JPH10180189A - Pulverizing classifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the working rate of a pulverizing classifier by preventing a pulverizer from being stopped at time of mesh replacement of the classifier. SOLUTION: This pulverizing classifier 2 is equipped with a pulverizer 6, a classifier 7 of classifying powder pulverized by the pulverizer 6 and a conveyance means for conveying powder from the pulverizer 6 to the classifier 7. A storage part 25 for temporarily storing a powder is provided between the pulverizer 6 and the classifier 7. The conveyance means is constituted of a first conveyance means 26 for conveying powder from the pulverizer 6 to the storage part 25 and of a second conveyance means 27 of conveying powder from the storage part 25 to the classifier 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for pulverizing and classifying a material such as a hydrogen storage alloy to produce powder.
It relates to a pulverizing and classifying apparatus.

[0002]

2. Description of the Related Art As is well known, nickel-metal hydride batteries, which are a kind of rechargeable batteries, use a hydrogen storage alloy. As the hydrogen storage alloy used for this nickel-metal hydride battery, a powdery one having an average particle size of about 40 μm to 70 μm is used.

The powder of the hydrogen storage alloy is produced as follows. First, a material to be a hydrogen storage alloy is melted in a vacuum and solidified in a mold to form an ingot. Then, after removing the oxide film of the ingot by sandblasting, the ingot is roughly pulverized into powder having a size of 5 mm or less. Further, the coarsely pulverized powder is pulverized by a pulverizer and classified by a classifier to obtain an average particle size of 4%.
A powder of 0 μm to 70 μm is produced. Since the hydrogen storage alloy has ignitability, there is a risk that a dust explosion may occur when the above-described pulverization and classification are performed in an oxygen atmosphere. Therefore, a series of steps of pulverization and classification are performed in an atmosphere in which oxygen is purged with an inert gas such as an argon gas.

[0004] In the above-described process for producing a powder of a hydrogen storage alloy, a pulverizing and classifying apparatus used in a process of pulverizing with the pulverizer and classifying into a powder having an average particle diameter of 40 μm to 70 μm by the classifier is shown in FIG. 3 is used. In the figure, reference numeral 1 is a building, and 2 is a pulverizing and classifying device.

[0005] The building 1 has a three-story structure, and the height from the ground to the roof is about 6 m. On the first floor, the second floor, the third floor, and the roof of the building 1, each part of the crushing and classifying device 2 is installed.

The pulverizing and classifying apparatus 2 has a supply hopper 4, a screw feeder 5, a pulverizer 6, a classifier 7, a left discharge hopper 8, and a right discharge hopper 9 as main components. The supply hopper 4 is disposed on the roof of the building 1 and is a container having an upper lid 4a at the top. The upper lid 4a is provided with a supply hopper supply port 4b for supplying argon gas and a supply hopper discharge port 4c for discharging the argon gas. A supply path 10 is provided below the supply hopper 4, and connects the supply hopper 4 and the screw feeder 5. This supply path 10
It is a hollow hose, and has a structure in which powder can flow through the inside of the supply path 10. The screw feeder 5 is located on the third floor of the building 1 and is disposed between the supply hopper 4 and the crusher 6. The screw feeder 5 is used to supply the powder supplied from the supply hopper 4 to the crusher 6 at a constant supply amount. The screw feeder 5 is provided with a screw feeder supply port 5a for supplying argon gas. The crusher 6 is located on the third floor of the building 1 and is used for crushing the powder supplied from the screw feeder 5 more finely. The crusher 6 is provided with a crusher supply port 6a for supplying argon gas. The lower end of the crusher 6 is connected to the upper end of the flow pipe 11. This distribution pipe 11
Is a hollow hose, and has a structure in which powder can flow through the inside of the flow pipe 11. The classifier 7 is located on the second floor of the building 1, and the lower end of the distribution pipe 11 is connected to the upper part of the classifier 7. The classifier 7 has a classifier 15 disposed therein, and a powder having a particle size distribution in which the classifier 15 has an average particle size of 40 μm to 70 μm (hereinafter, referred to as a classified powder), and an average particle size. 40 μm to 70
The powder is classified as a powder having a particle size distribution not reaching μm (hereinafter, referred to as an unclassified powder). The structure of the classifier 15 will be described later in detail. The lower end of the classifier 7 is connected to upper ends of a left discharge path 12 and a right discharge path 13. The left discharge hopper 8 and the right discharge hopper 9 are arranged on the first floor of the building 1, and the lower ends of the left discharge path 12 and the right discharge path 13 are connected to the upper part. The left and right discharge hoppers 8 and 9 have substantially the same shape as the supply hopper 4. A left discharge hopper discharge port 8b and a right discharge hopper discharge port 9b for discharging argon gas are provided in the upper lids 8a and 9a, respectively. Have been.

Next, the structure of the classifier 15 provided in the classifier 7 will be described with reference to FIG. The classifier 15 has a configuration in which three mesh plates 16, 17, 18 and four plate members 19, 20, 21, 22 are alternately stacked. The mesh plates 16, 17, 18
From above, the first mesh plate 16 and the second mesh plate 1
7 and the third mesh plate 18 are arranged in this order and have the same shape. The first mesh plate 16 is provided with a mesh 16a at a central portion, and two holes 16b, 16b,... Are formed on left and right sides of the mesh 16a. The mesh 16a is made of a wire net or the like. Like the first mesh plate 16, the second and third mesh plates 17 and 18 also have meshes 17a and 18a, and have holes 17b and 18b. Plate 19,
20, 21 and 22 respectively connect the mesh plates 16, 17, and 18 to the first plate 19, the second plate 20, the third plate 21, and the fourth plate 22 in this order from above. It is arranged through. The first plate 19 is a sloping part 1 that is inclined leftward.
9a, and a hole 19b is formed on the left side of the slope 19a. The second plate 20 has a slope 20a that is inclined leftward at the center. The second plate 20 is
A hole 20b is formed on the left side of the slope 20a.
The hole 20b communicates with the left end of the slope 20a. At the right end of the second plate 20, a bottom wall 20c is provided so as to close the hole 17b of the second mesh plate 17 disposed below the second plate 20. . The third plate 21 is similar to the second plate 20,
1a, a hole 20 formed in the second plate 20
The hole 21b communicating with b is formed. This hole 2
At the corner of the third plate body 21 adjacent to 1b, a second slope 21c inclined rightward is provided. The fourth plate 22 is similar to the second and third plates 20 and 21 and has the slope 2
2a, a hole 22b communicating with the holes 20b, 21b formed in the second and third plate bodies 20, 21 is formed. The side surfaces of the above-mentioned plate members 19, 20, 21 and 22 are substantially wedge-shaped with different left and right plate thicknesses, and these plate members 19, 20, 21, 22 and mesh plates 16, 1
When the layers 7 and 18 are stacked, the mesh plates 16, 17, 1
8 can be arranged in an inclined state

Next, the operation of the pulverizing and classifying apparatus 2 having the above configuration will be described with reference to FIG. The powder roughly crushed to 5 mm or less is stored in the supply hopper 4. The powder stored in the supply hopper 4 is sequentially supplied from the lower side to the supply path 10.
Through the screw feeder 5. The powder guided to the screw feeder 5 is supplied to the pulverizer 6 by the screw feeder 5 at a constant supply amount,
The crusher 6 further crushes the powder. The powder pulverized by the pulverizer 6 is guided to the classifier 7 through the flow pipe 11. The powder guided to the classifier 7 is classified in the classifier 7 into the classified powder and the non-classified powder. And
The classified powder is guided to the left discharge hopper 8, and the unclassified powder is guided to the right discharge hopper 9.

As shown in FIG. 4, the powder is classified in a classifier 7 as follows. The powder supplied from above is
The first plate body 19 is rolled on the slope 19 a and guided to the first mesh plate 16. The powder that has passed through the mesh 16a disposed on the first mesh plate 16 and dropped falls on the slope 20a of the second plate body 20 located below the first mesh plate 16, and It falls through the hole 20 b of the plate 20 and is guided to the left discharge hopper 8. The powder that does not pass through the first mesh 16a passes through the hole 16b on the right side of the first mesh plate 16 and passes through the second plate 20.
Is rolled on the bottom wall portion 20c and is guided to the second mesh plate 17. The powder that has passed through the mesh 17 a disposed on the second mesh plate 17 is applied to the slope 21 of the third plate 21.
a, and is guided to the left discharge hopper 8 through the hole 21 b of the third plate 21. The second mesh 1
The powder that does not pass through 7 a rolls on the second slope 21 c provided on the third plate 21 and is guided to the third mesh plate 18. The powder that has passed through the third mesh 18a rolls on the slope 22a of the fourth plate 22, and
It is guided to the left discharge hopper 8 through 2b. The powder that does not pass through the third mesh 18a is guided to the right discharge hopper 8 through the right hole 18b of the third mesh plate 18. As described above, the powder is classified by being passed through the mesh plates 16, 17, 18 three times.

The classified powder that has been classified as described above and stored in the left discharge hopper 8 is transported to the next step and used as a material for a nickel-metal hydride battery. The unclassified powder stored in the right discharge hopper 9 is supplied to the supply hopper 4.
And crushed and classified again.

The argon gas for purging oxygen in the pulverizing and classifying apparatus 2 is used as follows. The argon gas supplied from the supply hopper supply port 4b passes through the supply hopper 4 and is discharged from the supply hopper discharge port 4c, thereby purging oxygen in the supply hopper 4. A part of the argon gas supplied from the supply hopper supply port 4b also purges oxygen in the supply path 10 by passing through the supply path 10. The argon gas supplied from the screw feeder supply port 5a and the crusher supply port 6a is supplied to the screw feeder 5, the crusher 6, the flow pipe 11, the classifier 7, the left and right discharge paths 12, 1
3, through the left and right discharge hoppers 8, 9 and discharged from the left and right discharge hopper discharge ports 8b, 9b, these screw feeder 5, crusher 6, flow pipe 11,
The oxygen in the classifier 7, the left and right discharge paths 12, 13 and the left and right discharge hoppers 8, 9 is purged.

[0012]

However, the pulverizing and classifying apparatus 2 having the above configuration has the following problems. If the pulverizing and classifying apparatus 2 is continuously operated, the meshes 16a, 17a, 18a provided in the classifier 7 are clogged, and the work of replacing the mesh plates 16, 17, 18 is necessary. Was. In this case, during the replacement operation, the crusher 6 and the classifier 7 must be stopped for the reason that oxygen enters the crusher 6 and a risk of ignition may occur. This has led to a reduction in the operating rate.
The flow rate of the argon gas flowing through the classifier 7 is the integrated flow rate of the argon gas flowing from the screw feeder supply port 5a and the pulverizer supply port 6a. Since the argon gas must be flowed against the pressure loss in the flow path up to 9, the flow rate of the argon gas flowing in the classifier 7 has necessarily increased. Therefore, the powder flies in the air together with a large flow of argon gas flowing in the classifier 7, and does not pass through the meshes 16a, 17a, 18a, and the meshes 16a, 17
The powder to be passed through a and 18a rides on the flow of argon gas and is led to the right discharge hopper 9 for storing the unclassified powder. Therefore, the classified powder to be guided to the left discharge hopper 8 is mixed into the right discharge hopper 9, and the classification efficiency is reduced.

The present invention has been made in view of the above problems, and has as its first object to increase the operation rate by not stopping the crusher when replacing the mesh of the classifier. A second object is to increase the classification efficiency by reducing the flow rate of the inert gas flowing in the classifier.

[0014]

In order to solve the above-mentioned problems, the following means have been adopted in the pulverizing and classifying apparatus of the present invention.
The pulverizing and classifying apparatus according to claim 1 includes a pulverizer, a classifier that classifies the powder pulverized by the pulverizer, and a conveying unit that conveys the powder from the pulverizer to the classifier. In the pulverizing and classifying apparatus, a storage unit for temporarily storing the powder is provided between the pulverizer and the classifier, and the transport unit transports the powder from the pulverizer to the storage unit. A conveying means and a second conveying means for conveying from the storage section to the classifier are provided. The powder pulverized by the pulverizer is transported to the storage section by the first transport means, and is temporarily stored in the storage section. The powder stored in the storage section is transported by the second transport means to the classifier independently of the transport time and the transport amount of the powder by the first transport means.

The pulverizing and classifying apparatus according to the second aspect is the first aspect of the invention.
In the pulverizing and classifying apparatus according to the above, the first transporting means includes
It is a conveyance path for conveying the powder by its own weight falling. The powder pulverized by the pulverizer is transported to the storage section by a transport path that is transported by its own weight.

The pulverizing and classifying apparatus according to the third aspect is the first aspect.
The pulverizing and classifying apparatus according to claim 2 or 3, wherein the pulverizer is provided with a first supply port for supplying an inert gas, and an outlet for discharging the inert gas flowing from the pulverizer into the storage unit. And a second supply port for supplying an inert gas to the classifier. The inert gas flowing from the first supply port flows out of the discharge port provided in the storage unit, and does not flow to the classifier. Further, the inert gas flowing in the classifier is caused to flow independently of the inert gas flowing from the first supply port by the second supply port provided in the classifier.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In these figures, the same reference numerals are given to parts common to FIGS. 3 and 4 shown in the related art, and description thereof will be omitted.
FIG. 1 is a front view showing an embodiment of the present invention, wherein reference numeral 1 denotes a building, and 2 denotes a pulverizing and classifying apparatus.

The pulverizing and classifying apparatus 2 includes a supply hopper 4, a screw feeder 5, a pulverizer 6, an intermediate hopper (reservoir) 25, a classifier 7, and a left discharge hopper 8.
And the right discharge hopper 9 as main components. Crusher 6
Is provided with a crusher supply port (first supply port) 6a for supplying an argon gas (inert gas). The intermediate hopper 25 is located on the second floor of the building 1 and is disposed between the crusher 6 and the classifier 7. This intermediate hopper 25 is a container having an upper lid 25a. This upper lid 25a
Has an intermediate hopper outlet 25b for discharging argon gas.
And a lower end of a transport path (first transport means) 26 is connected to a side of the intermediate hopper discharge port 25b. The lower end of the conveyor (second conveying means) 27 is connected to the lower part of the intermediate hopper 25. Transport path 26
Are arranged vertically so as to connect a lower portion of the crusher 6 and an upper portion of the intermediate hopper 25. The transport path 26 is a hollow hose, and the powder is transported inside the transport path 26 by its own weight. As shown in FIG. 2, the conveyor 27 connects the lower part of the intermediate hopper 25 and the upper part of the classifier 7, and is a tube having a passage for conveying powder inside. The classifier 7 is provided with a classifier supply port (second supply port) 30 for supplying argon gas.
A classifier 15 is disposed inside the classifier 7.
reference).

Next, the operation of the pulverizing and classifying apparatus 2 having the above configuration will be described with reference to FIG. Particle size is 5mm
The coarsely pulverized powder is stored in the supply hopper 4 below. The powder stored in the supply hopper 4 is guided to the screw feeder 5 through the supply path 10 in order from below. This powder is supplied to the crusher 6 at a constant supply amount by the screw feeder 5, and is further finely crushed by the crusher 6. The powder pulverized by the pulverizer 6 falls under its own weight in the transport path 26 and is guided to the intermediate hopper 25. This powder is temporarily stored in the intermediate hopper 25. The powder temporarily stored in the intermediate hopper 25 is guided to the classifier 7 by the conveyor 27. The powder guided to the classifier 7 is classified into the classified powder and the non-classified powder. Then, the classified powder is guided to the left discharge hopper 8, and the unclassified powder is guided to the right discharge hopper 9.
The process of classifying the powder by the classifier 7 is the same as the case described in the related art, and a description thereof will be omitted.

The meshes 16a, 17a, 18 of the classifier 7
In order to replace the mesh plates 16, 17, 18 due to clogging of a, first, the classifier 7 is stopped, the mesh plates 16, 17, 18 provided inside the classifier 7 are taken out, and a new mesh plate or This is performed by replacing the mesh plate with the clogged one. Then, the classifier 7 is restarted. This classifier 7 is stopped, and the mesh plates 16, 1
The pulverizer 6 continues to operate continuously until the classifiers 7 and 18 are replaced and the classifier 7 is restarted. That is, the powder pulverized by the pulverizer 6 during that time is temporarily stored in the intermediate hopper 25. Usually, the processing capacity of the crusher 6 is set lower than the processing capacity of the classifier 7. for that reason,
The powder temporarily stored in the intermediate hopper 25 during the exchange operation is processed while the pulverizer 6 and the classifier 7 are simultaneously operated after the classifier 7 is restarted.

Argon gas for purging oxygen in the pulverizing and classifying apparatus 2 is used as follows. Screw feeder supply port 5a and crusher supply port 6a,
That is, the argon gas supplied from the pulverizer 6 side as viewed from the intermediate hopper 25 passes through the transport path 26 and the intermediate hopper 25 and is discharged from the intermediate hopper outlet 25b. Therefore, these screw feeder 5, crusher 6,
Oxygen in the transfer path 26 and the intermediate hopper 25 is purged. The argon gas supplied from the classifier supply port 30 is:
After passing through the classifier 7, the left and right discharge paths 12, 13 and the left and right discharge hoppers 8, 9, the left and right discharge hopper discharge ports 8b, 9 are provided.
By being discharged from b, oxygen in the classifier 7, the left and right discharge paths 12, 13 and the left and right discharge hoppers 8, 9 is purged.

According to the pulverizing and classifying apparatus 2 having the above configuration, the intermediate hopper 25 is provided between the pulverizer 6 and the classifier 7, so that when the mesh plates 16, 17, 18 are replaced, the intermediate hopper 25 is used. The powder can be temporarily stored in the mesh plate 16 and the mesh plates 16 and 1 without stopping the pulverizer 6.
The replacement work of 7 and 18 becomes possible. An intermediate hopper outlet 25b for discharging argon gas is provided in the intermediate hopper 25.
Is provided, it is possible to discharge the argon gas flowing from the pulverizer 6 side and not to flow the argon gas to the classifier 7. Also, the classifier supply port 3 is connected to the classifier 7.
Since 0 is provided, the flow rate of the argon gas flowing through the classifier 7 can be adjusted independently. Furthermore, classifier 7
The flow rate of the argon gas flowing through the inside may be a flow rate taking into account the pressure loss only in the classifier 7, the left and right discharge paths 12, 13 and the left and right discharge hoppers 8, 9, so that the conventional screw feeder 5 and pulverizer may be used. The flow rate of the argon gas flowing through the classifier 7 can be reduced as compared with the case where the pressure loss in the classifier 6 is considered.

In this embodiment, argon gas is used as the inert gas. However, the present invention is not limited to this. For example, nitrogen gas may be used. Although the conveyor 27 is used as the second transport path, the present invention is not limited to this. For example, the intermediate hopper 25 may be disposed at a position higher than the classifier 7 and may be a transport path that transports the powder by its own weight.

[0024]

As described above, the following effects can be obtained by using the pulverizing and classifying apparatus of the present invention. Since the pulverizing and classifying device according to claim 1 has a configuration in which a storage unit is provided between the pulverizer and the classifier, when the mesh of the classifier is exchanged, the exchanging operation can be performed without stopping the pulverizer. It is possible to increase the operation rate of the pulverizing and classifying apparatus.

In the pulverizing and classifying device according to the second aspect, since the first transport means is a transport path for transporting the powder by its own weight, it is possible to configure the first transport path with a simpler configuration. Become.

According to the third aspect of the present invention, since the discharge port for discharging the inert gas is provided in the storage section, the inert gas flowing from the pulverizer side is discharged, and the inert gas flows to the classifier. It is possible to make it not. Therefore, the flow rate of the inert gas in the classifier can be kept low, and the amount of powder that does not pass through the mesh due to the flow of the inert gas can be reduced. Therefore, the classification efficiency for classifying the powder can be improved. Further, since the second supply port is provided in the classifier, the flow rate of the inert gas flowing in the classifier can be adjusted independently. Further, since the flow rate of the inert gas may be considered in consideration of the pressure loss of the classifier and the portion communicating with the classifier, the supply port may be provided on the pulverizer side, which is upstream of the classifier. , The flow rate can be kept low.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a pulverizing and classifying apparatus according to the present invention.

FIG. 2 is a side view of the pulverizing and classifying apparatus of FIG.

FIG. 3 is a front view showing a conventional pulverizing and classifying apparatus.

4 is a perspective view showing the internal structure of the classifier in FIG.

[Explanation of symbols]

 2 Crushing and Classifying Device 6 Crusher 6a First Supply Port 7 Classifier 25 Reservoir 25b Discharge Port 26 Transport Path (First Transport Means) 27 Second Transport Means 30 Second Supply Port

Claims (3)

[Claims] 1. A pulverizing and classifying apparatus comprising: a pulverizer, a classifier for classifying powder pulverized by the pulverizer, and conveying means for conveying the powder from the pulverizer to the classifier, Providing a storage unit for temporarily storing the powder between the crusher and the classifier, the transfer means, a first transfer means for transferring the powder from the crusher to the storage unit, the A pulverizing and classifying apparatus, characterized in that the pulverizing and classifying apparatus is a second conveying means for conveying from the storage unit to the classifier. 2. The pulverizing and classifying apparatus according to claim 1, wherein the first conveying means is a conveying path for conveying the powder by falling under its own weight. 3. The pulverizing and classifying apparatus according to claim 1, wherein the pulverizer is provided with a first supply port for supplying an inert gas, and the pulverizer classifies the pulverizer into the storage section from the pulverizer side. A pulverizing and classifying apparatus comprising: a discharge port for discharging an active gas; and a second supply port for supplying an inert gas to the classifier.