JP2535469B2 - Vibration mill and method for manufacturing voltage non-linear resistor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration mill capable of safely crushing, mixing, etc. without raising the internal pressure of the pot to a dangerous state even if the temperature of the inside of the pot (crushing container) becomes high during operation, and this vibration. The present invention relates to a method for manufacturing a voltage non-linear resistor using a mill.

[0002]

2. Description of the Related Art A vibration mill for vibrating a pot containing a grinding medium such as balls and rods to grind, mix or disperse raw materials by impact or friction between the grinding medium and between the grinding medium and the inner wall of the pot. Has a higher crushing speed than other crushers such as ball mills and can shorten the crushing time, and is therefore used in a wide range of crushing and mixing processes in the ceramic industry, chemical industry, metal industry and the like. For example, a vibration mill is preferably used for finely pulverizing an additive and for mixing an additive and ZnO in manufacturing a ZnO-based voltage nonlinear resistor. The vibration mill is usually mainly composed of a pot, a highly elastic spring for supporting the pot, an oscillating mechanism such as an eccentric shaft,
It consists of a drive unit and a base, the pot is closed, and the lid is screwed to prevent the contents from leaking.

[0003]

However, since the vibrating mill has a higher power than the ball mill and the like, and the contents are liable to reach a high temperature, the pressure in the closed pot during operation rises, and in particular, the above ZnO-based In the case of pulverizing and mixing for a long time by a wet method like the production of a voltage non-linear resistor, the solvent of the content is gasified to a higher pressure, which causes a very dangerous state such as bursting. The present invention has been made in view of such a situation, and an object thereof is to continuously operate safely without increasing the internal pressure of the pot to a dangerous state even when the contents become hot. (EN) Provided is a vibrating mill that can be used, and a method for manufacturing a voltage non-linear resistor using the vibrating mill.

[0004]

According to the present invention, the outer circumference of a pot is set on the outer circumference of the pot when the vibration mill is set.
At least one open hole for leaking the pressure in the pot is provided at a position serving as an upper surface , and the open hole is a hose,
Or a balloon-shaped cap made of elastic and flexible material.
Or pressure leak that operates at a pressure of ² kg / cm ^2.
A wet oscillating mill with a valve is provided . Further, according to the present invention, in a method of manufacturing a voltage nonlinear resistor , which comprises mixing at least one kind of additive containing ZnO as a main component, mixing, granulating, molding and then firing, the mixing step is performed in advance in the mixing step. At least one of the finely pulverized additive and the mixture of additive and ZnO is placed in a pot with a hose and a wire.
Balloon cap and pressure made of flexible and flexible material
Method for producing a line power sale圧非linear resistor is provided by a wet <br/> vibration mill provided with an open hole provided with a one of a leak valve.

[0005]

The present invention is configured as described above, the opening hole for leaking pressure is provided in the pot, and the opening hole is a hose,
Or a balloon-shaped cap made of elastic and flexible material.
Or pressure leak that operates at a pressure of ² kg / cm ^2.
By providing the valve , the pressure in the pot does not rise to a dangerous state even if the temperature in the pot rises during operation. Therefore, there is no danger that the pot will burst even if it is continuously operated in a wet state for a long time, and a crushed product and a mixture having a desired particle size can be safely produced.

In the vibrating mill of the present invention, in order to prevent the leakage of the contents, as shown in FIGS. 1 and 2, the opening 2 of the pot 1 has a hose 3 and a balloon-like cap made of a stretchable and flexible material. 4 or operate at a pressure of 2 kg / cm ² .
The pressure leakage valve is provided that. When a hose is attached, it is preferable to raise it up about 20 cm as shown in FIG. 1 and then draw it in an arc and turn it downward. Further, from the viewpoint of preventing leakage of similarly contents, the open pores above the material charging surface, when the set pot <br/> vibration mill body as a position somewhat with a margin from the raw material charged surface, It is provided at a position that will be the upper surface of the outer circumference of the pot. The number of open holes may be one or plural, but usually one is sufficient effect can be obtained.

In the method of manufacturing a voltage non-linear resistor using this vibration mill, in order to prevent impurities from entering, M
It is preferable to use a CN (nylon) pot, and
It is preferable to use ZrO ₂ boulders as the grinding medium. MCNs commonly used in the manufacture of voltage nonlinear resistors
The pressure resistance of the pot is 100 when nylon does not contain water.
It is about 2.9 kg / cm ^{2 at} ° C, and becomes extremely dangerous when the inner pressure of the pot exceeds 2.0 kg / cm ² . Therefore, in the case of providing the pressure leakage valve to an open hole, the pressure 2 kg / cm ² In that use those to operate.

Further, the reliability of the ZnO-based voltage non-linear resistor largely depends on the uniformity of its fine structure, and ZnO which is the main component and a metal oxide such as Bi ₂ O ₃ which is added thereto. Therefore, it is preferable that the pulverization / mixing is usually performed by a wet method for about 3 hours.
Subsequent steps such as granulation, molding and firing are performed by conventionally known methods.

[0009]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples.

(Embodiment) As shown in FIG. 3 (plan view), FIG. 4 (front view) and FIG. 5 (side view), the internal volume 5.10 is shown.
1 vibrating mill pot (MCN (nylon) pot manufactured by Chuo Kakoki Co., Ltd.) 1 with through hole (open hole) 2 having a diameter of 15 mm
Was provided. Next, in the pot 1 provided with this through hole 2, Z having a diameter of 5 mm, which is about 60% of the inner volume of the pot 1, is used.
12 kg of rO ₂ cobblestone (specific gravity 5.9 g / cm ³ ), ZnO
1 kg of a powder containing as a main component and 2 l of water were added. The pot 1 was set in the main body with the through hole 2 facing upward, and a nylon hose having an inner diameter of 25 mm was attached to the through hole 2, and the nylon hose was raised upward by about 20 cm and then drawn downward in an arc. Next, amplitude 10 mm, frequency 1200
Crushing and mixing were performed for 3 hours at cpm, and the slurry temperature in the pot with respect to the crushing and mixing time was measured. Regarding the temperature, a K-thermocouple was installed inside the pot, and the temperature was read at each elapsed time during continuous operation. The crushing / mixing conditions in this example are crushing / mixing efficiency, particle size distribution, and ZrO ₂ from cobblestone.
It has been found in advance by experiments from the viewpoint of preventing contamination. The results obtained are shown in Table 1.

(Comparative Example) Grinding / mixing was carried out in the same manner as in Example except that the pot was used as it was without forming a through hole, and the slurry temperature in the pot with respect to the grinding / mixing time was measured. For safety of work, prior to this comparative example, the slurry temperature when the internal pressure reached ² kg / cm ² was calculated, and the operation was stopped at the time when the temperature reached near that temperature.

The slurry temperature, pot internal pressure and pot internal volume before operation are respectively set to T ₁ , P ₁ and V _1, and the slurry temperature, pot internal pressure and pot internal volume at one point during operation are respectively represented. Let T ₂ , P ₂ and V ₂ be P ₁ V ₁
/ T ₁ = P ₂ V ₂ / T ₂ holds. Moreover, assuming that the powder containing ZnO as a main component is completely dispersed in water, the empty volume in the pot V ₁ is: V ₁ = pot volume- (ZrO ₂ boulder input amount / ZrO ₂ boulder specific gravity) -water amount = 5- (12 / 5.9) -2≈0.97. Therefore, the temperature at which the pot internal pressure of the filled pot at room temperature of 30 ° C. becomes ² kg / cm ² is V ₁
= V ₂ = 0.97, P ₁ V ₁ / T ₁ = P ₂ V ₂ / T ₂
Therefore, 1 × 0.97 / 30 = 2 × 0.97 / T ₂ T ₂ ≈6
When the slurry temperature is about 60 ° C, the pressure becomes 2 kg /
It will reach cm ² . Therefore, in this comparative example, the operation was stopped when the slurry temperature reached around 60 ° C. The results obtained are shown in Table 1.

[0013]

[Table 1]

(Evaluation) In the embodiment in which the through hole is provided in the pot, the internal pressure of the pot does not rise even if the temperature rises.
The desired crushing and mixing was completed. On the other hand, in the comparative example using the conventional closed pot, as shown in Table 1, the slurry temperature is considered to be dangerous when the crushing / mixing time is 1 hour.
When the temperature exceeded 0 ° C, the intended pulverization and mixing could not be completed. If the comparative example is continuously operated for 1 hour or more, if the same temperature curve as that of the example is followed, the slurry temperature reaches 80 ° C. in 2 hours. The internal pressure of the pot at a slurry temperature of 80 ° C. is 1 × 0.97 / 30 = P ₂ from P ₁ V ₁ / T ₁ = P ₂ V ₂ / T ₂ under the condition of V ₁ = V ₂ = 0.97. × 0.97 / 80 P ₂ ≒
At 2.67, it is considered to be about 2.7 kg / cm ² . Further, it is considered that the boiling point is further increased by the increase of the internal pressure, and the internal pressure is further increased by the increase of the internal pressure, and it can be judged that the pulverization and mixing for 3 hours satisfying the pulverization and mixing conditions cannot be safely performed.

[0015]

As described above, according to the method of manufacturing the vibration mill and the voltage non-linear resistor of the present invention, the internal pressure does not rise to a dangerous state even if the temperature inside the pot becomes high during operation. Even when performing continuous operation for a long time, there is no danger of the pot bursting, and crushing and mixing can be performed safely.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a vibration mill pot showing an example in which a hose is attached to an open hole.

FIG. 2 is a schematic perspective view of a vibration mill pot showing an example in which a balloon-shaped cap made of a stretchable and flexible material is attached to an open hole.

FIG. 3 is a partial plan view of a vibration mill pot used in an example of the present invention.

FIG. 4 is a partial front view of a vibrating mill pot used in an example of the present invention.

FIG. 5 is a partial side view of a vibration mill pot used in an example of the present invention.

[Explanation of symbols]

 1 pot 2 open hole 3 hose 4 balloon cap

Claims (3)

(57) [Claims] 1. A vibrating mill is set on the outer circumference of the pot .
At that time, at least one opening hole for leaking the pressure in the pot is provided at a position which becomes the outer peripheral upper surface of the pot ,
The opening is made of a hose or a stretchable and flexible material
Wet balloon characterized by wearing
Type vibration mill. 2. A vibrating mill set around the pot .
At that time, at least one opening hole for leaking the pressure in the pot is provided at a position which becomes the outer peripheral upper surface of the pot ,
Pressure leak valve whose opening hole operates at a pressure of ² kg / cm ^2.
Wet vibration mill, characterized in that it comprises a. 3. A method of manufacturing a voltage non-linear resistor , wherein at least one additive containing ZnO as a main component is added, mixed, granulated, molded, and then fired. Finely pulverize or mix at least one of additive and ZnO into a pot with a hose and a wire.
Balloon cap and pressure made of flexible and flexible material
A method for producing a voltage non-linear resistor, which is performed by a wet type vibration mill having an open hole provided with any of leak valves .