EP0913200B1 - Agitator mill - Google Patents

Agitator mill Download PDF

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Publication number
EP0913200B1
EP0913200B1 EP98119177A EP98119177A EP0913200B1 EP 0913200 B1 EP0913200 B1 EP 0913200B1 EP 98119177 A EP98119177 A EP 98119177A EP 98119177 A EP98119177 A EP 98119177A EP 0913200 B1 EP0913200 B1 EP 0913200B1
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EP
European Patent Office
Prior art keywords
grinding
grinding chamber
interior
chamber
exterior
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP98119177A
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German (de)
French (fr)
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EP0913200A1 (en
Inventor
Norbert Dr. Stehr
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Buehler AG
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Draiswerke GmbH
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Publication date
Priority claimed from DE19834397A external-priority patent/DE19834397B4/en
Application filed by Draiswerke GmbH filed Critical Draiswerke GmbH
Publication of EP0913200A1 publication Critical patent/EP0913200A1/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
    • B02C17/166—Mills in which a fixed container houses stirring means tumbling the charge of the annular gap type

Definitions

  • the invention relates to an agitator mill according to the preamble of Claim 1.
  • Such an agitator mill is known from DE 40 10 928 A1. at this known agitator mill have the outside grinding chamber and the Indoor grinding room - as far as can be seen from the drawing of this publication is - same radial extension.
  • the regrind flows through a regrind feed chamber, through a transition area on the overflow channels over into the outside grinding room and through the deflection room into the inside grinding room.
  • the grinding aids run in a circle through the outside grinding chamber, the deflection chamber, the inside grinding chamber and the overflow channels back into the outside grinding room or into the one opening into it Transition area.
  • the regrind flows from the end of the interior grinding chamber to the separator.
  • the separator is not used in noteworthy measure for separating grinding aids on the one hand and Regrind on the other hand; nevertheless - also in this application - the term Separating device used because it is general in the technical language has prevailed. As follows from the above explanation the separation of the auxiliary grinding bodies from the regrind before the separating device.
  • each frustoconical rejuvenate i.e. the cross section of the grinding room is on everyone Cone-shaped side of the central longitudinal axis of the rotor and stator.
  • the Grist flows through the agitator mill from the inside out, i.e. it flows into the narrow diameter of the inner grinding chamber, flows through it then the radially expanding inner grinding chamber, the deflection chamber and then the radially widening outside grinding room. From there it flows radially inwards through a one-sided boundary of the agitator Space to a separator through which the regrind is discharged becomes.
  • the entry of an overflow channel is arranged downstream of this separating device, the inlet of which is arranged radially inside the separating device, So this is subordinate. From there, the grinding aids flow through Overflow channels in the rotor in the initial area of the inner grinding chamber.
  • the boundary walls of the grinding chamber are smooth-walled.
  • the width of the grinding gap, i.e. the radial width of the grinding chamber is constant; the distance to However, the axis of rotation increases steadily. It follows from this that the shear gradient increases over the path of the regrind from the inside to the outside. this leads to to the fact that it is either too low in the inside grinding room or in the outside grinding room is too high, which leads to an uneven loading of the Grist leads. (The shear gradient is defined as the quotient of speed the rotating surface and gap width.)
  • an agitator mill is known, the one Has agitator shaft with a cage which is part of the agitator shaft.
  • the cage is attached to a support part, between and the lid of the grinding container and an adjacent area of the inner wall of the grinding container a friction gap is formed.
  • the regrind is in this friction gap by friction of the walls of the grinding container delimiting these friction gaps and the agitator shaft activated.
  • the invention is based, an agitator mill of the generic type Kind in such a way that on the one hand intensive crushing and dispersing the regrind particles is maintained; that the crushed Grist particles but get a finely smoothed surface.
  • Claim 4 gives preferred lower ranges for the ratio of the cross-sectional areas from outside grinding room and inside grinding room.
  • the requirements 4 and 5 give preferred upper limits for the ratio of Cross-sectional areas of the outside grinding area and inside grinding area.
  • claims 6 to 9 are preferred limit values for the radial width indicated by outside grinding room and inside grinding room.
  • Claim 11 reflects measures by which the impact grinding in the outer grinding chamber can be optimized.
  • the claims 11 to 15 indicate a further embodiment in which the Grist before entering the outside grinding area of a predispersion is subjected to a narrow ring-cylindrical vortex.
  • This Effect is brought about in particular by the fact that the ring-cylindrical Vortex gap a very small extension radially to the central longitudinal axis and that the overflow channels enter this vortex gap, so that alternating wall sections of the rotor delimiting the vortex gap and the outlet openings of the overflow channels on the inner wall of the Run past the grinding container.
  • the agitator mill shown in Fig. 1 has in the usual way Stand 1 on which a cylindrical grinding container 3 can be attached.
  • Stand 1 On which a cylindrical grinding container 3 can be attached.
  • an electric drive motor 4 which with a V-belt pulley 5 is provided, one of which via V-belt 6 a drive shaft 7 rotatably connected V-belt pulley 8 rotating is drivable.
  • the grinding container 3 consists of a cylindrical, a grinding chamber 9 surrounding inner wall 10, the a substantially cylindrical outer jacket 11 is surrounded.
  • the Inner cylinder 10 and the outer jacket 11 delimit one between them Cooling chamber 12.
  • the lower end of the grinding chamber 9 is by an annular Base plate 13 formed on the grinding container by means of screws 14 is attached.
  • the grinding container 3 has an upper ring flange 15, by means of which it is fastened to the underside of a support housing 16 by means of screws 17, which is attached to stand 1 of the agitator mill.
  • the grinding chamber 9 is closed by a lid 18.
  • the support housing 16 has a medium Bearing and seal housing 19, which is coaxial to the central longitudinal axis 20 of the grinding container 3 is arranged. This seal housing 19th is driven by the drive shaft 7, which also runs coaxially to the axis 20 enforced, on which an agitator 21 is attached.
  • a regrind feed line opens into the adjacent area of the seal housing 19 22 a.
  • the cooling space 28 is connected to a cooling space 29 in the base plate 13, the cooling water is supplied via a cooling water supply nozzle 30 which via an outlet pipe 30a is discharged.
  • the cooling chamber 12 of the grinding container 3 cooling water is supplied via a cooling water supply nozzle 31, which is discharged via a cooling water discharge nozzle 32.
  • a grinding aid-grinding body separating device 34 is arranged, which is connected to a regrind drain line 35. Between the separator 34 and the drain line 35 is a regrind collecting funnel 36 provided.
  • the drain line 35 is in the range of Base plate 13 provided with a bracket 38, which by means of screws 39 with the base plate 13 or the inner stator fixedly connected to it 24 is releasably connected.
  • the separator 34 is opposite to the annular end face 33 of the inner stator 24 by means of a seal 40 sealed and after loosening the screws 39 together with the Drain line 35 and the collecting funnel 36 from the inner stator 24 after pulled out below.
  • the separator 34 can thus from the Grinding chamber 9 are pulled out without the located in it Grinding auxiliary body 41 must be removed from the grinding chamber, since the Filling the grinding chamber 9 with these auxiliary grinding bodies 41 when not driven Agitator 21 does not reach the front side 33.
  • the basic structure of the agitator 21 is pot-shaped, i.e. it shows one essentially ring-cylindrical rotor 42 by a cylindrical Outer wall 43 and one arranged coaxially thereto and coaxially to the axis 20 cylindrical inner wall 44 is formed. Between the outer wall 43 and the inner wall 44 of the rotor 42, a cooling space 45 is formed.
  • the rotor 42 is attached to a rotor support member 46 which is connected to the Wave 7 is connected.
  • the supply and discharge of cooling water to the cold room 45 is carried out by trained in the shaft 7 and in the rotor support member 46 Cooling water channels 47, 48.
  • the grinding chamber 9 is in a cylindrical ring External grinding chamber 9 'on the one hand and a cylindrical ring Internal grinding chamber 9 ", on the other hand, divided by a deflection chamber 49 are connected to one another in the area of the base plate 13.
  • the ground material flows through the grinding chamber 9 in accordance with the flow direction arrows 52 coming from the regrind feed line 22 a regrind feed space 53 between the rotor support part 46 on the one hand and the cover 18 and the adjacent area of the inner wall 10 on the other hand, down through the outside grinding chamber 9 ', through the deflection chamber 49 radially inwards and from there through the inner grinding chamber 9 '' up to the separator 34.
  • the deflection chamber 49 and the inner grinding chamber 9 " Regrind with rotating driven agitator 21 in cooperation with the grinding auxiliary bodies 41 processed.
  • the ground material leaves the grinding chamber 9 through the separator 34, from where it goes through the regrind drain line 35 flows off.
  • the separating device used to separate auxiliary grinding bodies 41 34 is arranged in a cylindrical recess 54 of the rotor support part 46. Between the cylindrical wall 55 of the recess 54 and the Separating device 34 are elongated on wall 55 in cross section about triangular driver 56 attached, each between them in cross-section approximately funnel-shaped inlet areas for overflow channels 57 form. Such a configuration with such drivers 56 is out EP 0 439 826 B (corresponding to US Pat. No. 5,133,508).
  • the overflow channels 57 are located in the rotor support part 46, specifically in the Transition area of the rotor support part 46 to the cylindrical rotor 42 and - seen in the direction of flow direction arrows 52 - in front of the separator 34. They connect - based on the flow direction accordingly flow direction arrows 52 - the end of the interior grinding chamber 9 '' with the beginning of the outer grinding chamber 9 ', i.e. with a transition area 58 of the regrind supply space 53, which enters the outer grinding space 9 ' transforms.
  • the overflow channels 57 run in relation to the direction of rotation 59 of the agitator 21 - radially from the inside outward against the Direction of rotation 59, so that in the inner grinding chamber 9 "with a centrifugal acceleration provided auxiliary grinding body 41 through the overflow channels 57 thrown out and thus brought back into the regrind feed space 53 become.
  • the outer grinding chamber 9 ' is a real grinding chamber in which the auxiliary grinding bodies 41 are subjected to an intensive pulse exchange with the rotating stirring tools 51 and the stationary stirring tools 50 be, in which the regrind is subjected to an intensive shearing and dispersing process by impact effects.
  • the individual particles of the millbase fed in the form of a dispersion or suspension are intensively comminuted in the outer milling chamber 9 '.
  • the inner grinding chamber 9 is designed as a grinding gap, the cross-sectional area of which is considerably smaller than the cross-sectional area of the outer grinding chamber 9 '.
  • the outer grinding chamber 9' has an outer diameter Da and an inner diameter Di.
  • the inner grinding chamber which is designed as a grinding gap 9 "has an outer diameter da and an inner diameter di.
  • the flow rate of the material to be ground in the interior grinding space 9 ′′ is at least four or five times greater than in the outer grinding space.
  • Grinding chamber 9 'is correspondingly about d he is 4 or 5 times longer than the dwell time of the material to be ground in the inner grinding chamber 9 '' designed as a grinding gap.
  • the upper limit is a ⁇ 300 mm.
  • As the top Limit applies b ⁇ 15 mm. It applies that the gap width b at least in each case correspond to 4 times the diameter c of the auxiliary grinding bodies 41 should.
  • the upper limit for the diameter c of the auxiliary grinding body 41 is: c ⁇ 1.5 mm.
  • the deflection chamber 49 is oriented towards the inner grinding chamber provided continuously tapering acceleration section 60, which works like a nozzle.
  • the agitator mill described can be arranged vertically or horizontally become, as described - a vertical central-longitudinal axis 20 or have a corresponding horizontally arranged central longitudinal axis. Especially with a horizontal arrangement of the agitator mill the drivers 56 are not required. Otherwise, of course further constructive adjustment measures may be necessary.
  • the embodiment according to FIG. 3 differs from that according to FIG. 2 only by the configuration of the cylindrical peripheral wall 61 of the rotor support part 46's of the rotor 42 '. Between this peripheral wall 61 and the the associated inner wall 10 of the grinding container 3 is a swirl gap 62 formed into the frustoconical area of the regrind feed space 53 flows into.
  • the overflow channels 57 ' open into the vortex gap 62 a.
  • the gap width e of the swirl gap 62 radially to the central longitudinal axis 20 is very small. The following applies: 3 mm ⁇ e ⁇ 8 mm and particularly 4 mm ⁇ e ⁇ 5 mm.
  • the grinding auxiliary body 41 also applies to the ratio of the gap width e to the diameter c 3 c ⁇ e ⁇ 4 c.
  • the flow rate of the ground material is Vortex gap 62 in the direction of the outer grinding chamber 9 'is very high, so that a Escape of grinding aids 41 in the frustoconical area of the regrind feed space 53 is excluded.
  • those interrupted by the respective outlet 64 of the overflow channels 57 ' Wall sections 65 of the circumferential wall 61 with the as it were an overflow channels 57 'forming a recess will alternate an extremely intensive swirling of the auxiliary grinding body 41 achieves what for an extremely intensive predispersion of the ground material in the Vortex gap 62 leads.
  • This configuration therefore makes one extremely Effective series connection of predispersion, impact grinding and polishing grinding of the ground material.

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  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Grinding (AREA)

Description

Die Erfindung betrifft eine Rührwerksmühle nach dem Oberbegriff des Anspruches 1.The invention relates to an agitator mill according to the preamble of Claim 1.

Eine derartige Rührwerksmühle ist aus der DE 40 10 928 A1 bekannt. Bei dieser bekannten Rührwerksmühle haben der Außen-Mahlraum und der Innen-Mahlraum - soweit der Zeichnung dieser Veröffentlichung entnehmbar ist - gleiche radiale Erstreckung. Das Mahlgut fließt durch einen Mahlgut-Zuführraum, durch einen Übergangsbereich an den Überströmkanälen vorbei in den Außen-Mahlraum und durch den Umlenkraum in den Innen-Mahlraum. Die Mahlhilfskörper laufen im Kreis durch den Außen-Mahlraum, den Umlenkraum, den Innen-Mahlraum und die ÜberströmKanäle zurück in den Außen-Mahlraum bzw. in den in diesen einmündenden Übergangsbereich. Das Mahlgut fließt vom Ende des Innen-Mahlraumes zur Trennvorrichtung. Die Trennvorrichtung dient nicht in nennenswertem Maße zum Trennen von Mahlhilfskörpern einerseits und Mahlgut andererseits; trotzdem wird - auch in dieser Anmeldung - der Begriff Trenneinrichtung verwendet, da er sich in der Fachsprache allgemein durchgesetzt hat. Wie sich aus der vorstehenden Erläuterung ergibt, erfolgt die Trennung der Mahlhilfskörper vom Mahlgut bereits vor der Trenneinrichtung. Such an agitator mill is known from DE 40 10 928 A1. at this known agitator mill have the outside grinding chamber and the Indoor grinding room - as far as can be seen from the drawing of this publication is - same radial extension. The regrind flows through a regrind feed chamber, through a transition area on the overflow channels over into the outside grinding room and through the deflection room into the inside grinding room. The grinding aids run in a circle through the outside grinding chamber, the deflection chamber, the inside grinding chamber and the overflow channels back into the outside grinding room or into the one opening into it Transition area. The regrind flows from the end of the interior grinding chamber to the separator. The separator is not used in noteworthy measure for separating grinding aids on the one hand and Regrind on the other hand; nevertheless - also in this application - the term Separating device used because it is general in the technical language has prevailed. As follows from the above explanation the separation of the auxiliary grinding bodies from the regrind before the separating device.

Aus der DE 28 11 899 C ist eine Rührwerksmühle bekannt, deren Außenmahlraum einerseits und Innen-Mahlraum andererseits sich jeweils kegelstumpfförmig verjüngen, d.h. der Querschnitt des Mahlraumes ist auf jeder Seite der Mittel-Längs-Achse von Rotor und Stator kegelförmig. Das Mahlgut durchströmt die Rührwerksmühle von innen nach außen, d.h. es strömt am engen Durchmesser des Innen-Mahlraumes in diesen ein, durchströmt dann den sich radial erweiternden Innen-Mahlraum, den Umlenkraum und dann den sich radial erweiternden Außen-Mahlraum. Von dort strömt es radial nach innen durch einen vom Rührwerk einseitig begrenzten Raum zu einer Trenneinrichtung, durch die das Mahlgut ausgetragen wird. Dieser Trenneinrichtung ist der Eintritt eines Überströmkanals nachgeordnet, dessen Eintritt radial innerhalb der Trenneinrichtung angeordnet, dieser also nachgeordnet ist. Von dort strömen die Mahlhilfskörper durch Überströmkanäle im Rotor in den Anfangsbereich des Innen-Mahlraumes. Die Begrenzungswände des Mahlraumes sind glattwandig. Die Mahlspalt-Weite, d.h. die radiale Weite des Mahlraumes ist konstant; der Abstand zur Drehachse nimmt aber stetig zu. Hieraus ergibt sich, daß der Schergradient über dem Weg des Mahlgutes von innen nach außen zunimmt. Dies führt dazu, daß er entweder im Innen-Mahlraum zu niedrig oder im Außen-Mahlraum zu hoch ist, was zu einer ungleichmäßigen Beanspruchung des Mahlgutes führt. (Der Schergradient ist definiert als Quotient aus Geschwindigkeit der rotierenden Oberfläche und Spaltweite.)From DE 28 11 899 C an agitator mill is known, the outside grinding area on the one hand and the inside grinding chamber on the other hand each frustoconical rejuvenate, i.e. the cross section of the grinding room is on everyone Cone-shaped side of the central longitudinal axis of the rotor and stator. The Grist flows through the agitator mill from the inside out, i.e. it flows into the narrow diameter of the inner grinding chamber, flows through it then the radially expanding inner grinding chamber, the deflection chamber and then the radially widening outside grinding room. From there it flows radially inwards through a one-sided boundary of the agitator Space to a separator through which the regrind is discharged becomes. The entry of an overflow channel is arranged downstream of this separating device, the inlet of which is arranged radially inside the separating device, So this is subordinate. From there, the grinding aids flow through Overflow channels in the rotor in the initial area of the inner grinding chamber. The boundary walls of the grinding chamber are smooth-walled. The width of the grinding gap, i.e. the radial width of the grinding chamber is constant; the distance to However, the axis of rotation increases steadily. It follows from this that the shear gradient increases over the path of the regrind from the inside to the outside. this leads to to the fact that it is either too low in the inside grinding room or in the outside grinding room is too high, which leads to an uneven loading of the Grist leads. (The shear gradient is defined as the quotient of speed the rotating surface and gap width.)

In der nicht vorveröffentlichten DE 196 32 757.1 A1 (entsprechend US-Serial No. 08/906 043) ist eine durch offenkundige Vorbenutzung bekannt gewordene Rührwerksmühle dargestellt und beschrieben, deren Außen-Mahlraum und deren Innen-Mahlraum als Mahlspalt ausgebildet sind. Diese Mahlspalte sind glattwandig, frei von Rührwerkzeugen ausgebildet. Durch die glattwandige Ausgestaltung der zylindrischen Begrenzungswände von Außen-Mahlraum und Innen-Mahlraum wird eine Strömung erzeugt, in der die Mahlhilfskörper in Schichten relativ zueinander bewegt werden. Der Schergradient und damit die örtliche Beanspruchungsintensität ist im Außen-Mahlraum einerseits und im Innen-Mahlraum andererseits über der jeweiligen Mahlraumhöhe konstant.In the unpublished DE 196 32 757.1 A1 (corresponding to US serial No. 08/906 043) is known by an obvious prior use agitator mill shown and described, its outside grinding room and the inner grinding chamber are designed as a grinding gap. This Grinding gaps are smooth-walled and free of stirring tools. Due to the smooth-walled design of the cylindrical boundary walls a flow is generated from the outside grinding chamber and inside grinding chamber, in which the grinding aid body moves in layers relative to each other become. The shear gradient and thus the local stress intensity is in the outside grinding room on the one hand and in the inside grinding room on the other constant above the respective grinding chamber height.

Aus der DE 38 44 380 C1 ist eine Rührwerksmühle bekannt, die eine Rührwelle mit einem Käfig aufweist, der Teil der Rührwelle ist. Der Käfig ist an einem Tragteil angebracht, zwischen dem und dem Deckel des Mahlbehälters und einem benachbarten Bereich der Innenwand des Mahlbehälters ein Reibspalt ausgebildet ist. In diesem Reibspalt wird das Mahlgut durch Reibung der diese Reibspalte begrenzenden Wände des Mahlbehälters und der Rührwelle aktiviert.From DE 38 44 380 C1 an agitator mill is known, the one Has agitator shaft with a cage which is part of the agitator shaft. The cage is attached to a support part, between and the lid of the grinding container and an adjacent area of the inner wall of the grinding container a friction gap is formed. The regrind is in this friction gap by friction of the walls of the grinding container delimiting these friction gaps and the agitator shaft activated.

Der Erfindung liegt die Aufgabe zugrunde, eine Rührwerksmühle der gattungsgemäßen Art so auszugestalten, daß einerseits ein intensives Zerkleinern und Dispergieren der Mahlgut-Partikel beibehalten wird; daß die zerkleinerten Mahlgut-Partikel aber eine fein geglättete Oberfläche erhalten.The invention is based, an agitator mill of the generic type Kind in such a way that on the one hand intensive crushing and dispersing the regrind particles is maintained; that the crushed Grist particles but get a finely smoothed surface.

Diese Aufgabe wird erfindungsgemäß durch die Merkmale im Kennzeichnungsteil des Anspruches 1 gelöst. Im Außen-Mahlraum erfolgt - wie bei der gattungsbildenden Rührwerksmühle - ein intensives Zerkleinern und Dispergieren der Mahlgut-Partikel überwiegend durch Pralleffekte, also eine Prallmahlung. Die Verweilzeit des Mahlgutes im Außen-Mahlraum ist - im Vergleich zur Verweilzeit im Innen-Mahlraum - sehr hoch. Im Innen-Mahlraum erfolgt dagegen ein Glätten, d. h. eine Art Polieren der Oberflächen der im Außen-Mahlraum durch Zerkleinern neu geschaffenen Mahlgut-Partikel, also eine Poliermahlung. Beim Übertritt vom Außen-Mahlraum in den Innen-Mahlraum erfolgt eine ausreichende Beschleunigung des Mahlgutes. Im Anspruch 2 ist angegeben, wie diese Beschleunigung optimiert werden kann.This object is achieved by the features in the labeling part of claim 1 solved. In the outside grinding room - as with the generic agitator mill - intensive crushing and Dispersion of the regrind particles mainly through impact effects, ie an impact grinding. The dwell time of the material to be ground is in the outside grinding room - very high compared to the time spent in the interior grinding room. In the indoor grinding room on the other hand, smoothing takes place, i.e. H. a kind of surface polishing the regrind particles newly created in the outside grinding chamber by crushing, a polishing grinding. When passing from the outside grinding room There is sufficient acceleration in the interior grinding chamber the regrind. Claim 2 specifies how this acceleration can be optimized.

Anspruch 4 gibt bevorzugte untere Bereiche für das Verhältnis der Querschnittsflächen von Außen-Mahlraum und Innen-Mahlraum an. Die Ansprüche 4 und 5 geben bevorzugte obere Grenzwerte für das Verhältnis der Querschnittsflächen von Außen-Mahlraum und Innen-Mahlraum an.Claim 4 gives preferred lower ranges for the ratio of the cross-sectional areas from outside grinding room and inside grinding room. The requirements 4 and 5 give preferred upper limits for the ratio of Cross-sectional areas of the outside grinding area and inside grinding area.

In den Ansprüchen 6 bis 9 sind bevorzugte Grenzwerte für die radiale Weite von Außen-Mahlraum und Innen-Mahlraum angegeben.In claims 6 to 9 are preferred limit values for the radial width indicated by outside grinding room and inside grinding room.

Anspruch 11 gibt Maßnahmen wieder, durch die die Prallmahlung im Außen-Mahlraum optimiert werden kann.Claim 11 reflects measures by which the impact grinding in the outer grinding chamber can be optimized.

Die Ansprüche 11 bis 15 geben eine weitere Ausgestaltung an, bei der das Mahlgut vor dem Eintritt in den Außen-Mahlraum einer Vordispergierung in einem engen ringzylindrischen Wirbelspalt unterworfen wird. Dieser Effekt wird insbesondere dadurch herbeigeführt, daß der ringzylindrische Wirbelspalt eine sehr geringe Erstreckung radial zur Mittel-Längs-Achse aufweist und daß die Überströmkanäle in diesen Wirbelspalt eintreten, so daß im Wechsel den Wirbelspalt begrenzende Wandabschnitte des Rotors und die Auslaßöffnungen der Überströmkanäle an der Innenwand des Mahlbehälters vorbeilaufen. The claims 11 to 15 indicate a further embodiment in which the Grist before entering the outside grinding area of a predispersion is subjected to a narrow ring-cylindrical vortex. This Effect is brought about in particular by the fact that the ring-cylindrical Vortex gap a very small extension radially to the central longitudinal axis and that the overflow channels enter this vortex gap, so that alternating wall sections of the rotor delimiting the vortex gap and the outlet openings of the overflow channels on the inner wall of the Run past the grinding container.

Weitere Merkmale, Vorteile und Einzelheiten der Erfindung ergeben sich aus der nachfolgenden Beschreibung eines Ausführungsbeispiels der Erfindung anhand der Zeichnung. Es zeigt:

Fig. 1
eine schematische Darstellung einer Rührwerksmühle in einer Seitenansicht,
Fig. 2
einen Längsschnitt durch den Mahlbehälter der Rührwerksmühle und
Fig. 3
einen Längsschnitt durch den Mahlbehälter einer abgewandelten Ausführungsform der Rührwerksmühle
Further features, advantages and details of the invention result from the following description of an embodiment of the invention with reference to the drawing. It shows:
Fig. 1
1 shows a schematic illustration of an agitator mill in a side view,
Fig. 2
a longitudinal section through the grinding container of the agitator mill and
Fig. 3
a longitudinal section through the grinding container of a modified embodiment of the agitator mill

Die in Fig. 1 dargestellte Rührwerksmühle weist in üblicher Weise einen Ständer 1 auf, an dem ein zylindrischer Mahlbehälter 3 anbringbar ist. In dem Ständer 1 ist ein elektrischer Antriebsmotor 4 untergebracht, der mit einer Keilriemenscheibe 5 versehen ist, von der über Keilriemen 6 eine mit einer Antriebs-Welle 7 drehfest verbundene Keilriemenscheibe 8 drehend antreibbar ist.The agitator mill shown in Fig. 1 has in the usual way Stand 1 on which a cylindrical grinding container 3 can be attached. In the stand 1 is an electric drive motor 4, which with a V-belt pulley 5 is provided, one of which via V-belt 6 a drive shaft 7 rotatably connected V-belt pulley 8 rotating is drivable.

Wie insbesondere aus Fig. 2 hervorgeht, besteht der Mahlbehälter 3 aus einer zylindrischen, einen Mahlraum 9 umgebenden Innenwand 10, die von einem im wesentlichen zylindrischen Außenrnantel 11 umgeben ist. Der Innenzylinder 10 und der Außenmantel 11 begrenzen zwischen sich einen Kühlraum 12. Der untere Abschluß des Mahlraumes 9 ist durch eine kreisringförmige Bodenplatte 13 gebildet, die am Mahlbehälter mittels Schrauben 14 befestigt ist.As can be seen in particular from FIG. 2, the grinding container 3 consists of a cylindrical, a grinding chamber 9 surrounding inner wall 10, the a substantially cylindrical outer jacket 11 is surrounded. The Inner cylinder 10 and the outer jacket 11 delimit one between them Cooling chamber 12. The lower end of the grinding chamber 9 is by an annular Base plate 13 formed on the grinding container by means of screws 14 is attached.

Der Mahlbehälter 3 weist einen oberen Ringflansch 15 auf, mittels dessen er an der Unterseite eines Traggehäuses 16 über Schrauben 17 befestigt ist, das am Ständer 1 der Rührwerksmühle befestigt ist. Der Mahlraum 9 ist mittels eines Deckels 18 verschlossen. Das Traggehäuse 16 weist ein mittleres Lager- und Dichtungsgehäuse 19 auf, das koaxial zur Mittel-Längs-Achse 20 des Mahlbehälters 3 angeordnet ist. Dieses Dichtungsgehäuse 19 wird von der ebenfalls koaxial zur Achse 20 verlaufenden Antriebs-Welle 7 durchsetzt, an der ein Rührwerk 21 angebracht ist. In den dem Mahlraum 9 benachbarten Bereich des Dichtungsgehäuses 19 mündet eine Mahlgut-Zuführleitung 22 ein.The grinding container 3 has an upper ring flange 15, by means of which it is fastened to the underside of a support housing 16 by means of screws 17, which is attached to stand 1 of the agitator mill. The grinding chamber 9 is closed by a lid 18. The support housing 16 has a medium Bearing and seal housing 19, which is coaxial to the central longitudinal axis 20 of the grinding container 3 is arranged. This seal housing 19th is driven by the drive shaft 7, which also runs coaxially to the axis 20 enforced, on which an agitator 21 is attached. In the grinding room 9 A regrind feed line opens into the adjacent area of the seal housing 19 22 a.

An der kreisringförmigen Bodenplatte 13 ist ein in den Mahlraum 9 hineinragender, etwa topfförmig ausgebildeter, zylindrischer Innenstator 24 befestigt, der aus einem den Mahlraum 9 begrenzenden, zur Achse 20 koaxialen, zylindrischen Außenmantel 26 und einem ebenfalls zur Achse 20 koaxialen, zylindrischen Innenmantel 27 besteht. Außenmantel 26 und Innenmantel 27 begrenzen zwischen sich einen Kühlraum 28. Der Kühlraum 28 ist mit einem Kühlraum 29 in der Bodenplatte 13 verbunden, dem Kühlwasser über einen Kühlwasser-Zuführstutzen 30 zugeführt wird, das über einen Auslaßstutzen 30a abgeführt wird. Dem Kühlraum 12 des Mahlbehälters 3 wird Kühlwasser über einen Kühlwasser-Zuführstutzen 31 zugeführt, das über einen Kühlwasser-Abführstutzen 32 abgeführt wird.On the circular base plate 13 is a protruding into the grinding chamber 9, approximately cup-shaped, cylindrical inner stator 24 fastened, that from a grinding chamber 9 delimiting, coaxial to axis 20, cylindrical outer jacket 26 and a coaxial to the axis 20, cylindrical inner shell 27 there. Outer jacket 26 and inner jacket 27 delimit a cooling space 28 between them. The cooling space 28 is connected to a cooling space 29 in the base plate 13, the cooling water is supplied via a cooling water supply nozzle 30 which via an outlet pipe 30a is discharged. The cooling chamber 12 of the grinding container 3, cooling water is supplied via a cooling water supply nozzle 31, which is discharged via a cooling water discharge nozzle 32.

An der oberen oberhalb des Mahlraums 9 befindlichen Stirnseite 33 des Innenstators 24 ist eine Mahlgut-Mahlhilfskörper-Trenneinrichtung 34 angeordnet, die mit einer Mahlgut-Ablaufleitung 35 verbunden ist. Zwischen der Trenneinrichtung 34 und der Ablaufleitung 35 ist ein Mahlgut-Sammeltrichter 36 vorgesehen. Die Ablaufleitung 35 ist im Bereich der Bodenplatte 13 mit einem Haltebügel 38 versehen, der mittels Schrauben 39 mit der Bodenplatte 13 bzw. dem fest mit dieser verbundenen Innenstator 24 lösbar verbunden ist. Die Trenneinrichtung 34 ist gegenüber der ringförmigen Stirnseite 33 des Innenstators 24 mittels einer Dichtung 40 abgedichtet und kann nach Lösen der Schrauben 39 zusammen mit der Ablaufleitung 35 und dem Sammeltrichter 36 aus dem Innenstator 24 nach unten herausgezogen werden. Die Trenneinrichtung 34 kann also aus dem Mahlraum 9 herausgezogen werden, ohne daß die in diesem befindlichen Mahlhilfskörper 41 aus dem Mahlraum entfernt werden müssen, da die Füllung des Mahlraums 9 mit diesen Mahlhilfskörpern 41 bei nicht angetriebenem Rührwerk 21 nicht bis zur Stirnseite 33 reicht.At the upper end 33 of the grinding chamber 9 located above Inner stator 24 is a grinding aid-grinding body separating device 34 is arranged, which is connected to a regrind drain line 35. Between the separator 34 and the drain line 35 is a regrind collecting funnel 36 provided. The drain line 35 is in the range of Base plate 13 provided with a bracket 38, which by means of screws 39 with the base plate 13 or the inner stator fixedly connected to it 24 is releasably connected. The separator 34 is opposite to the annular end face 33 of the inner stator 24 by means of a seal 40 sealed and after loosening the screws 39 together with the Drain line 35 and the collecting funnel 36 from the inner stator 24 after pulled out below. The separator 34 can thus from the Grinding chamber 9 are pulled out without the located in it Grinding auxiliary body 41 must be removed from the grinding chamber, since the Filling the grinding chamber 9 with these auxiliary grinding bodies 41 when not driven Agitator 21 does not reach the front side 33.

Das Rührwerk 21 ist in seinem Grundaufbau topfförmig, d.h. es weist einen im wesentlichen ringzylindrischen Rotor 42 auf, der durch eine zylindrische Außenwand 43 und eine koaxial hierzu und koaxial zur Achse 20 angeordnete zylindrische Innenwand 44 gebildet ist. Zwischen der Außenwand 43 und der Innenwand 44 des Rotors 42 ist ein Kühlraum 45 ausgebildet. Der Rotor 42 ist an einem Rotor-Tragteil 46 angebracht, das mit der Welle 7 verbunden ist. Die Zu- und Abfuhr von Kühlwasser zum Kühlraum 45 erfolgt über in der Welle 7 und im Rotor-Tragteil 46 ausgebildete Kühlwasserkanäle 47, 48. Durch den glattwandigen Innenzylinder 10 des Mahlbehälters 3 und die glattwandige zylindrische Außenwand 43 des Rotors 42 einerseits und durch die zylindrische glattwandige Innenwand 44 des Rotors 42 und den zylindrischen glattwandigen Außenmantel 26 des Innenstators 24 andererseits wird der Mahlraum 9 in einen zylinderringförmigen Außen-Mahlraum 9' einerseits und einen zylinderringförmigen Innen-Mahlraum 9" andererseits unterteilt, die durch einen Umlenkraum 49 im Bereich der Bodenplatte 13 miteinander verbunden sind. The basic structure of the agitator 21 is pot-shaped, i.e. it shows one essentially ring-cylindrical rotor 42 by a cylindrical Outer wall 43 and one arranged coaxially thereto and coaxially to the axis 20 cylindrical inner wall 44 is formed. Between the outer wall 43 and the inner wall 44 of the rotor 42, a cooling space 45 is formed. The rotor 42 is attached to a rotor support member 46 which is connected to the Wave 7 is connected. The supply and discharge of cooling water to the cold room 45 is carried out by trained in the shaft 7 and in the rotor support member 46 Cooling water channels 47, 48. Through the smooth-walled inner cylinder 10 of the Grinding container 3 and the smooth-walled cylindrical outer wall 43 of the rotor 42 on the one hand and through the cylindrical smooth-walled inner wall 44 of the rotor 42 and the cylindrical smooth-walled outer jacket 26 of the Inner stator 24, on the other hand, the grinding chamber 9 is in a cylindrical ring External grinding chamber 9 'on the one hand and a cylindrical ring Internal grinding chamber 9 ", on the other hand, divided by a deflection chamber 49 are connected to one another in the area of the base plate 13.

An den durch den Innenzylinder 10 und die Außenwand 43 gebildeten Mahlraum-Begrenzungswänden sind in den Außen-Mahlraum 9' vorstehende ortsfeste Rührwerkzeuge 50 bzw. mit dem Rotor 42 drehbare Rührwerkzeuge 51 angebracht. An den durch die Innenwand 44 und den Außenmantel 26 gebildeten Mahlraum-Begrenzungwänden sind dagegen keine in den Innen-Mahlraum 9" vorstehenden Rührwerkzeuge angebracht. Das Mahlgut durchströmt den Mahlraum 9 entsprechend den Strömungsrichtungspfeilen 52 von der Mahlgut-Zuführleitung 22 kommend durch einen Mahlgut-Zuführraum 53 zwischen dem Rotor-Tragteil 46 einerseits und dem Deckel 18 und dem benachbarten Bereich der Innenwand 10 andererseits, durch den Außen-Mahlraum 9' nach unten, durch den Umlenkraum 49 radial nach innen und von dort durch den Innen-Mahlraum 9'' nach oben bis zur Trenneinrichtung 34. Auf dem Wege durch den Außen-Mahlraum 9', den Umlenkraum 49 und den Innen-Mahlraum 9" wird das Mahlgut bei drehend angetriebenem Rührwerk 21 im Zusammenwirken mit den Mahlhilfskörpern 41 bearbeitet. Das Mahlgut verläßt den Mahlraum 9 durch die Trenneinrichtung 34, von wo es durch die Mahlgut-Ablaufleitung 35 abfließt.On the formed by the inner cylinder 10 and the outer wall 43 Grinding chamber boundary walls protrude into the outer grinding chamber 9 ' stationary stirring tools 50 or stirring tools rotatable with the rotor 42 51 attached. On the through the inner wall 44 and the outer jacket In contrast, the 26 grinding chamber boundary walls formed are none attached in the inner grinding chamber 9 "protruding stirring tools. The ground material flows through the grinding chamber 9 in accordance with the flow direction arrows 52 coming from the regrind feed line 22 a regrind feed space 53 between the rotor support part 46 on the one hand and the cover 18 and the adjacent area of the inner wall 10 on the other hand, down through the outside grinding chamber 9 ', through the deflection chamber 49 radially inwards and from there through the inner grinding chamber 9 '' up to the separator 34. On the way through the outside grinding room 9 ', the deflection chamber 49 and the inner grinding chamber 9 " Regrind with rotating driven agitator 21 in cooperation with the grinding auxiliary bodies 41 processed. The ground material leaves the grinding chamber 9 through the separator 34, from where it goes through the regrind drain line 35 flows off.

Die zur Abtrennung von Mahlhilfskörpern 41 dienende Trenneinrichtung 34 ist in einer zylindrischen Ausnehmung 54 des Rotor-Tragteils 46 angeordnet. Zwischen der zylindrischen Wand 55 der Ausnehmung 54 und der Trenneinrichtung 34 sind an der Wand 55 langgestreckte im Querschnitt etwa dreieckförmige Mitnehmer 56 angebracht, die jeweils zwischen sich im Querschnitt etwa trichterförmige Einlaufbereiche für Überströmkanäle 57 bilden. Eine derartige Ausgestaltung mit solchen Mitnehmern 56 ist aus der EP 0 439 826 B (entspr. US-PS 5 133 508) bekannt. The separating device used to separate auxiliary grinding bodies 41 34 is arranged in a cylindrical recess 54 of the rotor support part 46. Between the cylindrical wall 55 of the recess 54 and the Separating device 34 are elongated on wall 55 in cross section about triangular driver 56 attached, each between them in cross-section approximately funnel-shaped inlet areas for overflow channels 57 form. Such a configuration with such drivers 56 is out EP 0 439 826 B (corresponding to US Pat. No. 5,133,508).

Die Überströmkanäle 57 befinden sich im Rotor-Tragteil 46, und zwar im Übergangsbereich des Rotor-Tragteils 46 zum zylindrischen Rotor 42 und - in Richtung der Strömungsrichtungspfeile 52 gesehen - vor der Trenneinrichtung 34. Sie verbinden - bezogen auf die Strömungsrichtung entsprechend den Strömungsrichtungspfeilen 52 - das Ende des Innen-Mahlraums 9'' mit dem Beginn des Außen-Mahlraums 9', also mit einem Übergangsbereich 58 des Mahlgut-Zuführraums 53, der in den Außen-Mahlraum 9' übergeht. Die Überströmkanäle 57 verlaufen - bezogen auf die Drehrichtung 59 des Rührwerks 21 - radial von innen nach außen entgegen der Drehrichtung 59, so daß die im Innen-Mahlraum 9" mit einer Zentrifugalbeschleunigung versehenen Mahlhilfskörper 41 durch die Überströmkanäle 57 abgeschleudert und damit wieder in den Mahlgut-Zuführraum 53 zurückgebracht werden.The overflow channels 57 are located in the rotor support part 46, specifically in the Transition area of the rotor support part 46 to the cylindrical rotor 42 and - seen in the direction of flow direction arrows 52 - in front of the separator 34. They connect - based on the flow direction accordingly flow direction arrows 52 - the end of the interior grinding chamber 9 '' with the beginning of the outer grinding chamber 9 ', i.e. with a transition area 58 of the regrind supply space 53, which enters the outer grinding space 9 ' transforms. The overflow channels 57 run in relation to the direction of rotation 59 of the agitator 21 - radially from the inside outward against the Direction of rotation 59, so that in the inner grinding chamber 9 "with a centrifugal acceleration provided auxiliary grinding body 41 through the overflow channels 57 thrown out and thus brought back into the regrind feed space 53 become.

Der Außen-Mahlraum 9' ist mit den am Rotor 42 angebrachten Rührwerkzeugen 51 und den am Mahlbehälter 3 angebrachten ortsfesten Gegen-Rührwerkzeugen 50 ein echter Mahlraum, in dem die Mahlhilfskörper 41 einem intensiven Impulsaustausch mit den sich drehenden Rührwerkzeugen 51 und den ortsfesten Rührwerkzeugen 50 ausgesetzt werden, in dem also das Mahlgut einem intensiven Scher- und Dispergier-Prozeß durch Pralleffekte unterworfen wird. Im Außen-Mahlraum 9' werden die einzelnen Partikel des in Form einer Dispersion oder Suspension zugeführten Mahlgutes intensiv zerkleinert. Dagegen ist der Innen-Mahlraum 9" als Mahlspalt ausgeführt, dessen Querschnittsfläche erheblich kleiner ist als die Querschnittsfläche des Außen-Mahlraums 9'. Der Außen-Mahlraum 9' weist einen Außendurchmesser Da und einen Innendurchmesser Di auf. Der als Mahlspalt ausgebildete Innen-Mahlraum 9'' weist einen Außendurchmesser da und einen Innendurchmesser di auf. Für das Verhältnis der Querschnittsflächen des Außen-Mahlraums 9' und des Innen-Mahlraums 9'' gilt 4 ≤ (Da2 - Di2) / (da2 - di2) und bevorzugt 5 ≤ (Da2 - Di2) / (da2 - di2). Mit anderen Worten heißt dies, daß die Querschnittsfläche des Außen-Mahlraums 9' um das 4- bzw. 5-fache größer ist als die Querschnittsfläche des Innen-Mahlraums 9''. Diese Ausgestaltung hat zur Konsequenz, daß die Strömungsgeschwindigkeit des Mahlgutes im Innen-Mahlraum 9'' mindestens um das 4- bzw. 5-fache größer ist als im Außen-Mahlraum. Die Verweilzeit des Mahlgutes im Außen-Mahlraum 9' ist entsprechend etwa um das 4- bzw. 5-fache größer als die Verweilzeit des Mahlgutes im als Mahlspalt ausgebildeten Innen-Mahlraum 9''.The outer grinding chamber 9 ', with the stirring tools 51 attached to the rotor 42 and the stationary counter-stirring tools 50 attached to the grinding container 3, is a real grinding chamber in which the auxiliary grinding bodies 41 are subjected to an intensive pulse exchange with the rotating stirring tools 51 and the stationary stirring tools 50 be, in which the regrind is subjected to an intensive shearing and dispersing process by impact effects. The individual particles of the millbase fed in the form of a dispersion or suspension are intensively comminuted in the outer milling chamber 9 '. In contrast, the inner grinding chamber 9 "is designed as a grinding gap, the cross-sectional area of which is considerably smaller than the cross-sectional area of the outer grinding chamber 9 '. The outer grinding chamber 9' has an outer diameter Da and an inner diameter Di. The inner grinding chamber, which is designed as a grinding gap 9 "has an outer diameter da and an inner diameter di. For the ratio of the cross-sectional areas of the outer grinding chamber 9 'and the inner grinding chamber 9", 4 ≤ (Da 2 - Di 2 ) / (da 2 - di 2 ) and preferably 5 ≤ (Da 2 - Di 2 ) / (da 2 - Di 2 ) In other words, this means that the cross-sectional area of the outer grinding chamber 9 'is 4 or 5 times larger than the cross-sectional area of the The result of this configuration is that the flow rate of the material to be ground in the interior grinding space 9 ″ is at least four or five times greater than in the outer grinding space. Grinding chamber 9 'is correspondingly about d he is 4 or 5 times longer than the dwell time of the material to be ground in the inner grinding chamber 9 '' designed as a grinding gap.

Als obere Grenzwerte für das Verhältnis der Querschnittsflächen des Außen-Mahlraums 9' und des Innen-Mahlraums 9" haben sich folgende Werte ergeben: (Da2 - Di2) / (da2 - di2) ≤ 30 und bevorzugt (Da2 - Di2) / (da2 - di2) ≤ 25The upper limit values for the ratio of the cross-sectional areas of the outer grinding chamber 9 'and the inner grinding chamber 9 "were as follows: (Da 2 - Di 2 ) / (da 2 - di 2 ) ≤ 30 and preferably (Da 2 - Di 2 ) / (da 2 - di 2 ) ≤ 25

Für die Weite a des Außen-Mahlraums 9' radial zur Achse 20 gilt 15 mm ≤ a. Als oberer Grenzwert gilt a ≤ 300 mm. Für die Spaltweite b des Innen-Mahlraums ebenfalls radial zur Achse 20 gilt 3 mm ≤ b. Als oberer Grenzwert gilt b ≤ 15 mm. Hierbei gilt, daß die Spaltweite b jeweils mindestens dem 4-fachen des Durchmessers c der Mahlhilfskörper 41 entsprechen sollte. Für den Durchmesser c der Mahlhilfskörpers 41 gilt als Obergrenzwert: c ≤ 1,5 mm.The same applies to the width a of the outer grinding chamber 9 ′ radially to the axis 20 15 mm ≤ a. The upper limit is a ≤ 300 mm. For the gap width b des Internal grinding chamber, also radial to axis 20, applies 3 mm ≤ b. As the top Limit applies b ≤ 15 mm. It applies that the gap width b at least in each case correspond to 4 times the diameter c of the auxiliary grinding bodies 41 should. The upper limit for the diameter c of the auxiliary grinding body 41 is: c ≤ 1.5 mm.

Damit die außerordentliche Beschleunigung des Mahlgutes beim Übertritt vom Außen-Mahlraum 9' zu dem als Mahlspalt ausgebildeten Innen-Mahlraum 9" möglich ist, ist der Umlenkraum 49 mit einem sich zum Innen-Mahlraum stetig verjüngenden Beschleunigungsabschnitt 60 versehen, der also nach Art einer Düse wirkt.So that the extraordinary acceleration of the regrind when crossing from the outside grinding chamber 9 'to the inside grinding chamber designed as a grinding gap 9 "is possible, the deflection chamber 49 is oriented towards the inner grinding chamber provided continuously tapering acceleration section 60, which works like a nozzle.

Während im Außen-Mahlraum 9' in hohem Maße ein turbulenter Mahlprozeß stattfindet, wird aufgrund der glattwandigen Ausgestaltung der zylindrischen Begrenzungswände des Innen-Mahlraums 9'' dort eine Strömung erzeugt, in der die Mahlhilfskörper 41 in Schichten relativ zueinander bewegt werden. Der Schergradient und damit die örtliche Beanspruchungsintensität ist im Innen-Mahlraum 9" über dessen Höhe konstant. Aufgrund der geringen Verweildauer des Mahlgutes im Innen-Mahlraum 9" und der schichtenförmigen Relativbewegung der Mahlhilfskörper 41 findet nicht mehr ein hochintensives Dispergieren und Zerkleinern statt, sondern lediglich eine Beanspruchung eventuell durchgeschlüpfter Grob-Partikel bzw. insgesamt eine Abrundung und Oberflächenbehandlung der im Außen-Mahlraum 9' neu geschaffenen Partikeloberflächen statt. Es findet also eine Art Polieren der einzelnen Mahlgut-Partikel statt.While in the outer grinding chamber 9 'a turbulent grinding process to a high degree takes place due to the smooth-walled design of the cylindrical Boundary walls of the inner grinding chamber 9 '' there a flow generated in which the grinding aid body 41 moves in layers relative to each other become. The shear gradient and thus the local stress intensity is constant in the interior grinding chamber 9 "above its height the short dwell time of the ground material in the inner grinding chamber 9 "and the layered relative movement of the auxiliary grinding body 41 does not take place more intensive dispersing and crushing instead of just a load of possibly hatched coarse particles or overall a rounding and surface treatment of the outside grinding room 9 'newly created particle surfaces instead. So it finds one Type polishing of the individual regrind particles instead.

Die beschriebene Rührwerksmühle kann vertikal oder horizontal angeordnet werden, also eine - wie beschrieben - vertikale Mittel-Längs-Achse 20 oder eine entsprechend horizontal angeordnete Mittel-Längs-Achse aufweisen. Insbesondere bei einer waagerechten Anordnung der Rührwerksmühle sind die Mitnehmer 56 nicht erforderlich. Im übrigen können selbstverständlich weitere konstruktive Anpassungsmaßnahmen notwendig sein.The agitator mill described can be arranged vertically or horizontally become, as described - a vertical central-longitudinal axis 20 or have a corresponding horizontally arranged central longitudinal axis. Especially with a horizontal arrangement of the agitator mill the drivers 56 are not required. Otherwise, of course further constructive adjustment measures may be necessary.

Die Ausführungsform nach Fig. 3 unterscheidet sich von der nach Fig. 2 nur durch die Ausgestaltung der zylindrischen Umfangswand 61 des Rotor-Tragteils 46'des Rotors 42'. Zwischen dieser Umfangswand 61 und der zugeordneten Innenwand 10 des Mahlbehälters 3 ist ein Wirbelspalt 62 ausgebildet, in den der kegelstumpfförmige Bereich des Mahlgut-Zuführraums 53 einmündet. Die Überströmkanäle 57' münden in den Wirbelspalt 62 ein. Am Übergang 58 des Rotor-Tragteils 46' sind die Überströmkanäle 57' mit einer Begrenzung 63 abgeschlossen, so daß die Mahlhilfskörper 41 im Übergangsbereich 58 nicht direkt in den Außen-Mahlraum 9', sondern nur in den Wirbelspalt 62 eintreten können.The embodiment according to FIG. 3 differs from that according to FIG. 2 only by the configuration of the cylindrical peripheral wall 61 of the rotor support part 46's of the rotor 42 '. Between this peripheral wall 61 and the the associated inner wall 10 of the grinding container 3 is a swirl gap 62 formed into the frustoconical area of the regrind feed space 53 flows into. The overflow channels 57 'open into the vortex gap 62 a. At the transition 58 of the rotor support part 46 'are the overflow channels 57 'completed with a boundary 63, so that the auxiliary grinding bodies 41 in the transition area 58 not directly into the outside grinding area 9 ', but can only enter the swirl gap 62.

Die Spaltweite e des Wirbelspalts 62 radial zur Mittel-Längs-Achse 20 ist sehr gering. Es gilt: 3 mm ≤ e ≤ 8 mm und insbesondere 4 mm ≤ e ≤ 5 mm. Weiterhin gilt bezüglich des Verhältnisses der Spaltweite e zum Durchmesser c der Mahlhilfskörper 41 3 c ≤ e ≤ 4 c. The gap width e of the swirl gap 62 radially to the central longitudinal axis 20 is very small. The following applies: 3 mm ≤ e ≤ 8 mm and particularly 4 mm ≤ e ≤ 5 mm. The grinding auxiliary body 41 also applies to the ratio of the gap width e to the diameter c 3 c ≤ e ≤ 4 c.

Da der Wirbelspalt 62 im Verhältnis zum Außen-Mahlraum 9' einen sehr engen Querschnitt hat, ist die Strömungsgeschwindigkeit des Mahlgutes im Wirbelspalt 62 in Richtung zum Außen-Mahlraum 9' sehr hoch, so daß ein Entweichen von Mahlhilfskörpern 41 in den kegelstumpfförmigen Bereich des Mahlgut-Zuführraums 53 ausgeschlossen wird. Insbesondere dadurch, daß die durch den jeweiligen Austritt 64 der Überströmkanäle 57' unterbrochenen Wandabschnitte 65 der Umfangswand 61 sich mit den gleichsam einen Rücksprung bildenden Überströmkanälen 57' abwechseln, wird eine extrem intensive Verwirbelung der Mahlhilfskörper 41 erreicht, was zu einer außerordentlich intensiven Vordispergierung des Mahlgutes im Wirbelspalt 62 führt. Durch diese Ausgestaltung wird also eine äußerst wirksame Reihenschaltung von Vordispergierung, Prallmahlung und Poliermahlung des Mahlgutes bewirkt.Since the vortex gap 62 is very much in relation to the outer grinding chamber 9 ' has a narrow cross-section, the flow rate of the ground material is Vortex gap 62 in the direction of the outer grinding chamber 9 'is very high, so that a Escape of grinding aids 41 in the frustoconical area of the regrind feed space 53 is excluded. In particular, that those interrupted by the respective outlet 64 of the overflow channels 57 ' Wall sections 65 of the circumferential wall 61 with the as it were an overflow channels 57 'forming a recess will alternate an extremely intensive swirling of the auxiliary grinding body 41 achieves what for an extremely intensive predispersion of the ground material in the Vortex gap 62 leads. This configuration therefore makes one extremely Effective series connection of predispersion, impact grinding and polishing grinding of the ground material.

Claims (15)

  1. An agitator mill for the treatment of free flowing grinding stock, comprising a grinding receptacle (3), an interior wall (10) of which defines a substantially closed grinding chamber (9); and an agitator unit (21), which is disposed rotatingly drivably in the grinding receptacle (3) and is cup-shaped relative to a common central longitudinal axis (20) and which comprises an annular cylindrical rotor (42, 42'), within which an interior stator (24) is disposed, tightly joined to the grinding receptacle (3); an annular cylindrical exterior grinding chamber (9') being formed between the interior wall (10) of the grinding receptacle (3) and an outer wall (43) of the rotor (42, 42'), and an annular cylindrical interior grinding chamber (9"), which is disposed coaxially within the exterior grinding chamber (9') and is connected with the latter by way of a deflection chamber (49), being formed between an inner wall (44) of the rotor (42, 42') and an outer jacket (26) of the interior stator (24); agitator elements (51) being mounted on the outer wall (43) of the rotor (42, 42'), which project into the exterior grinding chamber (9'); the exterior grinding chamber (9'), the deflection chamber (49) and the interior grinding chamber (9") constituting the grinding chamber (9) partially filled with auxiliary grinding bodies (41); a grinding stock supply chamber (53), which is disposed upstream of the exterior grinding chamber (9') and opens into the latter in the direction of flow (52) of the grinding stock, and a separating device (34), which is disposed downstream of the interior grinding chamber (9") in the direction of flow (52) of the grinding stock, being disposed approximately on the same side of the grinding receptacle (3) for the grinding stock to pass through; and bypasses (57, 57') being provided in the agitator unit (21) for the return of the auxiliary grinding bodies (41) from the vicinity of the separating device (34) into the vicinity of the grinding stock supply chamber (53), the bypasses (57, 57') connecting the end of the interior grinding chamber (9") with the beginning of the exterior grinding chamber (9') and wherein the inner wall (44) of the rotor (42, 42') and the outer wall (26) of the interior stator (24) are smooth, free from agitator elements,
    characterized in that the interior grinding chamber (9") has the shape of an annular gap, constituting a grinding gap and
    in that 4 ≤ (Da2- Di2) / (da2- di2) applies to the ratio that the cross-sectional surface of the exterior grinding chamber (9') bears to the cross-sectional surface of the interior grinding chamber (9"),
    Da being the outside diameter of the exterior grinding chamber (9'),
    Di being the inside diameter of the exterior grinding chamber (9'),
    da being the outside diameter of the interior grinding chamber (9"), and
    di being the inside diameter of the interior grinding chamber (9").
  2. An agitator mill according to claim 1, characterized in that - related to the direction of flow (52) of the grinding stock - a grinding stock accelerating section (60), which tapers continuously towards the interior grinding chamber (9"), is provided between the exterior grinding chamber (9') and the interior grinding chamber (9").
  3. An agitator mill according to claim 1, characterized in that 4 ≤ (Da2 - Di2) / (da2- di2) applies to the ratio that the cross-sectional surface of the exterior grinding chamber (9') bears to the cross-sectional surface of the interior grinding chamber (9"),
    Da being the outside diameter of the exterior grinding chamber (9'),
    Di being the inside diameter of the exterior grinding chamber (9'),
    da being the outside diameter of the interior grinding chamber (9"), and
    di being the inside diameter of the interior grinding chamber (9").
  4. An agitator mill according to one of claims 1 to 3, characterized in that (Da2 - Di2) / (da2- di2) ≤ 30 applies to the ratio that the cross-sectional surface of the exterior grinding chamber (9') bears to the cross-sectional surface of the interior grinding chamber (9"),
    Da being the outside diameter of the exterior grinding chamber (9'),
    Di being the inside diameter of the exterior grinding chamber (9'),
    da being the outside diameter of the interior grinding chamber (9"), and
    di being the inside diameter of the interior grinding chamber (9").
  5. An agitator mill according to claim 4, characterized in that
    (Da2 - Di2) / (da2- di2) ≤ 25 applies to the ratio that the cross-sectional surface of the exterior grinding chamber (9') bears to the cross-sectional surface of the interior grinding chamber (9''),
    Da being the outside diameter of the exterior grinding chamber (9'),
    Di being the inside diameter of the exterior grinding chamber (9'),
    da being the outside diameter of the interior grinding chamber (9"), and
    di being the inside diameter of the interior grinding chamber (9").
  6. An agitator mill according to one of claims 1 to 5, characterized in that 15 mm ≤ a applies to the width a of the exterior grinding chamber (9').
  7. An agitator mill according to one of claims 1 to 6, characterized in that a ≤ 300 mm applies to the width a of the exterior grinding chamber (9').
  8. An agitator mill according to one of claims 1 to 7, characterized in that 3 mm ≤ b applies to the gap width b of the interior grinding chamber (9'').
  9. An agitator mill according to one of claims 1 to 8, characterized in that b ≤ 15 mm applies to the gap width b of the interior grinding chamber (9'').
  10. An agitator mill according to one of claims 1 to 19, characterized in that stationary agitator elements (50) which project into the exterior grinding chamber (9') are mounted on the interior wall (10) of the grinding receptacle (3).
  11. An agitator mill according to one of claims 1 to 10, characterized in that an annular cylindrical eddy gap (62) is formed between the grinding stock supply chamber (53) and the exterior grinding chamber (9'), which is defined by the rotor (42') and the interior wall (10) of the grinding receptacle (3) and into which the bypasses (57') discharge by outlets (64).
  12. An agitator mill according to claim 11, characterized in that the rotor (42') defines the eddy gap (62) by a cylindrical circumferential wall (61) in which the outlets (64) of the bypasses (57') are located, the outlets (64) and wall sections (65) of the circumferential wall (61) alternating in the circumferential direction of the rotor (42').
  13. An agitator mill according to claim 11 or 12, characterized in that 3 mm ≤ e ≤ 8 mm applies to the gap width e of the eddy gap (62) between the circumferential wall (61) and the interior wall (10) of the grinding receptacle (3) radial to the central longitudinal axis (20).
  14. An agitator mill according to claim 13, characterized in that 4 mm ≤ e ≤ 5 mm applies to the gap width e.
  15. An agitator mill according to claim 13, characterized in that 3 c ≤ e ≤ 4 c applies to the gap width e in relation to the diameter c of the auxiliary grinding bodies (41).
EP98119177A 1997-10-28 1998-10-10 Agitator mill Expired - Lifetime EP0913200B1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE19747474 1997-10-28
DE19747474 1997-10-28
DE19834397A DE19834397B4 (en) 1997-10-28 1998-07-30 agitating mill
DE19834397 1998-07-30

Publications (2)

Publication Number Publication Date
EP0913200A1 EP0913200A1 (en) 1999-05-06
EP0913200B1 true EP0913200B1 (en) 2003-04-23

Family

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Application Number Title Priority Date Filing Date
EP98119177A Expired - Lifetime EP0913200B1 (en) 1997-10-28 1998-10-10 Agitator mill

Country Status (8)

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US (1) US5897068A (en)
EP (1) EP0913200B1 (en)
JP (1) JPH11197526A (en)
CN (1) CN1101732C (en)
BR (1) BR9804288A (en)
ES (1) ES2195251T3 (en)
RU (1) RU2155100C2 (en)
TW (1) TW455508B (en)

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DE29814714U1 (en) * 1998-08-17 1998-12-10 Draiswerke Gmbh, 68305 Mannheim Agitator mill
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US6582285B2 (en) 2000-04-26 2003-06-24 Elan Pharmainternational Ltd Apparatus for sanitary wet milling
JP4451965B2 (en) * 2000-05-18 2010-04-14 株式会社井上製作所 Pipeline bead mill
DE502005000670D1 (en) * 2005-05-19 2007-06-14 Buehler Ag agitating mill
KR100928076B1 (en) * 2008-12-19 2009-11-23 (주)제이분체 Stirred ball mill
CA2751309C (en) 2009-02-03 2017-11-28 Michael E. Spahr New graphite material
DE102010053484A1 (en) * 2010-12-04 2012-06-06 Netzsch-Feinmahltechnik Gmbh Dynamic element for the separator of a stirred ball mill
CN103418462B (en) * 2012-05-18 2015-07-08 昆山市密友粉体设备工程有限公司 Structure of nano grade bead mill and dispersing and mixing system of environment-friendly intelligent bead mill
CN103480463B (en) * 2012-06-14 2015-01-28 谢小飞 Centrifugation type separation mesh-free material and bead separation medium stirring mill
CN102814217A (en) * 2012-08-31 2012-12-12 常州市龙鑫化工机械有限公司 Efficient recycling bead mill
DE102013111762A1 (en) * 2013-07-08 2015-01-08 Netzsch-Feinmahltechnik Gmbh Agitator ball mill with axial channels
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Also Published As

Publication number Publication date
ES2195251T3 (en) 2003-12-01
EP0913200A1 (en) 1999-05-06
CN1215632A (en) 1999-05-05
TW455508B (en) 2001-09-21
US5897068A (en) 1999-04-27
RU2155100C2 (en) 2000-08-27
CN1101732C (en) 2003-02-19
BR9804288A (en) 1999-12-07
JPH11197526A (en) 1999-07-27

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