JPS648574B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crushing and classifying device that continuously crushes and classifies powder and granules, and more specifically, it includes a jet mill-type crushing section and a classifying section equipped with a rotating classification impeller. The purpose of the present invention is to provide a device that is compact and effectively combined and has superior pulverization and classification performance.

Conventionally, in a crushing and classifying apparatus having a jet mill type crushing mechanism, a crushing section and a classifying section have been provided separately and somewhat separated from each other. Although this is necessary to suppress interference between the working surfaces of the crushing section and the classifying section and to ensure the performance of both mechanical sections, the longer distance between the crushing section and the classifying section does not affect the equipment itself. This increases the size of the equipment and increases the power required to transport it. In addition, in order to maximize the crushing and classification performance of this equipment, subtle changes must be made to the amount of granular raw material (hereinafter simply referred to as raw material) retained in the crushing section and the classification section, the amount of air introduced, etc. Adjustment is required, and the desired performance can only be achieved by balancing both parts. For example, Fig. 1 shows an example in which a classifying section b is arranged above and a crushing section a is arranged below, and the raw material crushed in the crushing section a is sent to the classifying section b by an air flow to be classified and sorted. This device is configured so that the fine powder is passed through the classification impeller c to be discharged and collected, while the coarse powder is circulated to the crushing section a again and crushed. However, in these devices, the amount of stagnation inside the machine gradually increases, and as the concentration of raw materials increases, the grinding and
Both the effects of classification were reduced, and the amount of new raw materials supplied was also reduced, making it difficult to maintain the original performance. In other words, the accumulation of a large amount of raw material in the machine inevitably reduces the processing capacity due to a reduction in the crushing effect in the crushing section a, a decrease in classification accuracy due to fluctuations in the throughput and air amount in the classifying section b, etc. Improvements were also needed due to increased power loss. In view of these points, the present invention provides a pulverizing and classifying device that combines a pulverizing and classifying performance with good pulverizing and classifying performance while reducing the required power by simply and effectively combining and configuring a pulverizing section and a classifying section. It is something to do. That is, an exhaust pipe is inserted into the vertical cylindrical fuselage from the center above, a partition board is provided at the lower end to form a boundary, and a raw material injection pipe and a collision member are arranged opposite to the injection pipe at the upper part. The lower portion is provided with a classification impeller close to the partition panel and a large number of fine inlets all around the outer peripheral wall corresponding to the classification impeller, and a lower coarse powder discharge port and the injection pipe are provided. It is constructed by communicating with each other using a connecting pipe. The present invention will be explained below with reference to Examples.

2 to 4, a vertical cylindrical fuselage 1 has an exhaust pipe 6 inserted from the center above and an exhaust port 7.
is placed on the top, and an air inlet 10 is placed on the side.
A coarse powder discharge port 9 is provided at the bottom, and an electric motor 18 is provided.
It is connected at the lower part and placed on a pedestal 20. Inside the machine body 1, a classification impeller 3 is connected to the electric motor 18 and is configured by arranging a large number of classification blades 4 in a radial manner, and a partition plate 5 is disposed close to the top of the classification impeller 3. ing. The partition board 5 is supported at its center by an exhaust pipe 6, and is provided so that the exhaust port 7 and the inside of the classification impeller 3 are communicated with each other.
It has a somewhat larger diameter than the classification impeller 3, and its outer peripheral edge 5
a is bent downward so as to overlap the classification impeller 4 with a slight gap so as to cover the classification impeller 3 from the upper end. In addition, the partition board 5
The structure and shape of the classification impeller 3 and the classification blades 4 are not particularly limited. For example, the classification impeller 3 may have a truncated conical shape whose diameter gradually decreases from the top to the bottom. or,
The classification blades 4 may also be arranged with the blade surfaces inclined by appropriately shifting the classification blades 4 from the radial arrangement toward the downstream side in the rotational direction as shown in FIG. And the partition plate 5
A pressurized air injection pipe 12 is disposed on the wall surface 2 on the upper side of the collision member 13 in correspondence with a collision member 13 at an appropriate distance. A gate valve 22 is provided in the injection pipe 12.
The raw material hopper 8 is connected to a compressor as a pressure air source (not shown) via the hopper 8. On the other hand, the lower wall surface 2 has a number of slit-shaped inlets 15 that have approximately the same length as the classification blades 4 over the entire circumference.
An air chamber 11 is provided around the outer periphery of the rectifying member 14, which communicates with the air inlet 10. Regarding the configuration of the inlet 15, in this embodiment, a flow regulating member having a slit-shaped inlet 15 is created by sequentially inserting a large number of fine notches d at an appropriate inclination angle θ with respect to the center of the ring. However, as shown in FIG. 6, the inlet 15a is constructed by sequentially arranging a large number of plate-shaped current plates 14a at predetermined intervals.
The rectifying plate 14a may be movable so that the inclination angle θ of the inlet 15a can be arbitrarily adjusted.Furthermore, a perforated plate having appropriate openings may be used as the rectifying member 14. In addition, the collision member 13 is made to collide with the jet flow against the jet pipe 12, and the collision member 13 is appropriately inclined to give a swirling component to the jet flow after the collision, and the mounting direction of the jet pipe 12 itself is adjusted appropriately. You may change it to Next, the above-mentioned coarse powder discharge port 9 is provided below the wall surface 2, and the discharge pipe 17 is connected to this. It may be attached to the downstream edge of the direction. A connecting pipe 16 is attached to a part of the discharge pipe 17 so as to communicate with the injection pipe 12, and a regulating valve 23 is provided in the path thereof. Note that the shape and mounting position of the collision member 13 are not particularly limited; for example, it may be ring-shaped as shown in FIG. 8, and the position of the collision surface can be sequentially changed by rotationally moving the collision member 13. It is effective against wear and can be used for long periods of time. and,
A collector (not shown) such as a cyclone or a bag filter is connected to the exhaust port 7, and a discharge device such as a rotary valve is connected to the exhaust pipe 17. In addition, in this embodiment, the classification impeller 3 is directly attached to the electric motor 18, and an inverter 19 is incorporated to change the rotation speed, resulting in a frequency conversion system, thereby simplifying the power transmission section. be able to.

In the above configuration, the raw material supplied into the fuselage 1 from the injection pipe 12 becomes an extremely high-velocity injection flow j together with pressure air, and is injected into the collision member 1.
3 violently collided. Due to the shock at this time,
Further, the particles are pulverized by a grinding effect caused by collisions and contact between particles generated in the jet flow j immediately after injection from the injection pipe 12. Thereafter, the raw material descends along the wall surface 2 due to the swirling component of the jet flow j or due to the swirling airflow r caused by the rotation of the classification impeller 3, while repeating the grinding impact effect due to contact and collision between particles. In this way, it reaches below the partition panel 5 and is subjected to the classification and sorting action by the classification impeller 3.
That is, they receive centrifugal force due to the rotation of the classification impeller 3 and centripetal force associated with the centripetal airflow e passing through the classification impeller 3, and classification and sorting is performed based on the difference between these forces. Fine powder particles, which are more influenced by centripetal force than by centrifugal force, pass through the classification impeller 3 together with the outflow airflow e, and are discharged and collected outside the machine through the exhaust port 7. On the other hand, coarse powder particles that are more affected by centrifugal force than by centripetal force are pushed toward the wall surface 2 and spiral downward. By the way, a large number of slit-shaped inflow ports 15 provided in the flow regulating member 14 are provided on the wall surface 2 around the outer periphery of the classification impeller 3, and the airflow i from the inflow ports 15 has a relatively high velocity. As a result, a dispersion force is effectively applied to the raw material particles whirling down along the wall surface 2, and classification by the classification impeller 3 can be promoted. In addition, since the adhering or agglomerated fine particles mixed in the coarse powder particles that are sorted and swirling near the wall surface 2 as coarse powder are separated and classified again, it is possible to prevent the fine powder from being mixed into the coarse powder, and the fine powder can increase the recovery rate. Further, the partition plate 5 for the classification impeller 3 has its outer peripheral edge 5a bent so as to cover the upper end of the classification impeller 3, and is configured to overlap the classification blade 4 to some extent with a slight gap. Therefore, in the rotary classification impeller, leakage from the 3 ends of the classification impeller, which is said to be the most prone to leakage, can be prevented, and anything other than air and fine powder particles, that is, coarse powder into the fine powder, can be prevented. This prevents the contamination of particles and produces high-quality products for both coarse and fine powders. For this reason, by taking advantage of the excellent classification characteristics of the classification impeller 3, the classification impeller 3 and the wall surface 2
and the rectifying member 14, the classification processing speed is improved by a classification mechanism that is more effective for raw material particles, and retention of raw materials in the machine body 1 is suppressed to maintain stable classification performance. Furthermore, it is possible to downsize the device. By the way, the raw material that has been sorted and classified in this way and remains without passing through the classification impeller 3 is discharged as coarse powder to the coarse powder discharge port 9 below the wall surface 2.
The air is discharged to the outside of the machine via an exhaust pipe 17, and the exhaust pipe 17 is provided with a connecting pipe 16 whose other end communicates with the injection pipe 12. All or part of the coarse powder particles are returned by the attraction effect caused by the ejection of the powder to be pulverized again, and can also be used as a medium to promote the dispersion of raw materials during classification.

As described above, in the present invention, the exhaust pipe 6 is brought close to the upper part of the classification impeller 3, the partition board 5 is arranged at the lower end, and the upper side of the partition board 5 is connected to the raw material hopper 8. A jet pipe 12 of pressurized air and a collision member 13 are arranged to face each other, and a large number of slit-shaped inlets 15 are provided along the entire circumference of the outer peripheral wall surface 2 of the classification impeller 3 on the lower side. This is a crushing and classifying device configured by connecting a coarse powder discharge port 9 provided below the wall surface 2 and the injection pipe 12 through a connecting pipe 16; By forming the lower surface into a concave shape so that the portion 5a overlaps the classification blade 4 with a slight gap, the crushing portion and the classification portion are appropriately and effectively connected. By repeating the action steps, it is possible to perform efficient crushing and classifying operations, thereby improving the performance of the crushing and classifying device. In other words, in the crushing section, fine powder particles that have been crushed are quickly discharged, and coarse particles that have not been sufficiently crushed are also sequentially discharged to prevent excess accumulation in the crushing section, and the inside of the crushing section is always kept in a state suitable for crushing. By holding it, efficient pulverization can be carried out stably, and it is also effective in improving the pulverization accuracy. On the other hand, by strongly dispersing the raw material particles, which is a major factor in terms of performance as a classification device, and by repeatedly measuring, it promotes the formation of adhered and agglomerated fine powder particles into single particles, making classification and sorting more efficient. In addition, the mixing of fine powder particles into the coarse powder is suppressed, and the leakage prevention structure of the partition plate 5 with respect to the classification impeller 3 prevents the mixing of coarse powder particles into the fine powder. Both fine powder and fine powder can be obtained. In this way, the crushing section and the classification section are separated by a single partition plate 5, and the fine powder crushed in the crushing section is quickly recovered, and the unpulverized coarse particles are transferred to the injection pipe 12, which has a greater crushing effect.
By sequentially circulating the material through the crushing process using the collision member 13, the retention of the raw material in the machine body 1 is suppressed,
Excellent performance can be obtained in both the grinding and classification processes. As a result, it is possible to downsize the device and reduce the required power.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a conventional example, Fig. 2 is a sectional view of essential parts of an embodiment showing the present invention, and Fig. 3 is Fig. 2A-
A′ sectional view, FIG. 4 is a perspective view of the rectifying member 14,
5 to 8 show other embodiments. In the figure, 1... fuselage, 2... wall surface, 3...
Classifying impeller, 4... Classifying impeller, 5... Partition plate, 5
a... Outer peripheral edge, 6... Exhaust pipe, 8... Raw material hopper, 9... Coarse powder discharge port, 12... Injection pipe, 13...
... Collision member, 14... Rectifying member, 15, 15a...
...Inflow port, 16... Connection pipe.

Claims (1)

[Claims] 1. An exhaust pipe 6 is inserted into the vertical cylindrical fuselage 1 from the center above, a partition plate 5 is provided at the lower end to define the boundary, and a raw material injection pipe 12 and the injection pipe are provided at the upper part. A collision member 13 is disposed facing the pipe 12, and a classification impeller 3 and a large number of fine inflow ports 1 are provided on the entire circumference of the outer peripheral wall surface 2 corresponding to the classification impeller 3 at the bottom close to the partition panel 5.
5, and the lower coarse powder discharge port 9 and the injection pipe 12 are communicated with each other through a connecting pipe 16. 2. The partition plate 5 has a larger diameter than the classification impeller 3,
The crushing and classifying device according to item 1 above, wherein the lower surface is formed in a concave shape so that the outer peripheral edge portion 5a overlaps the classification blade 4 somewhat with a slight gap.