EP0504836B1 - Rührwerksmühle - Google Patents

Rührwerksmühle Download PDF

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Publication number
EP0504836B1
EP0504836B1 EP92104678A EP92104678A EP0504836B1 EP 0504836 B1 EP0504836 B1 EP 0504836B1 EP 92104678 A EP92104678 A EP 92104678A EP 92104678 A EP92104678 A EP 92104678A EP 0504836 B1 EP0504836 B1 EP 0504836B1
Authority
EP
European Patent Office
Prior art keywords
cavity
agitator
grinding
mill according
agitator mill
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
Application number
EP92104678A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0504836A1 (de
Inventor
Horst Pausch
Klaus Dipl.-Ing. Ott (Fh)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Erich Netzsch GmbH and Co Holding KG
Original Assignee
Erich Netzsch GmbH and Co Holding KG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Erich Netzsch GmbH and Co Holding KG filed Critical Erich Netzsch GmbH and Co Holding KG
Publication of EP0504836A1 publication Critical patent/EP0504836A1/de
Application granted granted Critical
Publication of EP0504836B1 publication Critical patent/EP0504836B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • B02C17/161—Arrangements for separating milling media and ground material

Definitions

  • the separating device which is arranged centrally in the cavity of the agitator shaft, is directly flowed around by the grinding media ground material suspension, which essentially axially enters the cavity through the inner shaft end.
  • the end section of the rotating agitator shaft generates kinetic energy mainly transferred to the grinding media, so that they are exposed to increasing centrifugal forces as they move away from the inner shaft end and gradually flow back through the outlet openings in the end section of the stirring shaft into the grinding chamber. This counteracts the tendency of the grinding media to accumulate on the separating device under the action of a pressure gradient which conveys the ground material through the agitator mill and to block it.
  • the residence time of the grinding media in the cavity around the separating device can be shortened in the known generic agitator mills by conveying elements which are fastened to the inner wall of the hollow end section of the agitator shaft and have, for example, the shape of a helix.
  • Such conveying elements are indeed suitable for accelerating the grind bodies detected by them through the outlet openings in the hollow end section of the agitator shaft back into the grinding chamber, but they cannot prevent a part of the grind bodies which have flowed axially into the cavity in the intended manner for an undesirably long time in the immediate vicinity of the separating device.
  • the invention is therefore based on the object in a stirrer mill of the type described in the axial flow into the cavity in the end region of the agitator shaft to control millbase millbase suspension so that even under difficult pressure and viscosity conditions the immediate vicinity of the separating device is largely kept free of grinding media accumulations.
  • the intermediate cage according to the invention has the desired effect in operation, particularly in the case of highly viscous regrind and high pressure gradients between the grinding chamber and the regrind outlet, that it improves the flowability of the regrind and thus its readiness to release the grinding media in the immediate vicinity of the separating device. So that the inner zone is largely kept free of grinding media, the deflector prevents the general grinding media flow, which has entered the cavity through the inner shaft end of the agitator shaft, from direct access to the inner zone of the cavity.
  • the grinding media are prevented from entering the inner zone without exception. This can be the case in particular if the intermediate cage has a sieve whose mesh size is so small that grinding media, or the like through a gap. have accidentally entered the inner zone, cannot pass through the intermediate cage into the outer zone. In such cases, at least one outflow channel is provided for those grinding media that have entered the inner zone, through which these grinding media flow out of the inner zone either directly or via the outer zone into the grinding chamber.
  • the agitator mill shown in FIGS. 1 to 6 has an essentially cylindrical, horizontally arranged grinding container 12, which is removably attached to a bearing housing 14.
  • a gear housing 16 is also attached to the bearing housing 14, in which a controllable drive of a conventional type is accommodated.
  • the grinding container 12 contains a circular cylindrical grinding chamber 18 in which an agitator 20 is arranged.
  • the agitator 20 consists essentially of an agitator shaft 22, which is mounted in the bearing housing 14 and extends coaxially with the grinding container 12 through almost the entire grinding chamber 18, and a number of stirring elements 24.
  • the stirring elements 24 are rod-shaped in the example shown; they are fastened to the agitator shaft 22 at equal axial intervals and project into spaces between counter-bars 26 fastened to the grinding container 12.
  • a regrind inlet 28 is arranged, through which a suspension or slurry of regrind and liquid is continuously pumped into the grinding chamber 18 during operation.
  • a regrind outlet 30 is arranged on the right-hand end of the regrinding container 12 in FIG. 1, facing away from the regrind inlet 28, through which finished regrind flows continuously.
  • the regrind outlet 30 is formed by a threaded connector at the end of a tube 32 which is attached to a flange 34.
  • the flange 34 is screwed to an end wall 36 of the grinding container 12 facing away from the gear housing 16.
  • the pipe 32 extends - in the example shown coaxially with the agitator shaft 22 - through the end wall 36 and the adjoining area of the grinding chamber 18 into a cavity 40 which begins at the inner shaft end 38 of the agitator shaft 22 and is open at the end or end.
  • the cavity 40 extends over almost the entire length of the main part of the stirring shaft 22 arranged in the grinding chamber 18.
  • a separating device 42 is arranged in the cavity 40.
  • the separating device 42 is formed by a cylindrical sieve cartridge which is coaxial with the agitator shaft 22 over a little more than a third of the Total length of the cavity 40 extends and has a distance from the inner shaft end 38 which is slightly more than half the total length of the cavity 40. This distance is bridged by a rotationally symmetrical insert 44 which is fastened to the flange 34 and contains the tube 32.
  • slot-shaped, axially parallel outlet openings 46 are incorporated into the agitator shaft 22, which begin near the annular inner shaft end 38 and extend from there over the entire remaining length of the cavity 40.
  • the slot-shaped outlet openings 46 Viewed from the inner shaft end 38, the slot-shaped outlet openings 46 have a large width over approximately the first third of their total length and then a considerably smaller width over the rest of their total length; 2, the width of the outlet openings 46 in the first third of their total length is approximately 3: 1 in relation to the width over the entire rest of their total length.
  • the outlet openings 46 are narrow.
  • the outlet openings 46 are inclined backwards, based on the direction of rotation of the agitator shaft 22 indicated in FIG. 2 by an arrow 48.
  • the grinding chamber 18 contains a mixture of grinding media 50 and grinding stock 52, which is activated during operation by rotating the agitator shaft 22 at a speed which is customary in agitator mills in the order of, for example, 200 to 3000 revolutions per minute, depending on the nature of the grinding stock and Diameter of the agitator shaft and the grinding media.
  • a pressure drop which allows the grinding media 50 and regrind 52 to flow from the grinding chamber 18 through the inner shaft end 38 essentially axially into the cavity 40.
  • the finished regrind 52 passes through the separating device 42 into the tube 32, while the grinding media 50 are retained and flow back through the outlet openings 46 into the grinding chamber 18. This backflow is promoted by centrifugal forces which result from the action of the inner wall of the agitator shaft 22 around the cavity 40 and the surfaces of the agitator shaft 22 delimiting the outlet openings 46 on the grinding media 50.
  • the agitator mill shown in FIGS. 1 to 6 has the following further features:
  • An annular deflector 54 is attached to the insert 44 or, in an alternative, is formed in one piece.
  • the deflector 54 together with the inner wall of the agitator shaft 22, defines an annular constriction 56 which is at a distance from the inner shaft end 38 which approximately corresponds to the axial length of the wide sections of the outlet openings 46.
  • the constriction 56 contributes to the fact that a considerable part of the grinding media 50 is excreted from the grinding media-grinding material suspension flowing within the cavity 40 before it reaches the part of the cavity 40 lying behind in the axial direction, to the left of the constriction 56 in FIG. 1 .
  • An intermediate cage 60 is arranged behind the deflector 54, to the left in FIG. 1 thereof, which forms the axially inner end of the cavity 40 with a base plate 62 formed thereon and is exchangeably fastened to the agitator shaft 22.
  • the intermediate cage 60 has passages 64, the shape and size of which depends on the nature of the ground material 52 by exchanging the intermediate cage or individual parts thereof and the size of the grinding media 50 can be adjusted. Two exemplary embodiments are shown in FIGS. 3 and 4 on the one hand and in FIGS. 5 and 6 on the other hand.
  • the width of the passages 64 is at most thirty times the largest diameter of the grinding media 50.
  • the intermediate cage 60 has an annular free cage end 66, the inner and outer walls of which are conical and converge towards the inner shaft end 38.
  • the insert 44 forms, together with the deflector 54, an annular groove of V-shaped profile facing away from the inner shaft end 38, into which the annular cage end 66 engages in such a way that an annular gap 68 is also formed of a V-shaped profile.
  • the apex region of the annular gap 68 lies approximately in the middle of the total axial length of the cavity 40 and has a width b which is preferably not more than ten times as large as the largest diameter of the grinding bodies 50. In general, it is particularly advantageous if the width b is about three to five times as large as the largest grinding media diameter.
  • the intermediate cage 60 divides the part of the cavity 40 lying behind the deflector 54, seen from the inner shaft end 38, into an inner zone 70 and an outer zone 72, both of which are arranged in a ring and coaxially with the agitator shaft 22. With the specified dimensions of the passages 64 and the annular gap 68, the intermediate cage 60 does not rule out that grinding media 50 reach the inner zone 70 from the outer zone 72, although the relative grinding media density in the inner zone 70 will always be considerably lower than in the outer zone 72.
  • a plurality of outflow channels 74 are incorporated in the base plate 62 of the intermediate cage 60, 1 to 4 are offset in parallel by a radius, whereas the outflow channels 74 are arranged radially in the embodiment shown in FIGS. 5 and 6.
  • Each of the outflow channels 74 opens directly into one of the slot-shaped outlet openings 46 of the stirring shaft 22, so that the grinding media 50 are thrown out of the inner zone 70 in the shortest possible way into the grinding chamber 18.
  • the intermediate cage 60 has a conical inner wall 76, the inner diameter of which increases continuously in the direction of the outflow channels 74, ie away from the inner shaft end 38; in other words, the inner zone 70 widens towards the outflow channels 74. This expansion promotes the readiness of the grinding bodies 50 that have entered the inner zone 70, to the outflow channels 74, and then through these into the grinding chamber 18.
  • the intermediate cage 60 has four relatively wide axially parallel slots 78, which are enclosed by a cylindrical sieve 80.
  • the shape and size of the aforementioned passages 64 of the intermediate cage 60 are determined by the mesh of the sieve 80.
  • the intermediate cage 60 shown in FIGS. 5 and 6 has a plurality of rings 82 which are arranged concentrically to one another and are fastened to the base plate 62 by means of tie rods 84.
  • the rings 82 have interlocking conical sections 86, between which ring gaps remain free, which form the passages 64 of the intermediate cage 60.
  • the ring 82 furthest from the base plate 62 forms the annular free cage end 66.
  • the agitator shaft 22 can be heated or cooled as required; for this purpose channels 88 are provided which extend between the slot-shaped outlet openings 46 up to the vicinity of the inner shaft end 38 and are connected via the bearing housing 14 to a heating and / or cooling device of a conventional type, not shown.
  • the insert 44 and the deflector 54 attached to it can be heated or cooled as required;
  • 44 channels 90 are formed in the insert, which are connected to the heating and / or cooling device via the flange 34.
  • the embodiment according to FIG. 7 differs from that shown in FIGS. 1 to 6 in that the intermediate cage 60 is not fastened to the agitator shaft 20, but is attached to the insert 44 or is integrally formed on it, and in that the insert 44 in the end wall 36 of the grinding container 12 is mounted coaxially with the agitator shaft 20 and can be rotated by means of its own rotary drive 92. There is a choice of several modes of operation.
  • the intermediate cage 60 can rotate in the same or opposite direction of rotation at the same or a different speed as the agitator shaft 20.

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  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Grinding (AREA)
EP92104678A 1991-03-21 1992-03-18 Rührwerksmühle Expired - Lifetime EP0504836B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4109332A DE4109332A1 (de) 1991-03-21 1991-03-21 Ruehrwerksmuehle
DE4109332 1991-03-21

Publications (2)

Publication Number Publication Date
EP0504836A1 EP0504836A1 (de) 1992-09-23
EP0504836B1 true EP0504836B1 (de) 1995-06-14

Family

ID=6427904

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92104678A Expired - Lifetime EP0504836B1 (de) 1991-03-21 1992-03-18 Rührwerksmühle

Country Status (2)

Country Link
EP (1) EP0504836B1 (cs)
DE (2) DE4109332A1 (cs)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1992412A1 (de) 2005-10-11 2008-11-19 Bühler Ag Rührwerksmühle
KR20130118886A (ko) * 2010-10-27 2013-10-30 네취-파인말테크닉 게엠베하 교반 볼 분쇄기
CN104722368A (zh) * 2013-12-20 2015-06-24 耐驰干法研磨技术有限公司 具有悬臂式转子的机械
EP4032615A1 (de) 2021-01-25 2022-07-27 Wilhelm Niemann GmbH & Co KG Rührwerksmühle

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4240779C1 (de) * 1992-12-04 1994-02-10 Netzsch Erich Holding Rührwerksmühle
DE4307083B4 (de) * 1993-03-06 2007-07-12 Zoz Maschinenbau Gmbh Vorrichtung zur Feinstmahlung von Feststoffen
DE4432203A1 (de) * 1994-09-09 1996-03-14 Evv Vermoegensverwaltungs Gmbh Rührwerksmühle
US5853132A (en) * 1996-03-06 1998-12-29 Fuji Photo Film Co., Ltd. Dispersing machine
CN101884947B (zh) * 2005-10-11 2011-07-20 比勒股份公司 搅拌式研磨机
US7699250B1 (en) * 2007-03-02 2010-04-20 Progressive Industries, Inc. Media grinding mill
DE102012013279A1 (de) * 2012-07-05 2014-01-09 Roland Nied Verfahren zum Betrieb einer Rührwerkskugelmühle sowie Rührwerkskugelmühle dafür
PE20160022A1 (es) 2013-05-21 2016-02-03 Smidth As F L Metodos y aparato para el monitoreo continuo de desgaste en circuitos de molienda
EP3536406A1 (de) * 2018-03-07 2019-09-11 Bühler AG Rührwerksmühle
DE102018122395B4 (de) * 2018-09-13 2025-03-27 Netzsch Feinmahltechnik Gmbh Rührwelle für eine Rührwerkskugelmühle, Rührwerkskugelmühle und Verfahren zum Herstellen einer Rührwelle für eine Rührwerkskugelmühle
CN119237100B (zh) * 2024-11-22 2025-02-14 沈阳铝镁设计研究院有限公司 一种用于氧化铝微粉研磨的球磨机

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3345680A1 (de) * 1983-12-16 1985-06-20 Gebrüder Netzsch, Maschinenfabrik GmbH & Co, 8672 Selb Ruehrwerksmuehle

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1992412A1 (de) 2005-10-11 2008-11-19 Bühler Ag Rührwerksmühle
US7931222B2 (en) 2005-10-11 2011-04-26 Bühler AG Agitator mill
KR20130118886A (ko) * 2010-10-27 2013-10-30 네취-파인말테크닉 게엠베하 교반 볼 분쇄기
KR101575027B1 (ko) 2010-10-27 2015-12-21 네취-파인말테크닉 게엠베하 교반 볼 분쇄기
CN104722368A (zh) * 2013-12-20 2015-06-24 耐驰干法研磨技术有限公司 具有悬臂式转子的机械
CN104722368B (zh) * 2013-12-20 2017-06-13 耐驰干法研磨技术有限公司 具有悬臂式转子的机械
EP4032615A1 (de) 2021-01-25 2022-07-27 Wilhelm Niemann GmbH & Co KG Rührwerksmühle
DE102021101527A1 (de) 2021-01-25 2022-07-28 Wilhelm Niemann Gmbh & Co. Rührwerksmühle
DE102021101527B4 (de) 2021-01-25 2023-05-17 Wilhelm Niemann Gmbh & Co. Rührwerksmühle

Also Published As

Publication number Publication date
EP0504836A1 (de) 1992-09-23
DE59202485D1 (de) 1995-07-20
DE4109332A1 (de) 1992-09-24
DE4109332C2 (cs) 1992-12-24

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