EP0290840A2 - Gap-ball mill for continuously grinding, especially disintegrating microorganisms, and dispersing solids in fluids - Google Patents
Gap-ball mill for continuously grinding, especially disintegrating microorganisms, and dispersing solids in fluids Download PDFInfo
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- EP0290840A2 EP0290840A2 EP88106483A EP88106483A EP0290840A2 EP 0290840 A2 EP0290840 A2 EP 0290840A2 EP 88106483 A EP88106483 A EP 88106483A EP 88106483 A EP88106483 A EP 88106483A EP 0290840 A2 EP0290840 A2 EP 0290840A2
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- Prior art keywords
- gap
- grinding
- ball mill
- mill according
- rotor
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Classifications
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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
- B02C17/166—Mills in which a fixed container houses stirring means tumbling the charge of the annular gap type
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
- B01F27/27—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices
- B01F27/272—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices with means for moving the materials to be mixed axially between the surfaces of the rotor and the stator, e.g. the stator rotor system formed by conical or cylindrical surfaces
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
- B01F2025/91—Direction of flow or arrangement of feed and discharge openings
- B01F2025/911—Axial flow
Definitions
- Ball mills of this type are known in various designs.
- the term "balls” should not be understood exclusively to mean the preferred, precisely spherical grinding media, but basically all grinding media of a similar configuration which are suitable for comminuting the solid particles of the material to be ground by rolling them against one another and on the boundary surfaces of the grinding chamber.
- finely ground balls made of hard wear-resistant steel, hard metal, glass or ceramic are used, but grinding media made of other materials are also used.
- grains of sand were used, which could often only be made sufficiently passable during the pre-grinding process.
- CH-PS 639 567 already discloses a split ball mill set up for continuous operation which engages a cross-sectionally wedge-shaped displacement body of the rotor, which surrounds the mill axis at a radial distance, in an equally shaped grinding chamber of the stator.
- the regrind rotates around the entire displacement body attached to a rotor disk in a long acceleration phase around the wedge nose and is guided inwards by half the radius of rotation to the outlet.
- the grinding media which basically rotate in the same direction as the material to be ground, are separated out before the outlet by a separating device and conveyed back through a ball return duct, which is passed obliquely outwards through the rotor disk, under centrifugal force into the inlet area of the material to be ground, from where they return to their closed orbit.
- the invention is based on the gap ball mill defined at the outset and pursues the task of developing this mill, primarily for disrupting microorganisms, in the simplest possible way so that it can be used for a variety of tasks without the risk and disadvantages of ball build-up and is easy to use can be serviced, that is, it can manage with short downtimes.
- the design of individual, partly identical, partly individually or in groups interchangeable components within a grinding unit also has the advantage that almost any number of individual grinding units can be easily joined together, which only requires different, possibly again composed of unit elements mill housing with drive shafts .
- one or more grinding units can be operated in a larger housing, each with its own closed grinding media circulation.
- the individual grinding stages can therefore be fed with grinding media of different sizes, for example in such a way that in the first grinding unit larger grinding media are used, in the subsequent grinding units in each case with gradually thinner grinding media.
- This enables an increase in the intensity and uniformity of the shredding processes at least on average increased energy density and thus higher output with reduced mill volume.
- the design is also still relatively simple, since it is primarily about rotational shapes on stator disks and rotor disks, which can be accomplished inexpensively by conventional manufacturing methods.
- the flow paths can be made relatively long in the smallest space and therefore the exposure time can be made relatively long.
- the rotor disks in particular can be given a relatively large cross section with a corresponding thickness, which increases the breaking strength even in the case of material which is sensitive to bending and sensitive, such as ceramic.
- the split ball mill according to the invention is particularly suitable for disrupting microorganisms or microbes, the evaluation of which is of particular importance for biotechnology.
- microbes consist of a capsule-like cell with a cell fluid that has a species-specific active ingredient that should be obtained as completely as possible.
- Wet grinding in agitator ball mills has already been proposed for mechanical extraction. The one scored there However, yield is still limited. The percentage of recovery is largely determined by the pressure applied during the grinding process. Due to the rubber-like elasticity of the cell wall, the cell remains intact if the pressure is too low and is deformed elastically. If the pressure is too high, the cell wall, cell fluid and active substance are often processed so strongly that the separation to be carried out later is made more difficult.
- the pressure to be applied can be largely predetermined and possibly adjusted in order to achieve optimal digestion and extraction ratios.
- the split ball mill shown in FIGS. 1 and 2 consists essentially of a mill housing (1), which receives three grinding units (2) from a multi-part stator (3) and a likewise multi-part rotor (4), which the mill axis (5th ) rotates and is driven by a particularly controllable electric motor (6).
- This motor (6) is flanged to the stationary mill housing (1).
- the motor pin (7) engages in a rotationally fixed manner with a wedge (8) in the bore (9) in the rotor shaft (10) made at the left end in FIG. 1.
- the other end sits with a journal bearing (11) in an outer cover (12), which closes the pot-like mill housing (1) and receives the product outlet (13).
- Each of the three grinding units (2) comprises a stator unit (16) with a first stator disc (17) and a second stator disc (18). These each form a grinding chamber unit (19) between them, in which a rotor disk (20) designed as a friction disk rotates.
- the individual rotor disks (20) of the multi-stage rotor (4) sit with their hubs (21), separated by spacer bushings (23), one behind the other on the rotor shaft (10) between their shoulder (24) and that screwed towards the journal bearing (11) Mother (25).
- the spacer bushes (23) can in principle have the same length, but are preferably kept in stock in slightly different lengths in order to be able to precisely determine the position of the rotor disks (20).
- the first stator disks (17) have a central, conical part (171) with an inclination of 60 ° to the mill axis (5).
- An S-shaped part (171) follows on the inside and an approximately cylindrical partial flange (173) on the outside.
- every second stator disk (18) has an inner, approximately flat part (181) with an outer conical part (182), the surface line of which in turn encloses an angle of 60 ° with the mill axis (5). They each end inside and outside in radial surfaces and are sealed there against each other and against the mill housing (1) by sealing rings (33, 34) and support rings (35), the latter in particular ensuring a flexible and damping support effect.
- Each rotor disc (20) widens from its hub (21) initially by means of an approximately flat intermediate part (22) to form an outer conical ring (28), which is largely in the center of the grinding chamber unit (19) between conical parts (171, 182) of the two stator discs (17, 18) comes to rest, whereby a grinding gap (36) of approximately the same width is formed around the entire rotor disc (20), which forms a gap loop (37) which is closed towards the outside around the cone ring (28).
- the gap loop (37) is connected via approximately radially extending connecting gaps (38, 39) with connecting gaps (40, 41) and thereby with the radial end faces (42) of the stators of the individual grinding units (2) formed by the stator disks (17, 18) Connection.
- the grinding media (48) are preferably made of ceramic. However, they can also consist of specifically particularly heavy rock. In this way it can be achieved that the grinding media, as shown in the middle grinding unit in FIGS. 1 and 1a, rotate on a spatial ring path closed by at least two ball return channels (47), that is to say they remain in the respective grinding unit.
- the separation process can also be influenced by changing an angle, such as the inclination of the intermediate gap (49) of the inner edge surface of the cone ring (28).
- the grinding media (48) can also be filled separately into each grinding unit through a filling tube (51), which is placed in a holding bush (52) in the mill housing (1) and directly in a bore (53) of the ring flange (173) covering the loop (37) ) sits.
- the filling tube (51) is normally closed by a stopper (54) which is held by a screwed-on union nut (55).
- a probe or a measuring device (56) for example for pressure, temperature, viscosity or the like, of the material to be ground can also be inserted or attached.
- Spacer rings (61) can be inserted between adjacent stators (17, 18) in order to be able to influence the axial distances between the stators, but also between the stator and rotor disks.
- devices for continuous adjustment by means of pressure screws or the like can also be used.
- the screws (62) on the outer cover (12) can also be used for such adjustment processes.
- cooling spaces (64, 65) are provided on the outside, and annular cooling spaces (64) are also provided between adjacent grinding units (2). These are individually connected to jacket cooling chambers (85), which are each formed between the jacket of the mill housing (1) and the ring flange (172) of the associated first stator disk (17).
- the spacer rings (61) there are approximately radial openings for connecting the jacket cooling spaces (85) to the coolant circuit.
- a coolant another heat transfer medium can also be used, for example for heating or for optional cooling and / or heating. All cold rooms are e.g. Connected to a cold and / or heat source via two manifolds (66) offset at 180 ° to the mill axis (5) in order to be able to adjust the operating temperature during the grinding process as required.
- Stator disks (17, 18) and rotor disks (20) are made of sintered ceramic material with high temperature resistance speed and abrasion resistance. The compressive strength of these materials is sufficient for the stresses that occur. However, in order to compensate for the tensile stress caused in particular by centrifugal forces, on the one hand the rotor disks can be designed as prestressed construction elements in a manner known per se. On the other hand, the pressure of the cooling liquid is dimensioned much higher than is the case with comparable cooling systems. As a result, the stators are pressed radially inward out of the jacket cooling spaces (85) in order to at least compensate for the expansion deformations resulting from centrifugal forces and the like. The stator disks can also be mechanically preloaded.
- the grinding rooms or grinding gaps and other surfaces that come into contact with the material to be ground, as well as the rooms containing the cooling or tempering agents should be largely sterilized. This occurs primarily after the preceding cleaning processes in that steam is passed through these rooms at a pressure which is approximately 1 bar higher than the usual grinding pressure, the temperature being constantly increased to a maximum value of approximately 140.degree. This maximum value is maintained for a certain time, which depends on various operating factors and is expediently determined by tests.
- regrind is fed continuously to the inlet and flows through the serpentine annular gap from one grinding unit to the next until it comes from the second friction gap (58) to the material outlet (14), which leads to the motor through a mechanical seal (68) is completed.
- the grinding media which may be provided in different sizes, are filled while the mill is at a standstill, they usually have a diameter of 0.3 to 3 mm and are classified, for example in the right grinding unit with a diameter of 3 mm, in the middle with 1.5 mm and in the left with 0.8 mm.
- the balls which have initially accumulated at the bottom of the gap loop (37), are distributed to the remaining part of the ring-shaped gap loop and cyclically thrown outwards and concentrated by the centrifugal forces in the area of the grinding loop.
- a single return channel (47) there are expediently provided a plurality - six according to FIG. 2 - distributed uniformly around the circumference, depending on the rotational speed of the balls with regard to the processed material.
- the grinding media are always pressed against the outer conical ring (28) on the inner surface (46), which is an extension of the ball return channel, whereby a kind of high-performance grinding is effected, while when returning from the gap loop (37) to the intermediate gap (49) reduce the plant forces and, with a lower specific grinding capacity, the grinding process is evened out and completed.
- Three grinding cycles, which are largely independent of one another and also different, are run through until the ground material reaches the outlet (14). It is therefore possible to create extremely fine and particularly uniform dispersions in a relatively short time.
- the end faces here, as a whole, in particular the outer part of the rotor disk (20) are designed in a zigzag cross section. They can also have a wave-like shape. If possible, however, the mutually assigned surfaces, for example the end surfaces (76) and (77) leading to the outer edge (75), should run at least approximately parallel to one another and, if appropriate, also have constant distances.
- the outer cone ring (28) according to FIG. 1 thereby becomes a Z flange (80) with the cross-sectional shape of a rune.
- the split loop (37 ') of the two arms of the grinding gap (36') surrounding the Z flange is designed accordingly.
- ball return channels (47 ') attached to the lower end of the Z-flange.
- the grinding balls are also first introduced in the direction of flow and at the outlet from the ball return duct (47 ') deflected sharply outwards so that they remain concentrated in their gap loop (37') during operation, ie in the two outer parts of the grinding gap arms.
- the ball return channels (47 ') as the parts and arrangements not mentioned are formed in the same manner as in Figs. 1 and 2, so that on the remaining parts of the second embodiment need not be discussed.
- the grinding gap loop (37) of the conical surfaces provided with straight surface lines can be formed by concave and / or convexly curved conical barrel surfaces or the like, so that the loop has an approximately egg-shaped or elliptical cross-section.
- the angles of the surface line to the mill axis can be chosen to be the same or different, and the rotor disks can form a rotational connection with the rotor shaft over the entire circumference, for example that they form a polygonal cross section, in particular triangular and with rounded corners or with side surfaces curved transversely to the rotor axis.
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Abstract
Description
Kugelmühlen dieser Art sind in verschiedener Ausführung bekannt. Mit dem Begriff "Kugeln" sollen nicht ausschließlich die bevorzugten exakt sphärisch gestalteten Mahlkörper verstanden werden, sondern grundsätzlich alle Mahlkörper ähnlicher Konfiguration, die geeignet sind, durch Abwälzen aneinander und an den Begrenzungsflächen des Mahlraumes eine Zerkleinerung der Festkörperteilchen des Mahlgutes zu bewirken.Ball mills of this type are known in various designs. The term "balls" should not be understood exclusively to mean the preferred, precisely spherical grinding media, but basically all grinding media of a similar configuration which are suitable for comminuting the solid particles of the material to be ground by rolling them against one another and on the boundary surfaces of the grinding chamber.
In der Regel werden feingeschliffene Kugeln aus hartem verschleißfesten Stahl, Hartmetall, Glas oder Keramik eingesetzt, es kommen aber auch Mahlkörper aus anderen Werkstoffen zum Einsatz. Früher hat man Sandkörner verwendet, die sich oft erst beim Vormahlvorgang hinreichend abwälzbar gestalten ließen.As a rule, finely ground balls made of hard wear-resistant steel, hard metal, glass or ceramic are used, but grinding media made of other materials are also used. In the past, grains of sand were used, which could often only be made sufficiently passable during the pre-grinding process.
Durch die CH-PS 639 567 ist bereits eine für kontinuierlichen Betrieb eingerichtete Spalt-Kugelmühle bekannt, bei der ein die Mühlenachse mit radialem Abstand umgebender im Querschnitt keilförmiger Verdrängungskörper des Rotors in einen ebenso geformten Mahlraum des Stators eingreift. Das Mahlgut umläuft dabei den ganzen an einer Rotorscheibe angebrachten Verdrängungskörper in einer langdauernden Beschleunigungsphase um die Keilnase herum und wird um den halben Umlaufradius zum Auslaß nach innen geführt.CH-PS 639 567 already discloses a split ball mill set up for continuous operation which engages a cross-sectionally wedge-shaped displacement body of the rotor, which surrounds the mill axis at a radial distance, in an equally shaped grinding chamber of the stator. The regrind rotates around the entire displacement body attached to a rotor disk in a long acceleration phase around the wedge nose and is guided inwards by half the radius of rotation to the outlet.
Die grundsätzlich gleichsinnig mit dem Mahlgut umlaufenden Mahlkörper werden jedoch vor dem Auslaß durch eine Trennvorrichtung ausgesondert und durch einen schräg nach außen durch die Rotorscheibe hindurchgeführten Kugelrückführkanal unter Fliehkraftwirkung in den Einlaßbereich des Mahlgutes zurückgefördert, von wo sie erneut auf ihre geschlossene Umlaufbahn gelangen.The grinding media, which basically rotate in the same direction as the material to be ground, are separated out before the outlet by a separating device and conveyed back through a ball return duct, which is passed obliquely outwards through the rotor disk, under centrifugal force into the inlet area of the material to be ground, from where they return to their closed orbit.
Auf diese Weise wird große Energiedichte auf kleiner Fläche bzw. auf kleinem Raum konzentriert, was hohe Mahlleistung bei kleinen Mühlenabmessungen und geringem Herstellungsaufwand ermöglicht. Dabei erfordert jedoch die Ausbildung der Trennvorrichtung und der Kugelrückführeinrichtung besondere Sorgfalt, um die Gefahr eines Kugelstaus zu vermeiden. Dies zumal dort die zusammenwirkenden Teile wie Rotor und Stator einstückig ausgeführt sind und nur als Ganzes ausgewechselt bzw. zur Reparatur gegeben werden können.In this way, high energy density is concentrated in a small area or in a small space, which enables high grinding performance with small mill dimensions and low manufacturing costs. However, the design of the separating device and the ball return device requires special care in order to avoid the risk of a ball jam. Especially since the interacting parts such as rotor and stator are made in one piece and can only be replaced as a whole or given for repair.
Es gibt zwar andere bekannte Ausführungen, insbesondere bei Ringspaltmühlen, wobei mahlaktive Teile auswechselbar vorgesehen sind, wie etwa nach der DE-PS 35 26 724, aber dies führt vor allem bei schnelllaufenden Mühlen zu besonderen Problemen beim Wechselvorgang und bei der Halterung der auswechselbaren Mühlenelemente. Auf diese Weise können zwar auch mehrstufige und ggf. unterschiedliche Mahlvorgänge hintereinandergeschaltet werden, und es sind Rotor- und Statorscheiben mit axialen Durchbrechungen vorgesehen. Bei großem Gutdurchsatz müssen aber sämtliche umzuwälzende Mahlkörper von einer einzigen Trennvorrichtung angehalten werden. Die große Anzahl der Mahlkörper kann dadurch leicht kompaktiert werden und die Mühle blockieren.There are other known designs, in particular in the case of annular gap mills, with active grinding parts being provided interchangeably, such as according to DE-PS 35 26 724, but this leads to particular problems in the changing process and in the holding of the interchangeable mill elements, especially in high-speed mills. In this way, even multi-stage and possibly different grinding processes can be connected in series, and rotor and stator disks with axial openings are provided. In the case of large throughput, however, all grinding media to be circulated must be be stopped by a single separator. The large number of grinding media can be easily compacted and block the mill.
Die Erfindung geht aus von der eingangs definierten Spalt-Kugelmühle und verfolgt die Aufgabe, diese Mühle, vornehmlich zum Aufschließen von Mikroorganismen, auf möglichst einfache Weise so weiterzubilden, daß sie ohne die Gefahr und Nachteile einer Kugelstaubildung für vielseitige Aufgaben eingesetzt werden kann und sich leicht instandhalten läßt, also mit geringen Stillstandszeiten auskommt.The invention is based on the gap ball mill defined at the outset and pursues the task of developing this mill, primarily for disrupting microorganisms, in the simplest possible way so that it can be used for a variety of tasks without the risk and disadvantages of ball build-up and is easy to use can be serviced, that is, it can manage with short downtimes.
Eine Spalt-Kugelmühle zum kontinuierlichen Feinzerkleinern, insbesondere zum Aufschließen von Mikroorganismen und Dispergieren von Feststoffen in Flüssigkeit weist erfindungsgemäß die nachstehenden Merkmale auf:
- a) in einem Mühlengehäuse sind Statorscheiben leicht auswechselbar mit ihrem Außenrand festgelegt und
- b) einander wenigstens paarweise so zugeordnet und angepaßt, daß sie zwischen sich eine von der Mühlenachse etwa radial erstreckte Statoreinheit mit einer rotationssymmetrischen Mahlraumeinheit bilden.
- c) Zentrisch durch die Statoreinheit ist eine an einen Drehantrieb angeschlossene Mühlenwelle erstreckt und wenigstens mittelbar an einem Ende im Mühlengehäuse gelagert.
- d) Die Mühlenwelle trägt mindestens eine leicht auswechselbare Rotorscheibe, die mit zwei Statorscheiben in der Mahlraumeinheit einen rotationssymetrischen Mahlspalt bildet und
- e) sich von der Mühlenachse aus allseits etwa radial erstreckt und im Axialschnitt eine nach außen hin geschlossene Spaltschleife bildet,
- f) die durch vorzugsweise wenigstens zwei Kugelrückführkanäle, die sich als Zentrifugal-Leitelemente von der Mühlenachse weg nach radial/außen erstrecken, kurzgeschlossen ist.
- a) in a mill housing stator disks are easily replaceable with their outer edge and
- b) assigned and adapted to one another at least in pairs so that they form between them a stator unit which extends approximately radially from the mill axis and has a rotationally symmetrical grinding chamber unit.
- c) A mill shaft connected to a rotary drive extends centrally through the stator unit and is mounted at least indirectly at one end in the mill housing.
- d) The mill shaft carries at least one easily replaceable rotor disk, which forms a rotationally symmetrical grinding gap with two stator disks in the grinding chamber unit
- e) extends approximately radially from all sides of the mill axis and forms a gap loop closed to the outside in axial section,
- f) through preferably at least two ball return channels, which are centrifugal guide elements extend the mill axis radially / outward, is short-circuited.
Hier sind zunächst alle für den Mahlvorgang wesentlichen Teile, insbesondere die Statorscheiben und die Rotorscheiben, als Ganzes leicht auswechselbar vorgesehen. Dies mindert nicht nur die Verlustzeiten bei Ausbesserungen, sondern ermöglicht auch den gezielten Einsatz besonderer Werkstoffe nach den örtlich auftretenden Beanspruchungen, was sich trotz der Verwendung teurer Werkstoffe an einzelnen Stellen, evtl. in Form dünner Oberflächenschichten, als preisgünstig erweist. Vor allem aber wird ein Kugelumlaufbereich in den mittleren Teil der Mahleinheit verlegt und damit die Mahlkörper mit Abstand vom Auslaß der Einheit gehalten. Dort wird sicherheitshalber auch wieder eine Art Trenneinrichtung in Form eines Reibspaltes oder dergleichen vorgesehen, aber es ist vermieden, daß sich die Masse der Mahlkörper vor einer solchen Trenneinrichtung ansammeln und damit sich in der Mühle kompaktieren kann.First of all, all parts essential for the grinding process, in particular the stator disks and the rotor disks, are provided as easily replaceable as a whole. This not only reduces the loss times in the case of repairs, but also enables the targeted use of special materials according to the local stresses, which despite the use of expensive materials in individual places, possibly in the form of thin surface layers, proves to be inexpensive. Above all, however, a recirculating ball area is installed in the middle part of the grinding unit and thus the grinding media are kept at a distance from the outlet of the unit. For safety's sake, a type of separating device in the form of a friction gap or the like is again provided, but it is avoided that the mass of the grinding media collects in front of such a separating device and can thus compact in the mill.
Die Gestaltung aus einzelnen, teils identischen, teils einzeln oder in Gruppen auswechselbaren Bauelementen innerhalb einer Mahleinheit hat ferner den Vorteil, daß sich ohne weiteres eine nahezu beliebige Anzahl einzelner Mahleinheiten aneinanderfügen lassen, was lediglich unterschiedliche, ggf. wieder aus Einheitselementen zusammengesetzte Mühlengehäuse mit Antriebswellen erfordert. Im Prinzip kann man auch in einem größeren Gehäuse nach Bedarf eine oder mehrere Mahleinheiten betreiben, die jeweils ihren eigenen geschlossenen Mahlkörperumlauf besitzen. Die einzelnen Mahlstufen lassen sich daher mit unterschiedlich großen Mahlkörpern beschikken, etwa dergestalt, daß in der ersten Mahleinheit mit größeren Mahlkörpern,in den nächstfolgenden Mahleinheiten jeweils mit stufenweise dünneren Mahlkörpern gearbeitet wird. Dies wiederum ermöglicht eine Steigerung der Intensität und Gleichmäßigkeit der Zerkleinerungsvorgänge, eine wenigstens im Mittel gesteigerte Energiedichte und dadurch bei verringertem Mühlenvolumen höhere Leistung.The design of individual, partly identical, partly individually or in groups interchangeable components within a grinding unit also has the advantage that almost any number of individual grinding units can be easily joined together, which only requires different, possibly again composed of unit elements mill housing with drive shafts . In principle, one or more grinding units can be operated in a larger housing, each with its own closed grinding media circulation. The individual grinding stages can therefore be fed with grinding media of different sizes, for example in such a way that in the first grinding unit larger grinding media are used, in the subsequent grinding units in each case with gradually thinner grinding media. This in turn enables an increase in the intensity and uniformity of the shredding processes at least on average increased energy density and thus higher output with reduced mill volume.
Das aber läßt sich ohne weiteres erreichen, wenn man nur dafür sorgt, daß durch Gestaltung der unterschiedlichen Strömungswege von Mahlkörpern und Mahlgut an der Trennstelle entsprechend differenzierte und unterschiedlich gerichtete Kräfte zur Einwirkung kommen, wobei die Aussonderung der Mahlkörper vornehmlich durch entsprechend erhöhte Fliehkräfte bewirkt wird und der Ablenkwinkel so groß ist, daß das Mahlgut, Trägheit und Druckgefälle folgend, auf der vorgegebenen Bahn weiterströmt. Besser ist es noch, die Mahlkörper der einzelnen Mahleinheiten durch mechanische Trenneinrichtungen wie Reibspalte zu separieren.But this can easily be achieved if you only ensure that by designing the different flow paths of grinding media and regrind at the separation point, appropriately differentiated and differently directed forces come into play, the rejection of the grinding media being primarily caused by correspondingly increased centrifugal forces and the deflection angle is so large that, following inertia and pressure drop, the regrind continues to flow on the specified path. It is even better to separate the grinding media of the individual grinding units using mechanical separation devices such as friction gaps.
Die Ausgestaltung ist zudem noch verhältnismäßig einfach, da es vornehmlich um Rotationsformen an Statorscheiben und Rotorscheiben geht, was durch herkömmliche Fertigungsmethoden preisgünstig bewerkstelligt werden kann. Dabei lassen sich die Strömungswege auf kleinstem Raum verhältnismäßig lang und daher die Einwirkungszeit verhältnismäßig groß gestalten.The design is also still relatively simple, since it is primarily about rotational shapes on stator disks and rotor disks, which can be accomplished inexpensively by conventional manufacturing methods. The flow paths can be made relatively long in the smallest space and therefore the exposure time can be made relatively long.
Zudem können vor allem die Rotorscheiben verhältnismäßig großen Querschnitt mit entsprechender Dicke erhalten, was auch bei biege- und zugempfindlichem Werkstoff wie Keramik die Bruchfestigkeit steigert.In addition, the rotor disks in particular can be given a relatively large cross section with a corresponding thickness, which increases the breaking strength even in the case of material which is sensitive to bending and sensitive, such as ceramic.
Die erfindungsgemäße Spalt-Kugelmühle eignet sich vorzüglich zum Aufschließen von Mikroorganismen bzw. Mikroben, deren Auswertung besondere Bedeutung für die Biotechnik zukommt. Solche Mikroben bestehen aus einer kapselartigen Zelle mit einer Zellflüssigkeit, die einen arteigenen Wirkstoff aufweist, der möglichst vollständig gewonnen werden sollte. Zur mechanischen Gewinnung ist bereits die Naßvermahlung in Rührwerkskugelmühlen vorgeschlagen worden. Die dort erzielte Ausbeute ist jedoch noch begrenzt. Dabei ist der Gewinnungsanteil maßgeblich bestimmt durch den beim Mahlvorgang angewendeten Druck. Wegen der gummiartigen Elastizität der Zellwand bleibt die Zelle bei zu geringem Druck unter elastischer Verformung intakt. Bei zu hohem Druck werden Zellwand, Zellflüssigkeit und Wirkstoff oft so stark ineinander verarbeitet, so daß die später durchzuführende Trennung erschwert wird. Bei der erfindungsgemäßen Spalt-Kugelmühle läßt sich jedoch der aufzuwendende Druck weitgehend vorausbestimmen und ggf. einstellen, um optimale Aufschluß- und Gewinnungsverhältnisse zu erzielen.The split ball mill according to the invention is particularly suitable for disrupting microorganisms or microbes, the evaluation of which is of particular importance for biotechnology. Such microbes consist of a capsule-like cell with a cell fluid that has a species-specific active ingredient that should be obtained as completely as possible. Wet grinding in agitator ball mills has already been proposed for mechanical extraction. The one scored there However, yield is still limited. The percentage of recovery is largely determined by the pressure applied during the grinding process. Due to the rubber-like elasticity of the cell wall, the cell remains intact if the pressure is too low and is deformed elastically. If the pressure is too high, the cell wall, cell fluid and active substance are often processed so strongly that the separation to be carried out later is made more difficult. In the case of the split ball mill according to the invention, however, the pressure to be applied can be largely predetermined and possibly adjusted in order to achieve optimal digestion and extraction ratios.
Gerade für die Biotechnik ist aber auch die Möglichkeit einer intensiven Sterilisierung der mit dem Mahlgut in Berührung kommenden Flächen von erheblicher Bedeutung. Beim Erfindungsgegenstand wird sehr weitgehend mit großen glatten Flächen gearbeitet, die keine scharfkantigen Teile, Winkelecken, Nuten oder dergleichen aufweisen, welche die Bildung von Verunreinigungsnestern zulassen. Diese Flächen lassen sich daher leicht und gründlich sterilisieren.Especially for biotechnology, the possibility of intensive sterilization of the surfaces that come into contact with the regrind is of considerable importance. The subject matter of the invention is very largely worked with large smooth surfaces which have no sharp-edged parts, angular corners, grooves or the like, which allow the formation of contamination nests. These surfaces can therefore be sterilized easily and thoroughly.
Weitere Ausgestaltungen und Vorteile der Erfindung sind in den Unteransprüchen festgehalten und sollen jetzt anhand der Zeichnung ausführlicher erläutert werden.Further refinements and advantages of the invention are set out in the subclaims and will now be explained in more detail with reference to the drawing.
Die Zeichnung gibt eine bevorzugte Ausführungsform der Erfindung beispielsweise wieder. Es zeigen:
- Fig. 1 einen Längsschnitt durch eine erfindungsgemäße Spalt-Kugelmühle,
- Fig. 2 eine Ansicht einer Rotorscheibe von links in Fig. 1 gesehen,
- Fig. 3 einen der Fig. 1 entsprechenden Axialschnitt mit geänderter Mahlspaltform,
- Fig. 4 den zugehörigen Längsschnitt durch eine Rotorscheibe und
- Fig. 5 eine weitgehend der Fig. 2 entsprechende Stirnansicht einer solchen Rotorscheibe.
- 1 shows a longitudinal section through a split ball mill according to the invention,
- 2 is a view of a rotor disk seen from the left in FIG. 1,
- 3 shows an axial section corresponding to FIG. 1 with a modified grinding gap shape,
- Fig. 4 shows the associated longitudinal section through a rotor disk and
- Fig. 5 is a largely similar to Fig. 2 front view of such a rotor disk.
Die in den Fig. 1 und 2 dargestellte Spalt-Kugelmühle besteht im wesentlichen aus einem Mühlengehäuse (1), das drei Mahleinheiten (2) aus einem mehrteiligen Stator (3) und einem ebenfalls mehrteiligen Rotor (4) aufnimmt, der die Mühlenachse (5) umläuft und von einem insbesondere regelbaren Elektromotor (6) angetrieben wird.The split ball mill shown in FIGS. 1 and 2 consists essentially of a mill housing (1), which receives three grinding units (2) from a multi-part stator (3) and a likewise multi-part rotor (4), which the mill axis (5th ) rotates and is driven by a particularly controllable electric motor (6).
Dieser Motor (6) ist am ortsfest angebrachten Mühlengehäuse (1) angeflanscht. Der Motorzapfen (7) greift dabei drehfest mit Keil (8) in die am linken Ende in Fig. 1 angebrachte Bohrung (9) der Rotorwelle (10). Deren anderes Ende sitzt mit einem Zapfenlager (11) in einem Außendeckel (12), der das topfartige Mühlengehäuse (1) abschließt und den Gutauslaß (13) aufnimmt.This motor (6) is flanged to the stationary mill housing (1). The motor pin (7) engages in a rotationally fixed manner with a wedge (8) in the bore (9) in the rotor shaft (10) made at the left end in FIG. 1. The other end sits with a journal bearing (11) in an outer cover (12), which closes the pot-like mill housing (1) and receives the product outlet (13).
Jeder der drei Mahleinheiten (2) umfaßt eine Statoreinheit (16) mit einer ersten Statorscheibe (17) und einer zweiten Statorscheibe (18). Diese bilden jeweils zwischen sich eine Mahlraumeinheit (19), in der eine als Reibscheibe ausgebildete Rotorscheibe (20) umläuft.Each of the three grinding units (2) comprises a stator unit (16) with a first stator disc (17) and a second stator disc (18). These each form a grinding chamber unit (19) between them, in which a rotor disk (20) designed as a friction disk rotates.
Die einzelnen Rotorscheiben (20) des Mehrstufen-Rotors (4) sitzen mit ihren Naben (21), durch Abstandsbuchsen (23) getrennt, hinbtereinander auf der Rotorwelle (10) zwischen deren Schulter (24) und der zum Zapfenlager (11) hin aufgeschraubten Mutter (25). Die Abstandsbuchsen (23) können grundsätzlich gleiche Länge haben, werden aber vorzugsweise in leicht abweichenden Längen vorrätig gehalten, um die Lage der Rotorscheiben (20) exakt festlegen zu können.The individual rotor disks (20) of the multi-stage rotor (4) sit with their hubs (21), separated by spacer bushings (23), one behind the other on the rotor shaft (10) between their shoulder (24) and that screwed towards the journal bearing (11) Mother (25). The spacer bushes (23) can in principle have the same length, but are preferably kept in stock in slightly different lengths in order to be able to precisely determine the position of the rotor disks (20).
Zur Drehmomentübertragung dienen einzelne, auf die Länge der Naben (21) abgestimmte zylindrische Polygonprofil-Mitnahmebolzen (26), die in einer durchgehenden längslaufenden, annähernd halbzylindrischen Nut (27) der Rotorwelle (10) sitzen. Die ersten Statorscheiben (17) haben einen mittleren, kegelförmigen Teil (171) mit einer Neigung von 60° zur Mühlenachse (5). Innen schließt sich ein S-förmiger Teil (171) an und außen ein angenähert zylindrischer Teilflansch (173). Jede zweite Statorscheibe (18) hat dagegen einen inneren, etwa ebenen Teil (181) mit einem äußeren kegelförmigen Teil (182), dessen Mantellinie mit der Mühlenachse (5) wiederum einen Winkel von 60° einschließt. Sie enden jeweils innen und außen in Radialflächen und sind dort gegeneinander und gegenüber dem Mühlengehäuse (1) durch Dichtungsringe (33,34) und Auflageringe (35) abgedichtet, wobei vor allem die letzteren für eine nachgiebige und dämpfende Stützwirkung sorgen.Individual, polygonal profile driving bolts (26), which are matched to the length of the hubs (21) and are seated in a continuous longitudinal, approximately semi-cylindrical groove (27) of the rotor shaft (10), are used for torque transmission. The first stator disks (17) have a central, conical part (171) with an inclination of 60 ° to the mill axis (5). An S-shaped part (171) follows on the inside and an approximately cylindrical partial flange (173) on the outside. In contrast, every second stator disk (18) has an inner, approximately flat part (181) with an outer conical part (182), the surface line of which in turn encloses an angle of 60 ° with the mill axis (5). They each end inside and outside in radial surfaces and are sealed there against each other and against the mill housing (1) by sealing rings (33, 34) and support rings (35), the latter in particular ensuring a flexible and damping support effect.
Jede Rotorscheibe (20) erweitert sich von ihrer Nabe (21) aus zunächst mittels eines etwa ebenen Zwischenteiles (22) zu einem äußeren Kegelring (28), der weitgehend in der Mitte der Mahlraumeinheit (19) zwischen kegelförmigen Teilen (171,182) der beiden Statorscheiben (17,18) zu liegen kommt, wodurch rings um die ganze Rotorscheibe (20) ein etwa gleich breiter Mahlspalt (36) geformt wird, der eine nach radialaußen geschlossene Spaltschleife (37) um den Kegelring (28) bildet. Die Spaltschleife (37) steht über etwa radial verlaufende Verbindungsspalte (38,39) mit Anschlußspalten (40,41) und dadurch mit den radialen Endflächen (42) der durch die Statorscheiben (17,18) gebildeten Statoren der einzelnen Mahleinheiten (2) in Verbindung.Each rotor disc (20) widens from its hub (21) initially by means of an approximately flat intermediate part (22) to form an outer conical ring (28), which is largely in the center of the grinding chamber unit (19) between conical parts (171, 182) of the two stator discs (17, 18) comes to rest, whereby a grinding gap (36) of approximately the same width is formed around the entire rotor disc (20), which forms a gap loop (37) which is closed towards the outside around the cone ring (28). The gap loop (37) is connected via approximately radially extending connecting gaps (38, 39) with connecting gaps (40, 41) and thereby with the radial end faces (42) of the stators of the individual grinding units (2) formed by the stator disks (17, 18) Connection.
Dicht an der Innenfläche (46) des Kegelringes (28) sind die oberen Enden der Verbindungsspalte (38,39), jeweils durch wenigstens zwei Kugelrückführkanäle (47) verbunden, die ebenfalls um etwa 60° zur Rotorachse (5) geneigt sein können bzw. nach Fig.2 spiralförmig verlaufen. Dadurch werden auf schwere Partikel, insbesondere auf die Mahlkörper (48), größere Fliehkräfte ausgeübt als auf die unter Pumpendruck weitergeförderten Festkörperteilchen des Mahlgutes. Um diesen Effekt zu vergrößern, werden die Mahlkörper (48) vorzugsweise aus Keramik gefertigt. Sie können aber auch aus spezifisch besonders schwerem Gestein bestehen. Auf diese Weise läßt sich erreichen, daß die Mahlkörper, wie dies in der mittleren Mahleinheit in den Figuren 1 und 1a gezeigt ist, auf einer durch wenigstens zwei Kugelrückführkanäle (47) geschlossenen räumlichen Ringbahn rotieren, also in der jeweiligen Mahleinheit verbleiben.Close to the inner surface (46) of the conical ring (28) are the upper ends of the connecting gaps (38, 39), each connected by at least two ball return channels (47) which can also be inclined by approximately 60 ° to the rotor axis (5) or run spirally according to FIG. As a result, larger centrifugal forces are exerted on heavy particles, in particular on the grinding media (48), than on the solid particles of the grinding material which are conveyed further under pump pressure. To increase this effect, the grinding media (48) are preferably made of ceramic. However, they can also consist of specifically particularly heavy rock. In this way it can be achieved that the grinding media, as shown in the middle grinding unit in FIGS. 1 and 1a, rotate on a spatial ring path closed by at least two ball return channels (47), that is to say they remain in the respective grinding unit.
Der Trennvorgang kann ferner dadurch beeinflußt werden, daß man einen Winkel verändert, etwa die Neigung des Zwischenspaltes (49) der inneren Randfläche des Kegelringes (28).The separation process can also be influenced by changing an angle, such as the inclination of the intermediate gap (49) of the inner edge surface of the cone ring (28).
Die Mahlkörper (48) können auch in jede Mahleinheit gesondert durch ein Füllrohr (51) eingefüllt werden, das in einer Haltebuchse (52) im Mühlengehäuse (1) und unmittelbar in einer Bohrung (53) des die Schleife (37) überdeckenden Ringflansches (173) sitzt. Normalerweise ist das Füllrohr (51) durch einen Stopfen (54) verschlossen, der durch eine aufgeschraubte Überwurfmutter (55) gehalten wird. Anstelle des Stopfens (54) kann auch ein Meßtaster oder ein Meßgerät (56), etwa für Druck, Temperatur, Viskosität oder dgl. des Mahlgutes ein- bzw. aufgesetzt werden.The grinding media (48) can also be filled separately into each grinding unit through a filling tube (51), which is placed in a holding bush (52) in the mill housing (1) and directly in a bore (53) of the ring flange (173) covering the loop (37) ) sits. The filling tube (51) is normally closed by a stopper (54) which is held by a screwed-on union nut (55). Instead of the stopper (54), a probe or a measuring device (56), for example for pressure, temperature, viscosity or the like, of the material to be ground can also be inserted or attached.
Der Guteinlaß (13) ist ebenso wie der Gutauslaß (14) gegenüber dem benachbarten Mahlspalt durch einen Reibspaltring (57) abgeschlossen, der zwischen dem Gehäusesteg (59) bzw. dem Außendeckel (12) und der dort jeweils vorhandenen Abstandsbuchse (23) eingefügt ist. Die dadurch gebildeten, sich nach außen erweiternden Reibspalte (58) dienen zur Sicherung gegen den Verlust von Mahlkörpern, die aus irgendeinem Grund, z.B. beim Anfahren, ihre Umlaufbahn in der Spaltschleife (37) verlassen haben. Bei einem zwischenzeitigen Stillstand der Mühle sammeln sich solche Mahlkörper unten in der Spaltschleife (37) und werden beim Anlauf wieder nach außen geschleudert und dadurch in der Mahlschleife verteilt.The product inlet (13), like the product outlet (14), is closed off from the adjacent grinding gap by a friction gap ring (57) which is inserted between the housing web (59) or the outer cover (12) and the spacer bush (23) present there . The friction gaps (58) formed in this way, which widen outwards, serve to secure against the loss of grinding media for some reason, for example when starting off, have left their orbit in the gap loop (37). If the mill comes to a standstill in the meantime, such grinding media collect in the bottom of the gap loop (37) and are thrown outwards again during start-up and are thus distributed in the grinding loop.
Zwischen benachbarten Statoren (17,18) können Distanzringe (61) eingeschaltet werden, um die axialen Abstände zwischen den Statoren, aber auch zwischen Stator- und Rotorscheiben beeinflussen zu können. Abweichend von der dargestellten Ausführung mit Distanzringen und dgl. können auch Vorrichtungen zum kontinuierlichen Verstellen mittels Druckschrauben oder dgl. zum Einsatz kommen. Beispielsweiselassen sich auch die Schrauben (62) am Außendeckel (12) für solche Einstellvorgänge heranziehen.Spacer rings (61) can be inserted between adjacent stators (17, 18) in order to be able to influence the axial distances between the stators, but also between the stator and rotor disks. In contrast to the embodiment shown with spacer rings and the like, devices for continuous adjustment by means of pressure screws or the like can also be used. For example, the screws (62) on the outer cover (12) can also be used for such adjustment processes.
An den Längsenden der Mühle sind außen Kühlräume (64,65) vorgesehen, zwischen benachbarten Mahleinheiten (2) ebenfalls ringförmige Kühlräume (64). Diese stehen einzeln mit Mantel-Kühlräumen (85) in Verbindung, die jeweils zwischen dem Mantel des Mühlengehäuses (1) und dem Ringflansch (172) der zugehörigen ersten Statorscheibe (17) eingeformt sind.At the longitudinal ends of the mill, cooling spaces (64, 65) are provided on the outside, and annular cooling spaces (64) are also provided between adjacent grinding units (2). These are individually connected to jacket cooling chambers (85), which are each formed between the jacket of the mill housing (1) and the ring flange (172) of the associated first stator disk (17).
In den Distanzringen (61) sind dabei etwa radiale Durchbrechungen zum Anschluß der Mantel-Kühlräume (85) an den Kühlmittelkreislauf angebracht. Anstelle eines Kühlmittels kann auch ein anderes Wärmeträgermedium, etwa zum Aufheizen oder zum wahlweisen Kühlen und/oder Heizen verwendet werden. Alle Kühlräume sind dabei z.B. über zwei unter 180° zur Mühlenachse (5) versetzte Rohrverzweiger (66) an eine Kälte- und/oder Wärmequelle angeschlossen, um die Betriebstemperatur beim Mahlvorgang nach Bedarf einstellen zu können.In the spacer rings (61) there are approximately radial openings for connecting the jacket cooling spaces (85) to the coolant circuit. Instead of a coolant, another heat transfer medium can also be used, for example for heating or for optional cooling and / or heating. All cold rooms are e.g. Connected to a cold and / or heat source via two manifolds (66) offset at 180 ° to the mill axis (5) in order to be able to adjust the operating temperature during the grinding process as required.
Statorscheiben (17,18) und Rotorscheiben (20) bestehen aus gesintertem Keramikwerkstoff mit großer Temperaturbeständig keit und Abriebfestigkeit. Die Druckfestigkeit dieser Werkstoffe ist für die auftretenden Beanspruchungen hinreichend. Um jedoch die insbesondere auch durch Fliehkräfte verursachte Zugbeanspruchung zu kompensieren, können einerseits die Rotorscheiben in an sich bekannter Weise als vorgespannte Konstruktionselemente ausgeführt werden. Andererseits ist der Druck der Kühlflüssigkeit wesentlich höher bemessen, als dies bei vergleichbaren Kühlanlagen der Fall ist. Dadurch werden die Statoren aus den Mantel-Kühlräumen (85) heraus radial nach innen zusammengepreßt, um wenigstens die aus Fliehkräften und dgl. herrührenden Ausdehnungs-Verformungen zu kompensieren. Auch die Statorscheiben können in mechanischer Weise vorgespannt werden.Stator disks (17, 18) and rotor disks (20) are made of sintered ceramic material with high temperature resistance speed and abrasion resistance. The compressive strength of these materials is sufficient for the stresses that occur. However, in order to compensate for the tensile stress caused in particular by centrifugal forces, on the one hand the rotor disks can be designed as prestressed construction elements in a manner known per se. On the other hand, the pressure of the cooling liquid is dimensioned much higher than is the case with comparable cooling systems. As a result, the stators are pressed radially inward out of the jacket cooling spaces (85) in order to at least compensate for the expansion deformations resulting from centrifugal forces and the like. The stator disks can also be mechanically preloaded.
Um kleine Durchmesser zu erhalten, empfiehlt sich die Verwendung von zwei oder mehr, ggf. bis zu fünf oder mehr Mahleinheiten. Dadurch ist eine relativ große Zahl identischer Einzelelemente erforderlich, die eine Herstellung in größerer Serie und damit eine Verbilligung auch bei komplizierter Technik ermöglicht.In order to obtain small diameters, the use of two or more, possibly up to five or more grinding units is recommended. As a result, a relatively large number of identical individual elements is required, which enables production in a larger series and thus a reduction in price even with complicated technology.
Vor Betriebsaufnahme sollten bei Bearbeitung von kontaminationsempfindlichem Gut, etwa für die Lebensmittel- und Pharmaindustrie bzw. die Biotechnik, die Mahlräume bzw. Mahlspalte und andere mit dem Mahlgut in Berührung kommende Flächen ebenso wie die Kühl- bzw. Temperiermittel führenden Räume weitgehend sterilisiert werden. Dies geschieht nach den vorangehenden Reinigungsvorgängen vornehmlich dadurch, daß Dampf mit einem Druck, der etwa 1 bar größer ist als der übliche Mahldruck, durch diese Räume hindurchgeleitet wird, wobei man die Temperatur ständig bis auf einen Maximalwert von etwa 140° C steigert. Dieser Höchstwert wird für eine bestimmte Zeit aufrechterhalten, die von verschiedenen Betriebsfaktoren abhängig ist und zweckmäßigerweise durch Versuche festgelegt wird.Before the start of operations, the processing of contamination-sensitive goods, for example for the food and pharmaceutical industries or biotechnology, the grinding rooms or grinding gaps and other surfaces that come into contact with the material to be ground, as well as the rooms containing the cooling or tempering agents, should be largely sterilized. This occurs primarily after the preceding cleaning processes in that steam is passed through these rooms at a pressure which is approximately 1 bar higher than the usual grinding pressure, the temperature being constantly increased to a maximum value of approximately 140.degree. This maximum value is maintained for a certain time, which depends on various operating factors and is expediently determined by tests.
Nach Anlaufen des Motors (6) wird Mahlgut kontinuierlich dem Einlaß zugeführt und strömt durch den serpentinenartigen Ringspalt von einer Mahleinheit zur nächsten, bis es aus dem zweiten Reibspalt (58) zum Gutauslaß (14) gelangt, der durch eine Gleitringdichtung (68) zum Motor hin abgeschlossen ist.After the motor (6) has started, regrind is fed continuously to the inlet and flows through the serpentine annular gap from one grinding unit to the next until it comes from the second friction gap (58) to the material outlet (14), which leads to the motor through a mechanical seal (68) is completed.
Die ggf. in verschiedenen Größen vorgesehenen Mahlkörper werden noch im Stillstand der Mühle eingefüllt, sie haben in der Regel einen Durchmesser von 0,3 bis 3 mm und werden klassifiziert zugegeben, etwa in die rechte Mahleinheit mit einem Durchmesser von 3 mm, in die mittlere mit 1,5 mm und in die linke mit 0,8 mm. Beim Anlauf werden die Kugeln, die sich zunächst am Boden der Spaltschleife (37) angesammelt haben, auf den restlichen Teil der ringförmigen Spaltschleife verteilt und zyklisch nach außen geschleudert und durch die Fliehkräfte im Bereich der Mahlschleife konzentriert. Statt eines einzigen Rückführkanals (47) sind zweckmäßigerweise deren mehrere - nach Fig.2 sechs - gleichmäßig am Umfang verteilt vorgesehen, je nachdem, welche Umlaufgeschwindigkeit der Kugeln im Hinblick auf das verarbeitete Gut angestrebt wird.The grinding media, which may be provided in different sizes, are filled while the mill is at a standstill, they usually have a diameter of 0.3 to 3 mm and are classified, for example in the right grinding unit with a diameter of 3 mm, in the middle with 1.5 mm and in the left with 0.8 mm. When starting up, the balls, which have initially accumulated at the bottom of the gap loop (37), are distributed to the remaining part of the ring-shaped gap loop and cyclically thrown outwards and concentrated by the centrifugal forces in the area of the grinding loop. Instead of a single return channel (47) there are expediently provided a plurality - six according to FIG. 2 - distributed uniformly around the circumference, depending on the rotational speed of the balls with regard to the processed material.
Beim Umlauf werden die Mahlkörper stets an der sich in Verlängerung des Kugelrückführkanals anschließenden Innenfläche (46) gegen den äußeren Kegelring (28) gepreßt, wobei eine Art Hochleistungsmahlgang bewirkt wird, während beim Rücklauf aus der Spaltschleife (37) zum Zwischenspalt (49) hin sich die Anlagekräfte mindern und bei geringerer spezifischer Mahlleistung der Mahlvorgang vergleichmäßigt und vervollständigt wird. Es werden also drei voneinander weitgehend unabhängige und auch unterschiedliche Mahlzyklen durchlaufen, bis das Mahlgut zum Auslaß (14) gelangt. Es lassen sich daher hochfeine und besonders gleichmäßige Dispersionen in verhältnismäßig kurzer Zeit erstellen.During the circulation, the grinding media are always pressed against the outer conical ring (28) on the inner surface (46), which is an extension of the ball return channel, whereby a kind of high-performance grinding is effected, while when returning from the gap loop (37) to the intermediate gap (49) reduce the plant forces and, with a lower specific grinding capacity, the grinding process is evened out and completed. Three grinding cycles, which are largely independent of one another and also different, are run through until the ground material reaches the outlet (14). It is therefore possible to create extremely fine and particularly uniform dispersions in a relatively short time.
Bei der abgewandelten Ausführung gemäß den Fig. 3 bis 5 sind gleiche Bauteile mit den selben Bezugszeichen versehen, wobei abgewandelte Ausführungen durch einen hochgestellten Strich gekennzeichnet sind.3 to 5 are in the modified embodiment Identify the same components with the same reference numerals, modified versions being identified by a prime.
Der Unterschied dieser zweiten Ausführung gegenüber der erstbeschriebenen besteht im Prinzip darin, daß im Querschnitt eines jeden Mahlspaltes (36′), insbesondere der Spaltschleife (37′) in beiden Strömungszweigen eine zusätzliche Ringsicke bzw. Umlenkung angebracht ist, wobei an den Stirnseiten (71) und (72) zum Beispiel des Rotors sich jeweils ringförmige Erhebungen (73) und Vertiefungen (74) abwechseln. Die Stirnflächen sind hier wie insgesamt vor allem der Außenteil der Rotorscheibe (20) im Querschnitt zickzackförmig gestaltet. Sie können auch wellenartige Gestalt haben. Nach Möglichkeit sollten jedoch die einander zugeordneten Flächen, beispielsweise die zum Außenrand (75) hinführenden Endflächen (76) und (77) wenigstens annähernd parallel zueinander verlaufen und gegebenenfalls auch gleichbleibende Abstände haben. Dies gilt auch für die an den Statorscheiben (17′) und (18′) vorgesehenen Stirnflächen (78) und (79). Der äußere Kegelring (28) nach Fig. 1 wird dadurch zu einem Z-Flansch (80) mit der Querschnittsform einer Rune. Entsprechend gestaltet ist die den Z-Flansch umschließende Spaltschleife (37′) der beiden Arme des Mahlspaltes (36′).The difference of this second embodiment compared to the first described is in principle that in the cross section of each grinding gap (36 '), in particular the gap loop (37'), an additional ring bead or deflection is attached in both flow branches, with the end faces (71) and (72) for example of the rotor, alternate annular elevations (73) and depressions (74). The end faces here, as a whole, in particular the outer part of the rotor disk (20) are designed in a zigzag cross section. They can also have a wave-like shape. If possible, however, the mutually assigned surfaces, for example the end surfaces (76) and (77) leading to the outer edge (75), should run at least approximately parallel to one another and, if appropriate, also have constant distances. This also applies to the end faces (78) and (79) provided on the stator disks (17 ') and (18'). The outer cone ring (28) according to FIG. 1 thereby becomes a Z flange (80) with the cross-sectional shape of a rune. The split loop (37 ') of the two arms of the grinding gap (36') surrounding the Z flange is designed accordingly.
Diese beiden Mahlspaltarme sind durch am unteren Ende des Z-Flansches angebrachte Kugelrückführkanäle (47′) verbunden. Die Mahlkugeln werden auch hierbei zunächst in Strömungsrichtung eingeführt und am Austritt aus dem Kugelrückführkanal (47′) scharf nach außen umgelenkt, sodaß sie während des Betriebes jeweils in ihrer Spaltschleife (37′), d.h. in den beiden äußeren Teilen der Mahlspaltarme konzentriert bleiben. Hierbei sind die Kugelrückführkanäle (47′) so wie die nicht erwähnten Teile und Anordnungen in der gleichen Weise ausgebildet wie in den Fig. 1 und 2, sodaß auf die restlichen Teile der zweiten Ausführungsform nicht eingegangen werden muß.These two grinding gap arms are connected by ball return channels (47 ') attached to the lower end of the Z-flange. The grinding balls are also first introduced in the direction of flow and at the outlet from the ball return duct (47 ') deflected sharply outwards so that they remain concentrated in their gap loop (37') during operation, ie in the two outer parts of the grinding gap arms. Here, the ball return channels (47 ') as the parts and arrangements not mentioned are formed in the same manner as in Figs. 1 and 2, so that on the remaining parts of the second embodiment need not be discussed.
Die dargestellten Ausführungsformen können in mancherlei Weise abgewandelt werden, ohne daß der Erfindungsbereich verlassen wird. So kann die Mahlspaltschleife (37) etwa der mit geraden Mantellinien versehenen Kegelflächen durch konkav und/oder konvex gewölbte Kegeltonnenflächen oder dgl. gebildet werden, so daß die Schleife etwa eiförmigen oder ellipsenförmigen Querschnitt erhält. Die Winkel der Mantellinie zur Mühlenachse können gleich oder unterschiedlich gewählt sein, und die Rotorscheiben können am ganzen Umfang einen Drehschluß mit der Rotorwelle bilden, etwa daß sie einen polygonalen Querschnitt, insbesondere dreieckförmig und mit abgerundeten Ecken bzw. mit quer zur Rotorachse gewölbten Seitenflächen bilden.The illustrated embodiments can be modified in various ways without leaving the scope of the invention. For example, the grinding gap loop (37) of the conical surfaces provided with straight surface lines can be formed by concave and / or convexly curved conical barrel surfaces or the like, so that the loop has an approximately egg-shaped or elliptical cross-section. The angles of the surface line to the mill axis can be chosen to be the same or different, and the rotor disks can form a rotational connection with the rotor shaft over the entire circumference, for example that they form a polygonal cross section, in particular triangular and with rounded corners or with side surfaces curved transversely to the rotor axis.
Claims (24)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT88106483T ATE90886T1 (en) | 1987-05-15 | 1988-04-22 | SPLIT BALL MILL FOR CONTINUOUS FINE GRINDING, IN PARTICULAR DECOMPOSITION OF MICROORGANISMS AND DISPERSING OF SOLIDS IN LIQUID. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3716295 | 1987-05-15 | ||
DE19873716295 DE3716295A1 (en) | 1987-05-15 | 1987-05-15 | SPLIT BALL MILL FOR CONTINUOUS FINE-SIZING, ESPECIALLY UNLOCKING MICRO-ORGANISMS AND DISPERSING SOLIDS IN LIQUID |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0290840A2 true EP0290840A2 (en) | 1988-11-17 |
EP0290840A3 EP0290840A3 (en) | 1990-01-10 |
EP0290840B1 EP0290840B1 (en) | 1993-06-23 |
Family
ID=6327628
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP88106483A Expired - Lifetime EP0290840B1 (en) | 1987-05-15 | 1988-04-22 | Gap-ball mill for continuously grinding, especially disintegrating microorganisms, and dispersing solids in fluids |
Country Status (5)
Country | Link |
---|---|
US (1) | US4824033A (en) |
EP (1) | EP0290840B1 (en) |
JP (1) | JP2652194B2 (en) |
AT (1) | ATE90886T1 (en) |
DE (2) | DE3716295A1 (en) |
Cited By (4)
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DE3918092A1 (en) * | 1988-06-09 | 1989-12-14 | Buehler Ag Geb | Stirrer mill |
DE3943765C3 (en) * | 1988-06-09 | 2003-07-17 | Buehler Ag | agitating mill |
RU2504436C1 (en) * | 2012-06-27 | 2014-01-20 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Ярославский государственный технический университет" | Multichamber mill |
WO2020207609A1 (en) | 2019-04-08 | 2020-10-15 | Arcolor Ag | Milling method and milling device |
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DE4029252A1 (en) * | 1990-09-14 | 1992-03-19 | Fryma Masch Ag | METHOD AND DEVICE FOR CONTINUOUS FINE SIZING AND DISPERSING SOLIDS IN LIQUID |
ES2030619A6 (en) * | 1990-10-31 | 1992-11-01 | Oliver & Battle Sa | Grinding body separator in mills for triturating and breaking up solids dispersed in liquids. |
ES2031788A6 (en) * | 1991-06-27 | 1992-12-16 | Oliver & Battle Sa | Improvements in the separators of grinding bodies in mills for comminuting and crushing and deagglomerating solids, predispersed in liquids. |
DE4402609C2 (en) * | 1994-01-28 | 1997-05-07 | Hosokawa Alpine Ag | Agitator ball mill |
KR100500480B1 (en) * | 1997-07-30 | 2005-11-14 | 어네스트 센데스 | Dry grinding method and apparatus of solid |
DE29819508U1 (en) * | 1998-11-02 | 1999-01-14 | VMA-GETZMANN GmbH, 51580 Reichshof | Dispersing device |
GB9901828D0 (en) * | 1999-01-27 | 1999-03-17 | Withdeal Limited | Milling machine |
US8133527B2 (en) | 2006-06-16 | 2012-03-13 | Kraft Foods Global Brands Llc | Production of stabilized whole grain wheat flour and products thereof |
US20170056889A1 (en) * | 2015-08-26 | 2017-03-02 | Bayram Suha Aksoy | Gravity aided grinding mill apparatus and method |
CN105362230B (en) * | 2015-11-27 | 2018-08-24 | 中牧南京动物药业有限公司 | The process of hydrochloric acid sarafloxacin soluble powder is prepared based on solid dispersions technique |
US20170252751A1 (en) * | 2016-03-01 | 2017-09-07 | Enagon Wave Technology, Llc | Pressure Interference Wave Mill |
ES2713001T3 (en) | 2016-10-18 | 2019-05-17 | Bachofen Willy A Ag | Ball mill |
JP6679684B2 (en) * | 2018-09-26 | 2020-04-15 | 杉山重工株式会社 | Powder liquid dispersion device |
DE102018009752A1 (en) * | 2018-12-12 | 2020-06-18 | Hugo Nienhaus | Easily handled refinement of biochar in a shredding device with high sustainability of the use in feed |
WO2020124263A1 (en) * | 2018-12-21 | 2020-06-25 | Nanorial Technologies Ltd. | Apparatus, methods, and systems for mixing, dispersing substances |
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- 1988-04-22 AT AT88106483T patent/ATE90886T1/en active
- 1988-04-22 EP EP88106483A patent/EP0290840B1/en not_active Expired - Lifetime
- 1988-04-22 DE DE8888106483T patent/DE3881955D1/en not_active Expired - Fee Related
- 1988-05-03 US US07/189,801 patent/US4824033A/en not_active Expired - Fee Related
- 1988-05-13 JP JP63115011A patent/JP2652194B2/en not_active Expired - Lifetime
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DE3918092A1 (en) * | 1988-06-09 | 1989-12-14 | Buehler Ag Geb | Stirrer mill |
DE3918092C2 (en) * | 1988-06-09 | 1999-08-12 | Buehler Ag Geb | Agitator mill |
DE3943765C3 (en) * | 1988-06-09 | 2003-07-17 | Buehler Ag | agitating mill |
RU2504436C1 (en) * | 2012-06-27 | 2014-01-20 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Ярославский государственный технический университет" | Multichamber mill |
WO2020207609A1 (en) | 2019-04-08 | 2020-10-15 | Arcolor Ag | Milling method and milling device |
Also Published As
Publication number | Publication date |
---|---|
DE3881955D1 (en) | 1993-07-29 |
JPS63302962A (en) | 1988-12-09 |
US4824033A (en) | 1989-04-25 |
JP2652194B2 (en) | 1997-09-10 |
EP0290840B1 (en) | 1993-06-23 |
DE3716295A1 (en) | 1988-11-24 |
ATE90886T1 (en) | 1993-07-15 |
EP0290840A3 (en) | 1990-01-10 |
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