• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to an agitator shaft (1) for an agitator ball mill (50), the agitator shaft (1) having a longitudinal axis (L) and an outer surface (5) equipped with agitator elements (3), the agitator shaft (1) with the agitator elements ( 3) is formed in one piece and consists of a ceramic material. The invention further relates to a method for producing an agitator shaft (1) for an agitator ball mill (50).
    公开号:CH715322A2
    申请号:CH01056/19
    申请日:2019-08-23
    公开日:2020-03-13
    发明作者:Flessa Ludwig；Enderle Udo；Moeschl Holger
    申请人:Netzsch Feinmahltechnik；
    IPC主号:
    专利说明:

    The present invention relates to an agitator shaft for an agitator ball mill, an agitator ball mill and a method for producing an agitator shaft for an agitator ball mill according to the features of the independent claims.
    State of the art
    The invention relates to an agitator ball mill, in particular an agitator for an agitator ball mill. The agitator ball mill is a device for coarse, fine and very fine comminution or homogenization of regrind. An agitator ball mill consists of a vertically or horizontally arranged, mostly approximately cylindrical grinding container, which is filled to 70% to 90% with auxiliary grinding media. In the case of agitator ball mills, the grinding container is usually stored stationary. Many conventionally known mills are filled through a central opening in one of the end walls. Alternatively, the filling can also be done directly via the grinding cylinder. The product to be ground flows continuously during the grinding process from a product inlet axially through the grinding chamber to a product outlet. The suspended solids are crushed or dispersed between the grinding media by impact and shear forces. The grinding auxiliary bodies are then separated from the product stream in an outlet area. The discharge depends on the design and is carried out, for example, through a sieve at the end of the mill.
    The agitator is usually formed by an agitator shaft, which serves to rotate agitator elements in the form of disks or radially projecting pins, in particular to deagglomerate and comminute solids of the ground material distributed in liquid. The agitator shaft is usually driven by a motor. Disk stirrers with a plurality of grinding disks arranged on a stirrer shaft are used in particular as suitable stirring elements. The grinding disks are usually circular and can be provided with through openings. The product flow is ensured in particular via the passage opening.
    Between the inside of the grinding cylinder and the agitator, an annular grinding gap is formed, in which the material to be ground is to be comminuted during operation of the agitator ball mill. The agitator is driven in rotation and thus loads the material to be ground within the grinding gap, as a result of which it is comminuted, which is supported on the one hand by the auxiliary grinding bodies and on the other hand by the stirring elements of the agitator. In particular, the material to be ground and the auxiliary grinding bodies are moved intensively by means of a stirring shaft. The solid particles of the ground material are crushed by impact, pressure, shear and friction.
    The agitator shafts or agitators preferably consist of an abrasion-resistant material, in particular of a metal or a ceramic material, for example WO 2000/054 884 A describes an agitator ball mill in which the agitator, in particular the disk-shaped agitator elements, consists of a ceramic material . DE 2 626 757 A1 discloses a stirrer propeller which is constructed in such a way that only relatively simple and inexpensive parts are exposed to wear and that these parts are easily replaceable. Where it is economically feasible, these simple parts are made from a particularly abrasion-resistant material, such as ceramic.
    Many processes, chemical, mechanical or other, run with the generation of process heat, which can negatively influence the process itself or the raw materials used, for example, because the substances involved in the process are temperature sensitive or the temperature change affects the process speed and thus orderly process management is difficult. For this reason, it is common to stabilize a process flow, for example by dissipating the process heat generated by means of suitable cooling devices or processes. Processes running in containers are usually tempered via the container wall, for example by cooling or hot water pipes running on the wall or by guiding another outer container, which is spaced radially from the first container, around the first container, so that there is a cavity between the two containers forms, through which a fluid flow, which can be a hot water flow or a coolant flow, can be conducted to transport the process heat.
    Heat also arises in the grinding process. Depending on the product, this heat must be dissipated or heat generation must be prevented. The problem exists particularly with agitator ball mills with a large grinding volume or when a higher power input is desired. For cooling during the grinding process, it is provided, for example, to design the grinding cylinder to be coolable. For example, the published patent application DE 3614721 A1 describes the equipment of the grinding container with a cooling jacket as known prior art. This document also discloses that the agitator rotor can also be provided with at least one cooling channel on its circumference. A grinding container with a cooling jacket is also shown in the published patent application WO 2007/042 059 A1. Furthermore, the agitator mill described in this document has an inner stator, which can also be cooled. The agitator is cup-shaped and comprises an annular cylindrical rotor.
    [0008] As already mentioned in connection with DE 3 614 721 A1, cooling can alternatively or additionally also be implemented via the agitator rotor. The published patent application DE 3 015 631 A1 describes an agitator consisting of an inner and an outer cylinder, between which an annular cooling space is formed, a cooling line supplying cooling medium being arranged axially parallel within the cooling chamber for cooling and being connected to a supply pipe for coolant.
    Another coolable agitator shaft is disclosed in the patent DE 10 241 924 B3, wherein for cooling tubular material in various cross-sectional shapes is used, within which an inner tube is arranged, which extends over almost the entire length, the interior of the Tube is connected to the coolant inlet and the outside space to the coolant outlet.
    From a certain size, stirrer shafts or agitators made of ceramic must be constructed from several components. A lot of grinding work is necessary to produce the individual parts to each other, which means that the costs are very high due to the necessary working time. In addition, when the agitator shaft is assembled from a plurality of parts, so-called dead spaces arise, in which ground material and / or auxiliary grinding bodies can become lodged and thus contaminate the machine room. Such multi-part ceramic stirrer shafts are also very sensitive to breakage, especially during assembly, disassembly, cleaning and maintenance. In addition, it has so far not been possible to produce ceramic rotors with cooling.
    description
    The object of the invention is to produce an agitator shaft for an agitator ball mill easily and inexpensively, in particular a coolable agitator shaft for use in high-performance agitator ball mills.
    The above object is achieved by an agitator shaft for an agitator ball mill, an agitator ball mill and a method for producing an agitator shaft for an agitator ball mill, which comprise the features in the independent patent claims. Further advantageous configurations are described by the subclaims.
    The agitator ball mill is used for processing and, in particular, grinding material to be ground with the aid of grinding aids and has a grinding container with a grinding material inlet and a product outlet to which an agitator is assigned, which is at least partially arranged within the grinding container.
    The agitator comprises a drive, a stirrer shaft arranged on the drive and rotating in one direction of rotation and at least one stirrer element arranged on the stirrer shaft. The stirring shaft has a preferably cylindrical base body with a longitudinal axis, at least one stirring element, preferably a plurality of stirring elements, being / are arranged on the base body. In particular, the agitator shaft has an outer lateral surface equipped with agitating elements. The longitudinal axis of the agitator shaft usually coincides with the longitudinal axis of the grinding container. The drive is usually arranged outside the grinding container and connected to the stirring shaft arranged inside the grinding container via a drive shaft penetrating the container wall.
    The grinding container is preferably cylindrical and arranged lying or standing, so that the agitator shaft is arranged lying or standing accordingly. The grinding container can also have a different shape and, for example, be designed in the shape of a truncated cone. In this case, the agitator shaft is preferably also frustoconical.
    The at least one stirring element is designed, for example, as a cam, which preferably extends approximately radially away from the stirring shaft in the direction of an inside of the grinding container of the agitator ball mill.
    An annular grinding gap is formed between the outer surface of the agitator shaft and the inner surface of the grinding container, in which there is a mixture of regrind and auxiliary grinding bodies. Due to the rotation of the agitator shaft, the ground material is crushed within the grinding gap due to the stress, for example, by particles colliding with one another, by shear forces, etc. The stirring elements support this by causing an additional energy input, in particular on the auxiliary grinding bodies, through the stirring elements.
    The stirrer shaft with the stirrer elements is formed and manufactured in one piece and preferably consists of a ceramic material. The stirrer shaft is particularly preferably produced from silicon carbide (SiC), from silicon carbide with free silicon (SiSiC), from silicon nitride, from zirconium oxide or from mixed ceramics. Silicon carbide ceramics have a high wear resistance, low thermal shock sensitivity, low thermal expansion, high thermal conductivity, good resistance to acids and alkalis and are also light and retain their positive properties up to temperatures above 1400 ° C. In addition, silicon carbide is toxicologically safe and can therefore also be used in the food sector. Silicon nitride has a reduced hardness in comparison to silicon carbide, but a sintering process can cause a recrystallization of the β-silicon nitride crystals, which leads to increased fracture toughness of the material. The high fracture toughness in combination with small defect sizes gives silicon nitride one of the highest strengths among the engineering ceramic materials. The combination of high strength, low coefficient of thermal expansion and a relatively small modulus of elasticity make silicon nitride ceramic particularly suitable for components subject to thermal shock. In contrast to other ceramic materials, zirconium oxide has a very high resistance to the spread of cracks. In addition, zirconium oxide ceramic has a very high thermal expansion and is therefore often chosen when realizing connections between ceramic and steel.
    [0019] The stirrer shaft with the stirrer elements is particularly preferably produced by means of a 3D printing process. In this way it is possible to produce a component with internal cavities that can be manufactured using conventional methods such as injection molding or the like. would not be producible in one process step without further post-processing, for example without subsequent drilling of holes or the like. However, it is now possible to easily and inexpensively form at least one integrated cooling channel within the agitator shaft. It is preferably provided that the cooling channel extends at least in regions parallel to the longitudinal axis of the agitator shaft. According to one embodiment, it is provided that the at least one cooling duct is meandering, for example at least two regions of the cooling duct each extend parallel to the longitudinal axis of the agitator shaft, a deflection region being formed between the two regions running in parallel.
    According to one embodiment of the invention, there are two parallel regions, through which coolant flows in opposite flow directions, on a common radial of the agitator shaft. Countercurrent cooling of the agitator shaft is thereby achieved. In particular, the coolant is guided near the longitudinal axis of the agitator shaft from the regrind inlet side to the product outlet side. The coolant is returned from the product outlet side to the regrind inlet side within the agitator shaft in an area adjacent to the outer surface of the agitator shaft. This ensures that the freshest and therefore coolest coolant is first led into the area of the agitator ball mill in which the ground material is the warmest. This is in particular the area near the product outlet after the millbase has flowed through the agitator ball mill in the conveying direction from the millbase inlet side. In particular, the coolant flows through the agitator shaft on the surface of the agitator shaft in the opposite direction to the conveying direction of the ground material through the agitator ball mill. The cooling process can be further optimized with this countercurrent cooling.
    One embodiment of the agitator shaft provides that it comprises at least two partial sections, in particular a first terminal partial section on which the agitator shaft is connected to the drive shaft of the agitator. For example, the first terminal sub-section has a receiving area, in particular a shaft receiving device, in which the free end of the drive shaft can be arranged and non-rotatably connected to the agitator shaft. Furthermore, at least one second section is provided. The second section is preferably hollow on the inside. In addition, passage openings are preferably formed in the second partial section between the outer surface area and the hollow interior or interior area. In particular, a plurality of passage openings are provided which extend parallel to the longitudinal axis of the agitator shaft. A separating device can preferably be formed within the second partial section. The ground material / grinding aid mixture flowing through the grinding gap is deflected at the open end of the second section and flows via the separating device into the hollow interior of the second section. The separating device, which can be designed, for example, as a separating sieve or classifying rotor, in particular holds back the auxiliary grinding bodies and conveys them back together with possibly not yet sufficiently comminuted regrind through the passage openings into the grinding gap. The ground material, which has been comminuted sufficiently, is conducted through the hollow interior to a product outlet of the agitator ball mill and can be removed there.
    The auxiliary grinding bodies are preferably concentrated in this so-called grinding chamber due to the only small grinding gap between the agitator shaft and the inner wall of the grinding container. Only a small part of the auxiliary grinding bodies is deflected together with the regrind and flows through the separating device into the hollow interior of the second section.
    [0023] According to one embodiment, the second partial section is a central partial section, to which a further third terminal partial section adjoins. This third section also has a hollow interior. In the case of a cylindrical base body of the agitator shaft, the interior spaces of the second and optionally third section are preferably likewise cylindrical and have a circular cross section, the radius of the cross section of the interior in the third section being greater than or equal to the radius of the cross section of the interior is in the second part section. In addition, the cylindrical inner cavities each have a longitudinal axis which is congruent to the longitudinal axis of the agitator shaft.
    In the third section there are preferably no passage openings between the interior and the outer surface of the agitator shaft. Instead, a wear protection sleeve can be arranged in the interior of the third section, which is preferably also cylindrical. In particular, the wear protection sleeve is arranged between a container bottom of the grinding container and the separating device in the second interior area. In this embodiment, the grinding stock / auxiliary grinding mixture flowing through the grinding gap is deflected at the open end of the third partial section within the annular gap formed between the wear protection sleeve and the agitator shaft in the direction of the second partial section by separating the grinding stock from the auxiliary grinding bodies, such as it has already been described above.
    It is preferably provided that the at least one cooling channel extends within the first terminal section and at least in regions within the second, central section. In one embodiment of a stirrer shaft comprising three sections, it can be provided that the at least one cooling channel extends through all three sections. A meandering cooling channel can, for example, comprise parallel sections which are formed within the second partial section of the agitator shaft in each case between passage openings. The parallel sections can extend at least partially into the first and / or third section of the agitator shaft. Corresponding deflection regions are formed in particular at the terminal regions of the first and third sub-sections of the agitator shaft, which deflect the coolant from one parallel section to the next parallel section, so that the coolant preferably flows in opposite directions through mutually directly arranged parallel sections.
    In particular, it is provided that such a cooling channel comprises an even number of parallel sections, so that the coolant inlet and the coolant outlet are each located at the same end of the agitator shaft. In this case, the coolant flows through, for example, the first, third and fifth parallel section etc. in a first flow direction and the second, fourth and sixth parallel section etc. in an opposite second flow direction. The material to be ground / auxiliary grinding medium flows through the grinding gap in a first conveying direction, which corresponds, for example, to the first flow direction and is redirected within the second and / or third section of the agitator shaft, in particular to a second conveying direction, which corresponds to the second flow direction. The cooling water guide, in particular the cooling water inlet and outlet, can be formed by an insertion part, which can be arranged and fastened, for example, together with the drive shaft on the first partial section of the agitator shaft; For example, the insert part can be placed on the end of the drive shaft and arranged and fastened together with it in the shaft bushing, the cooling water supply and discharge line being connected to the at least one cooling channel of the agitator shaft.
    [0027] A plurality of stirring elements is preferably arranged on the stirring shaft. In particular, a regular arrangement of stirring elements arranged in rows parallel to the longitudinal axis of the stirring shaft and / or in a row in succession along a circumferential line of the base body of the stirring shaft is provided. All stirring elements can be of identical design or can also have different shapes. In addition, areas can be provided on the agitator shaft in which more cams are formed than in other areas, etc.
    Preferably, the stirring elements are designed as cams protruding from the base body of the agitator shaft, the connecting surface of the cams formed on the base body being relatively large, in particular in comparison to the height of the cams with which they project radially beyond the base body.
    The cam has a connection surface formed on the main body of the agitator shaft, an upper side facing the inside of the grinding container, a side leading in the direction of rotation of the agitator shaft, a trailing side in the direction of rotation of the agitator shaft and two sides arranged between the leading side and the trailing side . The leading side is also referred to as the flow side and the trailing side is also referred to as the side facing away from the flow. The distance between the connection surface and the top is called the height of the cams.
    Heat can advantageously be dissipated from the ground material / grinding auxiliary body mixture into the stirrer shaft and in particular into the coolant within the at least one cooling channel of the stirrer shaft via the relatively large connecting surface of the cams. The shape of the cams, described in more detail below, reduces the sensitivity of the ceramic material to breaking off or breaking off. The base body and cams are produced together as a monolithic component from a ceramic material, in particular by means of a 3D printing process, so that there is a direct material connection between the base body of the agitator shaft and the cams. The one-piece design of the agitator shaft promotes both stability and heat conduction, as there are no potential breakages and heat conduction barriers.
    For good stability of the cams and to achieve a uniformly good grinding result, it is advantageous if each cam has a connecting surface to the base body of the agitator shaft and a leading side, a ratio of the projection of the leading side to a normal to the base body of the Stirrer shaft standing level and the size of the connecting surface is less than 1.
    The leading side is referred to below as the face-side inflow surface. Preferably, an angle of inclination of the face-side inflow surface with respect to the plane perpendicular to the base body can be in a range from -45 ° to 85 °. An angle of 0 ° corresponds to an inflow surface arranged at right angles to the base body, whereas an angle with a negative sign denotes an undercut inflow surface, i. H. an inflow surface that is inclined so that they virtually cover a certain area of the connecting surface. Tilt angles with a positive sign therefore characterize a face-side inflow surface that is tilted in reverse, ie. H. in which the end of the inflow surface located on the base body is flowed to first.
    Furthermore, it has proven to be advantageous if each cam has a connecting surface to the agitator shaft with the greatest width and the ratio of the height of each cam to the agitator shaft and the greatest width is greater than 0.2. The connection surface just mentioned corresponds in particular to a base surface of each cam and means the surface with which each cam is in contact with the agitator shaft. It has also proven to be advantageous if each cam has a connecting surface to the agitator shaft with a greatest length and the ratio of the height of each cam and the greatest length is less than 1.
    It is also advantageous if each cam has a connecting surface to the agitator shaft with a greatest length and a greatest width, the ratio of the greatest width and the greatest length being less than 1.
    If several cams are arranged in a row in the circumferential direction of the main body of the agitator shaft in a row along a circumferential line of the main body of the agitator shaft, then it may be advantageous, for example, to select a distance between the cams in a row which are successive in the circumferential direction, which is equal to or greater than the greatest length of a cam in the circumferential direction. If a plurality of cams are successively arranged in a row along a plurality of circumferentially spaced circumferential lines, then an axial distance between two axially adjacent rows of cams can advantageously be selected to be greater than or equal to 1.1 times the greatest width of a cam. If cams spaced apart from one another in the axial direction are arranged on the base body of the agitator shaft, provision can be made for the cams to be arranged axially in line with one another or offset.
    As already described above, a wear protection sleeve can be arranged in the third terminal partial section of the agitator shaft, in particular in the third interior area, and installed within the agitator ball mill in such a way that it can be easily replaced.
    The wear protection sleeve is cylindrical at least in some areas, in particular as a hollow cylinder. The hollow cylinder has an outside diameter that is smaller than the inside diameter of the third interior area. A fastening area, for example a flange, can be provided on an end region of the wear protection sleeve in order to position and fasten the wear protection sleeve in or on the agitator ball mill.
    In particular, a grinding gap is again formed between the inner surface of the agitator shaft in the third interior or interior area and the outer surface of the preferably cylindrical anti-wear sleeve, in which the material to be ground / grinding aid mixture is guided in the direction of the second interior area of the second section. The wear protection sleeve is preferably also made in one piece and in particular made of a ceramic material and can be produced analogously to the stirrer shaft, for example using the SD printing process.
    Furthermore, it can be provided that the wear protection sleeve comprises at least one cooling channel, which for example is also meandering and thus forms a large cooling surface. The outer surface of the wear protection sleeve can also be designed with cam-shaped elevations. The shape of the elevations can correspond, for example, to the shape of the above-described cams arranged on the agitator shaft. The elevations reduce the gap between the inner surface of the agitator shaft in the third interior area and the outer surface of the wear protection sleeve. The elevations serve in particular as wipers in order to prevent ground material and / or auxiliary grinding bodies from adhering to the inner surface of the agitator shaft. Instead, the surveys ensure that the material to be ground / auxiliary grinding body mixture flows in the direction of the passage openings for returning the auxiliary grinding bodies in the direction of the grinding chamber formed between the outer surface of the stirring shaft and the inner wall of the grinding container.
    The wear protection sleeve can preferably be used in an agitator ball mill in connection with the above-described agitator shaft. The wear protection sleeve can also be used in connection with an agitator shaft manufactured according to conventional methods. In this respect, it should be emphasized that the monolithic design of the wear protection sleeve with or without elevations formed on the outer lateral surface and / or with or without at least one cooling channel constitutes an independent invention.
    A previously described, monolithic with cams or the like. and at least one cooling channel designed agitator shaft combines the advantages of optimal cooling with maximum wear resistance and is therefore particularly suitable for use in high-performance mills.
    The application also includes in particular one-piece stirrer shafts, in particular made of a ceramic material, which are designed without a cooling channel. These agitator shafts preferably also have at least two differently designed partial sections, in particular at least one first terminal partial section for fastening the agitator shaft to a drive shaft and at least one second partial section with a hollow inner area and passage openings between the inner area and the outer surface of the Stirrer shaft in the second section.
    At this point it should be expressly mentioned that all aspects and design variants which were explained in connection with the device according to the invention relate to or may be partial aspects of the method according to the invention. If, therefore, at one point in the description or also in the definition of claims for the device according to the invention, certain aspects and / or relationships and / or effects are mentioned, this applies equally to the method according to the invention. Conversely, the same applies, so that all aspects and design variants which have been explained in connection with the method according to the invention also relate to or can be partial aspects of the device according to the invention. Therefore, if there are certain aspects and / or relationships and / or effects at a point in the description or also in the definition of claims for the method according to the invention, then this applies equally to the device according to the invention.
    Figure description
    In the following, exemplary embodiments are intended to explain the invention and its advantages with reference to the attached figures. The size ratios of the individual elements to one another in the figures do not always correspond to the real size ratios, since some shapes are simplified and other shapes are shown enlarged in relation to other elements for better illustration.<tb> Fig. 1 shows a perspective illustration of an embodiment of an agitator shaft designed in one piece according to the invention.<tb> Fig. 2 <SEP> shows a technical representation of a side view of the agitator shaft according to FIG. 1.<tb> Fig. 3 <SEP> shows a sectional illustration of the agitator shaft along the section line AA according to FIG. 2.<tb> Fig. 4 <SEP> shows a further sectional illustration of the agitator shaft along the section line BB according to FIG. 3.<tb> Fig. 5 <SEP> shows a technical representation of a perspective view of the agitator shaft.<tb> Fig. 6 <SEP> shows a cut agitator shaft with exposed meandering cooling channels.<tb> Fig. 7 <SEP> shows a side view of a wear protection sleeve.<tb> Fig. 8 <SEP> shows a perspective view of the wear protection sleeve.<tb> Fig. 9 <SEP> shows a front view of an agitator ball mill.<tb> Fig. 10 <SEP> shows a sectional view of the agitator ball mill along the section line AA according to FIG. 9.<tb> Fig. 11 <SEP> shows a sectional view of the agitator ball mill along the section line BB according to FIG. 10.<tb> Fig. 12 <SEP> shows a sectional view of the agitator ball mill along the section line CC according to FIG. 11.<tb> Fig. 13 <SEP> shows a sectional view of the agitator ball mill along the section line D – D according to FIG. 12.<tb> Fig. 14 <SEP> shows a sectional view of the agitator ball mill according to the section lines E-E according to FIG. 9.<tb> Fig. 15 <SEP> shows a perspective view of a further embodiment of a stirrer shaft with countercurrent cooling which is designed in one piece according to the invention.<tb> Fig. 16 <SEP> shows a longitudinal section of an agitator ball mill with a cooling channel designed as countercurrent cooling.<tb> Fig. 17 <SEP> shows a cross section of an agitator ball mill with an agitator shaft according to FIG. 16 along a section line AA.<tb> Fig. 18A to 18E <SEP> each show further embodiments of agitator shafts.
    Identical reference numerals are used for identical or identically acting elements of the invention. Furthermore, for the sake of clarity, only reference numerals are shown in the individual figures which are necessary for the description of the respective figure. The illustrated embodiments merely represent examples of how the device according to the invention or the method according to the invention can be designed and do not constitute a final limitation.
    1 to 6 show different views and sectional representations of a stirrer shaft 1 designed in one piece according to the invention. Such a stirrer shaft 1 is preferably used in an agitator ball mill 50, as will be explained in more detail below with reference to FIGS. 9 to 14. The agitator shaft 1 has a cylindrical base body 2 with a longitudinal axis L, wherein 2 stirring elements 3, in particular cams 4, are formed on the outer surface of the cylindrical base body. The outer surfaces of the cams 4 and the outer surfaces of the cylindrical base body 2 not covered by cams 4 together form the outer surface 5 of the agitator shaft 1. The agitator elements 3 are formed in several rows, in particular in an aligned arrangement, on the outside of the cylindrical base body 2, whereby the rows are arranged and / or formed parallel to the longitudinal axis L of the agitator shaft 1.
    According to the invention it is provided that the agitator shaft 1 is formed in one piece and in particular consists of a ceramic material. The stirrer shaft 1 is particularly preferably produced from the ceramic material by a single process step. A 3D printing method is particularly preferably used for this purpose, since cavities within the agitator shaft 1 can also be generated with this method in a single method step.
    The ceramic material can be, for example, silicon carbide (SiC), in particular sintered silicon carbide (SSiC), silicon carbide with free silicon (SiSiC), silicon nitride, zirconium oxide or mixed ceramics. Silicon carbide ceramics have a high wear resistance, low thermal shock sensitivity, low thermal expansion, high thermal conductivity, good resistance to acids and alkalis and are also light and retain their positive properties up to temperatures above 1400 ° C. In addition, silicon carbide is toxicologically safe and can therefore also be used in the food sector. Silicon nitride has a reduced hardness compared to silicon carbide. However, a stalk recrystallization of the β-silicon nitride crystals can be brought about by a sintering process, which leads to an increased fracture toughness of the material. The high fracture toughness in combination with small defect sizes gives silicon nitride one of the highest strengths among the engineering ceramic materials. The combination of high strength, low coefficient of thermal expansion and a relatively low modulus of elasticity make silicon nitride ceramic particularly suitable for components subject to thermal shock. In contrast to other ceramic materials, zirconium oxide has a very high resistance to the spread of cracks. In addition, zirconium oxide ceramic has a very high thermal expansion and is therefore often chosen when realizing connections between ceramic and steel.
    In the technical representation of a side view of the agitator shaft 1 according to. FIG. 2 and in the cut-away representation according to FIG. 6, a cooling channel 6 can be seen, which is formed within the one-piece agitator shaft 1. Preferably, this extends at least in regions parallel to the longitudinal axis L of the agitator shaft 1. It is particularly preferably provided that the cooling channel 6 extends in a meandering manner between the end regions of the agitator shaft 1 and in particular is deflected at the end regions, the regions between the deflections in each case Can be arranged substantially parallel to each other. In FIG. 2, for example, three parallel sections 61, 62, 63 of the cooling channel 6 can be seen, which are parallel to one another and are also arranged parallel to the longitudinal axis L of the agitator shaft. Between the three parallel sections 61, 62, 63, two deflection areas 67, 68 are formed in the end areas of the agitator shaft 1.
    A coolant flowing through the first parallel section 61 in a first flow direction SR1 is deflected in the first deflection region 67 into the second parallel section 62 and flows through it in a second flow direction SR2, which runs opposite to the first flow direction SR1. The coolant is then deflected in the second deflection area 68 into the third parallel section 63 and in turn flows through it in the first flow direction SR1.
    The sectional view of the agitator shaft 1 along the section line AA in FIG. 2 shown in FIG. 3 shows that the cooling channel 6 formed within the agitator shaft 1 has six parallel sections 61, 62, 63, 64, 65 and 66 , each of which the first parallel section 61 and the second parallel section 62 are connected via a first deflection area 67, the second parallel section 62 and the third parallel section 63 are connected via a second deflection area 68, the third parallel Section 63 and the fourth parallel section 64 are connected via a third deflection area (not shown), the fourth parallel section 64 and the fifth parallel section 65 are connected via a fourth deflection area (not shown) and the fifth parallel section 65 and the sixth parallel section 66 are connected via a fifth deflection region 69 (cf. FIG. 6). In particular, it can be provided that the coolant is introduced into the stirring shaft 1 via the first parallel section 61 of the cooling channel 6 and is discharged from the stirring shaft 1 via the sixth parallel section 66 of the cooling channel 6.
    The agitator shaft 1 has three sections, in particular a first terminal section I, a second central section II and a third terminal section III. The agitator shaft 1 can be connected at its first terminal section I to a drive shaft 70 of the agitator ball mill (not shown). For this purpose, a shaft holder 7 is formed in the first terminal section I, for example. The agitator shaft 1 is at least partially designed as a hollow shaft, in particular the second partial section II and the third partial section III and optionally the first partial section I in some areas each have interior areas. In particular, the second middle section II has a first hollow interior or interior area 12 and the third section III has a second hollow interior or interior area 13. These preferably also have a cylindrical shape, the longitudinal axis of which is congruent with the longitudinal axis L of the agitator shaft 1. Furthermore, it is provided that the third section III is designed to be open at the end and, in particular, to have a further enlarged hollow interior in this open area. As will be explained below in connection with FIGS. 9 to 14, a wear element or the like can be placed in this hollow interior. to be ordered.
    It can further be provided that through openings 15 are formed in the second middle section II between the hollow interior area 12 and the outer surface 5 of the agitator shaft 1, the function of which is also explained below in connection with FIGS. 9 to 14. The second middle section II is therefore also referred to as an open section, while the first section I and the third section III each represent closed sections. The passage openings 15 extend in particular parallel to the longitudinal axis L of the agitator shaft, preferably in each case between the rows with agitator elements 3, as have been described in particular in connection with FIG. 1.
    As can be clearly seen, for example, with reference to FIG. 6, the at least one cooling channel 6 preferably extends through all three sub-sections I, II and III of the agitator shaft 1, the deflection regions 67, 68, 69 each in the end Sub-sections I and III are formed. In particular, the cooling channel 6 can be formed in a meandering manner - this is shown in more detail below.
    FIG. 4 shows a longitudinal section of the stirring shaft 1, in particular a sectional view of the stirring shaft 1 along the section line BB according to FIG. 3. 3 is in particular a cross section of the agitator shaft 1 in the second partial section II, which in particular passes through the agitator elements 3. Here, the passage openings 15 between the first hollow interior area 12 and the outer surface 5 of the agitator shaft 1 are clearly visible. 4 that the cooling duct 6 is formed in particular parallel to the longitudinal axis L and to the passage openings 15 extending parallel axially, with a parallel section 61, 62, 63, 64, 65, 66 of the cooling duct 6 adjacent to each extends in a series of stirring elements 3.
    Fig. 7 shows a side view of a wear protection sleeve 30 and Fig. 8 shows a perspective view of the wear protection sleeve 30. The arrangement of the wear protection sleeve 30 within an agitator ball mill 50 and its function is particularly in connection with FIGS. 10, 12 and 13th described below.
    The wear protection sleeve 30 is at least partially cylindrical, in particular the wear protection sleeve 30 has as the base body 32 a hollow cylinder 33, on the outside of which elevations 34, in particular in the form of cams 35 described in more detail below, are formed. The hollow cylinder has an outer diameter d30, which is smaller than the smallest inner diameter dlll of the third interior area III of the agitator shaft 1 (see FIG. 2). A fastening area, for example a flange 36, can be provided at an end region of the wear protection sleeve 30 in order to position and fasten the wear protection sleeve 30 in or on the agitator ball mill 50, in particular around the wear protection sleeve 30 on the grinding container base 59, in particular in a suitable receptacle on the grinding container base 59 to be determined - compare FIGS. 10 and 12.
    The wear protection sleeve 30 is preferably also made in one piece and in particular made of a ceramic material and can be produced analogously to the agitator shaft 50, for example in a 3D printing process, from one of the ceramic materials described above.
    Furthermore, it can be provided that the wear protection sleeve 30 comprises at least one cooling channel, which, for example, is also meandering and thus forms a large cooling surface (not shown). The formation of the at least one cooling duct of the wear protection sleeve can correspond to the formation of a cooling duct 6 of the agitator shaft 1. The supply lines for coolant supply and coolant discharge can be formed, for example, by the base of the grinding container (59, compare FIGS. 10, 12).
    The wear protection sleeve 30 can preferably be used in an agitator ball mill 50 shown in FIGS. 9 to 14 with an agitator shaft 1 according to FIGS. 1 to 6. However, the wear protection sleeve 30 can also be used in connection with an agitator shaft produced by conventional methods.
    9 to 14 show different views and representations of an agitator ball mill 50 with an agitator shaft 1 according to the invention, in particular FIG. 9 shows a front view of an agitator ball mill 50, FIG. 10 shows a sectional view of the agitator ball mill along the section line AA according to FIG. 9 and FIG. 11 shows a sectional illustration of the agitator ball mill 50 along the section line BB according to FIG. 10.
    The agitator ball mill 50 comprises a cylindrical grinding container 51 which extends along a horizontal axis L50 and has an inner circumferential surface 52. The grinding container 51 can be formed from a metal or, analogously to the stirring shaft 1, from a ceramic material. It can further be provided that the grinding container is designed to be coolable and comprises, for example, an outer cylinder 53 and an inner cylinder 54, between which a cooling space 55 is formed, into which coolant K can be introduced via a suitable coolant inlet 56 and a coolant outlet 57. The grinding container 51 further comprises a grinding container cover 58 and a grinding container base 59.
    A stirring shaft 1 with a longitudinal axis L is arranged horizontally within the grinding container 1. The longitudinal axis L of the agitator shaft 1 also represents its axis of rotation and is also congruent with the horizontal axis L50 of the grinding container 51. The agitator shaft 1 corresponds to the agitator shaft 1 described in FIGS. 1 to 6, so that reference is made to it for the description of the features thereof.
    A drive shaft 70 is arranged through the grinding container cover 58 and is connected to a drive, for example an electric motor or the like. (not shown) is connected. The drive shaft 70 is connected in a rotationally fixed manner to the agitator shaft 1, in particular the end of the drive shaft 70 protruding into the grinding container 51 engages in the shaft receptacle 7 in the first part section I of the stirring shaft 1. Furthermore, the grinding container cover 58 comprises the grinding material inlet 71, via which the grinding material M is filled into the agitator ball mill 50. A product outlet 72 is provided in the grinding container bottom 59, through which the ground product P leaves the agitator ball mill 50.
    An annular grinding gap MS is formed between the inner circumferential surface 52 of the grinding container 51 and the outer circumferential surface 5 of the stirring shaft, in particular in the area of the stirring elements 3. During operation of the agitator ball mill 50, the ground material / grinding aid mixture is located therein. By rotating the agitator shaft 1 in combination with the auxiliary grinding bodies (not shown), the regrind M in the grinding gap MS is stressed in such a way that it is comminuted, for example by impacting regrind particles with one another, by shear forces, etc. To reinforce the comminution effect, provision can be made that projections such as cams, rods or the like can also be arranged on the inner lateral surface 52 of the grinding container 51, which on the one hand bring about additional mixing of the ground material / grinding aid mixture and on the other hand increases the number of collision processes taking place in the grinding gap MS and thus the comminution effect of the agitator ball mill 50 increases.
    Furthermore, it is provided that the product outlet 72 is formed within a so-called receiving part 75, which extends through a central opening in the grinding container bottom 59. This receiving part 75 can also have cooling channels 76 through which coolant K is passed for cooling the product P. The receiving part 75 extends in particular axially in the inner cavity of the agitator shaft 1 in the direction of the regrind inlet 71 and is surrounded in regions in the area of the product outlet 72 by the wear protection sleeve 30. At the end region of the receiving part 75, which is arranged axially opposite the product outlet 72, a separating sieve 40, which will be described in more detail below, is preferably arranged, which serves to retain the auxiliary grinding bodies in the interior of the agitator ball mill while the product P is being removed.
    The cross section of the agitator ball mill 50 shown in FIG. 11 shows in particular a cross section in the region of the second middle section II of the agitator shaft 1, comparable to FIG. 3. The enlargement of the detail shows in particular an alternative embodiment of a cooling channel 6 *, which does not have a circular cross section, but is designed with an optimized, enlarged cross section.
    In this connection, the shape of the cams 4 will be discussed in more detail. As already described, the agitator shaft 1 is produced in one piece, in particular the agitator elements 3 are formed directly with the manufacture of the agitator shaft 1 and are not subsequently attached. The stirring elements 3 are designed in particular as cams 4 protruding from the cylindrical base body 2 of the stirring shaft 1. The connecting surface 20 of the cams 4 formed on the base body 2 of the agitator shaft 1 is designed to be relatively large, in particular in relation to the radial height h of the cams 4. The shape of the cams 4 can assume any geometrical shape, for example in axial section as well as in radial view trapezoidal, with rounded corners, with chamfered edges etc. The connecting surface 20 corresponds in particular to a base surface of each cam 4 and means the surface with which each cam 4 is in contact with the outer surface of the agitator shaft 1.
    Since in the illustrated embodiment the cooling channel 6, 6 * is formed adjacent to the cams 4, heat can advantageously be dissipated from the material to be ground / grinding aid mixture into the coolant within the cooling channel 6, 6 * via the large connecting surface 20 of the cams 4, since the large connecting surface 20 dissipates the heat more effectively. Furthermore, the shape, in particular in the case of ceramic material, significantly reduces the sensitivity of the cams 4 to breaking off or breaking off. The one-piece design of the agitator shaft 1 promotes both stability and heat conduction, since potential breaking points and heat conduction barriers are eliminated.
    For good stability of the cams 4 and to achieve a consistently good grinding result, it is advantageous if each cam 4 has a connecting surface 20 to the base body 2 of the agitator shaft 1 and an end face inflow surface 21 (see also FIG. 1), a The ratio of a projection of the face-side inflow surface 21 onto a plane perpendicular to the base body 2 of the agitator shaft 1 and the size of the connecting surface 20 is less than 1.
    It is advantageous, for example, if each cam 4 has a connecting surface 20 to the agitator shaft 1 with the greatest width and the ratio of the height of each cam 4 to the agitator shaft 1 and the greatest width is greater than 0.2. Furthermore, each cam 4 can have a connecting surface 20 to the agitator shaft 1 with a greatest length, the ratio of the height of each cam 4 and the greatest length preferably being less than 1. According to a further embodiment, it is advantageous if each cam 4 has a connecting surface 20 to the stirrer shaft 1 with a greatest length and a greatest, the ratio of the greatest width and the greatest length being less than 1.
    In this connection, reference is also made to FIGS. 18A to 18E. FIGS. 18A to 18E each show further embodiments of agitator shafts 1. These each show a cross section of the outer surface 5, the representation of the passage openings, cooling channels, etc., analogous to FIG. 3, has been omitted here. In particular, the arrangement and design of the stirring elements 3 or cams 4 on the outer lateral surface 5 are different in the various embodiments. For example, the inclination of the side or inflow surface 21 leading in the direction of rotation D and the inclination of the side lagging in the direction of rotation D are formed to different degrees.
    In this case, an angle of inclination of the face-side inflow surface 21 with respect to a plane normal to the inside of the grinding container 59 and / or a plane normal to the cylindrical outer surface of the agitator shaft 1 can be in a range from plane in a range from −45 ° to 85 ° . An angle of 0 ° corresponds to an inflow surface 21, which is located within a plane normal to the inside of the grinding container 59 (see FIG. 18C), whereas an angle with a negative sign denotes an undercut inflow surface 21, i. H. an inflow surface 21 which is inclined so that it virtually covers a certain area of the connection surface 20 (compare in particular FIGS. 18D, 18E). Tilt angles with a positive sign accordingly characterize an end face inflow surface 21 which is inclined in reverse, ie. H. in which the end of the inflow surface 21 located on the base body 2 is flowed to first (compare in particular FIGS. 18A, 18B, 18E).
    In principle, it is advantageous to provide a plurality of cams 4 on the agitator shaft 1 in order to promote the desired interaction with the material to be ground / grinding auxiliary body mixture. The agitator shaft 1 can also have cam-free areas, or can have more cams 4 in some areas and fewer cams 4 in other areas. In addition, not all cams 4 have to be of the same design, but can be arranged in different shapes and sizes in different areas.
    As can be seen in particular from FIG. 1, it can be advantageous to arrange several cams 4 in a row in the circumferential direction of the main body 2 of the agitator shaft 1 in a row along a circumferential line of the main body 2 of the agitator shaft 1. For example, a distance between successive cams 4 of a row in the circumferential direction can be formed equal to or greater than the greatest length of a cam 4 in the circumferential direction.
    If a plurality of cams 4 are successively arranged in a row along a plurality of circumferentially spaced circumferential lines, then an axial distance between two axially adjacent rows of cams is advantageously greater than or equal to 1.1 times the greatest width of a cam 4 If cams 4 are formed at a distance from one another in the axial direction on the base body 2 of the agitator shaft 1, then these cams 4 can either be axially aligned or also offset from one another.
    12, which shows the agitator ball mill 50 along the section line C - C according to FIG. 11, in particular the path of the ground material / grinding aid mixture G within the agitator ball mill 50 will be described. Grist M is filled into the interior of the grinding container 51 via the grist inlet 71. This is already partially filled with grinding aids, for example the interior of the grinding container is already about 80% filled with grinding aids. Due to the rotation of the agitator shaft 1, the millbase M and the auxiliary grinding media (not shown) are mixed to form a millbase / auxiliary grinding media mixture G, which along the agitator shaft 1 between the inner lateral surface 52 of the grinding container 51 and the outer lateral surface 5 of the stirring shaft 1 in a first conveying direction FR1 in Direction of the grinding container bottom 59 flows. A distance is formed between the open end region of the third partial section III of the agitator shaft 1 and the grinding container base 59, in which the flow of the material to be ground / grinding aid mixture G is deflected, so that it is now hollow in a second conveying direction FR2 opposite the first conveying direction FR1 Flows through interior area 13 of the third section III of the agitator shaft 1.
    A wear protection sleeve 30 (see also FIG. 10) is arranged within the second interior area 13. Such a wear protection sleeve 30 has already been described in connection with FIGS. 7 and 8, the description of which is hereby incorporated by reference. Between the inner lateral surface of the agitator shaft 50 in the third inner region III and the outer outer surface of the wear protection sleeve 30, a type of grinding gap is again formed, in which the material to be ground / grinding auxiliary mixture G is guided in the direction of conveyance FR2 in the direction of the first hollow interior region 12 of the second middle section II. This grinding gap is particularly small between the cams 35 of the wear protection sleeve 30 and the inner lateral surface of the agitator shaft 50 in the third interior area III. The cams 35 serve in particular as wipers in order to prevent ground material and / or auxiliary grinding bodies from adhering to the inner surface of the agitator shaft 1. Instead, the cams 35 ensure that the material to be ground / auxiliary grinding mixture G is kept in flow and is fed in the conveying direction FR2 to the passage openings 15 in the second partial section, where the auxiliary grinding bodies are returned in the direction of between the outer surface of the stirring shaft 1 and the inner surface 52 of the grinding container 51 formed grinding chamber or grinding gap MS.
    A separating sieve 40, a classifying rotor 41 or another suitable device is arranged within the first hollow interior area 12, which retains the auxiliary grinding media of the grinding stock / grinding auxiliary mixture G, while sufficiently milled regrind passes through as finished product P and out through the product outlet 72 the agitator ball mill 50 can be removed. The through the separating screen 40, the classifying rotor 41 or the like. retained auxiliary grinding media and, if appropriate, not yet sufficiently ground grinding material M return via the openings 15 in the second middle section II of the stirring shaft 1 back into the grinding gap MS between the grinding container 51 and the stirring shaft 1 and are moved again in the conveying direction FR1.
    13 shows a sectional illustration of the agitator ball mill 50 along the section line D - D according to FIG. 12, in which the arrangement of the wear protection sleeve 30 within the second hollow interior area 13 of the third partial section III of the agitator shaft 1 can be seen.
    14 shows a sectional illustration of the agitator ball mill 50 with a meandering cooling channel 6 according to the section lines E-E according to FIG. 9. In particular, the course of the first parallel section 61 of the cooling channel 6 and the course of the sixth parallel section 66 of the cooling channel 6 are visible. The coolant K is supplied via the coolant inlet 56 and flows through the first parallel section 61 of the cooling channel 6 in a first flow direction SR1. As described in connection with FIG. 6, the coolant 6 is deflected several times and finally flows through the sixth parallel section 66 of the cooling channel 6 in a second flow direction SR2, opposite to the first flow direction SR1, before it is discharged from the agitator shaft 1 via the coolant outlet 57 becomes.
    15 shows a perspective illustration of a further embodiment of a stirrer shaft 1 designed in one piece according to the invention. In this embodiment, the representation of the stirrer elements 3, in particular cams 4, and the more precise configuration of the features of the three sub-sections I, II and III waived. However, the features described in connection with FIG. 1 also apply to this embodiment, since the formation of the at least one cooling channel 6 will be discussed in more detail below.
    The cooling duct 6 shown here represents a so-called countercurrent cooling. On the one hand, the cooling duct 6 has two parallel sections 81, 82 on a first radial R1 extending first between the longitudinal axis L and the outer circumferential surface 5 of the agitator shaft 1. In particular, it is provided that the coolant is introduced into the first parallel section 81 and flows through it in a first flow direction SR1 from the first part section I in the direction of the third part section III, the first flow direction SR1 preferably for the first delivery direction FR1 the regrind / auxiliary grinding mixture G corresponds to FIGS. 9 to 14. In countercurrent cooling, it is provided in particular that the coolant K flows through two parallel sections 81 and 82, 83 and 84, 85 and 86, 87 and 88 in succession, each on a common radial R, R1, R2, R3, R4 the agitator shaft 1. In particular, coolant K flows through each of the parallel sections 81, 83, 85, 87 running closer to the longitudinal axis L. The coolant K is then deflected in the end region of the third partial section III in a deflection region 95 into the parallel section 82, 84, 86 or 88 arranged on the same radial R1, R2 or R3 and flows through it in a direction opposite to the first flow direction SR1 second flow direction SR2. A deflection area 91 is formed in the free end area of the first partial section I, which deflects the coolant K from the second parallel section 82 on the first radial R2 into the third parallel section 83 on the second, closer to the longitudinal axis L of the agitator shaft Radial R2 redirects. The coolant now flows through the third parallel section 83 again in the first flow direction SR1 and can subsequently, via a further deflection area 95 in the third partial section III, into the fourth parallel section 84, which is formed on the same second radial R2 and is further spaced from the longitudinal axis L. Finally, the coolant flows in the second flow direction SR2 through the last parallel section 88 formed on the fourth radial R4 and is derived from the agitator shaft 1. In the counterflow cooling described here, there are two parallel parallel sections 81 and 82, 83 and 84 etc. of the cooling channel 6, through which coolant K flows in opposite flow directions SR1, SR2, on a common radial R of the agitator shaft 1. In particular the coolant K is guided near the longitudinal axis L of the agitator shaft 1 from the regrind inlet side to the product outlet side. The coolant K is returned from the product outlet side to the regrind inlet side within the agitator shaft 1 in a region adjacent to the outer surface of the agitator shaft 1.
    It can preferably be provided that the coolant K does not flow through the parallel sections 81 to 88 one after the other, but that fresh coolant K flows into and out of each of the parallel sections 81, 83, 85, 87 formed closer to the longitudinal axis L. the parallel sections 82, 84, 86, 88 formed closer to the outer surface of the agitator shaft 1 are discharged. The deflection area 91 is in this case in particular designed as an annular gap 92. This ensures that the freshest and therefore coolest coolant K is first led into the area of the agitator ball mill in which the ground material is the warmest. This is in particular the area near the product outlet after the millbase has flowed through the agitator ball mill from the millbase inlet side. The cooling process can be further optimized with this countercurrent cooling.
    16 shows a longitudinal section of an agitator ball mill with a further embodiment of an agitator shaft 1 with a cooling channel 6 designed as countercurrent cooling, and FIG. 17 shows a cross section of the agitator ball mill with an agitator shaft according to FIG. 16 along a section line AA. It is provided here that the coolant is supplied in a first flow direction SR1 via a coolant supply line 93 within the drive shaft 70 of the agitator shaft 1 and flows through the first parallel sections 81 of the cooling channel 6 in the flow direction SR1. This first flow direction SR1 preferably corresponds to the first conveying direction FR1 for the ground material / grinding aid mixture G according to FIGS. 9 to 14. The first parallel sections 81 are also referred to as inner flow channels 94.
    In the end region of the third partial section III, a deflection region 95 is formed in each case, which connects an inner flow channel 94 to a second parallel section 82 of the cooling channel 6. The second parallel section 82 is also referred to as an outer flow channel 96. In particular, the coolant K is deflected in the deflection area 95 and now flows through an outer flow channel 96 in a second flow direction SR2 opposite the first flow direction SR1 and then leaves the agitator shaft 1 via coolant discharge lines 97 within the drive shaft 70. In each case, an inner flow channel 94 and an outer flow channel 96 are arranged on a radial R of the agitator shaft 1, the inner flow channel 94 being arranged closer to the longitudinal axis L of the agitator shaft 1 than the outer flow channel 96.
    In this type of countercurrent cooling, there are two parallel parallel sections 81 and 82 of the cooling channel 6 on a common radial R of the agitator shaft 1 and the coolant K flows through them in opposite flow directions SR1, SR2. It is particularly advantageous that the coolant K is removed again after it has flowed through the agitator shaft 1 once in the first flow direction SR1 and once in the second flow direction SR2. Thus, all the parallel sections 82 are cooled to the same degree, whereas in the exemplary embodiment according to FIG. 15 the cooling in the last parallel section 88 is significantly reduced compared to the cooling in the second parallel section 82. The cooling of an agitator shaft 1 according to FIG. 16 is thus further optimized compared to the cooling of a first embodiment of the agitator shaft 1 according to FIG. 15.
    16 also shows the supply of regrind M, the flow of the regrind / auxiliary grinding mixture G within the agitator ball mill 50 and the removal of product P - also compare the description of FIG. 12.
    Furthermore, embodiments are conceivable in which an annular gap is formed in the first partial region I of the agitator shaft 1 for the coolant supply. Starting from this annular gap, a plurality of cooling channels run in a first flow direction SR1 in the direction of the third partial region III. Several deflection channels are then formed here, which then return the cooling medium in a counterflow to the first flow direction SR1 and in a counterflow to the conveying direction FR of the regrind / grinding aid mixture G in a second flow direction SR2, in particular to a further annular gap which collects the “used” cooling medium . This ensures that each shaft section is cooled with fresh coolant.
    The embodiments, examples and variants of the preceding paragraphs, the claims or the following description and the figures, including their different views or respective individual features, can be used independently of one another or in any combination. Features described in connection with an embodiment are applicable to all embodiments unless the features are inconsistent.
    Although there is generally talk of “schematic” representations and views in the context of the figures, it is by no means meant that the figure representations and their description should be of subordinate importance with regard to the disclosure of the invention. The person skilled in the art is quite capable of extracting enough information from the schematically and abstractly drawn representations that facilitate his understanding of the invention, without having to draw from the drawn and possibly not to scale proportions of the piece goods and / or parts of the device or other drawn elements would be impaired in any way. The figures thus enable the person skilled in the art as a reader to derive a better understanding of the inventive concept formulated in the claims and in the general part of the description in more general terms and / or in more abstract terms on the basis of the specifically explained implementations of the method according to the invention and the specifically explained mode of operation of the device according to the invention.
    The invention has been described with reference to a preferred embodiment. However, it is conceivable for a person skilled in the art that modifications or changes of the invention can be made without leaving the scope of the following claims.
    Reference list
    [0093]<tb> 1 <SEP> stirring shaft<tb> 2 <SEP> cylindrical body<tb> 3 <SEP> stirring element<tb> 4 <SEP> cam<tb> 5 <SEP> outer surface<tb> 6.6 * <SEP> cooling channel<tb> 7 <SEP> wave recording<tb> 12 <SEP> first interior area<tb> 13 <SEP> second interior area<tb> 15 <SEP> passage opening<tb> 20 <SEP> interface<tb> 21 <SEP> face face<tb> 30 <SEP> wear protection sleeve<tb> 32 <SEP> cylindrical body<tb> 33 <SEP> hollow cylinders<tb> 34 <SEP> survey<tb> 35 <SEP> cam<tb> 36 <SEP> flange<tb> 40 <SEP> separating sieve<tb> 41 <SEP> classifying rotor<tb> 50 <SEP> agitator ball mill<tb> 51 <SEP> grinding bowl<tb> 52 <SEP> inner surface<tb> 53 <SEP> outer cylinder<tb> 54 <SEP> inner cylinder<tb> 55 <SEP> cold room<tb> 56 <SEP> coolant inlet<tb> 57 <SEP> coolant outlet<tb> 58 <SEP> grinding container lid<tb> 59 <SEP> grinding container bottom<tb> 61 <SEP> (first) parallel section of the cooling duct<tb> 62 <SEP> (second) parallel section of the cooling channel<tb> 63 <SEP> (third) parallel section of the cooling duct<tb> 64 <SEP> (fourth) parallel section of the cooling duct<tb> 65 <SEP> (fifth) parallel section of the cooling duct<tb> 66 <SEP> (sixth) parallel section of the cooling duct<tb> 67 <SEP> (first) deflection area of the cooling duct<tb> 68 <SEP> (second) deflection area of the cooling duct<tb> 69 <SEP> (fifth) deflection area of the cooling duct<tb> 70 <SEP> drive shaft<tb> 71 <SEP> regrind inlet<tb> 72 <SEP> product outlet<tb> 75 <SEP> receiving part<tb> 76 <SEP> cooling channel<tb> 81 <SEP> (first) parallel section<tb> 82 <SEP> (second) parallel section<tb> 83 <SEP> (third) parallel section<tb> 84 <SEP> (fourth) parallel section<tb> 85 <SEP> (fifth) parallel section<tb> 86 <SEP> (sixth) parallel section<tb> 87 <SEP> (seventh) parallel section<tb> 88 <SEP> (eighth / last) parallel section<tb> 91 <SEP> deflection area<tb> 92 <SEP> annular gap<tb> 93 <SEP> coolant supply line<tb> 94 <SEP> inner flow channel<tb> 95 <SEP> deflection area<tb> 96 <SEP> outer flow channel<tb> 97 <SEP> coolant discharge line<tb> <SEP><tb> d30 <SEP> outer diameter wear protection sleeve<tb> dlll <SEP> inside diameter third section<tb> D <SEP> direction of rotation<tb> FR1 <SEP> first conveying direction<tb> FR2 <SEP> second conveying direction<tb> G <SEP> regrind / auxiliary grinding mixture<tb> h <SEP> Height of the cams<tb> I <SEP> first terminal section<tb> II <SEP> second middle section<tb> III <SEP> third terminal section<tb> K <SEP> coolant<tb> L <SEP> longitudinal axis of the agitator shaft<tb> L50 <SEP> Axis of the grinding bowl of the agitator ball mill<tb> M <SEP> regrind<tb> MS <SEP> grinding gap<tb> P <SEP> product<tb> R <SEP> radial<tb> R1 <SEP> first radial<tb> R2 <SEP> second radial<tb> R3 <SEP> third radial<tb> SR1 <SEP> first flow direction<tb> SR2 <SEP> second flow direction
    权利要求:
    Claims (15)
    [1]
    1. agitator shaft (1) for an agitator ball mill (50), the agitator shaft (1) having a longitudinal axis (L) and an outer surface (5) equipped with agitator elements (3), the agitator shaft (1) with the agitator elements (3) is formed in one piece and consists of a ceramic material.
    [2]
    2. stirrer shaft (1) according to claim 1, wherein the stirrer shaft (1) has at least one cooling channel (6) which preferably extends at least in regions parallel to the longitudinal axis (L) of the stirrer shaft (1).
    [3]
    3. stirrer shaft (1) according to claim 2, wherein the at least one cooling channel (6) is meandering.
    [4]
    4. stirrer shaft (1) according to claim 2 or 3, wherein the at least one cooling channel (6) extends in at least two areas in each case parallel to the longitudinal axis (L) of the stirrer shaft (1), wherein a deflection area is formed between the two parallel areas is, in particular wherein a coolant flows through the at least two areas connected to one another via a deflection area in opposite flow directions.
    [5]
    5. stirrer shaft (1) according to claim 4, wherein two parallel ones. Areas through which coolant flows in opposite flow directions are arranged on a common radial (R1, R2 or R3) of the agitator shaft (1).
    [6]
    6. stirrer shaft (1) according to any one of the preceding claims, wherein the stirrer shaft (1) has a first terminal portion (I) on which the stirrer shaft (1) can be arranged on a drive shaft (70), the stirrer shaft (1 ) furthermore has a second middle section (II) and a third terminal section (III).
    [7]
    7. stirrer shaft (1) according to claim 5, wherein the at least one cooling channel (6) within the first terminal section (I) and at least partially within the second, middle section (II), in particular wherein the at least a cooling channel (6) extends through all three sections.
    [8]
    8. stirrer shaft (1) according to claim 6 or 7, wherein the second, central section (II) has a first hollow interior (12), in particular a cylindrical first hollow interior (12) with a longitudinal axis which is congruent with the longitudinal axis (L) of the agitator shaft (1) is formed.
    [9]
    9. agitator shaft (1) according to claim 6 or 7, wherein the third terminal portion (III) has a second hollow interior (13), in particular a cylindrically shaped second hollow interior (13) with a longitudinal axis which is congruent with the longitudinal axis ( L) the agitator shaft (1) is formed.
    [10]
    10. stirrer shaft (1) according to claim 8, wherein between the first hollow interior (12) of the second, middle section (II) and the outer surface (5) of the stirrer shaft (1) in the region of the second, middle section ( II) passage openings (15) are formed.
    [11]
    11. agitator shaft (1) according to one of the preceding claims, wherein the agitator elements (3) are designed as cams (4) projecting from a base body (2) of the agitator shaft (1), the connection surface of the cams (2) formed on the base body (2) 4) is relatively large, in particular where each cam (4) has a connecting surface to a base body of the agitator shaft (1) and a leading side, a ratio of the projection of the leading side onto a plane normal to the base body of the agitator shaft and the size the connection area is less than 1.
    [12]
    12. stirrer shaft (1) according to one of the preceding claims, wherein the stirrer shaft (1) with the stirring elements (3) can be produced in a 3D printing process.
    [13]
    13. agitator ball mill (50) with a grinding container (51) extending along a horizontal or vertical axis (L50) with an inner lateral surface (52), with an inside the grinding container (51) about the horizontal or vertical axis (L50) rotatable stirring shaft (1) with an outer lateral surface (5), with stirring elements (3) being formed on the outer lateral surface (5), a grinding gap (3) between the stirring elements (3) of the stirring shaft (1) and the inner lateral surface (52) of the grinding container (51) MS), the stirrer shaft (1) being formed in one piece with the stirrer elements (3) and consisting of a ceramic material, in particular an agitator ball mill (50) with a stirrer shaft (1) according to one of claims 1 to 12.
    [14]
    14. agitator ball mill (50) according to claim 13, comprising a wear protection sleeve (30) which can be arranged in an interior of the agitator shaft (1) and which consists of a ceramic material and is formed in one piece.
    [15]
    15. A method for producing an agitator shaft (1) for an agitator ball mill (50), wherein the agitator shaft (1) is made in one piece from a ceramic material, in particular a method for producing an agitator shaft (1) according to one of claims 1 to 12, in particular wherein the Stirring shaft (1) with the stirring elements (3) is produced by means of 3D printing.
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    同族专利:
    公开号 | 公开日
    CN110893367A|2020-03-20|
    CH715322B1|2020-06-15|
    DE102018122395A1|2020-03-19|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE2626757C2|1975-07-09|1984-03-15|Meyer AG Zuchwil, Zuchwil|Agitator mill, especially colloid mill|
    DE3015631A1|1980-04-23|1981-10-29|Gebrüder Netzsch, Maschinenfabrik GmbH & Co, 8672 Selb|AGITATOR MILL|
    DE3614721C2|1986-04-30|1995-04-06|Buehler Ag Geb|Agitator mill|
    DE4109332C2|1991-03-21|1992-12-24|Erich Netzsch Gmbh & Co Holding Kg, 8672 Selb, De|
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    DE10241924B3|2002-09-10|2004-05-27|Netzsch-Feinmahltechnik Gmbh|Agitating mixer with cooled agitating shaft, e.g. for sour dough, has tubular elements of round, square, rectangular, semicircular, triangular or polygonal cross section|
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    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE102018122395.1A|DE102018122395A1|2018-09-13|2018-09-13|Agitator shaft for an agitator ball mill, agitator ball mill and method for producing an agitator shaft for an agitator ball mill|
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