DE202017002406U1 - Apparatus for comminuting regrind - Google Patents

Abstract

Apparatus (19) for comminuting regrind with - a grinding container (2) having in the axial direction opposite end faces (20, 21), between which at least one sieve tray (6, 7, 8) extends, which together with another Sieve shell or (6, 7, 8) or also between the end faces (20, 21) extending outer wall (38) defines at least one annular space (27, 28, 29), wherein the or an innermost sieve shell (6) a grinding chamber ( 17), are arranged in the grinding body (18), - a bearing (12) for rotatably holding the grinding container (2) on a foundation (14) and - drive means (15) for rotating the grinding container (2) about a horizontal axis (3) in a grinding direction, characterized in that the bearing (12) has rotatably mounted rollers (34) and the grinding container (2) rests on the rollers (34), wherein at least one end face (21, 22) has a maintenance opening (25) is an insight into allows the grinding container (2).

Description

The invention relates to a device for comminuting ground material with a grinding container having in the axial direction opposite end faces, between which extends at least one sieve tray, which defines at least one annulus together with another sieve tray or also extending between the end faces outer wall, wherein the or an innermost sieve bowl delimits a grinding chamber in which grinding bodies are arranged, with a bearing for rotatably holding the grinding container on a foundation and with drive means for rotating the grinding container about a horizontal axis in a grinding direction.

Such a device is known to the person skilled in the art. The known device has a grinding container which is rotatably mounted about a horizontal axis. The grinding container is cylindrical and has two in a plan view circular end faces, which are centrally connected to a respective pipe socket, which opens into the grinding chamber, so that grinding material on the respective pipe socket in the painting container on or can be performed. Each pipe socket is rotatably supported by a rotary bearing on a foundation. Between the end faces extend a plurality of concentrically arranged sieve shells, which are each designed as a cylindrical wall with openings of constant size. The spaces lying between the sieve shells are referred to here as annular spaces. The size of the sieve bowl openings decreases from sieve bowl to sieve bowl, wherein the outermost sieve bowl is finally designed as a fine-pored mesh sieve. The innermost sieve bowl, however, is mechanically stable and surrounds an inner grinding chamber in which about ten kilograms of grinding media are arranged. One of the pipe sockets of the grinding container is connected to an electric motor which rotates the grinding container about the horizontal axis. The millbase introduced through the other pipe socket is smashed in the grinding chamber by the grinding media. Sufficiently finely ground grinding material finally penetrates the outermost sieve tray and reaches a discharge funnel located below the grinding drum.

The EP 2 907 577 A1 discloses a ball mill, which also has a cylindrical grinding drum with pipe sockets at their end faces. Again, the grinding drum is rotatably supported at its pipe socket by a rotary bearing. The ball mill disclosed therein is used for grinding liquid-solid mixtures and is designed for continuous operation. Instead of radial sieve shells here a circular sieve plate is arranged in the grinding drum, which extends parallel to the end faces. The grinding drum is equipped with Mitnehmerleisten that transfer the material to be ground from an inlet pipe socket through the screen plate to the other pipe socket, which serves as a Ausgangsrohrstutzen upon rotation of the grinding drum.

A device of the type mentioned at the outset, which is also referred to as a screen ball mill, has been used for many years for the grinding of ground material, such as, for example, slag residues from incinerators or built-in furnace linings made of fireclay bricks. The comminution of such furnace residues has proven to be useful from an economic point of view, especially when the slag or firebricks contain precious metals such as copper, gold or silver. Such a screen ball mill is also used for comminuting the interior of catalytic converters for motor vehicles.

The device mentioned above, however, has the disadvantage that the grinding container is not accessible from the outside. The grinding container and in particular the inner sieve tray are exposed to heavy wear due to the heavy grinding media. A maintenance opening in the grinding container itself would therefore result in an undesirable structural weakening of the grinding container. In addition, the opening would also have to lead through at least one inner sieve shell, resulting in further difficulties.

An opening on one of the end faces of the grinding container is also not possible because there the pivot bearing is arranged for rotatably holding the end-side pipe socket. Because of the lack of accessibility, it is not possible to monitor the progress of the crushing process by simple inspection. Furthermore, blockages or damage due to residues inside the grinding container are not detected or recognized late. The removal of the residues is complicated.

The object of the invention is therefore to provide a device of the type mentioned, which can be easily monitored and maintained.

This object is achieved in that the bearing has rotatably mounted rollers and the grinding container rests on the rollers, wherein on at least one end face a maintenance opening is formed, which allows an insight into the grinding container.

According to the invention, the rotary bearing is realized by rollers, which are arranged rotatably in the foundation, for example. The grinding container rests on the rollers. Spacious pivot bearings on the front sides of the grinding container are become superfluous according to the invention. For this reason, it is possible to form a maintenance opening on at least one or else both end faces of the grinding container. The maintenance opening is suitably so large that residues from the grinding container through the maintenance opening can be easily removed. Such residues are, for example, not crushable sheets or the like. If such residues have settled in the grinding container, they can be removed within the scope of the invention simply and quickly through the maintenance opening from the grinding container and in particular from the grinding chamber. Long downtimes due to maintenance are thus avoided within the scope of the invention. The inspection also makes it possible to quickly detect blockages of the openings of the innermost sieve bowl and remove them if necessary. Also, the condition of the media can be easily monitored so that damaged media can be replaced before major damage occurs. In addition, it can also be recognized whether a grinding process has lasted long enough to comminute the material to be ground to the desired extent.

As grinding media are preferably spherical Mahlköper into consideration and in particular grinding balls, which are made of steel. In the context of the invention, however, differently shaped grinding media and / or materials can also be used.

In an advantageous further development of the invention, at least two sieve shells and preferably three sieve shells are provided, which likewise extend between the end faces. The sieve shells are designed as hollow cylindrical and arranged concentrically to one another. With the exception of an outermost sieve bowl all sieve shells on receding openings, which is slightly larger than the openings of the respective sieve tray and allows falling back of ground material in the grinding chamber. Further, a driving element is provided, which is arranged in the immediate vicinity of the return opening and rotatably connected to the rotatable grinding container.

The contour of the maintenance opening is basically arbitrary. Advantageously, however, the maintenance opening is designed rectangular, wherein the height and width of the rectangle each vary between 20 cm and 70 cm. Deviating from the maintenance opening is circular, with its diameter varies between 20 cm and 70 cm.

Advantageously, a maintenance flap is provided which is set up for quick opening and closing of the maintenance opening. The maintenance flap is articulated, for example, on the front side. It can also consist of a transparent material, so that a continuous insight into the grinding container is made possible.

Due to the better monitoring options, the wear of the device according to the invention is reduced. In addition, the operation of the device can be made more effective, so that in comparison to a device according to the prior art, a larger yield of separated, finished ground millbase can be achieved.

The device according to the invention is preferably used for recovering or, in other words, recycling precious metals. The noble metals are contained, for example, in electrical waste, furnace linings, catalysts or the like. This raw material to be ground is introduced into the grinding container, for example, by means of a feed opening provided in one of the end faces. This is done, for example, batchwise so in batch mode. In a different embodiment of the invention, however, a continuous operation of the device according to the invention is possible. During a rotation of the grinding container, the grinding media shatters the material to be ground. Grist with sufficiently small grain size penetrates through the sieve shells and is finally discharged from the grinding container.

As drive means, for example, a commercial electric motor is suitable. The electric motor advantageously drives at least one of the rollers on which the grinding container rests. By this drive, the grinding container is thus placed in a rotational movement about the horizontal axis. The horizontal axis extends in an end view expediently through the center of the preferably circular-shaped end faces.

The sieve shells usually have openings that allow the passage of regrind with a sufficiently small grain size. The openings of a Sieschale are preferably all the same size. With increasing distance of the sieve bowl to the horizontal axis, ie towards the outside, however, the openings of the sieve bowl to the sliding bowl become smaller. On the outside, the grinding container is delimited by an outer wall, which likewise extends between the end faces and has no openings. The outer wall bounded with the adjacent radial inner sieve bowl, which has the smallest openings, an outer annulus.

According to a preferred embodiment, the bearing comprises four rollers. Four rollers allow optimal weight distribution of the preferably hollow cylindrical grinding container and therefore a particularly low maintenance rotation.

Further advantages result in the context of the invention, when the bearing has at least two axes of rotation extending in the axial direction, which are each rotatably connected to rollers, wherein the axes of rotation are arranged on different sides of the grinding container. The rollers, which are connected to the same axis of rotation, are coupled together. This mechanical coupling of the rollers further increases the mechanical stability of the device.

The term "roller" as used herein should in principle include all rotatably mounted means having a circular outer contour. Conveniently, each roller has on its outside, with which it rests against the grinding container, on a material for increasing the friction between the roller and the grinding container. The material is, for example, an elastomer, a rubber or the like. A role may in the context of the invention also consist of several individual roles and be executed, for example, as a pair of rollers.

According to a preferred embodiment of the invention, the end faces are formed as end plates and each define a cavity which is connected via an inlet opening with the grinding container. The end disks are preferably annular and have a circular outer contour in an end view. The thickness of the end disks is preferably between 10 cm and 50 cm, wherein the cavity is formed in the radially outer region of the end disks. In the center or the center of at least one end plate, the maintenance opening is provided. The cavity is connected via the inlet opening with the grinding container. In addition, the cavity of each end plate is equipped with an outlet opening which faces away from the grinding container and over which the ground material can be removed from the cavity again. In the cavity conveyor means, for example suitably curved entrainment bars, which are connected to the inner wall of the cavity of the end plates, or guide channels formed which transport the material to be ground from the inlet opening to the outlet opening, from where the material passes into appropriate further processing units.

According to a preferred embodiment of the invention, the cavity of a discharge end plate are connected via the inlet opening with a first annulus and the cavity of a feed end disc with a second annulus. According to this development can be determined by the assignment of the inlet opening to an annulus, which degree of comminution or which grain size should reach the reaching into the respective cavity regrind. In this way, a separation between little crushed regrind and regrind with comparable smaller grain size is possible.

According to an expedient further development, a first annular space has coarse conveying means which, during a rotation of the grinding container in a discharge direction which is opposite to the grinding direction, transfer material to be ground into the cavity of the discharge end disk. Another preferably radially outwardly lying annular space which is connected to a feed end disk is equipped with fine conveying means, which transfer during a rotation of the grinding container in the grinding direction millbase in the cavity of the feed end disk. According to this further development, no material to be ground passes into the cavity of the discharge end disk when the grinding container is rotated in the grinding direction. Only the feed end disk is supplied with regrind having the desired degree of comminution. This embodiment is suitable for the batchwise or English expressed batch mode of the device. If no regrind passes into the feed end disk or if no highly comminuted feed material is released from the feed end disk, a user of the device according to the invention can reverse the rotation of the grinding container, whereupon the grind stock which has been comminuted to a lesser extent, for example, from the first or innermost annulus via the discharge end disk discharged outside. Of course, the roles so the function of the end plates can also be replaced, so that the fine material to be ground is guided over the end plate, which is opposite to the feed end, over which the material to be ground is introduced into the grinding chamber. The discharge of only roughly crushed ground material would then take place at the feed end disk. The cavity of the feed end disk would be connected to the first or innermost annulus via the input port, with the input port of the opposite end disc forming an input port in the outermost annulus. The funding in the ring and cavities would be adjusted accordingly.

In a variant deviating from this, the first, ie innermost, annular space has coarse conveying means which, during a rotation of the grinding container in the grinding direction, transfer material to be ground into the cavity of the discharge end disk, another preferably further outwardly situated annular space having fine conveying means which, during a rotation of the grinding container in the grinding direction Transfer regrind into the cavity of the feed end disk. The inlet opening of the cavity of the discharge end plate can be closed by means of an externally operable flap. In this variant of the invention, the grinding container can be rotated in only one direction. In this variant, the material to be ground is first placed in the grinding chamber and the grinding container in Rotation offset. The flap of the inlet opening of the discharge end plate initially remains closed, so that the simultaneous discharge of coarse and fine ground material at the discharge end plate is avoided. In a further development, the flap is provided with openings corresponding to the openings of the outermost sieve tray. Finely ground material can then be tapped off at both end disks when the flap is closed. If the output of fine grinding material clears significantly, the flap can be opened from the outside, so that now the coarse material to be ground is discharged from the grinding container via the discharge end plate. Also in this variant, the roles or the function of the end plates can be reversed, so that the discharge of the coarse material to be ground at the loading end takes place.

According to a further expedient embodiment of the invention, an end plate has a central feed opening, which is set up for feeding ground material into the grinding chamber. According to this variant, only one of the end plates is equipped with a maintenance opening. The other end disk, the feed end disk, on the other hand, has a feed opening, which is used to feed the ground material into the grinding chamber. The feeding can take place, for example, by means of suitable feeding means. The supply means may be designed to be pivotable in order to be able to use the charging opening as a service opening if required.

Advantageously, the grinding container rests only on its end disks on the rollers. The end plates therefore form with their radial outer sides raceways on which the rollers roll. According to this advantageous further development, the portion of the grinding container extending between the mechanically stable end disks, that is to say the tray shells with the exception of the innermost sieve tray, and the outer wall can be made mechanically less rigid. In this way, the production of the device according to the invention is simplified, which sets a further cost advantage.

Advantageously, the sieve shells each form openings of constant size, the size of the opening decreasing in the radial direction from sieve bowl to sieve bowl. The outer wall has no openings. According to this advantageous further development, the grain size in the outermost annular space is significantly smaller than in the or the radially inner annular spaces.

Further expedient embodiments and advantages of the invention are the subject of the following description of embodiments of the invention with reference to the figures of the drawing, wherein like reference numerals refer to like-acting components and wherein

1 a device according to the prior art and

2 an embodiment of the device according to the invention illustrate schematically.

1 shows an embodiment of the device according to the invention 1 according to the prior art. The device 1 has a cylindrical grinding drum 2 for rotation about a horizontal axis 3 is set up. This is indicated by the grinding drum 2 an entrance frontal 4 and an exit end face 5 on. Between the front of the entrance 4 and the output front 5 extend an innermost sieve bowl 6 , an intermediate sieve bowl 7 as well as a fine sieve shell 8th , which are arranged one behind the other in the radial direction.

In the middle of the entrance front side 4 is an inlet pipe 9 provided, which has a loading opening 10 limited. In the middle of the exit front 5 is an outlet pipe 11 intended. For holding the inlet pipe socket 9 and the outlet pipe socket 11 serves a pivot bearing 12 , the two pivot supports 13 includes. The pivot bearing supports 13 keep the grinding drum 2 to the pipe socket 9 and 11 rotatable on a foundation 14 , For driving the grinding drum 2 is an electric motor 15 provided with the outlet pipe 11 connected is.

The grinding drum 2 is arranged in a housing made of sheet metal, of which in 1 only a lower housing funnel 16 is shown. Each sieve bowl 6 . 7 and 8th has identical openings, for example in the form of slots, holes or meshes, which are designed for the passage of grains of a certain size. The size of these openings decreases from sieve shell to sieve shell from inside to outside. In the example shown, the openings are the innermost sieve tray 6 for passage of grains with a size of 20 mm, the intermediate sieve tray 7 for the passage of grains with a size of 5 mm and the fine sieve shell 8th designed for the passage of grain sizes of 1 mm. The innermost sieve bowl 6 is mechanically stable. It limits a grinding room 17 in which grinding media 18 are arranged. The intermediate sieve bowl 7 and especially the fine sieve tray 8th have in comparison to the innermost sieve bowl 6 over a lower mechanical strength.

Figurative not shown regrind is through the feed opening 10 introduced into the grinding chamber. Then the electric motor moves 15 the grinding drum 2 in rotation, causing the grinding media 18 the regrind in the grinding chamber 17 mince. Undegraded ground material remains in the grinding chamber 17 ,

In the two annular spaces, by the sieve bowls 6 and 7 respectively 7 and 8th are limited, one figuratively not shown Zwangsmitnahmeelement is arranged in the form of a longitudinal beam, which also limits the respective annular space or in other words terminates. The co-driving element is non-rotatable with the grinding container 2 connected and thus rotates during operation of the device 1 , In this way, with each revolution of the grinding container 2 Grist taken from the Zwangsmitnahmeelement. The sieve bowls 6 and 7 do not completely enclose the annular spaces. Rather, every sieve dish has 6 . 7 just before the co-driving element relapse openings, which are slightly larger than the openings of the sieve shells 6 . 7 are. Grist that is not through the sieve bowls 6 or 7 fallen in this way enters the grinding chamber 17 back and will from the grinding media 18 crushed again.

Finely comminuted regrind finally passes the fine sieve shell 8th and is via the housing funnel 16 for further processing.

As already stated in the introduction, the grinding container of the prior art device is not accessible from the outside. The crushing process can not therefore be monitored by simply looking into the grinding container. This may result in crushing being too short or longer than necessary. In both cases, the yield of sufficiently finely ground and discharged millbase is reduced within a predetermined period of time. Furthermore, blockages or damage inside the grinding container are not detected or only very late.

2 shows an exemplary embodiment of the device according to the invention 19 , which also has a grinding container 2 having. In contrast to the prior art device 1 according to 1 the end faces of the device according to the invention are designed as end plates, which here with reference to the material guide as Beschickungsendscheibe 20 or discharge end disk 21 be designated. The said end discs 20 and 21 each define a cavity in their interior 22 who at his from the grinding room 17 opposite side, an outlet opening 23 respectively 24 having. The outlet opening 23 the feed end disk 20 encloses a circular feed opening 10 ring shape. The outlet opening 24 the discharge end disc 21 is one in the middle in the discharge disc 21 arranged maintenance opening 25 guided around, by a maintenance flap 26 can be closed.

Between the feed end disc 20 as well as the discharge end disc 21 extend an innermost sieve bowl 6 , an intermediate sieve bowl 7 as well as a fine sieve shell 8th , The innermost sieve tray is made sufficiently thick to provide the necessary mechanical strength for the grinding chamber 17 in which the about ten kilograms grinding media 18 are arranged. Each sieve bowl 6 . 7 and 8th again has uniform openings, for example in the form of slots, holes or mesh, which are designed for the passage of grains of a certain size. The size of these openings decreases again from Siebschale to Siebschale from inside to outside. In the example shown, the openings are the innermost sieve tray 6 for passage of grains with a size of 20 mm, the intermediate sieve tray 7 for the passage of grains with a size of 5 mm and the fine sieve shell 8th designed for the passage of grain sizes of 1 mm. An outer wall 38 has no openings and serves as an outer housing, which contains the grinding container 2 closes to the outside. Between the innermost sieve bowl 6 and the intermediate sieve bowl 7 is a first annulus 27 Are defined. The intermediate sieve bowl 7 as well as the fine sieve shell 8th limit a second annulus 28 , A third annulus 29 extends between the fine screen shell 8th and the outer wall 38 ,

The feed end disk 20 has an entrance opening 30 which the third annulus 29 with her cavity 22 combines. The discharge end disc 21 limits an entrance opening 31 which the cavity formed by it 22 with the first annulus 27 combines.

In the two annular spaces 27 and 28 is in each case a figuratively not shown Zwangsmitnahme arranged for example in the form of a longitudinal beam, the respective annulus 27 . 28 also limited or in other words terminates. The co-driving element is non-rotatable with the grinding container 2 connected and thus rotates during operation of the device 19 , In this way, with each revolution of the grinding container 2 Grist carried by the Zwangsmitnahmeelement. The sieve shells limit this 6 and 7 the annular spaces 27 . 28 not fully. Rather, the sieve shells 6 . 7 just before the co-driving element relapse openings, which are slightly larger than the openings of the sieve shells 6 . 7 are. Grist that is not through the sieve bowls 6 or 7 fallen in this way enters the grinding chamber 17 back and will from the grinding media 18 crushed again.

In the third annulus 29 are figuratively not shown conveying means arranged during a rotation of the grinding container 2 Grinding material in a grinding direction, which is in the third annulus 29 has arrived, to the entrance opening 30 of the cavity 22 the feed end disk 20 transport. The cavity 22 is also equipped with funds that the Grist to the outlet 23 convict. From there, the regrind enters a drainage channel 32 and can be further edited. Conveying means are designed for example as entrainment strips, channels or the like.

The same applies to the annulus 27 and the cavity 22 the discharge end disc 21 , which are also equipped with subsidies. However, these funds are at a rotation of the grinding container 2 ineffective in the grinding direction. In a rotation in a discharge direction, which is opposite to the grinding direction, convey the conveying means of the first annulus 27 However, the regrind into the cavity 22 the discharge end disk 21 , The less crushed regrind is then through the cavity 22 the output disk 21 arranged and in rotation in the discharge direction also effective funding to the outlet opening 24 transported from where it is in a discharge hopper 33 falls.

To a grinding container 2 with a maintenance opening 25 in the middle of the front end, the device features 19 according to the invention over one of the device 1 deviating pivot bearing 12 that about roles 34 has, in the embodiment shown via an axis of rotation 35 connected to each other. In 2 is only a rotation axis 35 with two rollers 34 recognizable. This is on the front of the grinding container 2 arranged. On the back, so exactly aligned with the illustrated axis of rotation 35 , However, a further axis of rotation is arranged, the figurative therefore not shown. The second axis of rotation also has two rotatably connected with her roles. Overall, four rolls are thus provided on which the grinding container 2 with its feed end disk 20 and its discharge end plate 21 rests. These have the feed end disk 20 as well as the discharge end disc 21 each over raceways 36 in which the roles 34 roll.

One of the rotary axes 35 is by an electric motor 15 driven as a drive means for rotation. Deviating from this, the drive means may also have chains, sprockets or the like, which engage directly on the grinding drum.

In order to avoid a displacement of the grinding drum in the axial direction, are guide rollers 37 provided with match to the respective end disc 20 respectively. 21 are arranged.

According to the invention, the millbase is conveyed via the feed opening 10 in the grinding room 17 introduced. Subsequently, the drive means rotate 15 , For example, an electric motor, the grinding container 2 in the grinding direction, so that the grinding media 18 grind the millbase. Sufficiently comminuted material finally passes through the fine sieve tray 8th in the outermost third annulus 29 , The funding of the third annulus 29 transport the finely comminuted material into the cavity 22 the feed end disk 20 , From there it gets into the drop channel 32 and can be further processed as desired to isolate any precious metals from the finely ground stock. In order to discharge the material, which has only been crushed slightly, the direction of rotation of the grinding container becomes 2 changed. In the Austragsdrehrichtung convey the funding of the first annulus 27 the only slightly comminuted material in the input opening 31 of the cavity 22 the discharge end disc 21 from where it enters the hopper 33 arrives.

In a variant of the device according to the invention, which is not shown figuratively, the discharge end is not on a roll 34 but stored in a rolling or sliding bearing.

The grinding container 2 is expediently rotationally symmetrical, and preferably has a substantially cylindrical outer contour. Such a grinding container 2 can also be referred to as a grinding drum.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2907577 A1 [0003]

Claims (10)

Contraption ( 19 ) for comminuting regrind with - a grinding container ( 2 ), in the axial direction opposite end faces ( 20 . 21 ), between which at least one sieve bowl ( 6 . 7 . 8th ), which together with another sieve shell or ( 6 . 7 . 8th ) or one also between the end faces ( 20 . 21 ) extending outer wall ( 38 ) at least one annulus ( 27 . 28 . 29 ), wherein the or an innermost sieve bowl ( 6 ) a grinding chamber ( 17 ), in the grinding body ( 18 ), - a warehouse ( 12 ) for rotatably holding the grinding container ( 2 ) on a foundation ( 14 ) and - drive means ( 15 ) for turning the grinding container ( 2 ) about a horizontal axis ( 3 ) in a grinding direction, characterized in that the bearing ( 12 ) via rotatably mounted rollers ( 34 ) and the grinding container ( 2 ) on the rollers ( 34 ) rests on at least one end face ( 21 . 22 ) a maintenance opening ( 25 ), which gives an insight into the grinding container ( 2 ). Contraption ( 19 ) according to claim 1, characterized in that the bearing ( 12 ) at least four roles ( 34 ) having. Contraption ( 19 ) according to claim 1 or 2, characterized in that the bearing ( 12 ) at least two axes of rotation extending in the axial direction ( 35 ), each rotatably with rollers ( 34 ), wherein the axes of rotation ( 35 ) on different sides of the grinding container ( 2 ) are arranged. Contraption ( 19 ) according to one of the preceding claims, characterized in that the end faces as end discs ( 20 . 21 ) are formed and each have a cavity ( 22 ), which has an entrance opening ( 30 . 31 ) with the grinding container ( 2 ) and with conveying means for discharging ground material from an exit opening ( 23 . 24 ) is equipped. Contraption ( 19 ) according to claim 4, characterized in that the cavity ( 22 ) of a discharge end disk ( 21 ) via the entrance opening ( 31 ) with a first annulus ( 27 ) and the cavity ( 22 ) of a feed end disk ( 20 ) with a second annulus ( 29 ) connected is. Contraption ( 19 ) according to claim 4, characterized in that the first annulus ( 27 ) has coarse conveying means which, during a rotation of the grinding container ( 2 ) in a discharge direction, which is opposite to the grinding direction, millbase in the cavity ( 22 ) of the discharge end disk ( 21 ), and another annulus ( 29 ) has fine conveying means which, during a rotation of the grinding container ( 2 ) in the grinding direction regrind into the cavity ( 22 ) of the feed end disk ( 20 ). Contraption ( 19 ) according to claim 4, characterized in that the first annulus ( 27 ) has coarse conveying means which, during a rotation of the grinding container ( 2 ) in the grinding direction regrind into the cavity ( 22 ) of the discharge end disk ( 21 ), and another annulus ( 29 ) has fine conveying means which, during a rotation of the grinding container ( 2 ) in the grinding direction regrind into the cavity ( 22 ) of the feed end disk ( 20 ), the entrance opening ( 31 ) of the cavity ( 22 ) of the discharge end disk ( 21 ) Can be closed by means of an externally operable flap. Contraption ( 19 ) according to one of the preceding claims, characterized in that the loading end disk ( 20 ) a central feed opening ( 10 ) which is suitable for feeding ground material into the grinding chamber ( 17 ) is set up. Contraption ( 19 ) according to one of claims 4 to 8, characterized in that the grinding container ( 2 ) only with its end discs ( 29 . 21 ) on the rollers ( 34 ) rests. Contraption ( 19 ) according to one of the preceding claims, characterized in that the sieve shells are at least partially ( 6 . 7 . 8th ) each form openings of constant size, wherein the size of the openings in the radial direction of Siebschale ( 6 . 7 . 8th ) to sieve bowl ( 6 . 7 . 8th ) decreases.

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