JPH0376978B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides a body of a crusher that is stationary, an upward airflow forming means for forming an upward airflow within the body, and a support body fixed to a vertical rotating shaft within the body. The grinding body cooperates with the inner surface of the body to crush the pulverized raw material rising by the upward airflow, and the classifying means classifies the pulverized raw material pulverized by the grinding body, and has a grinding effect on the pulverized raw material. This invention relates to a pulverizer that obtains ultrafine powder by giving . [Prior Art] Recently, so-called ultrafine powders used as raw materials for new ceramic materials, electronics materials, etc. have attracted attention, and techniques for ultrafine pulverization of pulverized raw materials have been developed. Generally, ultrafine powder means that the specific surface area of powder particles is 8000.
These ultrafine powders, which are said to have a particle size of more than cm ² /g, have been conventionally obtained using pulverizers using various principles or in combination with classifiers. Fine pulverization is performed by applying pressure, impact, grinding, or scraping force to the pulverized raw material. [Problems to be Solved by the Invention] According to various studies conducted by the present inventor, conventional fine grinders include (1) a high-speed rotation/impact/shear type grinder, and (2) a ball mill type grinder. , (3) media agitation pulverizers, (4) jet pulverizers, and (5) other special types of pulverizers (vessels). These various types of pulverizers suffer from (a) contamination of the ultrafine powder as a pulverized product due to abrasion of mechanical materials or media, (b) low pulverization efficiency, and (c) It is said to have drawbacks such as low grinding capacity, which prevents it from being used as an industrial mass production machine, and (iv) high grinding cost, which means it can only be used for special purposes. Further, according to the research of the present inventor, various fine pulverization techniques involve the various forces mentioned above acting on the raw material in a complex manner to achieve fine pulverization, but in order to obtain finer powder, , pressure (squeezing)
It has been found that a grinding action is more advantageous than a crushing action or an impact action. There is no other conventional pulverizer (vessel) that primarily utilizes this grinding action, other than the millstone. Therefore, the present inventor studied the pulverization properties of the pulverized raw material due to this grinding action, and found that the particle size distribution of the pulverized product due to this action is as shown in Figure 3. It is relatively clearly distributed in the powder part (→a in the figure), and if this is classified in the middle and the coarse powder is pulverized again, it is possible to obtain an ultrafine powder with the above-mentioned specific surface area. I discovered something. In addition, the above-mentioned millstone certainly performs fine grinding by grinding action, but since the grinding action continues while the fine powder obtained by grinding the raw material is mixed with the coarse powder, the grinding action becomes weaker and gradually becomes smaller. It was found that the production rate of fine powder was reduced and the pulverization efficiency was poor, so that it could not be used as a pulverizer for industrial mass processing. The present invention was developed in view of the above circumstances, and it is possible to apply a uniform crushing force to the raw material over a long period of time through a grinding action, and there is no risk of damage even if foreign matter gets mixed in, and the crushing process is smooth. The object of the present invention is to provide a pulverizer that can easily cope with changes in conditions and efficiently produce ultrafine powder. [Means for Solving the Problems] The above object is achieved according to the present invention by the following configuration. That is, the grinding body is pivotally attached to the free end side of the support body so as to be swingable in the radial direction of the body, and is pressed against the inner surface of the body due to the centrifugal force exerted by the rotation of the support body while sliding. It is formed as a sliding body having a sliding part that moves, and is characterized by grinding and pulverizing the pulverized raw material interposed between the grinding body and the body. Therefore, according to the present invention, the raw material can be pulverized by the grinding action, and the fine powder produced by the pulverization is immediately separated, so that mainly only the coarse powder is present at the position where the pulverization is performed. It is possible to process large quantities with high efficiency. [Example] Hereinafter, the configuration of the present invention will be explained along with its operation based on the drawings. FIG. 1 is an example of a crusher for carrying out the present invention. In the figure, 1 is a storage tank for raw materials, 2 is a screw feeder for supplying raw materials, and 13 is a raw material supply port. Further, 3 is a ventilation duct for sending upward airflow from the lower part of the crusher into the inside of the crusher. This air blowing is performed by a blower (not shown) (a blower may be provided outside the exhaust port, which will be described later). and,
4 is an outlet for the classified ultrafine powder and rising air. Next, numeral 5 is stationary in the crusher body, and a band 6 is attached to the inner peripheral wall surface of the lower part of the body. This band 6 is used to prevent the inner circumferential wall of the body from being abraded and to grind and crush the body, but if the inner circumferential wall of the body is made of a wear-resistant material, the band 6 is not necessary. Reference numeral 7 denotes a grinding body, which is a support 10 fixed to a vertical rotating shaft 15 rotated by an electric motor 8 and bevel gears 9, 9', and a hinge 14 on the free end side of the spider 10 in this embodiment. It is pivoted by. That is, the grinding body 7 is rotatable around the hinge 14 and slides along the lower band 6 of the body 5 as the spider 10 rotates. The pulverized raw material is continuously fed into the pulverizer by the screw feeder 2, but this raw material falls into the pulverizer, is interposed between the band 6 and the sliding grinding body 7, and is pulverized by the grinding action. be done. The grinding body 7 is provided so as to slide along, for example, the band 6 on the lower inner circumferential wall surface of the body 5 while spreading outward due to the action of centrifugal force as the spider 10 rotates. Unlike a so-called roller, it must have a structure that does not rotate on its own axis. That is, when it rotates, it becomes a so-called roller that rolls on the inner circumferential wall surface of the body 5, so that the crushing action is the main one, and no grinding action can be obtained. The shape and number of the grinding bodies 7 are not particularly limited. In addition, the grinding body 7 in the present invention is located facing the band 6 on the inner peripheral wall surface, and mainly performs a grinding action while sliding in contact with the pulverized raw material interposed between the band 6 and the grinding body 7. give. The attachment mechanism between the grinding body 7 and the spider 10 must be such that the distance between the grinding body 7 and the band 6 is variable even during operation. In this embodiment, the grinding body 7 is rotatably attached around the hinge 14 by a hinge 14 provided on the free end side of the spider 10, and is supported so as to be swingable in the radial direction of the body 5. .
Therefore, when the spider 10 rotates, the grinding body 7 slides along the band 6 as the spider 10 rotates while expanding outward due to the action of centrifugal force, and as a result, the grinding body 7 spreads outward due to the action of centrifugal force, and as a result, the grinding body 7 slides along the band 6 as the spider 10 rotates. It slides and gives a grinding effect. The action of centrifugal force is the rotational speed of the spider 10,
Therefore, the sliding speed of the grinding body 7 or the grinding body 7
You can adjust the amount by changing the weight. This means that the pressing force exerted on the pulverized particles by the grinding bodies 7 can be adjusted, and by appropriately combining this and increasing or decreasing the number of the grinding bodies 7, the pulverization particle size, capacity, etc. can be adjusted. It can be adjusted to some extent. In this embodiment, the grinding body 7 is made using centrifugal force.
is pressed against the inner circumferential wall surface of the body 5, but the pressing force of the grinding body 7 can be applied not only by centrifugal force but also by an elastic body such as a coil spring. Next, the fine powder generated by pulverization further rises inside the fuselage 5 along with the upward air current, and moves to the classification rotor 11.
The coarse powder is blown against the inner peripheral wall of the body by the centrifugal force generated by the rotation of the main body (an electric conductor providing rotational power, etc., not shown), falls along the wall, and is used as a raw material for pulverization again. On the other hand, the ultrafine powder is separated from the coarse powder and discharged from the upper discharge port 4 along with the upward air current. Here, the classification of coarse powder and ultrafine powder is not limited to the one shown in this embodiment, and other classification devices can also be used. It is also possible to perform this classification outside the discharge port 4 and return the coarse powder to the pulverization position. Next, the rising air is 12 in Figures 1 and 2.
The powder is supplied from the lower part of the crusher body 5 as shown in FIG.
The area, shape, etc. of this air supply port 12 are not particularly limited, and may be, for example, mesh-shaped or perforated plate-shaped. Fine pulverization according to the present invention requires that the pulverized raw material is sufficiently interposed between the band 6 and the grinding body 7, but the centrifugal material generated by the rotation of the classification rotor 11 and the sliding of the grinding body The raw material gathers around the lower part of the body due to the force, which is effective in maintaining crushing efficiency. However, if this intervention is still insufficient, a suitable scraping device may be provided around the lower part of the body to scrape up the material deposited on the bottom. Next, Table 1 shows examples of limestone crushed using the crusher of the present invention.

〔Effect of the invention〕

As mentioned above, the pulverizer for obtaining ultrafine powder according to the present invention mainly utilizes the grinding action, which has rarely been used in the past, and has high pulverization efficiency, less contamination and foreign matter, and a 10000
Since it can efficiently produce ultrafine powder of cm ² /g, it has great value as an industrial machine. Further, the grinding body is pivotally attached to the free end side of the support body fixed to the vertical rotation shaft, and is supported so as to be swingable in the radial direction of the body, and the rotation of the support body causes centrifugal force to act on the body. Since it is formed as a sliding body with a sliding part that slides while being pressed against the inner surface, the distance between the grinding body and the inner surface of the crusher body is automatically adjusted depending on the amount of the crushed raw material, and the The applied crushing force is always kept constant. Therefore, a uniform pulverized product can always be obtained.
In addition, even if the grinding body is worn out due to long-term operation, the grinding force applied to the grinding material by the grinding body does not change, so it is possible to obtain a uniform pulverized product over a long period of time. . In addition, even if foreign matter is mixed into the crushed raw material, the sliding part of the grinding body automatically moves in the radial direction of the crusher body to avoid it, thereby preventing damage to the crushing body itself or the crusher body. can. In addition, the crushing force against the crushed raw material can be freely changed by simply changing the rotational speed of the support that slides the crushing body along the inner circumferential surface of the crusher body, or by changing the weight and shape of the crushing body. Therefore, it is possible to easily deal with changes in the grinding conditions such as the properties of the grinding raw material and the purpose of grinding. In addition, since the body of the crusher is stationary and does not need to be rotated, there is no need to take special consideration to the mechanical strength of the body itself, its support, vibration countermeasures, etc. This allows flexibility in selecting the mold size. Furthermore,
For example, when the body rotates at high speed, the pulverized raw material is compacted by centrifugal force on the inner circumferential surface of the rotating body, and the resulting layer has a certain thickness and is subjected to the pulverizing action by the crushing body. Since the body is stationary, the raw material is ground and crushed between the grinding body and the body as it moves in a spiral along the inner circumferential surface of the body.
For example, there is an advantage that even a single-stage grinder can efficiently grind and grind the powder to obtain the desired ultrafine powder.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an example of a crusher used to carry out the present invention, and FIG.
The plan view of section A', FIG. 3, is a diagram showing the particle size distribution of the pulverized product obtained mainly by the grinding action. 1... Raw material storage tank, 3... Air duct, 4... Discharge port, 5... Crusher body, 6... Band body, 7... Grinding body, 10... Support body (spider), 11
... Classification rotor, 12 ... Air supply port, 13 ... Raw material supply port, 14 ... Hinge, 15 ... Vertical rotation axis.

Claims (1)

[Claims] 1 A body of a crusher disposed stationary, an upward airflow forming means for forming an upward airflow within the body, and an upward airflow forming means that is attached to a support fixed to a vertical rotation shaft within the body and cooperates with the inner surface of the body to generate the upward airflow. It has a grinding body that grinds the ground raw material rising due to the air flow, and a classification means that classifies the ground raw material ground by the grinding body, and the grinding body is pivotally mounted on the free end side of the support. and is formed as a sliding body having a sliding part that is supported so as to be swingable in the radial direction of the body and that slides while being pressed against the inner surface of the body due to the action of centrifugal force due to the rotation of the support body,
A pulverizer for obtaining ultrafine powder, characterized by grinding and pulverizing the pulverized raw material interposed between the grinding body and the body.