JPH01317552A - Grinding method and device - Google Patents

Abstract

PURPOSE:To enhance crushing efficiency by providing a plurality of screw shafts in a tower mill. CONSTITUTION:In a vertical treatment cylinder 11, a plurality of vertical screw shafts 12 and a crushing medium b (e.g., steel ball) are provided. The materials a to be crushed are admitted into the treatment cylinder 11 and caused to flow therein, while rotating the screw shafts 12. The materials a are crushed between one another and by the crushing medium b into fine article particles, which are carried out of the treatment cylinder 11 together with the liquid outflowing therefrom by operating a plurality of screw shafts 12, resulting in a reduction in the disrupted flow of the materials being crushed and hence considerable reduction in the amount of the rough article particles with improved crushing efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a grinding method and apparatus for producing granules.

C. PRIOR TECHNOLOGY AND PROBLEMS THEREOF] This type of grinding and grinding device is called a tower mill, and as shown in FIG. At the same time, a grinding medium such as a steel ball is filled, and while the screw shaft 2 is being rotated, the workpiece a is introduced into the processing cylinder 1 and made to flow, and the workpiece a is moved between the two and the grinding medium. The produced particles C are made into fine particles C by grinding with a grinder, and the produced particles C are placed on a fluid such as air or water passing through the processing tube 1.
Extract outside.

In this grinding and pulverizing apparatus, there are cases where the material to be processed a is short-circuited from the input section 7 to the discharge port 8. For this reason, conventionally,
As shown in the figure, a capture device S for coarse production particles C such as a sedimentation classifier is installed downstream of the discharge port 8, and the production particles C captured here are fed back into the processing cylinder 1 via a bomber or the like. ing.

The intervention of this trap 9 leads to an increase in the size of the equipment and makes fluid control complicated. In addition, since a circulation action is added to the trapped BS that does not perform a grinding action, it leads to an increase in operating power, and as a result, the grinding efficiency is poor.
Compared to the case where no short circuit occurs in the processing tube 1, the lining cost is higher and the grinding efficiency is much lower.

In addition, conventionally, only one screw shaft 2 is provided in one processing cylinder 1, so the flow of the grinding media tends to be uniform, and the above-mentioned short-circuit effect occurs frequently, causing coarse particles in the product. A large amount of produced particles C is mixed in, and as a result, the grinding efficiency is reduced.

The present invention takes the above points into consideration and aims to reduce the short circuit as much as possible and increase the grinding efficiency.

(!!Means for solving Ill) In order to achieve the above purpose, in the tower mill mentioned above,
The number of the screw shafts is plural.

A plate may be provided between each of the screw shafts to partition the upper part of the packed bed of grinding media, and the plate may be provided along the entire length of the packed bed in the vertical direction to serve as a partition wall, and the upper or lower part of each partition wall may be It is also possible to form communication holes so that the produced particles move in a zigzag pattern up and down between the partition walls.

In addition, there are two screw shafts, a partition wall is provided between the screw shafts, communication holes are formed in the upper and lower parts of the partition wall, and the grinding medium is circulated between both screw shafts through the communication holes. It is also possible to carry out the grinding. This circulation means includes: slowing down the rotational speed of the screw shaft in the front stage of the attrition action than that in the rear stage; moving the screw shaft in the latter stage of the attrition action closer to the partition wall than that in the front stage; and It is conceivable to make the pitch smaller than that of the subsequent stage.

Furthermore, it is also possible to install a screen in the communication hole that prevents the grinding medium from passing through, and to make the dimensions (size and diameter) of the grinding medium smaller in the rear stage than in the front stage of the grinding action, with the partition wall as the boundary. can.

Further, the screw height, pitch, or rotation speed of adjacent screw shafts can also be made different.

[Effect]

When multiple screw shafts rotate within one processing cylinder,
The flow action of each screw interferes with each other, so that the flow of the grinding medium is not uniform, that is, a grinding action is performed while a kneading action is performed.

If a partition plate or partition wall is provided, the above-mentioned short circuit can be reliably prevented. In addition, by circulating the grinding media through the partition wall, the material to be processed will circulate and flow smoothly as it circulates, eliminating dead spaces where conventionally no flow occurred.
Driving becomes smooth.

If a screen is provided in the communication hole of the partition wall, movement of the grinding medium between the two screw shafts is prevented.

Therefore, the size of the grinding medium in the grinding area of each screw shaft can be made different, and by filling the front stage with a large size grinding medium, it is possible to charge a larger workpiece into the front stage than before.

By varying the pitch, height, or rotation speed of the screw shaft, the flow of the grinding medium in the processing cylinder becomes smoother and the dead space is eliminated.
Driving becomes smooth.

[Example 1] As shown in FIG. 1, the grinding and grinding device 10 has a cylindrical processing cylinder 11 filled with grinding media to a required height, and two screw shafts 12 in the processing cylinder 11. .12 is rotatably provided, and when a workpiece a is put into the processing cylinder 11 from the supply bin 60 while the shaft 12 is rotating, the workpiece a is rotated as shown by the arrow in the figure. Then, the grinding medium moves up and down and stirs (flows), and the material to be processed a is ground into fine particles (C) by grinding between them and with the grinding medium.

The two screw shafts 12.12 may be driven by separate motors, but the two shafts 12.12 may be driven by one motor in succession using gears, belts, etc.

An auxiliary bin 80 is connected to the bottom of the processing cylinder 11 via an on-off valve v1.
is connected, and when the valve (1) is opened, the water in the processing cylinder 11 and the material to be processed a (produced particles C) naturally fall into the auxiliary bin 80 and are stored therein. Instead of letting it fall naturally, it can also be forcibly pulled out using a pump.

Outflow pipe 17 led out from the upper outlet 11a of the processing cylinder 11
are connected to the intermediate bin 21 and the product bin 31 via on-off valves V, , V, respectively, and overflow water (slurry containing production particles C) from the outlet 11a of the processing cylinder 11 flows through the valve When v2 is open, v2 is closed, and v2 is closed, the liquid flows into the product bin 31.

A return pipe 16 with a pump Pl and an on-off valve v4 interposed therebetween is provided from the intermediate bin 21 to the inflow part 13a of the processing cylinder 11. When the on-off valve v4 is opened and the pump P1 is driven, the intermediate bin 21 Slurry water containing produced particles C (hereinafter simply referred to as water) is returned to the processing cylinder 11. In addition, the intermediate bin 21 includes a pump Pu and an on-off valve vS.
A liquid feeding pipe 81 from an auxiliary bottle 80 with a auxiliary bottle 80 interposed therebetween is connected, and water in the auxiliary bottle 80 is sent to the intermediate bottle 21 by a pump P. In addition, in the figure, T is a stirrer.

This embodiment is constructed as described above, and its operation will now be explained with reference to the time chart shown in FIG. 2. In addition, in FIG. 2, the thick solid line indicates the state in action (driving) or in the open state.

First, open/close valve V! is opened, the grinding device 10 is driven, and the material to be processed a flows into the processing cylinder 11 together with water. In the processing cylinder 11, the material to be processed a is pulverized by the vertical flow and classified by the flow of water, and the classified product particles C are transferred from the processing cylinder 11 outlet 11a to the intermediate pipe 17. The water flows into the bin 21 and is stored therein.

During the grinding action inside the processing cylinder 11, the two screw shafts 1
Since the flow action is performed in step 2.12, the flow becomes complex and smooth, and the flow of the grinding media is not uniform, and the grinding is performed smoothly. That is, compared to a single screw shaft 12, the synergistic effect of having two screw shafts allows smooth flow of the material to be processed and the grinding medium, resulting in smooth operation, and as a result, the grinding efficiency is improved. will improve.

Note that the directions of rotation of the screw shafts 12, 12 may be the same or may be opposite directions (and the number of rotations may be different).

Further, the directions of both screws can also be reversed.

When the intermediate bin 21 becomes full, the introduction of the material to be processed a is stopped, the on-off valve v4 is opened, and the water in the intermediate bin 21 is sent into the processing cylinder 11 by the pump P1.
Fluid circulation among the processing cylinder 11, intermediate bin 21, and processing cylinder 11 is performed to perform the grinding.

When the particle size of the product particles C coming out of the processing cylinder 11 reaches a required value, the on-off valve ■□ is closed, the valve v3 is opened, and the fluid containing the product particles C of the desired particle size flows into the product bottle 31 and is stored therein. When the water stored in the intermediate bottle 21 runs out, the pump P1 is stopped and the on-off valve v4 is closed.

Next, the on-off valve v1 is opened, and the water in the processing cylinder 11 flows into the auxiliary bottle 80 and is stored therein. The water in the processing cylinder 11 may also be sent to the product bin 31 by drawing out a pump or the like, but the water in the auxiliary bottle 80 is
It is not desirable as a product because it contains coarse particles that remain unringed and are not sufficiently crushed. Therefore, during the next crushing cycle, the stored water is sent from the auxiliary bin 80 to the intermediate bin 21 during the crushing action.

Thereafter, the above-mentioned action is repeated, and the grinding action is performed by continuously driving the grinding and grinding device 10.

In this embodiment, an intermediate bin 21 is provided to circulate the produced particles C into the processing tube 11, but the grinding action within the processing tube 11 is smoothly performed and the produced particles C have a desired particle size. In this case (if the coarse production particles C do not flow into the product bin 31), the coarse production particles C may flow directly into the product bin 31 without going through the intermediate bin 21. In particular, this is sufficient for low-concentration grinding.

[Embodiment 2] In the embodiment shown in FIG. 3, a partition wall 13 made of a plate or the like is provided between the screw shafts 12 and 12, and a communication hole 14 is formed in the lower part of the partition wall 13.

With this configuration, due to the presence of the partition wall 13, there is no short circuit of the workpiece a (after the workpiece a is ground by the previous stage screw shaft 12 (on the left side in the figure), the workpiece a is ground through the communication hole 14. From there, the process proceeds to the screw shaft 12 at the subsequent stage, so that the grinding action is performed evenly on all the objects to be processed, and uniform product particles C without coarse particles can be obtained.

Note that, as shown in FIG. 4, the partition wall 13 may be provided only above the packed bed of the grinding media. In addition, as shown in FIG. 5, when three or more screw shafts 2 are provided, the communication holes 14 are formed so as to alternate up and down toward the latter stage of the grinding action, so that the produced particles C are separated from each partition. The transition between the walls 13 is made in a vertical zigzag pattern.

[Embodiment 3] The embodiment shown in FIG. 6 differs from Embodiment 2 in that a communication hole 15 is also formed in the upper part of the partition wall 13, and the rotation speed of the screw shaft 12 in the rear stage is made faster than that in the front stage. be.

With this configuration, due to the difference in rotation speed, the level of the grinding medium on the rear stage side becomes higher than that on the front stage side, and the powder medium flows between both screw shafts 12.12 via the double speed passage hole 14.15. The water circulates and the grinding action becomes more efficient. In particular, it is effective for grinding the processed material a with low fluidity.

Note that the outlet 11a of the processing cylinder 11 is located lower than the upper communication hole 15, and has a screen 15 for preventing the crushing medium from flowing out.
Add a. The screen 15a may be a perforated plate, a bar screen, or the like.

A level difference in the level of the grinding media between the two screw shafts 12.12 can also be created by moving the rear screw shaft 12 closer to the partition wall 13 than the front screw shaft. At this time, the degree of approach can be made variable, and furthermore, the degree may be changed continuously during driving, and the zero rotation speed can also be similarly made variable.

Furthermore, by making the screw pitch of the screw shaft 12 at the front stage of the grinding operation smaller than that at the rear stage, a difference in the level of the grinding media can be created.

[Embodiment 4] In the embodiment shown in FIG. 7, a screen 14 similar to the screen 15a is provided in the communication hole 14 in the embodiment 2.
A is stretched, and the size of the grinding media in the former stage is larger than that in the latter stage.

With this configuration, it is possible to charge a larger object a than before, and the grinding action is performed in stages.

[Embodiment 5] The embodiment shown in FIG. 8 is the same as the embodiment 2, except that the height of the screw shaft 12.12'' is different.

With this configuration, the flow of the grinding medium is directed to the processing cylinder 11.
The entire inside is smooth and the operation is smooth, resulting in improved grinding efficiency.

Note that the screw height may be the opposite of that illustrated, and also in the first embodiment, the screw height can be made different.

[Example 6] In the example shown in FIG. 9, a communication hole 14 is formed only in the upper part of the partition wall 13, and the processed material a (produced particles C) is transferred to the subsequent stage from this communication hole 14. .

[Embodiment 7] In the embodiment shown in FIG. 10, the heights of the screw shafts 12 and 12 (levels of the bottoms of the front and rear stages of the processing cylinder 11) are also different from those of the fifth embodiment, and the upper part of the partition wall 13 is also different. A communication hole 15 is formed to allow circulation of the grinding medium.

With this configuration, the grinding media flows smoothly from the first stage to the second stage.

The level difference between the bottom of the front and rear stages of the processing cylinder does not circulate (the third
It can also be used in figures (e.g., figures).

In each of the above embodiments, the fluid was liquid (water), but
This invention does not apply to gases such as air, unless there is a problem.
In other words, it goes without saying that a dry method can also be used.

Further, the number of screw shafts 12 is not limited to two, but may be more than two, and the pitch of the screws can also be varied for each screw shaft 12 or for the same screw shaft 12.

〔Effect of the invention〕

As can be understood from the above description, this invention reduces the number of short circuits in the processed material, thereby minimizing the number of coarse production particles in the product, and as a result, improves the grinding efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic piping diagram of an embodiment of the grinding and pulverizing apparatus according to the present invention, FIG. 2 is an operation time chart of the same embodiment, and FIG.
1 to 1θ are schematic diagrams of other embodiments, and FIG. 11 is a schematic piping diagram of a conventional example. 10... Grinding and crushing device, 11... Processing cylinder, 12... Screw shaft, 13...
Partition wall, 14.15...Communication hole, 14a...
...Screen, a...Product to be processed (raw material),
b... Grinding media, C... Production particles. Patent Applicant Kubota Iron Works Co., Ltd. Agent Kama 1) Text 2 Figure 4 Figure 5 Figure 8 ] 4 Figure 10 Figure 9

Claims (9)

[Claims] (1) A vertical processing cylinder is provided with a vertical screw shaft and filled with grinding media, and while the screw shaft is turned, the material to be processed is introduced into the processing cylinder and allowed to flow. In the grinding and pulverizing device, the screw shaft is turned into fine particles by grinding the particles with each other and with the grinding medium, and the produced particles are carried out of the processing cylinder by a fluid flowing inside the processing cylinder. A grinding and grinding device characterized by having multiple pieces. (2) The grinding and grinding apparatus according to claim (1), characterized in that a plate is provided between each of the screw shafts to partition the upper part of the packed bed of grinding media. (3) A partition wall is provided between each of the screw shafts, and a communication hole is formed in the upper or lower part of each partition wall so that the produced particles can move between the partition walls in an upward and downward zigzag pattern. The grinding and grinding apparatus according to claim (1). (4) The grinding and grinding apparatus according to claim (1), wherein there are two screw shafts, a partition wall is provided between the screw shafts, and communication holes are formed in the upper and lower parts of the partition wall, respectively.
A grinding and grinding method characterized in that grinding is carried out by circulating a grinding medium between both screw shafts through the communication hole. (5) The grinding and grinding method according to claim (4), characterized in that the rotational speed of the screw shaft in the front stage of the grinding action is slower than that in the latter stage to circulate the grinding medium. (6) The grinding and grinding method according to claim (4), characterized in that the screw pitch of the screw shaft in the front stage of the grinding action is made smaller than that in the latter stage to circulate the grinding medium. (7) The grinding and grinding method according to claim (4), characterized in that the screw shaft in the latter stage of the grinding action is closer to the partition wall than that in the earlier stage to circulate the grinding medium. (8) The communication hole is provided with a screen through which the grinding medium cannot pass, and the size of the grinding medium on the rear stage side of the grinding action is made smaller than on the front stage side with the partition wall as a boundary. (3) The grinding and grinding device as described. (9) Claim (1) characterized in that adjacent screw shafts have different screw heights, pitches, or rotation speeds.
, (2), (3) or (8).