to 5, characterized in that, The guide (60) formed by the guide element (25) closes flush with the edge of the striker inside.

19. The apparatus (1) for spheroidizing graphite-based material (GM) according to any one of claims 1 to 5, characterized in that, Some or all of the main impact surfaces (73) of the strikers have a tangent (r2) at their radial outer ends, which forms an angle α with the radial direction (r1).

20. The apparatus (1) for spheroidizing graphite-based material (GM) according to any one of claims 1 to 5, characterized in that, The striking device (5) is composed of a plate that arches outward in an arc shape.

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