EP4000735A1 - Agitator ball mill - Google Patents

Agitator ball mill Download PDF

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Publication number
EP4000735A1
EP4000735A1 EP21208681.3A EP21208681A EP4000735A1 EP 4000735 A1 EP4000735 A1 EP 4000735A1 EP 21208681 A EP21208681 A EP 21208681A EP 4000735 A1 EP4000735 A1 EP 4000735A1
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EP
European Patent Office
Prior art keywords
grinding chamber
agitator
ball mill
agitator ball
ground
Prior art date
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Granted
Application number
EP21208681.3A
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German (de)
French (fr)
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EP4000735B1 (en
EP4000735C0 (en
Inventor
Guillaume Martin
Benedikt SIMONS
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Willy A Bachofen AG
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Willy A Bachofen AG
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Publication of EP4000735B1 publication Critical patent/EP4000735B1/en
Publication of EP4000735C0 publication Critical patent/EP4000735C0/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/16—Mills in which a fixed container houses stirring means tumbling the charge
    • B02C17/163—Stirring means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/04—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls with unperforated container
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/16—Mills in which a fixed container houses stirring means tumbling the charge
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/18—Details
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/18—Details
    • B02C17/1815—Cooling or heating devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/18—Details
    • B02C17/24—Driving mechanisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C19/00—Other disintegrating devices or methods
    • B02C19/18—Use of auxiliary physical effects, e.g. ultrasonics, irradiation, for disintegrating

Definitions

  • the present invention relates to an agitator ball mill.
  • a well-known agitator ball mill is, for example, in EP 3 102 332 B1 described.
  • the agitator ball mill described there comprises an essentially cylindrical grinding chamber, which is delimited by a jacket and an inlet and an outlet end wall, as well as a rotatably mounted agitator shaft, on which agitator elements, also known as accelerators, are axially mounted inside the grinding chamber (i.e. in the direction of the longitudinal axis the agitator shaft) are arranged at a distance from one another.
  • the agitator shaft and thus the agitator elements connected to it in a rotationally fixed manner are set in rotation by an external motor.
  • the material to be ground it is desirable or necessary for the material to be ground to be heated during the grinding process, e.g. to improve the grinding process or to activate or support chemical reactions.
  • Agitator ball mills with heating devices for the material to be ground have therefore already been proposed.
  • an agitator ball mill in which a separate heating and cooling chamber is arranged around the grinding chamber, through which a heating or cooling medium can flow.
  • the agitator shaft itself can also be heated or cooled.
  • an agitator ball mill is shown in which a heater is arranged outside on the wall of the grinding chamber.
  • This is an electrical heating band that heats the wall of the grinding chamber by contact.
  • a high-frequency induction heater can be provided, which also heats the wall of the grinding chamber.
  • JP 2009 000633 A describes an agitator ball mill which has an electric coil around the outside of the wall of the grinding chamber.
  • the coil creates a magnetic field that induction heats the wall of the grinding chamber.
  • an agitator bead mill with induction heating is shown.
  • an electrical coil is arranged as an inductor around the agitator shaft.
  • two coils are arranged at an axial distance as inductors on the stirring shaft.
  • the stirring elements arranged on the stirring shaft are designed as electrically conductive susceptors and are inductively heated by the magnetic field of the coil(s). The heat from the stirring elements is transferred to the material to be ground, so that the material to be ground is heated more or less indirectly. All components of the induction heating are arranged inside the grinding chamber of the agitator bead mill.
  • an inductively heated agitator ball mill of the generic type is to be improved by the present invention in that in connection with the WO 2019/228983 A1 described disadvantages are avoided.
  • an agitator ball mill with inductive heating is to be proposed, which is structurally less complex than the known agitator ball mill of this type.
  • the agitator ball mill comprises a grinding chamber which has a jacket, and also a rotatably mounted agitator shaft which protrudes into the grinding chamber and on which at least one agitator element is arranged inside the grinding chamber. It also includes an inlet for supplying material to be ground and grinding bodies into the grinding chamber and an outlet for removing the ground material, and an induction heater comprising an inductor and a susceptor for the material to be ground in the grinding chamber.
  • the at least one stirring element includes the susceptor.
  • the inductor comprises at least one coil which is arranged outside the casing of the grinding chamber and encloses the grinding chamber.
  • the shell of the grinding chamber consists of an electrically and magnetically non-conductive material.
  • the inductor Due to the (static) arrangement of the inductor outside the grinding chamber, it is protected from the influences of the material to be ground and, above all, the grinding body, and the energization of the inductor is structurally simple. Because the shell of the grinding chamber consists of an electrically and magnetically non-conductive material, the magnetic field generated by the inductor (namely the coil) can penetrate the shell and act on the susceptor material contained by the at least one stirring element, whereby the susceptor material and so that the stirring element is also heated. In particular, the stirring element can be produced as a whole from the susceptor material, so that the stirring element consists of the susceptor material.
  • the susceptor of the induction heating consists of an electrically and/or magnetically conductive material which is inductively heated by the alternating magnetic field of the inductor (the coil) of the induction heating.
  • the susceptor is preferably at least electrically conductive. In such an electrically conductive susceptor, eddy currents are induced by the alternating magnetic field of the inductor, which then heat the susceptor (and thus also the stirring element).
  • two or more agitators are arranged on the agitator shaft at a distance from one another along the agitator shaft.
  • the inductor comprises two or more coils, which are arranged along the shell of the grinding chamber in such a way that the magnetic field they generate only acts on one of the stirring elements.
  • the two or more coils are preferably designed to be separately controllable.
  • the agitator ball mill comprises a high-frequency generator for supplying the coil or coils with alternating current at a working frequency of the high-frequency generator, the working frequency of the high-frequency generator being in the range from 1 kHz to 1 MHz.
  • the induction heating has a natural frequency
  • the working frequency of the high-frequency generator is at or near the natural frequency of the induction heating. This optimizes the efficiency of the induction heating and its energy consumption.
  • the jacket of the grinding chamber is surrounded by a cooling jacket through which a cooling medium can be conducted. This can further support the control of the temperature of the ground material.
  • the agitator ball mill comprises a cylindrical grinding chamber 1, which is delimited by a jacket 2 and one end wall 3 on the inlet side and one end wall 4 on the outlet side.
  • the stirring elements 11, 12 and 13 are designed as accelerators in the exemplary embodiment shown; they are connected to the stirring shaft 5 in a rotationally fixed manner and are rotationally driven by the stirring shaft 5 during operation.
  • an annular channel 9 which is open towards the interior of the grinding chamber 1 educated.
  • the stirring shaft 5 and thus the stirring elements 11, 12, 13 (here: the accelerators) which are connected to it in a rotationally fixed manner are set in rotation by an external motor (not shown).
  • the stirring elements 11, 12 and 13 can, as shown, be designed in the manner of a paddle wheel or else, for example, as simple stirring discs.
  • the grinding chamber 1 is surrounded by an outer cooling jacket 10 in such a way that an annular cavity 15 is formed between the cooling jacket 10 and the jacket 2 of the grinding chamber 1, through which a cooling medium can be conducted if required.
  • the supply and discharge lines for the cooling medium are not shown for the sake of simplicity.
  • the agitator ball mill according to the invention corresponds to the state of the art in terms of structure and function, for example as described above EP 3 102 332 B1 is represented. The person skilled in the art therefore does not need any further explanation.
  • the agitator ball mill In order to heat the material to be ground, which flows through the grinding chamber 1 from the inlet 6 to the outlet 7 during operation of the agitator ball mill, the agitator ball mill is equipped with an induction heating system which comprises a coil 20 as an inductor, which during operation of the agitator ball mill is supplied by a high-frequency generator G is powered by alternating current.
  • the induction heating also includes a susceptor.
  • the coil 20 is arranged outside the grinding chamber 1 in the cavity 15 formed between the cooling jacket 10 and the jacket 2 of the grinding chamber.
  • the coil 20 supplied with alternating current generates an (electro)magnetic alternating field which penetrates through the jacket 2 of the grinding chamber 1 into the interior of the grinding chamber, since the jacket 2 of the grinding chamber 1 consists of an electrically and magnetically non-conductive material.
  • the alternating magnetic field acts on the stirring elements 11, 12 and 13, which are made of a suitable electrically conductive material here, e.g. chrome steel or nickel-based alloys, which is also suitable for the grinding process, and generates eddy currents in them, which the stirring elements 11, 12 and 13 heat.
  • the in this way in the stirring elements 11, 12 And 13 generated heat is transferred from the stirring elements 11, 12 and 13 to the material to be ground and heats it.
  • the casing 2 of the grinding chamber 1 consists of a material which can be penetrated by the magnetic field of the coil 20 as unhindered as possible.
  • the material of the jacket 2 of the grinding chamber 1 is therefore neither electrically nor magnetically conductive, as already mentioned.
  • a suitable material for the shell 2 of the grinding chamber 1 is, for example, a ceramic, for example silicon carbide.
  • the stirring elements 11, 12 and 13 consist as a whole of an electrically conductive susceptor material in which eddy currents can be induced.
  • the stirring elements 11, 12 and 13 can also only partially consist of a susceptor material or comprise such a susceptor material, but the remaining stirring element then consists of a material with high thermal conductivity and must also be suitable for the grinding process .
  • a magnetic shield 30 surrounding the coil 20 on the outside and on the side concentrates the magnetic field generated by the coil 20 inward on the stirring elements 11, 12 and 13.
  • the stirring shaft 5 can consist of an electrically and magnetically non-conductive material, so that it itself can the magnetic field of the coil 20 is not heated.
  • the exemplary embodiment of the agitator ball mill according to the invention differs from the exemplary embodiment according to FIG 1 only because instead of the single coil 20, which extends almost over the entire length of the grinding chamber 1, there are three axially shorter coils 21, 22 and 23, which can be controlled separately and are arranged along the grinding chamber in such a way that they each form one of the stirring elements 11, 12 and 13 enclose radially.
  • the inductor is thus formed by the three coils 21, 22 and 23 here.
  • Three magnetic shields 31, 32 and 33 concentrate the magnetic fields of the coils 21, 22 and 23 on the stirring elements 11, 12 and 13 and shield the magnetic fields from the outside. All other parts of the agitator ball mill are the same as in the embodiment of FIG 1 and accordingly bear the same reference numbers.
  • the magnetic fields generated by the three coils 21, 22 and 23 act only on the stirring element 11 or 12 or 13 radially opposite the respective coil.
  • the division of the inductor into (here) three independent coils 21, 22 and 23 allows an (axially ) Zone-by-zone different heating of the regrind, which is an advantage in certain applications.
  • the coils 21, 22 and 23 can be controlled individually, which can be done either by means of three independent high-frequency generators or by means of a high-frequency generator with several outputs.
  • zone-wise control of the temperature of the material to be ground can be achieved.
  • the control of the temperature can also be supported by cooling by means of a cooling medium that can be conducted through the cavity 15 .
  • the coil 20 or the coils 21, 22 and 23 are fed by the high-frequency generator G shown only schematically in the drawing.
  • the working frequency of the high-frequency generator G can be in the range from 1 kHz to 1 MHz.
  • the induction heating has a natural frequency that is given by the coil or coils and the susceptors or stirring elements.
  • the operating frequency of the generator G for feeding the coil or coils with alternating current (which has this operating frequency) is as close as possible to or at the natural frequency of the induction heating.
  • the optimum working frequency can be determined empirically.
  • the invention was explained above using exemplary embodiments, but should not be limited to these exemplary embodiments. Rather, numerous modifications are conceivable for the person skilled in the art without deviating from the teaching of the invention.
  • more or fewer than three stirring elements can be provided in the grinding chamber and the stirring elements can be designed as desired.
  • the induction heating can also include only two or more than three inductor coils.
  • one of these coils can also have two or act on several agitators at the same time. The scope of protection is therefore defined by the following claims.

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  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Crushing And Grinding (AREA)
  • General Induction Heating (AREA)

Abstract

Eine Rührwerkskugelmühle umfasst eine Mahlkammer (1), die einen Mantel (2) aufweist, und ferner eine in die Mahlkammer (1) hineinragenden, drehbar gelagerte Rührwelle (5), auf der innerhalb der Mahlkammer (1) mindestens ein Rührorgan (11, 12, 13) angeordnet ist. Sie umfasst ferner einen Einlass (6) zur Zufuhr von Mahlgut und Mahlkörpern in die Mahlkammer sowie einem Auslass (7) zur Entnahme des gemahlenen Guts, und eine einen Induktor und einen Suszeptor umfassende Induktionsheizung für das in der Mahlkammer (1) befindliche Mahlgut. Das mindestens eine Rührorgan (11, 12, 13) umfasst ein Suszeptor-Material, welches den Suszeptor der Induktionsheizung bildet, wobei der Induktor mindestens eine ausserhalb des Mantels (2) der Mahlkammer (1) angeordnete und die Mahlkammer (1) umschliessende Spule (20; 21, 22, 23) aufweist, und wobei der Mantel (2) der Mahlkammer (1) aus einem elektrisch und magnetisch nicht leitenden Material besteht.An agitator ball mill comprises a grinding chamber (1) which has a casing (2) and also a rotatably mounted agitator shaft (5) which projects into the grinding chamber (1) and on which at least one agitator element (11, 12 , 13) is arranged. It also comprises an inlet (6) for supplying material to be ground and grinding bodies into the grinding chamber and an outlet (7) for removing the ground material, and an induction heating system comprising an inductor and a susceptor for the material to be ground in the grinding chamber (1). The at least one stirring element (11, 12, 13) comprises a susceptor material which forms the susceptor of the induction heating, the inductor having at least one coil ( 20; 21, 22, 23), and wherein the jacket (2) of the grinding chamber (1) consists of an electrically and magnetically non-conductive material.

Description

Die vorliegende Erfindung betrifft eine Rührwerkskugelmühle.The present invention relates to an agitator ball mill.

Eine bekannte Rührwerkskugelmühle ist beispielsweise in EP 3 102 332 B1 beschrieben. Die dort beschriebene Rührwerkskugelmühle umfasst eine im Wesentlichen zylindrische Mahlkammer, die durch einen Mantel und je eine einlass- und eine auslassseitige Stirnwand begrenzt ist, sowie eine drehbar gelagerte Rührwelle, auf der innerhalb der Mahlkammer auch als Akzeleratoren bezeichnete Rührorgane axial (also in Richtung der Längsachse der Rührwelle) voneinander beabstandet angeordnet sind. In der Nähe der einlassseitigen Stirnwand ist ein Einlass zur Zufuhr von Mahlgut und Mahlkörpern angeordnet, und in der auslassseitigen Stirnwand ist ein Auslass zur Entnahme des gemahlenen Guts vorgesehen, welcher durch ein die Mahlkörper zurückhaltendes Separator-Sieb von der Mahlkammer abgetrennt ist. Im Betrieb werden die Rührwelle und damit die mit ihr drehfest verbundenen Rührorgane durch einen externen Motor in Rotation versetzt.A well-known agitator ball mill is, for example, in EP 3 102 332 B1 described. The agitator ball mill described there comprises an essentially cylindrical grinding chamber, which is delimited by a jacket and an inlet and an outlet end wall, as well as a rotatably mounted agitator shaft, on which agitator elements, also known as accelerators, are axially mounted inside the grinding chamber (i.e. in the direction of the longitudinal axis the agitator shaft) are arranged at a distance from one another. In the vicinity of the inlet-side end wall, there is an inlet for supplying material to be ground and grinding media, and in the outlet-side end wall there is an outlet for removing the ground material, which is separated from the grinding chamber by a separator screen retaining the grinding media. During operation, the agitator shaft and thus the agitator elements connected to it in a rotationally fixed manner are set in rotation by an external motor.

In manchen Anwendungsfällen ist es wünschenswert oder erforderlich, dass das Mahlgut während des Mahlvorgangs erwärmt wird, z.B. um den Mahlvorgang zu verbessern oder chemische Reaktionen zu aktivieren oder zu unterstützen. Es sind daher auch schon Rührwerkskugelmühlen mit Heizvorrichtungen für das Mahlgut vorgeschlagen geworden.In some applications it is desirable or necessary for the material to be ground to be heated during the grinding process, e.g. to improve the grinding process or to activate or support chemical reactions. Agitator ball mills with heating devices for the material to be ground have therefore already been proposed.

In der DE 100 64 828 A1 ist eine Rührwerkskugelmühle gezeigt, bei der um die Mahlkammer herum eine separate Heiz- und Kühlkammer angeordnet ist, durch die ein Heiz- bzw. Kühlmittel strömen kann. Auch die Rührwelle selbst kann beheizt oder gekühlt werden.In the DE 100 64 828 A1 an agitator ball mill is shown in which a separate heating and cooling chamber is arranged around the grinding chamber, through which a heating or cooling medium can flow. The agitator shaft itself can also be heated or cooled.

In der JP 2001 180933 A ist eine Rührwerkskugelmühle gezeigt, bei der eine Heizung aussen auf der Wand der Mahlkammer angeordnet ist. Dabei handelt es sich um ein elektrisches Heizband, das die Wand der Mahlkammer durch Kontakt erwärmt. Alternativ kann anstelle des Heizbands eine Hochfrequenz-Induktionsheizung vorgesehen sein, welche ebenfalls die Wand der Mahlkammer erwärmt.In the JP 2001 180933 A an agitator ball mill is shown in which a heater is arranged outside on the wall of the grinding chamber. This is an electrical heating band that heats the wall of the grinding chamber by contact. Alternatively, instead of the heating band, a high-frequency induction heater can be provided, which also heats the wall of the grinding chamber.

In der JP 2009 000633 A ist eine Rührwerkskugelmühle beschrieben, die aussen um die Wand der Mahlkammer herum eine elektrische Spule aufweist. Die Spule erzeugt ein Magnetfeld, welches die Wand der Mahlkammer durch Induktion aufheizt.In the JP 2009 000633 A describes an agitator ball mill which has an electric coil around the outside of the wall of the grinding chamber. The coil creates a magnetic field that induction heats the wall of the grinding chamber.

In der WO 2019/228983 A1 ist eine Rührwerkskugelmühle mit einer Induktionsheizung gezeigt. Bei dieser Rührwerkskugelmühle ist eine elektrische Spule als Induktor um die Rührwelle herum angeordnet. In einer alternativen Ausführungsform sind axial beabstandet zwei Spulen als Induktoren auf der Rührwelle angeordnet. Die auf der Rührwelle angeordneten Rührorgane sind als elektrisch leitende Suszeptoren ausgebildet und werden vom Magnetfeld der Spule(n) induktiv erwärmt. Die Wärme der Rührorgane wird auf das Mahlgut übertragen, sodass das Mahlgut quasi indirekt erwärmt wird. Sämtliche Komponenten der Induktionsheizung sind im Inneren der Mahlkammer der Rührwerkskugelmühle angeordnet.In the WO 2019/228983 A1 an agitator bead mill with induction heating is shown. In this agitator bead mill, an electrical coil is arranged as an inductor around the agitator shaft. In an alternative embodiment, two coils are arranged at an axial distance as inductors on the stirring shaft. The stirring elements arranged on the stirring shaft are designed as electrically conductive susceptors and are inductively heated by the magnetic field of the coil(s). The heat from the stirring elements is transferred to the material to be ground, so that the material to be ground is heated more or less indirectly. All components of the induction heating are arranged inside the grinding chamber of the agitator bead mill.

Eine indirekte Erwärmung des Mahlguts über induktiv beheizte Rührorgane ist unter anderem wegen der Effizienz von Induktionsheizungen grundsätzlich vorteilhaft. Allerdings hat die in der WO 2019/228983 A1 beschriebene Anordnung auch Nachteile. Zum einen ist es bei Rührwerkskugelmühlen, deren Mahlkammer einen kleinen Durchmesser aufweiset, aus Platzgründen sehr schwierig oder sogar unmöglich, die relativ grossen Induktor-Spulen auf der Rührwelle unterzubringen. Zum anderen verringert sich bei Rührwerkskugelmühlen, deren Mahlkammer einen grösseren Durchmesser aufweiset, die Effizienz der Induktionsheizung, weil einerseits die induktive Erwärmung der Rührorgane mit zunehmendem radialen Abstand der Rührorgane von den Induktor-Spulen nachlässt, aber andererseits das Mahlgut sich während des Mahlvorgangs vornehmlich in den peripheren Bereichen der Mahlkammer befindet. Unabhängig von der Grösse der Rührwerkskugelmühle stellt aber auch die Zuführung der elektrischen Energie zu den sich mit der schnell rotierenden Rührwelle mitdrehenden Induktor-Spulen ein Problem dar. Eine weitere Schwierigkeit besteht darin, dass der Schutz der Induktor-Spulen vor der aggressiven/abrasiven Wirkung der Mahlkörper aufwändig ist.Indirect heating of the ground material via inductively heated stirring elements is fundamentally advantageous, among other things because of the efficiency of induction heating. However, the in the WO 2019/228983 A1 described arrangement also disadvantages. On the one hand, in the case of agitator ball mills, the grinding chamber of which has a small diameter, it is very difficult or even impossible to accommodate the relatively large inductor coils on the agitator shaft for reasons of space. On the other hand, in agitator bead mills, whose grinding chamber has a larger diameter, the efficiency of the induction heating decreases, because on the one hand the inductive heating of the stirring elements decreases with increasing radial distance of the stirring elements from the inductor coils, but on the other hand the material to be ground during the grinding process primarily in the peripheral areas of the grinding chamber. Irrespective of the size of the agitator bead mill, however, the supply of electrical energy to the inductor coils rotating with the rapidly rotating agitator shaft also poses a problem. Another difficulty is that the protection of the inductor coils from the aggressive/abrasive effect of the Grinding body is complex.

Ausgehend von diesem Stand der Technik soll durch die vorliegende Erfindung eine induktiv beheizte Rührwerkskugelmühle der gattungsgemässen Art dahingehend verbessert werden, dass die im Zusammenhang mit der WO 2019/228983 A1 beschriebenen Nachteile vermieden werden. Insbesondere soll eine Rührwerkskugelmühle mit induktiver Heizung vorgeschlagen werden, welche konstruktiv weniger aufwändig ist als die bekannte Rührwerkskugelmühle dieser Art.Based on this prior art, an inductively heated agitator ball mill of the generic type is to be improved by the present invention in that in connection with the WO 2019/228983 A1 described disadvantages are avoided. In particular, an agitator ball mill with inductive heating is to be proposed, which is structurally less complex than the known agitator ball mill of this type.

Diese Aufgabe wird erfindungsgemäss durch eine Rührwerkskugelmühle gelöst, wie sie durch die Merkmale des unabhängigen Patentanspruchs spezifiziert ist. Weitere vorteilhafte Aspekte ergeben sich aus den Merkmalen der abhängigen Patentansprüche.According to the invention, this object is achieved by an agitator ball mill as specified by the features of the independent patent claim. Further advantageous aspects emerge from the features of the dependent patent claims.

Die erfindungsgemässe Rührwerkskugelmühle umfasst eine Mahlkammer, die einen Mantel aufweist, ferner eine in die Mahlkammer hineinragende, drehbar gelagerte Rührwelle, auf der innerhalb der Mahlkammer mindestens ein Rührorgan angeordnet ist. Sie umfasst weiterhin einen Einlass zur Zufuhr von Mahlgut und Mahlkörpern in die Mahlkammer sowie einen Auslass zur Entnahme des gemahlenen Guts, und eine einen Induktor und einen Suszeptor umfassende Induktionsheizung für das in der Mahlkammer befindliche Mahlgut. Das mindestens eine Rührorgan umfasst den Suszeptor. Der Induktor umfasst mindestens eine ausserhalb des Mantels der Mahlkammer angeordnete und die Mahlkammer umschliessende Spule. Der Mantel der Mahlkammer besteht aus einem elektrisch und magnetisch nicht leitenden Material.The agitator ball mill according to the invention comprises a grinding chamber which has a jacket, and also a rotatably mounted agitator shaft which protrudes into the grinding chamber and on which at least one agitator element is arranged inside the grinding chamber. It also includes an inlet for supplying material to be ground and grinding bodies into the grinding chamber and an outlet for removing the ground material, and an induction heater comprising an inductor and a susceptor for the material to be ground in the grinding chamber. The at least one stirring element includes the susceptor. The inductor comprises at least one coil which is arranged outside the casing of the grinding chamber and encloses the grinding chamber. The shell of the grinding chamber consists of an electrically and magnetically non-conductive material.

Durch die (statische) Anordnung des Induktors ausserhalb der Mahlkammer ist dieser vor den Einflüssen des Mahlguts und vor allem der Mahlkörper geschützt und die Bestromung des Induktors ist konstruktiv einfach. Dadurch, dass der Mantel der Mahlkammer aus einem elektrisch und magnetisch nicht leitendem Material besteht, kann das vom Induktor (nämlich der Spule) erzeugte Magnetfeld den Mantel durchdringen und das von dem mindestens einen Rührorgan umfasste Suzeptor-Material beaufschlagen, wodurch das Suszeptor-Material und damit auch das Rührorgan erwärmt wird. Insbesondere kann das Rührorgan als Ganzes aus dem Suszeptor-Material hergestellt sein, sodass das Rührorgan aus dem Suszeptor-Material besteht.Due to the (static) arrangement of the inductor outside the grinding chamber, it is protected from the influences of the material to be ground and, above all, the grinding body, and the energization of the inductor is structurally simple. Because the shell of the grinding chamber consists of an electrically and magnetically non-conductive material, the magnetic field generated by the inductor (namely the coil) can penetrate the shell and act on the susceptor material contained by the at least one stirring element, whereby the susceptor material and so that the stirring element is also heated. In particular, the stirring element can be produced as a whole from the susceptor material, so that the stirring element consists of the susceptor material.

Der Suszeptor der Induktionsheizung besteht aus einem elektrisch und/oder magnetisch leitenden Material, welches durch das magnetische Wecheselfeld des Induktors (der Spule) der Induktionsheizung induktiv erwärmt wird. Vorzugsweise ist der Suszeptor zumindest elektrisch leitend. In einem solchen elektrisch leitenden Suszeptor werden durch das magnetische Wechselfeld des Induktors Wirbelströme induziert, die dann den Suszeptor (und damit auch das Rührorgan) erwärmen.The susceptor of the induction heating consists of an electrically and/or magnetically conductive material which is inductively heated by the alternating magnetic field of the inductor (the coil) of the induction heating. The susceptor is preferably at least electrically conductive. In such an electrically conductive susceptor, eddy currents are induced by the alternating magnetic field of the inductor, which then heat the susceptor (and thus also the stirring element).

Gemäss einem weiteren Aspekt der erfindungsgemässen Rührwerkskugelmühle sind auf der Rührwelle zwei oder mehrere Rührorgane längs der Rührwelle voneinander beabstandet angeordnet. Der Induktor umfasst zwei oder mehrere Spulen, die längs des Mantels der Mahlkammer so angeordnet sind, dass das von ihnen erzeugte Magnetfeld jeweils nur eines der Rührorgane beaufschlagt. Vorzugsweise sind dabei die zwei oder mehreren Spulen separat ansteuerbar ausgebildet. Dadurch lässt sich (in axialer Richtung betrachtet) eine zonenweise Erwärmung des Mahlguts erreichen, wodurch eine gewünschte Temperaturführung während des Mahlprozesse möglich ist.According to a further aspect of the agitator ball mill according to the invention, two or more agitators are arranged on the agitator shaft at a distance from one another along the agitator shaft. The inductor comprises two or more coils, which are arranged along the shell of the grinding chamber in such a way that the magnetic field they generate only acts on one of the stirring elements. The two or more coils are preferably designed to be separately controllable. As a result (viewed in the axial direction) zone-wise heating of the material to be ground can be achieved, as a result of which a desired temperature control during the grinding process is possible.

Gemäss einem weiteren Aspekt der erfindungsgemässen Rührwerkskugelmühle umfasst die Rührwerkskugelmühle einen Hochfrequenzgenerator zur Speisung der Spule bzw. Spulen mit Wechselstrom einer Arbeitsfrequenz des Hochfrequenzgenerators, wobei die Arbeitsfrequenz des Hochfrequenzgenerators im Bereich von 1 kHz bis 1 MHz liegt.According to a further aspect of the inventive agitator ball mill, the agitator ball mill comprises a high-frequency generator for supplying the coil or coils with alternating current at a working frequency of the high-frequency generator, the working frequency of the high-frequency generator being in the range from 1 kHz to 1 MHz.

Gemäss einem weiteren Aspekt der erfindungsgemässen Rührwerkskugelmühle weist die Induktionsheizung eine Eigenfrequenz auf, und die Arbeitsfrequenz des Hochfrequenzgenerators liegt bei oder nahe der Eigenfrequenz der Induktionsheizung. Dadurch wird die Effizienz der Induktionsheizung bzw. deren Energieverbrauch optimiert.According to a further aspect of the agitator ball mill according to the invention, the induction heating has a natural frequency, and the working frequency of the high-frequency generator is at or near the natural frequency of the induction heating. This optimizes the efficiency of the induction heating and its energy consumption.

Gemäss einem weiteren Aspekt der Erfindung ist der Mantel der Mahlkammer von einem Kühlmantel umschlossen, durch den ein Kühlmedium leitbar ist. Dadurch kann die Steuerung der Temperatur des Mahlguts noch weiter unterstützt werden.According to a further aspect of the invention, the jacket of the grinding chamber is surrounded by a cooling jacket through which a cooling medium can be conducted. This can further support the control of the temperature of the ground material.

Weitere vorteilhafte Aspekte ergeben sich aus der nachfolgenden Beschreibung von Ausführungsbeispielen der erfindungsgemässen Rührwerkskugelmühle mit Hilfe der Zeichnung. Es zeigen:

Fig. 1
einen Axialschnitt durch ein erstes Ausführungsbeispiel der erfindungsgemässen Rührwerkskugelmühle und
Fig. 2
einen Axialschnitt durch ein zweites Ausführungsbeispiel der erfindungsgemässen Rührwerkskugelmühle.
Further advantageous aspects emerge from the following description of exemplary embodiments of the agitator ball mill according to the invention with the aid of the drawing. Show it:
1
an axial section through a first embodiment of the inventive agitator ball mill and
2
an axial section through a second embodiment of the inventive agitator ball mill.

Für die nachstehende Beschreibung gilt folgende Festlegung: Sind in einer Figur zum Zweck zeichnerischer Eindeutigkeit Bezugszeichen angegeben, aber im unmittelbar zugehörigen Beschreibungsteil nicht erwähnt, so wird auf deren Erläuterung in vorangehenden oder nachfolgenden Beschreibungsteilen verwiesen. Umgekehrt sind zur Vermeidung zeichnerischer Überladung für das unmittelbare Verständnis weniger relevante Bezugszeichen nicht in allen Figuren eingetragen. Hierzu wird auf die jeweils übrigen Figuren verwiesen.The following definition applies to the following description: If reference symbols are given in a figure for the purpose of clarity in the drawing, but are not mentioned in the directly associated description part, reference is made to their explanation in the preceding or following description parts. Conversely, in order to avoid graphic overload, reference symbols that are less relevant for immediate understanding are not entered in all figures. For this purpose, reference is made to the respective remaining figures.

Wie die Schnittansicht der Fig. 1 zeigt, umfasst die erfindungsgemässe Rührwerkskugelmühle eine zylindrische Mahlkammer 1, die durch einen Mantel 2 und je eine einlassseitige Stirnwand 3 und eine auslassseitige Stirnwand 4 begrenzt ist. Durch die einlassseitige Stirnwand 3 ist eine extern oder in der Stirnwand drehbar gelagerte Rührwelle 5 durchgeführt, auf der innerhalb der Mahlkammer 1 in dem gezeigten Ausführungsbeispiel drei Rührorgane 11, 12 und 13 axial, d.h. längs (also in Richtung der Längsachse) der Rührwelle voneinander beabstandet angeordnet sind. Die Rührorgane 11, 12 und 13 sind in dem gezeigten Ausführungsbeispiel als Akzeleratoren ausgebildet, sie sind mit der Rührwelle 5 drehfest verbunden und werden im Betrieb von der Rührwelle 5 drehend angetrieben. In der einlassseitigen Stirnwand 3 ist ein Einlass 6 zur Zufuhr von Mahlgut und Mahlkörpern in die Mahlkammer 1 angeordnet, und in der auslassseitigen Stirnwand 4 ist ein Auslass 7 zur Entnahme des gemahlenen Guts vorgesehen, der durch ein die Mahlkörper zurückhaltendes Separator-Sieb 8 von der Mahlkammer 1 abgetrennt ist. In der auslassseitigen Stirnwand 4 ist ein gegen das Innere der Mahlkammer 1 hin offener Ringkanal 9 ausgebildet. Im Betrieb werden die Rührwelle 5 und damit die mit ihr drehfest verbundenen Rührorgane 11, 12, 13 (hier: die Akzeleratoren) durch einen nicht dargestellten externen Motor in Rotation versetzt. Die Rührorgane 11, 12 und 13 können wie dargestellt schaufelradartig oder aber beispielsweise auch als einfache Rührscheiben ausgebildet sein.Like the sectional view of the 1 shows, the agitator ball mill according to the invention comprises a cylindrical grinding chamber 1, which is delimited by a jacket 2 and one end wall 3 on the inlet side and one end wall 4 on the outlet side. An agitator shaft 5, which is rotatably mounted externally or in the end wall, is passed through the end wall 3 on the inlet side, on which, in the exemplary embodiment shown, three agitator elements 11, 12 and 13 are mounted axially, i.e. along (i.e. in the direction of the longitudinal axis) of the agitator shaft, within the grinding chamber 1 are arranged. The stirring elements 11, 12 and 13 are designed as accelerators in the exemplary embodiment shown; they are connected to the stirring shaft 5 in a rotationally fixed manner and are rotationally driven by the stirring shaft 5 during operation. In the inlet-side end wall 3, there is an inlet 6 for supplying material to be ground and grinding media into the grinding chamber 1, and in the outlet-side end wall 4 there is an outlet 7 for removing the ground material, which is removed by a separator screen 8, which retains the grinding media, from the Grinding chamber 1 is separated. In the end wall 4 on the outlet side there is an annular channel 9 which is open towards the interior of the grinding chamber 1 educated. During operation, the stirring shaft 5 and thus the stirring elements 11, 12, 13 (here: the accelerators) which are connected to it in a rotationally fixed manner are set in rotation by an external motor (not shown). The stirring elements 11, 12 and 13 can, as shown, be designed in the manner of a paddle wheel or else, for example, as simple stirring discs.

Die Mahlkammer 1 ist von einem äusseren Kühlmantel 10 umschlossen derart, dass zwischen dem Kühlmantel 10 und dem Mantel 2 der Mahlkammer 1 ein ringförmiger Hohlraum 15 gebildet ist, durch welchen bei Bedarf ein Kühlmedium leitbar ist. Die Zu- und Abführleitungen für das Kühlmedium sind der Einfachheit halber nicht dargestellt.The grinding chamber 1 is surrounded by an outer cooling jacket 10 in such a way that an annular cavity 15 is formed between the cooling jacket 10 and the jacket 2 of the grinding chamber 1, through which a cooling medium can be conducted if required. The supply and discharge lines for the cooling medium are not shown for the sake of simplicity.

Soweit entspricht die erfindungsgemässe Rührwerkskugelmühle in Aufbau und Funktionsweise dem Stand der Technik, wie er beispielsweise durch die eingangs genannte EP 3 102 332 B1 repräsentiert ist. Der Fachmann bedarf daher soweit keiner näheren Erläuterung.To this extent, the agitator ball mill according to the invention corresponds to the state of the art in terms of structure and function, for example as described above EP 3 102 332 B1 is represented. The person skilled in the art therefore does not need any further explanation.

Zur Erwärmung des im Betrieb der Rührwerkskugelmühle durch die Mahlkammer 1 vom Einlass 6 zum Auslass 7 strömenden Mahlguts ist die Rührwerkskugelmühle mit einer Induktionsheizung ausgestattet, die eine Spule 20 als Induktor umfasst, welche im Betrieb der Rührwerkskugelmühle von einem in der Zeichnung nur symbolisch dargestellten Hochfrequenzgenerator G mit Wechselstrom gespeist wird. Die Induktionsheizung umfasst einen neben dem Induktor (Spule 20) auch einen Suszeptor. Die Spule 20 ist ausserhalb der Mahlkammer 1 in dem zwischen dem Kühlmantel 10 und dem Mantel 2 der Mahlkammer gebildeten Hohlraum 15 angeordnet. Die mit Wechselstrom gespeiste Spule 20 erzeugt ein (elektro)magnetisches Wechselfeld, das durch den Mantel 2 der Mahlkammer 1 hindurch in den Innenruam der Mahlkammer dringt, da der Mantel 2 der Mahlkammer 1 aus einem elektrisch und magnetisch nicht leitenden Material besteht. Das magnetische Wechselfeld beaufschlagt die Rührorgane 11, 12 und 13, die hier aus einem geeigneten elektrisch leiteden Material hergestellt sind, z.B. aus Chromstahl oder Nickelbasislegierungen, welches auch für den Mahlprozess geeignet ist, und erzeugt in diesen Wirbelströme, welche die Rührorgane 11, 12 und 13 erwärmen. Die auf diese Weise in den Rührorganen 11, 12 und 13 erzeugte Wärme wird von den Rührorganen 11, 12 und 13 auf das Mahlgut übertragen und erwärmt dieses.In order to heat the material to be ground, which flows through the grinding chamber 1 from the inlet 6 to the outlet 7 during operation of the agitator ball mill, the agitator ball mill is equipped with an induction heating system which comprises a coil 20 as an inductor, which during operation of the agitator ball mill is supplied by a high-frequency generator G is powered by alternating current. In addition to the inductor (coil 20), the induction heating also includes a susceptor. The coil 20 is arranged outside the grinding chamber 1 in the cavity 15 formed between the cooling jacket 10 and the jacket 2 of the grinding chamber. The coil 20 supplied with alternating current generates an (electro)magnetic alternating field which penetrates through the jacket 2 of the grinding chamber 1 into the interior of the grinding chamber, since the jacket 2 of the grinding chamber 1 consists of an electrically and magnetically non-conductive material. The alternating magnetic field acts on the stirring elements 11, 12 and 13, which are made of a suitable electrically conductive material here, e.g. chrome steel or nickel-based alloys, which is also suitable for the grinding process, and generates eddy currents in them, which the stirring elements 11, 12 and 13 heat. The in this way in the stirring elements 11, 12 And 13 generated heat is transferred from the stirring elements 11, 12 and 13 to the material to be ground and heats it.

Damit die Induktionsheizung funktionieren kann, besteht der Mantel 2 der Mahlkammer 1 aus einem Material, welches von dem Magnetfeld der Spule 20 möglichst ungehindert durchdrungen werden kann. Das Material des Mantels 2 der Mahlkammer 1 ist daher weder elektrisch noch magnetisch leitend, wie bereits erwähnt. Ein geeignetes Material für den Mantel 2 der Mahlkammer 1 ist z.B. eine Keramik, beispielsweise Siliziumkarbid. Wie ebenfalls erwähnt, bestehen bei dem gezeigten Ausführungsbeispiel die Rührorgane 11, 12 und 13 als Ganzes aus einem elektrisch leitenden Suszeptor-Material, in welchem Wirbelströme induzierbar sind. Die Rührorgane 11, 12 und 13 können aber alternativ auch nur teilweise aus einem Suszeptor-Material bestehen bzw. ein solches Suszeptor-Material umfassen, wobei dann aber das restliche Rührorgan aus einem Material mit einer hohen Wärmeleitfähigkeit besteht und ebenfalls für den Mahlprozess geeignet sein muss. Eine die Spule 20 aussen und seitlich umschliessende magnetische Abschirmung 30 konzentriert das von der Spule 20 erzeugte Magnetfeld nach innen auf die Rührorgane 11, 12 und 13. Die Rührwelle 5 kann dabei aus einem elektrisch und magnetisch nicht leitenden Material bestehen, so dass sie selbst durch das Magnetfeld der Spule 20 nicht erhitzt wird.So that the induction heating can function, the casing 2 of the grinding chamber 1 consists of a material which can be penetrated by the magnetic field of the coil 20 as unhindered as possible. The material of the jacket 2 of the grinding chamber 1 is therefore neither electrically nor magnetically conductive, as already mentioned. A suitable material for the shell 2 of the grinding chamber 1 is, for example, a ceramic, for example silicon carbide. As also mentioned, in the exemplary embodiment shown, the stirring elements 11, 12 and 13 consist as a whole of an electrically conductive susceptor material in which eddy currents can be induced. Alternatively, the stirring elements 11, 12 and 13 can also only partially consist of a susceptor material or comprise such a susceptor material, but the remaining stirring element then consists of a material with high thermal conductivity and must also be suitable for the grinding process . A magnetic shield 30 surrounding the coil 20 on the outside and on the side concentrates the magnetic field generated by the coil 20 inward on the stirring elements 11, 12 and 13. The stirring shaft 5 can consist of an electrically and magnetically non-conductive material, so that it itself can the magnetic field of the coil 20 is not heated.

Das in Fig. 2 ebenfalls im Axialschnitt dargestellte Ausführungsbeispiel der erfindungsgemässen Rührwerkskugelmühle unterscheidet sich vom Ausführungsbeispiel gemäss Fig. 1 lediglich dadurch, dass anstelle der einzigen, sich fast über die gesamte Länge der Mahlkammer 1 erstreckenden Spule 20 drei axial kürzere Spulen 21, 22 und 23 vorhanden sind, welche separat ansteuerbar ausgebildet und längs der Mahlkammer so angeordnet sind, dass sie je eines der Rührorgane 11, 12 und 13 radial umschliessen. Der Induktor ist also hier durch die drei Spulen 21, 22 und 23 gebildet. Drei magnetische Abschirmungen 31, 32 und 33 konzentrieren die Magnetfelder der Spulen 21, 22 und 23 auf die Rührorgane 11, 12 und 13 und schirmen die Magnetfelder nach aussen hin ab. Alle übrigen Teile der Rührwerkskugelmühle sind gleich wie beim Ausführungsbeispiel der Fig. 1 und tragen dementsprechend dieselben Bezugszeichen.This in 2 The exemplary embodiment of the agitator ball mill according to the invention, which is also shown in axial section, differs from the exemplary embodiment according to FIG 1 only because instead of the single coil 20, which extends almost over the entire length of the grinding chamber 1, there are three axially shorter coils 21, 22 and 23, which can be controlled separately and are arranged along the grinding chamber in such a way that they each form one of the stirring elements 11, 12 and 13 enclose radially. The inductor is thus formed by the three coils 21, 22 and 23 here. Three magnetic shields 31, 32 and 33 concentrate the magnetic fields of the coils 21, 22 and 23 on the stirring elements 11, 12 and 13 and shield the magnetic fields from the outside. All other parts of the agitator ball mill are the same as in the embodiment of FIG 1 and accordingly bear the same reference numbers.

Die von den drei Spulen 21, 22 und 23 erzeugten Magnetfelder beaufschlagen jeweils nur das der jeweiligen Spule radial gegenüberstehende Rührorgan 11 bzw. 12 bzw. 13. Die Aufteilung des Induktors in (hier) drei unabhängige Spulen 21, 22 und 23 erlaubt eine (axial) zonenweise unterschiedliche Beheizung des Mahlguts, was in bestimmten Anwendungsfällen von Vorteil ist. Aus diesem Grund sind die Spulen 21, 22 und 23 individuell ansteuerbar, was entweder mittels dreier unabhängiger Hochfrequenzgeneratoren oder mittels eines Hochfrequenzgenerators mit mehreren Ausgängen erfolgen kann.The magnetic fields generated by the three coils 21, 22 and 23 act only on the stirring element 11 or 12 or 13 radially opposite the respective coil. The division of the inductor into (here) three independent coils 21, 22 and 23 allows an (axially ) Zone-by-zone different heating of the regrind, which is an advantage in certain applications. For this reason, the coils 21, 22 and 23 can be controlled individually, which can be done either by means of three independent high-frequency generators or by means of a high-frequency generator with several outputs.

Durch entsprechende Ansteuerung der Spule bzw. der Spulen kann eine zonenweise Steuerung der Temperatur des Mahlguts erreicht werden. Unterstützt werden kann die Steuerung der Temperatur zusätzlich durch Kühlung mittels eines durch den Hohlraum 15 leitbaren Kühlmediums.By appropriately controlling the coil or coils, zone-wise control of the temperature of the material to be ground can be achieved. The control of the temperature can also be supported by cooling by means of a cooling medium that can be conducted through the cavity 15 .

Die Spule 20 bzw. die Spulen 21, 22 und 23 werden von dem in der Zeichnung nur schematisch dargestellten Hochfrequenzgenerator G gespeist. Die Arbeitsfrequenz des Hochfrequenzgenerators G kann im Bereich von 1 kHz bis zu 1 MHz liegen.The coil 20 or the coils 21, 22 and 23 are fed by the high-frequency generator G shown only schematically in the drawing. The working frequency of the high-frequency generator G can be in the range from 1 kHz to 1 MHz.

Die Induktionsheizung besitzt eine Eigenfrquenz, die durch die Spule bzw. Spulen und die Suszeptoren bzw. Rührorgane gegeben ist. Idealerweise liegt die Arbeitsfrequenz des Generators G zur Speisung der Spule bzw. der Spulen mit Wechselstrom (der diese Arbeitsfrequenz aufweist) möglichst nahe oder bei der Eigenfrequenz der Induktionsheizung. Die optimale Arbeitsfrequenz lässt sich empirisch ermitteln.The induction heating has a natural frequency that is given by the coil or coils and the susceptors or stirring elements. Ideally, the operating frequency of the generator G for feeding the coil or coils with alternating current (which has this operating frequency) is as close as possible to or at the natural frequency of the induction heating. The optimum working frequency can be determined empirically.

Die Erfindung wurde vorstehend anhand von Ausführungsbeispielen erläutert, soll jedoch nicht auf diese Ausführungsbeispiele beschränkt sein. Vielmehr sind für den Fachmann zahlreiche Modifikationen denkbar, ohne dabei von der Lehre der Erfindung abzuweichen. So können zum Beispiel in der Mahlkammer auch mehr oder weniger als drei Rührorgane vorgesehen sein und die Rührorgane können beliebig gestaltet sein. Ausserdem kann die Induktionsheizung auch nur zwei oder mehr als drei Induktor-Spulen umfassen. Ferner können bei mehreren Spulen einzelne dieser Spulen auch zwei oder mehrere Rührorgane gleichzeitig beaufschlagen. Der Schutzbereich wird daher durch die nachstehenden Patentansprüche definiert.The invention was explained above using exemplary embodiments, but should not be limited to these exemplary embodiments. Rather, numerous modifications are conceivable for the person skilled in the art without deviating from the teaching of the invention. For example, more or fewer than three stirring elements can be provided in the grinding chamber and the stirring elements can be designed as desired. In addition, the induction heating can also include only two or more than three inductor coils. Furthermore, in the case of several coils, one of these coils can also have two or act on several agitators at the same time. The scope of protection is therefore defined by the following claims.

Claims (6)

Rührwerkskugelmühle mit einer Mahlkammer (1), die einen Mantel (2) aufweist, ferner mit einer in die Mahlkammer (1) hineinragenden, drehbar gelagerten Rührwelle (5), auf der innerhalb der Mahlkammer (1) mindestens ein Rührorgan (11, 12, 13) angeordnet ist, mit einem Einlass (6) zur Zufuhr von Mahlgut und Mahlkörpern in die Mahlkammer sowie einem Auslass (7) zur Entnahme des gemahlenen Guts, und mit einer einen Induktor und einen Suszeptor umfassenden Induktionsheizung für das in der Mahlkammer (1) befindliche Mahlgut, wobei das mindestens eine Rührorgan (11, 12, 13) den Suszeptor umfasst, wobei der Induktor mindestens eine ausserhalb des Mantels (2) der Mahlkammer (1) angeordnete und die Mahlkammer (1) umschliessende Spule (20; 21, 22, 23) umfasst, und wobei der Mantel (2) der Mahlkammer (1) aus einem elektrisch und magnetisch nicht leitenden Material besteht.Agitator ball mill with a grinding chamber (1) which has a casing (2), furthermore with a rotatably mounted agitator shaft (5) which projects into the grinding chamber (1) and on which at least one agitator element (11, 12, 13) is arranged, with an inlet (6) for supplying material to be ground and grinding bodies into the grinding chamber and an outlet (7) for removing the ground material, and with an induction heating system comprising an inductor and a susceptor for the in the grinding chamber (1) material to be ground, the at least one stirring element (11, 12, 13) comprising the susceptor, the inductor having at least one coil (20; 21, 22 , 23), and wherein the jacket (2) of the grinding chamber (1) consists of an electrically and magnetically non-conductive material. Rührwerkskugelmühle nach Anspruch 1, wobei auf der Rührwelle (5) zwei oder mehrere Rührorgane (11, 12, 13) längs der Rührwelle voneinander beabstandet angeordnet sind, und wobei der Induktor zwei oder mehrere Spulen (21, 22, 23) umfasst, die längs des Mantels (2) der Mahlkammer (1) so angeordnet sind, dass das von ihnen erzeugte Magnetfeld jeweils nur eines der Rührorgane (11, 12, 13) beaufschlagt.Agitator ball mill according to claim 1, wherein on the agitator shaft (5) two or more agitators (11, 12, 13) are spaced apart from one another along the agitator shaft, and wherein the inductor comprises two or more coils (21, 22, 23) which are longitudinally of the jacket (2) of the grinding chamber (1) are arranged in such a way that the magnetic field they generate only acts on one of the stirring elements (11, 12, 13). Rührwerkskugelmühle nach Anspruch 2, wobei die Spulen (21, 22, 23) separat ansteuerbar ausgebildet sind.Agitator ball mill according to Claim 2, in which the coils (21, 22, 23) are designed so that they can be controlled separately. Rührwerkskugelmühle nach einem der vorangehenden Ansprüche, welche einen Hochfrequenzgenerator (G) zur Speisung der Spule (20) bzw. der Spulen (21, 22, 23) mit Wechselstrom einer Arbeitsfrequenz des Hochfrequenzgenerators (G) umfasst, wobei die Arbeitsfrequenz des Hochfrequenzgenerators im Bereich von 1 kHz bis 1 MHz liegt.Agitator ball mill according to one of the preceding claims, which comprises a high-frequency generator (G) for feeding the coil (20) or the coils (21, 22, 23) with alternating current of an operating frequency of the high-frequency generator (G), the operating frequency of the high-frequency generator being in the range from 1 kHz to 1 MHz. Rührwerkskugelmühle nach Anspruch 4, wobei die Induktionsheizung (20, 11, 12, 13; 21, 22, 23, 11, 12, 13) eine Eigenfrequenz aufweist, und wobei die Arbeitsfrequenz des Hochfrequenzgenerators (G) bei oder nahe der Eigenfrequenz der Induktionsheizung liegt.Agitator ball mill according to claim 4, wherein the induction heating (20, 11, 12, 13; 21, 22, 23, 11, 12, 13) has a natural frequency, and wherein the working frequency of the high frequency generator (G) is at or near the natural frequency of the induction heater. Rührwerkskugelmühle nach einem der vorangehenden Ansprüche, wobei der Mantel (2) der Mahlkammer (1) von einem Kühlmantel (10) umschlossen ist, durch den ein Kühlmedium leitbar ist.Agitator ball mill according to one of the preceding claims, wherein the jacket (2) of the grinding chamber (1) is surrounded by a cooling jacket (10) through which a cooling medium can be conducted.
EP21208681.3A 2020-11-18 2021-11-17 Agitator ball mill Active EP4000735B1 (en)

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EP3102332A1 (en) 2014-02-07 2016-12-14 Willy A. Bachofen AG Agitator ball mill
WO2019228983A1 (en) 2018-05-29 2019-12-05 Deasyl Sa Three-dimensional grinder, method for implementing same and uses thereof

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Publication number Priority date Publication date Assignee Title
JP2001180933A (en) 1999-12-22 2001-07-03 Nippon Shokubai Co Ltd Titanium black dispersion solution and manufacturing method
DE10064828A1 (en) 2000-12-22 2002-06-27 Netzsch Erich Holding Stirrer mill has grinding container defining with stirrer shaft a grinding chamber with separating device with tubular screens forming part of rotating cage to return flow of material
JP2009000633A (en) 2007-06-21 2009-01-08 Nisshin Engineering Co Ltd Rotary treatment apparatus
EP3102332A1 (en) 2014-02-07 2016-12-14 Willy A. Bachofen AG Agitator ball mill
EP3102332B1 (en) 2014-02-07 2018-03-28 Willy A. Bachofen AG Agitator ball mill
WO2019228983A1 (en) 2018-05-29 2019-12-05 Deasyl Sa Three-dimensional grinder, method for implementing same and uses thereof

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