Agitator bead mill with external grinding media separation unit

Abstract

The present invention provides an agitator ball mill equipped with an external pulverizer separation unit. The agitator ball mill comprises a grinding container equipped with a grinding chamber, a product inlet for introducing the material to be ground into the grinding chamber, an agitator equipped with grinding elements rotatably positioned in the grinding chamber (100), and a plurality of pulverizers positioned in the grinding chamber. According to the present invention, a pulverizer recirculation passage is also provided, comprising an inlet from which the pulverizer / material to be ground mixture positioned in the grinding chamber during operation can enter the pulverizer recirculation passage from the grinding chamber, and an outlet from which the pulverizer / material to be ground mixture is returned to the grinding chamber. A tangential flow separator is positioned in the pulverizer recirculation passage and has separation means for separating the pulverizer from the material to be ground, and a product outlet for discharging the ground material from the agitator mill downstream of the separation means. Furthermore, means for exerting a pumping action is provided to assist the circulation of the pulverizer / material to be ground mixture through the pulverizer recirculation passage.

Description

Technical Field

[0001] The present invention relates to an agitator ball mill provided with a grinding body, particularly to the separation of the grinding body from the material to be ground.

Background Art

[0002] Agitator ball mills have a wide range of applications in the grinding and dispersion of solids in liquids. Agitator ball mills are used, for example, in the production of adhesives, coating agents, printing inks, cosmetics, pharmaceuticals, or raw materials for battery pastes (particularly silicon). In such mills, a processing and dispersion area is formed within the grinding container, which area is usually defined by an inner wall having a cylindrical shape and is hereinafter also referred to as the grinding chamber. The agitator shaft is rotatable about the axis of the agitator shaft extending through the central longitudinal axis of the grinding chamber, and the agitator shaft has a plurality of grinding elements, particularly grinding disks or grinding pins, attached thereto. The material to be ground is supplied to the grinding chamber through the material-to-be-ground inlet and is usually ground by the rotation of the grinding elements under the action of a grinding body or an auxiliary grinding body, such as ceramic balls, arranged in the grinding chamber, and is taken out of the grinding chamber through the outlet of the material to be ground after processing. Agitator ball mills are known, for example, based on European Patent No. 1992412 or European Patent No. 2178642.

[0003] Agitator ball mills are available in various designs, such as a full-space mill having a grinding disk on the agitator, or an annular-gap type high-performance mill having grinding elements on a rotor and a stator. However, in order to efficiently use extremely small but expensive grinding bodies, high-performance mills with a power input of 2 kW or more per liter of the volume of the grinding chamber are recommended.

[0004] The pumping action is integrated into the grinding chamber, and the pumping action is generated by a pressure-generating element attached to the rotor shaft, which interacts with a static element attached to the grinding vessel as needed. The pressure-generating rotating element includes, for example, a conveying grinding disc, a screw conveyor, a centrifugal pump impeller, or a side-channel pump impeller, and the geometry of the static grinding vessel may act as a pump housing or a conveying trough.

[0005] Figure 1 illustrates an agitator ball mill with grinding discs 17 positioned on an agitator shaft 11 of a grinding chamber 100. The agitator shaft 11 is rotated by a motor 110 via a belt drive 120. Figure 1 also shows a bearing 130 for the agitator shaft 11 and a seal 140 for sealing the grinding chamber 100. The material to be ground is supplied to the grinding chamber 100 through an inlet 13, and the product is removed from the grinding chamber through an outlet 15 after processing. The direction of product flow within the grinding chamber 100 is indicated by arrow 19'.

[0006] The pulverized material may be separated by a dynamic separation gap or screen (e.g., a central screen or plug-in screen), which is located at the product outlet of the processing area, i.e., inside the grinding chamber. As shown in Figure 1, a deflector basket 31 is provided as part of the rotor, which rotates around a screen 32, thereby blowing the pulverized material and coarse particles, i.e., unwanted particles or unground material, off the screen surface. However, the deflector basket 31 is relatively heavy, preferably made of steel. Since the rotor is usually suspended on only one side, i.e., overhanging via a bearing 130, the basket 31 is in an inconvenient position in a horizontally arranged rotor, i.e., at the outermost end of the shaft, as shown in Figure 1. In a vertically arranged rotor, shaft deflection is not expected to occur, but even in that case, the design of the deflector basket is relatively complex and costly. Furthermore, access for cleaning the pulverized material separator is difficult. It is unavoidable to empty and release the processing area.

[0007] Attempts have already been made to solve this problem, with the separation of the pulverized material being performed outside the processing area. For example, according to German Patent No. 4432200, the discharge line of the material to be pulverized / pulverized material is led from the agitator mill to a separately located separation means 24 for the material to be pulverized / pulverized material, which is equipped with a cylindrical screen as a means for holding the pulverized material. This eliminates the need for additional space required for the separation of the pulverized material, but it may lead to the problem of the pulverized material concentrating upstream of the separation means.

[0008] As shown in Figure 1, so-called total filtration can cause the pulverized material to concentrate due to the product flow, which poses a risk of flow disturbance at the product outlet. The pulverized material separator is susceptible to mechanical wear caused by the pulverized material and requires additional space. Clogging or fouling of the pulverized material separator screen can necessitate emptying the entire processing area during maintenance, for example. In particular, when the product processing volume is high or the product viscosity is high during operation, the pulverized material can concentrate upstream of the pulverized material separator, and in some cases, it may no longer be possible to separate the pulverized material by separation systems such as screens or friction gaps. This can lead to an increase in product temperature, an increase in pressure in the processing area, increased wear on the pulverized material, mill rotor and stator, and even clogging of the pulverized material separator. This can potentially interrupt production.

[0009] Therefore, the separation of pulverized material can limit the amount of product that can be processed, or in some cases even halt the entire process. In particular, when using extremely small pulverized material (0.3 mm in diameter or less) in combination with high-viscosity products, conventional pulverized material separation units often become clogged, or blocked, due to total filtration.

[0010] Further agitator ball mills equipped with a pulverizer separation section are known based on German Patent Application Publication No. 3536918 and German Patent Invention No. 4432200. [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] The objective of the present invention is to improve the separation of pulverized material in an agitator ball mill, and in particular to solve this problem more efficiently. Furthermore, the aforementioned problems must be solved. [Means for solving the problem]

[0012] This objective is achieved by the present invention as defined in the claims.

[0013] In particular, the present invention provides an agitator ball mill equipped with an external pulverizer recirculation unit, wherein pulverizer separation is performed by tangential flow separation using a screen body arranged in the pulverizer recirculation passage. The circulation of the material to be pulverized through the pulverizer recirculation passage is supported by a pumping means.

[0014] According to an aspect of the present invention, an agitator ball mill equipped with an external pulverizer separation unit is provided. The agitator ball mill comprises a grinding container having a grinding chamber, a product inlet for introducing the material to be ground into the grinding chamber, an agitator equipped with grinding elements rotatably positioned in the grinding chamber, and a plurality of pulverizers positioned in the grinding chamber. According to the present invention, a pulverizer recirculation passage is also provided, comprising an inlet from which the pulverizer / material to be ground mixture positioned in the grinding chamber during operation can enter the pulverizer recirculation passage from the grinding chamber, and an outlet from which the pulverizer / material to be ground mixture is returned to the grinding chamber. A tangential flow separator is positioned in the pulverizer recirculation passage and has separation means for separating the pulverizer from the material to be ground, and a product outlet for discharging the ground material from the agitator mill downstream of the separation means. Furthermore, means for exerting a pumping action is provided to assist the circulation of the pulverizer / material to be ground mixture through the pulverizer recirculation passage.

[0015] The entrance to the pulverized material recirculation passage may be located on the side of the grinding chamber opposite the product entrance. Furthermore, the exit to the pulverized material recirculation passage may be located on the side of the product entrance.

[0016] The means for exerting the pumping action may include a pump located in the pulverized material recirculation passage either upstream or downstream of the tangential flow separator.

[0017] The agitator comprises an agitator shaft, on which multiple grinding elements, particularly grinding discs or grinding pins, may be spaced apart from each other. Means for exerting a pressurized action include at least one conveyor disc provided on the agitator, which may be adapted to assist the flow of the grinding material / material to be ground in the grinding chamber from the product inlet toward the inlet of the grinding material recirculation passage. For this purpose, the conveyor disc may be positioned on the outlet side and / or inlet side of the grinding material recirculation passage.

[0018] The ratio of the length of the separating means to the diameter of the separating means is 0.25 to 10, preferably 0.4 to 4.

[0019] The separation means preferably includes a screen body, and the product outlet for the material to be ground, separated from the pulverizer, is positioned radially with respect to the screen body.

[0020] The separation means may be subjected to vibration or ultrasound. The screen body may also be equipped with means for cleaning the screen body to remove pulverized material and coarse particles from the screen body. The means for cleaning may also be designed to rotate or move up and down in a pulverized material recirculation passage. Commercial edge gap filters typically have a sump chamber for collecting separated particles, i.e., residues. According to the present invention, the edge gap filter may be used as a tangential flow filter, with the outlet line of the sump chamber always remaining open, recirculating the pulverized material / material to be ground mixture to the grinding chamber.

[0021] The inlet of the grinding medium recirculation passage may be arranged radially inside the grinding chamber with respect to the agitator. In this case, a grinding medium / material to be ground mixture with a low filling of the grinding medium flows through the grinding medium recirculation passage.

[0022] According to an embodiment, the grinding chamber of the agitator ball mill may be cylindrical with a central longitudinal axis aligned vertically. In this case, the product inlet and the outlet of the grinding medium recirculation passage may be located at the upper part of the grinding chamber, and the inlet of the grinding medium recirculation passage may be located at the lower part of the grinding chamber. Alternatively, the product inlet and the outlet of the grinding medium recirculation passage may be located at the lower part of the grinding chamber, and the inlet of the grinding medium recirculation passage may be located at the upper part of the grinding chamber.

[0023] The present invention can be particularly advantageously used when the grinding medium has a diameter of at most 0.3 mm, preferably at most 0.15 mm or less, and more preferably at most 0.075 mm.

[0024] Two or more tangential flow separators may be arranged in the grinding medium recirculation passage either functionally in parallel or in series, and may be used simultaneously or alternately.

[0025] The ratio of the inner diameter of the grinding chamber to the diameter of the grinding medium recirculation passage is preferably 5 to 30, particularly 6 to 15.

[0026] The velocity of the grinding medium / material to be ground mixture in the grinding medium recirculation passage is preferably at least 2 m / s.

[0027] The present invention also provides a passage member for use as a grinding medium recirculation passage for separating a grinding medium in an agitator ball mill. The passage member has an inlet connection portion and an outlet connection portion adapted to connect to the grinding chamber of the agitator ball mill. Further, a tangential flow separator having a product outlet configured to discharge the ground material to be ground from the agitator ball mill is arranged in the passage member. Using this passage member, it can be retrofitted to an existing agitator ball mill.

[0028] The tangential flow separation used according to the present invention, also known as tangential flow filtration or crossflow filtration, is a method of filtration and is generally used to separate coarse particles or foreign substances from a suspension. According to the present invention, the tangential flow separation is used to separate the comminuted material from the material to be comminuted.

[0029] Furthermore, the comminuted material separator according to the present invention is located outside the grinding chamber and is thus spatially separated from the grinding chamber. The comminuted material separator is not affected by significant mechanical wear and may be controlled to be cleaned and replaced when the mill is full. For example, when two or more comminuted material separators arranged in parallel by a parallel screen with a branch and an optional valve in a pipeline are used, one screen can be operated while the other screen is being maintained during the operation of the machine. In principle, the comminuted material separators may be arranged in series.

[0030] The present invention will be described in detail below with reference to the accompanying drawings.

Brief Description of the Drawings

[0031] [Figure 1] It is a diagram showing a conventional agitator ball mill. [Figure 2a] It is a diagram showing an embodiment of an agitator ball mill according to the present invention. [Figure 2b] It is a diagram showing an embodiment of an agitator ball mill according to the present invention. [Figure 2c] It is a diagram showing an embodiment of an agitator ball mill according to the present invention. [Figure 2d] It is a diagram showing an embodiment of an agitator ball mill according to the present invention. [Figure 2e] It is a diagram showing an embodiment of an agitator ball mill according to the present invention. [Figure 3a] It is a diagram showing different embodiments of a tangential flow separator used according to the present invention. [Figure 3b] This figure shows different embodiments of the tangential flow separator used in the present invention. [Modes for carrying out the invention]

[0032] The present invention will be illustrated below using a horizontally arranged agitator ball mill with a plurality of grinding discs. However, the present invention is equally applicable to other types of agitator ball mills, such as a vertically arranged agitator ball mill. In this agitator ball mill, the grinding chamber is formed by a rotor and a stator that rotate about a vertically aligned central longitudinal axis, and in the grinding chamber a dispersion is produced using the pulverized material. For this purpose, grinding elements, for example, in the shape of round pins, may be attached to the rotor and / or stator.

[0033] The present invention provides an agitator ball mill comprising an external pulverized material recirculation unit and an integrated pulverized material separation unit by tangential flow separation, which includes separation means such as a screen or one or more friction gaps. Embodiments of the mill according to the present invention are shown in Figures 2a to 2e, and these embodiments differ only in the arrangement of the tangential flow separator. The agitator ball mill may be filled with 50% to 100% of the pulverized material relative to the pulverizing chamber volume (i.e., the container volume excluding the agitator).

[0034] To ensure that the pulverized product flows through the pulverizer recirculation device together with the pulverized material, the inlet to the pulverizer recirculation line may be located on the side of the grinding chamber opposite the outlet of the pulverizer recirculation line. The inlet is preferably located near the stator wall or on the stator wall as shown in Figure 2a, in any case, in a region away from the center. This region is a localized overpressure region. The outlet of the pulverizer recirculation device preferably opens upstream of the center of the grinding chamber on the product inlet side, i.e., into a localized negative pressure region of the grinding chamber. The pressure difference between the inlet and outlet of the pulverizer recirculation passage is preferably 0.3 to 3 bar. This ensures uniform and stable circulation of the pulverized material, thereby achieving a high processing rate of the material to be pulverized and a uniform power input across the entire processing area. Furthermore, means are provided to exert a pumping action to support the circulation of the pulverized material / material to be pulverized mixture through the pulverizer recirculation device. The flow rate through the pulverizer recirculation passage should be at least 50 L / min, preferably 100 L / min or more. In relation to the diameter of the pulverized material recirculation passage, the flow rate may be, for example, 0.9 to 20 L / (min·mm). That is, for example, if the flow rate through a pulverized material recirculation passage with a diameter of 35 mm is 115 L / min, the flow rate will be 3.3 L / (min·mm). The flow rate through the pulverized material recirculation passage is preferably 3 to 150 relative to the actual circulating processing volume of the agitator ball mill.

[0035] In the mill according to the embodiment of the present invention shown in Figure 2a, the grinding chamber 100 is formed by a grinding container as usual. The agitator 11 is rotatably positioned in the grinding chamber and has a plurality of grinding discs 17 arranged parallel to each other. The material to be ground is introduced into the grinding chamber 100 through the product inlet 13 and dispersed under the action of the grinder. In the figure, there is a product flow direction within the grinding chamber, indicated by arrow 19, due to the product inlet 13 located on the upstream right side and the inlet 23 located on the left outer circumference of the grinding container and opening to a grinder recirculation passage 20 that leads to the product outlet 15.

[0036] According to the present invention, a pulverized material recirculation passage 20 is provided, through which the pulverized material / material to be pulverized mixture may flow during operation. This pulverized material recirculation passage 20 is supported by a device for exerting a pumping action, which may be provided in the form of a pump 27 in the pulverized material recirculation passage 20, for example. Alternatively, at least one of the pulverizing discs 17 may be designed as a conveyor disc 18, which moves the material to be pulverized in the direction of the pulverizing flow direction 19. This conveyor disc 18 is preferably the pulverizing disc closest to the inlet 23 of the pulverized material recirculation passage 20. However, alternatively, as shown in Figure 2, this conveyor disc 18 may be the first pulverizing disc located at the outlet 25, or it may be located at both the inlet 23 and the outlet 25, i.e., at least two conveyor discs. The flow velocity in the pulverized material recirculation passage is preferably at least 2 m / s. The pulverized material recirculation passage 20 opens to return to the grinding chamber 100 at the opposite end of the grinding chamber 100, preferably near the center of the longitudinal axis of the grinding chamber 100. According to the illustrated embodiment, the outlet 25 of the pulverized material recirculation passage 20 is located on the same side as the inlet 13 for the product.

[0037] To enable a sufficient flow rate through the recirculation passage for the pulverized material, and thereby ensure the efficient removal of the pulverized material, the ratio of the inner diameter D of the grinding chamber to the diameter d of the recirculation passage for the pulverized material is preferably 5 to 30, and particularly 6 to 20.

[0038] A particle separator is provided in the particle recirculation passage 20 to discharge the pulverized product and, consequently, separate the pulverized product from the particle. This separator according to the present invention is designed as a tangential flow separator 21 in the form of a tangential flow filter. Here, the particle / pulverized material mixture flows through a screen body 22, and only the portion of the pulverized material that has already been pulverized passes through the screen body 22 to the product outlet 15 for the pulverized material separated from the particle, thereby separating it from the particle. This configuration prevents the particle from concentrating against the screen at the edges of the processing area, where it must be pressurized and finally removed from the screen surface by a rotor basket, as in the prior art. Instead, the particle needs to re-enter the grinding chamber 100 and flow along the entire length of the screen with a portion of the pulverized material to further disperse the material. The forced flow of the particle along the entire length of the screen or the entire screen surface prevents the accumulation of the particle and coarse product particles, i.e., portions of the product that have not yet been sufficiently pulverized.

[0039] The flow velocity of the material to be pulverized / pulverized mixture is ideally high, and the flow pattern is ideally turbulent. This allows the material to be pulverized / pulverized mixture to flow across the entire screen surface and be cleaned. The screen surface is kept clean by the force of the already present product flow. Shaking or deflecting the pulverized material with an energy-consuming deflector cage is unnecessary. This can be achieved, in particular, by achieving the aforementioned flow velocity, for example, at least 2 m / s. Furthermore, if necessary, the separation surface may be cleaned with a pure liquid.

[0040] The type of separation element 22 of the tangential flow separator 21 may be selected from, for example, a wire mesh screen, a slotted foil support, a mesh filter cloth, or a membrane. It is also possible to arrange multiple modular screen cartridges in the pulverized material circulation line. In principle, the separation element may be at least one dynamic separation gap.

[0041] The size of the pulverized material used is typically in the range of 0.03 mm to 3.0 mm. In particular, when using extremely small pulverized material (less than 0.3 mm in diameter) in combination with high-viscosity products, conventional total filtration methods often result in clogging and blockage of the pulverized material separator. In conventional methods, the pulverized material separator is usually located in the grinding chamber, making it difficult to access for cleaning, which necessitates emptying and opening the grinding chamber.

[0042] In contrast, the pulverizer separator according to the present invention is easily accessible and, thanks to the tangential separation used in the present invention, can be easily accessed even when necessary for maintenance or cleaning, thereby significantly reducing the frequency of maintenance or cleaning.

[0043] To further improve separation, the pulverizer separator may be additionally subjected to vibration or ultrasound according to the present invention. Additionally or alternatively, the screen body in the pulverizer recirculation unit may be designed to rotate. In this case, the screen body may rotate during operation, but this is not essential. In particular, it is not necessary to rotate the screen body during cleaning. Furthermore, the pulverizer separator may be provided with a device for cleaning the filter, in which, for example, a scraper plate scrapes along the tubular screen 22, thereby removing foreign matter, impurities, pulverizer, or even coarse particles of the material to be pulverized.

[0044] A further embodiment of the agitator ball mill according to the present invention is shown in Figure 2b. This embodiment differs from the embodiment in Figure 2a only in that, as already mentioned, two tangential flow separators 21a and 21b are arranged in the pulverized material recirculation passage 20. Therefore, in Figures 2b, 2c, and 2d, only these elements are given reference numerals, and the remaining elements correspond to the elements in Figure 2a.

[0045] The two tangential flow separators 21a and 21b are constructed based on the tangential flow separator 21 shown in Figure 2a, and each comprises separation elements 22a and 22b, in particular a screen, and product outlets 15a and 15b. The tangential flow separators 21a and 21b are located in passages 201 and 202, which branch off from the pulverized material recirculation passage 20 by appropriate valves 203. By arranging the two tangential flow separators 21a and 21b in parallel, one of the tangential flow separators 21a and 21b can be used while the other is being maintained during machine operation.

[0046] Further embodiments are shown in Figure 2c, where the tangential flow separator 21 is located in the pulverized material recirculation passage 20, just upstream of the outlet 25 of the pulverized material recirculation passage 20. Generally, it is advantageous to position the separation means 22 near the product supply point 13, thereby minimizing the distance from the concentration of pulverized material, i.e., the area where the liquid content is reduced, as much as possible. This is further improved by positioning the separator 21 near the outlet.

[0047] Furthermore, Figure 2d shows an embodiment in which the outlet 25 of the pulverized material recirculation passage 20 is integrated with the product inlet 13. This may be achieved by a T-joint 205 that connects the passage of the outlet 25 and the passage of the product inlet 13. However, this only needs to be done downstream of the separator 21 in the pulverized material recirculation passage 20, so that the newly supplied product does not pass through the separator 21. Thus, further simplification of the agitator mill design is possible because only a single access to the grinding chamber needs to be provided.

[0048] Finally, Figure 2e shows an embodiment having essentially the same structure as that shown in Figure 2d. However, here the pulverized material recirculation passage 20 according to the present invention is used in a vertically arranged high-performance agitator mill. In the embodiment shown in Figure 2e, the outlet 25 of the pulverized material recirculation passage 20 is integrated with the product inlet 13, which is achieved by a T-joint 205. However, here again, the merging by the T-joint in the pulverized material recirculation passage 20 may occur only downstream of the separator 21, so that the newly supplied product does not pass through the separator 21. Alternatively, when using a vertically arranged agitator mill, the product may be supplied to the grinding chamber from above. In this case, the flow direction of the product and pulverized material in the pulverized material passage 20 is also reversed accordingly.

[0049] Figures 3a and 3b illustrate in detail possible embodiments of the tangential flow separator 21 used in the present invention. Figure 3a shows an embodiment also shown in Figures 2a to 2e, in which the material to be ground / ground mixture enters the tangential flow separator 21 from above, and the processed product passes through a separation element in the form of a cylindrical screen 22 to the product outlet 15. That is, the product passes through the screen 22 from inside to outside. A portion of the material to be ground returns to the grinding chamber along the screen 22 together with the ground 50. Alternatively, as shown in Figure 3b, the material to be ground is introduced to the screen 22' from the right side, and the portion of the material to be ground that has already been processed passes through the screen 22' (from outside to inside) to the product outlet 15. The remaining portion of the material to be ground returns to the grinding chamber along the screen 22' together with the ground 50.

[0050] The length of the screen 22 or the separation means is preferably 0.25 to 10, and particularly preferably 0.4 to 4, relative to the diameter of the separation element.

[0051] The present invention significantly reduces the compression of the pulverized material compared to the prior art. A simple, inexpensive, and removable screen may be used, and the length, diameter, and type of the separation element may be freely selected. Expensive materials are not required, and the deflector basket commonly used in the prior art is also unnecessary.

[0052] To demonstrate the effectiveness of the pulverized material recirculation passage according to the present invention, a comparative test was conducted between a structure according to the present invention, which includes a pulverized material recirculation section equipped with a tangential flow separator similar to that shown in Figure 2a, and a conventional total separation section using a deflector basket, i.e., substantially as shown in Figure 1. As the material to be pulverized, glass powder with a solid content of 38% in water was used as an example. After a 5-hour test, no wear was observed in the tubular separation device of the structure according to the present invention, and the separation device was completely clean. In the comparative test device with a deflector basket, it was observed that power consumption increased by 25% and pressure increased by 3 to 4 times compared to the device according to the present invention. This leads to a significant advantage of the solution according to the present invention in terms of machine wear and load.

[0053] In the embodiments described by Figures 2a, 2b, 2c, and 2d, the inlet 23 of the pulverized material recirculation passage 20 is located radially outward from the grinding chamber 100. During operation, a large concentration of pulverized material is present in this region, so a heavily packed pulverized material / material suspension, i.e., a mixture containing a relatively large amount of pulverized material, is introduced into the pulverized material recirculation passage 20. On the other hand, if the inlet of the pulverized material recirculation passage is located radially inward, i.e., in the direction of the rotor axis, a less packed pulverized material / material suspension is introduced into the pulverized material recirculation passage, thereby enabling more efficient separation of the pulverized material by the tangential flow separator.

[0054] The pulverizer recirculation device according to the present invention may be retrofitted to an existing agitator ball mill. For this purpose, the present invention also provides a passage member suitable for use as a pulverizer recirculation passage in an agitator ball mill. One end of the passage member is designed as an inlet connection to the grinding chamber of the agitator ball mill, and the other end is designed as an outlet connection to the grinding chamber of the agitator ball mill. The passage member is provided with a tangential flow separator, through which the pulverizer may be separated from the material to be ground.

Claims

1. an agitator ball mill equipped with an external pulverizer separation unit, A grinding container equipped with a grinding chamber (100), The grinding chamber (100) has a product inlet (13) for introducing the material to be ground, An agitator (11) equipped with a grinding element is rotatably arranged in the grinding chamber (100), A plurality of pulverized bodies (50) are arranged in the aforementioned pulverization chamber (100), A pulverized material recirculation passage (20), An inlet (23) is provided that allows the pulverized material / material to be pulverized mixture located in the pulverizing chamber (100) during operation to enter the pulverized material recirculation passage (20) from the pulverizing chamber (100), The outlet (25) through which the pulverized material / material to be pulverized mixture is recirculated to the pulverization chamber (100) A pulverized material recirculation passage (20) equipped with, A tangential flow separator (21) is provided in the aforementioned pulverized material recirculation passage (20) and includes a separation means (22) for separating the pulverized material from the material to be pulverized, and a product outlet (15) for discharging the pulverized material from the agitator mill downstream of the separation means (22). Means for exerting a pumping action to assist the circulation of the pulverized material / material to be pulverized mixture through the pulverized material recirculation passage (20), An agitator ball mill equipped with this feature.

2. The agitator ball mill according to claim 1, wherein the inlet (23) of the pulverized material recirculation passage (20) is located on the side of the grinding chamber (100) opposite to the product inlet (13), and / or the outlet (25) of the pulverized material recirculation passage (20) is located on the side of the product inlet (13).

3. The agitator ball mill according to claim 1 or 2, wherein the means for exerting the pumping action comprises at least one conveyor disc (18) provided on the agitator, the conveyor disc (18) being adapted to assist the flow of the pulverizer / material to be pulverized mixture in the grinding chamber (100) from the product inlet (13) toward the inlet (23) of the pulverizer recirculation passage (20), and the conveyor disc (18) is preferably located on the side of the outlet (25) and / or the inlet (23) of the pulverizer recirculation passage (20).

4. The agitator ball mill according to any one of claims 1 to 3, wherein the means for exerting the pumping action is provided with a pump (27) located upstream or downstream of the tangential flow separator (21) in the pulverized material recirculation passage.

5. The agitator ball mill according to any one of claims 1 to 4, wherein the agitator comprises an agitator shaft, and a plurality of grinding elements, particularly grinding discs or grinding pins, are arranged spaced apart from each other on the agitator shaft.

6. The separation means is subjected to vibration and / or ultrasound, according to any one of claims 1 to 5.

7. The agitator ball mill according to any one of claims 1 to 6, wherein the length of the separating means relative to the diameter of the separating means is 0.25 to 10, preferably 0.4 to 4.

8. The agitator ball mill according to any one of claims 1 to 7, wherein the separation means has a screen body (22), and the product outlet (15) for the material to be pulverized, separated from the pulverizer, is arranged radially with respect to the screen body (22).

9. The agitator ball mill according to claim 8, wherein the screen body (22) has means for cleaning the screen body (22) to remove the pulverized material and coarse particles from the screen body (22), and the means for cleaning rotates or performs a vertical movement.

10. The agitator ball mill according to any one of claims 1 to 9, wherein the inlet (23) of the pulverized material recirculation passage (20) is located radially inward of the grinding chamber (100) relative to the agitator, thereby allowing a pulverized material / material to be ground mixture with less pulverized material filling to flow through the pulverized material recirculation passage (20).

11. The agitator ball mill according to any one of claims 1 to 10, wherein the grinding chamber (100) is cylindrical with a central longitudinal axis aligned vertically, and preferably the product inlet (13) and the outlet (25) of the pulverized material recirculation passage (20) are located at the top of the grinding chamber, and the inlet of the pulverized material recirculation passage is located at the bottom of the grinding chamber, or the product inlet (13) and the outlet (25) of the pulverized material recirculation passage (20) are located at the bottom of the grinding chamber, and the inlet of the pulverized material recirculation passage is located at the top of the grinding chamber.

12. The agitator ball mill according to any one of claims 1 to 11, wherein the pulverized material has a maximum diameter of 0.3 mm, preferably a maximum diameter of 0.15 mm, and more preferably a maximum diameter of 0.075 mm.

13. The agitator ball mill according to any one of claims 1 to 12, wherein two or more tangential flow separators (21) are arranged in a functional configuration in parallel or in series in the pulverized material recirculation passage (20) and can be used simultaneously or alternately.

14. The agitator ball mill according to any one of claims 1 to 13, wherein the ratio of the inner diameter D of the grinding chamber (100) to the diameter d of the pulverized material recirculation passage (20) is 5 to 30, particularly 6 to 20, and / or the velocity of the pulverized material / material to be ground in the pulverized material recirculation passage (20) is at least 2 m / sec.

15. A passage member for use as a recirculation passage for separating pulverized material, in an agitator ball mill according to any one of claims 1 to 14, comprising: an inlet connection and an outlet connection adapted to connect to the grinding chamber (100) of the agitator ball mill; and a tangential flow separator (21) disposed in the passage member and having a product outlet (15) configured to discharge the pulverized material from the agitator mill.

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