JP2680738B2 - Agitation mill with separation means in a rotating cage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a grinding container and a stirring shaft rotatably arranged therein, which limits a grinding space, and further, an inlet for a material to be ground and a stirring shaft. A cage that rotates with a stirring shaft as part of the agitator, and a separating means disposed within the cage that holds the untreated material and optionally milling auxiliary medium and treats the treated material. An inlet zone in which the crushing space is arranged adjacent to the inlet of the material and in which an agitation shaft is arranged axially over at least most of its length; The present invention relates to a stirring mill which is divided into a zone adjacent to an axial direction of the zone and a separation zone arranged around the cage.

Known stirring mills of the type described above (EP 01
46852B1), the separation zone is arranged to extend up to 25% of the total length of the grinding space, at least 75% of which is occupied by the inlet zone. The effective area of the separating means is generally 5 to 10% of the internal area of the crushing container which limits the crushing space. As a result, the separating means considerably impede the discharge of the material to be ground. Therefore, the velocity component of the material flow in the axial direction of the grinding vessel is relatively small and each individual particle of the material to be ground has a probability of being gradually reduced to the desired size on the long path between the material inlet and the separating means. Is high. However, the throughput per unit time is not very high for a given overall size of the known mill. this is,
The single processing of the material through the grinding space of the agitating mill cannot achieve the required grinding sufficiently, so that the material has to be sucked and circulated through the grinding space several times, or the material is fed and ground. It is clear from the need to repeatedly reciprocate between the spaces.

The problem underlying the present invention is to propose a stirring mill which can significantly improve the crushing performance per unit time and enables a particularly uniform crushing treatment of the material to be crushed.

In order to solve this problem, the present invention provides a stirring mill of the type described at the beginning, in which the separation zone extends over 40 to 80% of the entire length of the grinding space, and the effective area of the separating means is set to the grinding space. Is at least 20% of the internal area of the crushing container.

As used herein, the effective area of the separating means means the surface area of the separating means provided with an annular gap located between the sieve mesh or the separating rings.

The stirring mill according to the invention has a relatively long separation zone,
Due to the relatively large effective area of the separating means, it is possible to pass through relatively quickly, so that for each individual particle of material to be ground, the probability of being ground in one pass of the grinding space is very low. . Therefore, the individual particles of the material, from a statistical average point of view, have to pass through the grinding space much more frequently than in the known stirring mills described in the preamble in order to be ground to the desired particle size. . Nevertheless, the surprising effect that the stirring mill according to the invention makes it possible to achieve a considerably higher grinding power than in the known stirring mills described in the preamble. The uniformity of milling can be further increased. Due to the short mean residence time of the individual particles in the agitator mill, the risk of material damage due to overheating is essentially less than in the known art.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Each of FIGS. 1 to 11 shows a stirring mill in a vertical section.

Each of the illustrated stirring mills includes a substantially cylindrical crushing container 10 in which a stirring shaft 12 is coaxially mounted, an inlet 14 for a material to be crushed, and a separating means 16, and a downstream side of the separating means. The material outlet 18 is arranged. Grinding container 10 and stirring shaft 12
To form a grinding chamber, i.e., a grinding space 20, which, in each of the illustrated agitating mills, is an inlet zone.
22 and separation zone 24 shall be included. Entrance zone 22
Shall include an inlet 14 for material (FIGS. 1 and 7-11) or be axially connected to said inlet (FIGS. 2-6). Separation zone 24 axially ingress zone
It is arranged in the range of a cage 25 so as to be connected to 22, and the cage is formed on the majority shaft 12 and has at least a substantially cylindrical shape so as to surround the separating means 16 and open at one end side. The length of the separation zone 24 is set to match the length of the cage 25.

The separating means 16 may be constituted by a plurality of individual separating rings or by a sieve mesh, and in all the illustrated embodiments it is at least substantially cylindrical and the effective length is the length of the cage 25 and thus the separating means. Match the length of zone 24. In all the illustrated embodiments, the length of the separating means 16 measured in the axial direction of the stirring shaft 12 is about 1/2 of the total length of the crushing space 20 (see FIGS. 1 to 8, 10, 10 and 11). ) ~
Approximately 2/3 (Fig. 9). The outer diameter of the working surface of the separating means 16 which plays a crucial role for the throughput is set to be slightly smaller than the inner diameter of the cage 25. The product of the length and the diameter of the working surface of the separating means 16 is about 20 to 25% of the product of the length and the inner diameter of the grinding container 10.

The stirring mills shown in FIGS. 1 to 5 and 7 to 11 are of a horizontal type in which the stirring shaft 12 is horizontally arranged. On the other hand, FIG. 6 shows a stirring mill of vertical type.

In the stirring mill shown in FIG. 1, the material inlet 14 is formed by a hole in the stirring shaft 12. In the region from the start of the inlet zone 22 toward the end, the stirring shaft 12 has a small diameter: that is, its outer diameter is about 1/4 to 1/3 of the inner diameter of the grinding container 10.
The outer diameter of the stirring shaft 12 is gradually increased to about 2/3 of the inner diameter of the grinding container 10 toward the end of the inlet zone 22: the stirring shaft 12
Has a structure in which its large diameter is retained in the separation zone 24.

The stirring element 26 is supported by the region of the stirring shaft 12 arranged in the inlet zone 22: the stirring element, in the embodiment of FIG. 1, is a long radial pin extending towards the cylindrical inner wall of the grinding vessel 10. Formed by. A stirring element 28 is also provided by the cage 25 in the region of the stirring shaft 12 which is arranged in the separation zone 24.
And the stirring element is formed by a short radial pin. As shown in FIG. 1, the grinding space 20 is partially filled with the material 30 to be ground and the auxiliary grinding medium 32.

The cage 25, in the embodiment of FIG. 1, is provided with a slot 34 parallel to the axis and is open at the end facing the material outlet 18. The separating means 16 is formed by a cylindrical sieve arranged coaxially with the stirring shaft 12 and attached to the crushing container 10. A packing 36, which is coaxial with the separating means 16, is arranged inside said means, which remains with the separating means 16 a relatively narrow annular space 38 which expands towards the outlet 18 of the material. Place it.

The material 30 to be ground is mainly processed in the inlet zone 22, in which the grinding support medium, i.e. the auxiliary medium 32, is strongly activated by the long stirring element 26. Nevertheless, the material inlet 14 is relatively well protected so that the grinding aid medium 32, which has a high speed of movement, is used.
Therefore, there is no risk of rapid wear due to a large number of collisions. The short stirring element 28 in the separation zone 24 is essentially
The function of avoiding or eliminating the aggregation of the crushing support medium 32 is exclusively exerted.

The material 30 mixed with the grinding support medium 32 is
Through the separation zone 24, through the open end of the stirring shaft 12 and into its cage 25. From the cage, the treated material 30 flows through the separating means 16 and the annular space 38 to the material outlet 18. In contrast, the grinding aid or grinding aid medium 32 repeats the cycle after being projected outward through the slot 34.

The stirring mill according to the embodiment of FIG. 2 differs from that shown in FIG. 1 in that the material inlet 14 is arranged on the end side of the grinding container 10 and opened directly into the grinding space 20. . Also, facing elements 40 are mounted on the cylindrical inner wall in the inlet zone 22 of the grinding container 10, which facing elements are formed as radial pins and extend between the stirring elements 26 just before the stirring shaft 12. Further, a coolant channel 42 is formed in the stirring shaft 12:
This flow path extends from the drive end at the left end in the drawing of the stirring shaft 12 into the filling body 36, which is formed integrally with the stirring shaft 12 in the embodiment of FIG. 2 or on the stirring shaft 12. Install on. The separating means in the embodiment of FIG. 2 is also constituted by a sieve, but unlike in FIG. 1, the sieve is attached to the stirring shaft 12 instead of the grinding container 10 so that the separating means 16 rotates with the stirring shaft 12. .

In the embodiment of FIG. 3, the stirring element 26 is formed by a circular or non-circular disc mounted on the stirring shaft 12 in the inlet zone 22. The separating means 16 are attached to the grinding vessel 10 as in FIG. 1, but in the example of FIG. 3 are formed by a ring device with radial gaps between the individual rings. In the separation zone 24, the stirring shaft 12 is not provided with a stirring element: however, with the cage 25 arranged around the separating means 16, its slot 34 provides sufficient movement for the various materials to be ground. The material 30 and the grinding aid medium 32 can be used.

The embodiment shown in FIG. 4 is particularly suitable for agitating a stationary counter element 40 between disc-shaped agitating elements 26 in the inlet zone 22.
It differs from the one shown in FIG. 3 in that it is attached to 10 and the opposing elements are formed by radial pins as in FIG. As shown in FIG. 4, a solid shaft core 44 is provided on the stirring shaft 12, and the disc-shaped stirring element 2 is mounted on this core.
6. Install the spacer bushing 46 located between the stirring elements, as well as the hollow shaft portion 48 supporting the cage 25. The outer diameter contour shape of the stirring shaft 12 shown in FIG. 4 is the same as that shown in FIG. However, the disk-shaped stirrer element 26 located on the left side of FIG. 4 forms a radial slot 50 which corresponds to the counter-element whose shape and arrangement is pin-shaped. These slots allow the stirring element 26 to move the stirring element 26 into the shaft core 44 with the shaft core 44 already assembled in the grinding container 10 or prior to inserting the shaft core 44 from the right side to the left side as shown in FIG. What is needed to be able to fit over.

The stirring mills shown in FIGS. 1 to 4 and 6 to 11 are intended to be operated using a grinding auxiliary medium, while the stirring mills shown in FIG. An agitating element 26 formed as an attached dispersion disk is provided to enable operation without using a grinding support medium. The separating means 16 is formed as in FIGS. 3 and 4, but in the example of FIG. 5 it has the function of retaining the coarse particles of material and allowing only the processed material to reach the material outlet 18. It is something to demonstrate.

In all the illustrated embodiments, the stirrer shaft 12 is mounted in a cantilevered manner, so that the bearing 52 and shaft seal 54 are located at only one end of the grinding vessel 10 as shown. A drive device having a normal structure is or can be connected to this end portion or its vicinity. In each of the stirring mills shown in FIGS. 1 to 5 and FIGS. 7 to 11, the separating means 16 is a crushing container separated from the driving device and the mount.
Place in half of 10.

However, in the vertical type stirring mill shown in FIG. 6, the separating means 16 is disposed in the half of the drive unit side of the crushing container 10 and the material outlet 18 is provided via the discharge chamber 56 adjacent to the shaft seal 54. Connect to. Therefore, the stirring element 26 is mounted at or near the free end of the stirring shaft 12.

In the agitating mill shown in FIG. 7, the agitating shaft 12 has a small diameter only in the region of the bearing 52 and the shaft seal 54 leading to the start of the inlet zone 22. The diameter is about 1/4 to 1/3 of the inner diameter of the crushing container 10. A conical portion forming a part of the stirring shaft 12 at a position slightly separated from the shaft seal 54 in the axial direction.
58 is initiated and a conical friction gap 62 is defined by this conical portion and its corresponding conical shaped inner end wall of the grinding container 10. Material inlet 14, shaft seal 54
To the radially inner region of the conical friction gap 62 proximate to. Connected to the conical friction gap 62 is a cylindrical friction gap 64 of approximately the same width, which cylindrical friction gap extends to the end of the inlet zone 22. The material 30 to be ground is activated in the friction gap by friction with the walls of the grinding vessel and the stirring shaft which define the friction gaps 62,64. In the separation zone 24 around the separation means 16, the outer diameter of the stirring shaft 12 is set to be slightly smaller than the maximum diameter of the conical portion 58.

The embodiment shown in FIG. 8 corresponds to the embodiment shown in FIG. 7 in that the outer diameter of the stirring shaft 12 is significantly reduced within a range of a slight axial distance from the shaft seal 54. The outer diameter of the stirring shaft 12 is about 2/3 of the inner diameter of the crushing container 10 over most of the inlet zone 22 and all of the separation zone 24. Entrance zone 2
2 and in the separation zone 24, the stirring shaft 12 is provided with a stirring element 26 consisting of a relatively short radial pin. But,
Opposing elements 40, which are likewise attached to the inner wall of the grinding vessel as short radial pins, are arranged only in the inlet zone 22: Such an opposed element 40 is arranged in the separating cylinder 24 around the separating means 16. Absent.

The stirring mill shown in FIG. 9 corresponds to the example of FIG. 7 in that the conical portion 58 and the inner end wall 60 of the grinding container 10 are included. That is, also in this example, the conical friction gap 62 and the cylindrical friction gap 64 are provided. However, the conical portion 58 ends with an axially narrow collar 66, and immediately after that, ie on the right side of FIG.
By connecting the cage 25 with a smaller outer diameter, the cylindrical friction gap 64 is made very short. Cage 25
The length of the separation zone 24 and thus of the separation zone 24 is approximately 3/4 of the length of the grinding space 20. A pin-shaped stirring element 28 is attached to the cage 25, and a pin-shaped opposed element 40, which is likewise interposed therebetween, is attached to the grinding container 10 so as to protrude radially inward. As a result, the material 30 and the grinding aid medium 32 are activated relatively strongly. However, the milling auxiliary medium 32 thus activated does not reach the region of the material inlet 14 by being reliably blocked by the collar 66. The material inlet is therefore particularly effectively protected from wear.

In the embodiment shown in FIG. 10, the cage 25 is connected in the axial direction from its open free end side in three regions, that is, in the radial continuation starting from a position close to the open cage end and parallel to the axial direction. Divided into a region 66 provided with slots 34, a closed central region 68 without any such slots, and a region 70 located away from the open cage end and provided with radial continuous slots 34. To do. As in FIG. 1, the length of the closed central region 68 of the cage 25 is approximately one half the length of the separation zone 24.

In the embodiment shown in FIG. 11, the cage 25 is completely closed not only in the central area 68, but also in the area adjacent to the open cage ends. Apertures, such as radial continuous slots 34, which are parallel to the axial direction, pass through them through the grinding aid media 32.
Is to be discharged from the cage 25, but it is arranged only in the area 70 distant from the open cage end and the separating means
It extends around the 16 end regions 72.

According to the configuration of the cage 25 shown in FIGS. 10 and 11,
The uniformity of the flow around the relatively long and large area separating means is improved, which makes it possible to further increase the grinding power per unit time. Material 30 and grinding support medium 32
Are blocked from radial flow in the central region of the cage. In its central region, it is possible to generate only a flow that contains substantially no radial component. As a result, the annular space between the separating means 16 and the inner wall of the cage 25
It is possible to prevent blockages within 38 and allow the separating means to exert maximum efficiency over its entire length under any normal operating conditions.

 ─────────────────────────────────────────────────── ───Continued from the front page (56) Bibliographic references Sho 56-28756 (JP, U) Special table Sho 61-500715 (JP, A) US patent 3172609 (US, A)

Claims (13)

(57) [Claims] 1. A crushing container (10), and a stirring shaft (12) rotatably disposed inside the crushing container (10) for limiting a crushing space (20), and further, an inlet for a material to be crushed ( 14), a cage (25) rotating with the stirring shaft as a part of the stirring shaft (12), and a separating means (16) arranged in the cage (25), the separating means being untreated. Material (3
0) and the grinding auxiliary medium (32) as required, and the processed material (30) can flow out to the material outlet (18). Furthermore, the grinding space (20) is
An inlet zone (22) arranged adjacent to the material inlet (14) and having an axial stirring shaft (12) over at least a major part of its length, and the axial direction of the inlet zone (22) In a stirring mill which is divided into a separation zone (24) arranged adjacent to the cage (25), the separation zone (24) is 40 to 80 of the total length of the grinding space (20).
%, And the effective area of the separating means (16) limits the crushing space (20).
0) at least 20% of the internal area. 2. The stirring mill according to claim 1, wherein the effective area of the separating means (16) is 25 to 50% of the internal area of the crushing container (10) which limits the crushing space (20). Characteristic stirring mill. 3. The stirring mill according to claim 1 or 2, wherein at least 90% of the total driving power of the stirring shaft (12) of the grinding container (10) and the stirring shaft (12) is in the inlet zone (22). ), And up to 10% in the separation zone (24),
A stirring mill, characterized in that it is formed so as to be introduced into the material (30) to be ground. 4. The stirring mill according to any one of claims 1 to 3, wherein the stirring element (26) is supported by a stirring shaft (12), and an opposing element ( 40)
A stirring mill characterized in that the opposing element (40) is arranged exclusively in the inlet zone (22) in the crushing container (10) attached. 5. The stirring mill according to any one of claims 1 to 3, wherein the stirring element (26) is supported by a stirring shaft (12), the stirring element (26) being exclusively the inlet zone. (22) An agitating mill characterized by being placed inside. 6. The stirring mill according to claim 1, wherein the diameter of the stirring shaft (12) in the inlet zone (22) adjacent to the material inlet (14) is defined by the separation zone (24). ) The stirring mill is characterized in that it is set considerably smaller than the diameter in). 7. The stirring mill according to claim 6, wherein the diameter of the stirring shaft (12) extends over at least a part of the entire length of the inlet zone (22).
Separation zone (24) up to at least twice the smallest diameter of 2)
A stirring mill characterized by gradually increasing in the direction of. 8. A stirring mill according to claim 6 or 7, characterized in that the stirring shaft (12) is provided with a smooth conical portion (58) in the inlet zone (22). 9. Stirring mill according to claim 8, characterized in that the conical part (58) is arranged directly adjacent to the material inlet (14). 10. The stirring mill according to any one of claims 1 to 9, wherein the stirring shaft (12) has a separation zone (24).
In the end area of the entrance zone (22) close to the cage (2
A stirring mill provided with a collar (66) having a diameter larger than that of 5). 11. The stirring mill according to claim 1, wherein the cage (25) is formed in a closed shape in the central area (68), and the central area is the entire length of the separation zone (24). Of at least 1/4 of the stirring mill. 12. The stirring mill as claimed in claim 11, wherein the closed area (68) of the cage (25) extends over the entire length of the separation zone (24).
A stirring mill characterized by being extended over 1/3 to 2/3. 13. Stirring mill according to claim 12, wherein the cage (25) is opened radially outward, exclusively around the end region (72) remote from the open end of the cage (25). An agitating mill characterized by being formed into a predetermined shape.