JP4174811B2 - Air classifier and fine powder manufacturing equipment using the same - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an air classifier that classifies powder into fine powder, coarse powder, and intermediate powder therebetween, and a fine powder production facility using the same.
[0002]
[Prior art]
Conventionally, ball mills and vertical mills have been used to pulverize sentiment and coal to produce fine powder.
A ball mill supplies raw material (for example, a cement clinker) into a mill drum containing a large number of mill balls, rotates it around its axis, and finely pulverizes the raw material by grinding action such as impact and friction of the mill ball. is there. Such a ball mill has a feature that it can produce fine fine powders, but has a problem of low grinding efficiency because it drives mill balls and mill drums other than raw materials.
[0003]
On the other hand, the vertical mill illustrated in FIG. 6 includes a pulverizer 1, a coarse particle separator 2, and the like. The pulverizer 1 includes a rotary table 1a, a pulverization roller 1b, and the like, and the raw material is rotated by a feeder. The raw material is supplied to the table 1a, the raw material is pulverized by the crushing roller 1b by the rotation of the rotary table 1a, and the finely pulverized raw material supplied from below is pneumatically transported to the coarse powder separator 2 for coarse powder separation. Coarse particles are returned into the mill by the vessel 2, and the finely divided fine powder is taken out as a product. Such a vertical mill has the characteristics that the required power is small and the installation area is small as compared with the ball mill, but there is a problem that the fan power of the primary air for pneumatically transporting the raw material is large.
[0004]
[Problems to be solved by the invention]
In order to solve the problems of the ball mill and vertical mill described above, the inventors of the present invention have already developed and implemented a fine powder production facility shown in FIG. This manufacturing equipment includes a preliminary pulverizer 3, elevators 4a and 4b, a vibrating sieve 5, a ball mill 6, an air separator 7, and the like. The raw material pulverized by the preliminary pulverizer 3 is supplied to the vibrating sieve 5 by the elevator 4a, and vibrations are generated. The coarse powder is classified by the sieve 5 and returned to the preliminary pulverizer 3, and the remainder is supplied to the ball mill 6 and further pulverized. This is supplied to the air separator 7 by the elevator 4b, and the fine powder is taken out as a product. Return to 6. In this figure, 7b is a bug filter.
[0005]
In this fine powder production facility, (1) since the preliminary pulverizer 3 is composed of a rotary table, a pulverizing roller, etc., and has the same configuration as the vertical mill pulverizer, the pulverizing power of coarse powder is particularly small. (2) Features such as mechanical transportation means (conveyor and bucket elevator) instead of pneumatic transportation, transportation power is small, and (3) ball milling is performed while raw materials are ground while separating fine powder, so ball milling efficiency is improved. There is. The air separator 7 includes, for example, a rotating rotor inside a normal cyclone separator, and the particle size of fine powder (product) is adjusted by the rotational speed of the rotor.
[0006]
The fine powder production facility in FIG. 7 achieves a significant increase in crushing capacity and power saving compared to conventional fine powder production facilities using a ball mill or a vertical mill. However, this fine powder production facility has a problem that the particle classification efficiency is still low, although the raw material grinding efficiency and the transportation efficiency are high.
That is, the above-mentioned vibrating sieve can separate coarse powder from the pulverized raw material, but when trying to classify fine powder and medium powder, the screen becomes very fine and the efficiency is extremely reduced. There is a problem that becomes large. Therefore, at present, fine powder sufficiently fine as a product is also supplied to the ball mill, which hinders the ball mill's grinding ability. On the other hand, the air separator can classify fine powder and medium powder relatively efficiently, but has a problem that a relatively coarse raw material cannot be classified from coarse powder to fine powder.
[0007]
The present invention has been developed to solve the above-described problems. That is, an object of the present invention is to further improve not only the classification efficiency but also the pulverization efficiency and the transportation efficiency by using an air classification apparatus capable of efficiently classifying powder into fine powder, medium powder and coarse powder. It is to provide a fine powder production facility capable of performing the above.
[0008]
[Means for Solving the Problems]
According to the present invention, a hollow cylindrical rotary rotor (12) having a plurality of rotary vanes (12a) that are rotationally driven around a vertical axis Z and spaced apart in the circumferential direction, and the rotary rotor A hollow cylindrical fixed separator plate (14) having a plurality of fixed vanes (14a) fixed concentrically and spaced apart from each other in a circumferential direction; A rotating dispersion plate (16) for closing the upper portion, rotating the rotating dispersion plate at a relatively low speed to disperse the supplied powder so as to spread gently and gently, and relatively rotating the rotating rotor The rotating vanes and the fixed vanes each rotate at a high speed to adjust the particle size of the fine particles. Each rotating vane and each stationary vane includes a rotating rotor front end and a rotating rear end, and the front end is the rear end. Than the rotating shaft of the rotor As such, each rotating vane and the respective stationary vanes extends from said front end obliquely inclined on the same side from the rotational direction to the rear end, so that the air flow is directed to the side of the rotary shaft in contact, An air classification device is provided, characterized in that it passes between a plurality of stationary vanes and then passes between a plurality of rotating vanes . According to a preferred embodiment of the present invention, the fine powder duct (18) that communicates with the inside of the rotary rotor to the outside, and the medium grain chute (20) that communicates with the rotary rotor provided below the fixed separator plate. A powder supply pipe (22a) for enclosing the rotary dispersion plate, the fixed separator plate and the medium grain chute at intervals, and supplying powder onto the rotary dispersion plate, and a coarse grain chute (22b) for discharging the coarse particles A hollow cylindrical casing (22) having an air introduction pipe (22c) for introducing air is provided.
[0009]
According to the configuration of the present invention, the pre-ground powder is supplied onto the rotary dispersion plate (16) through the powder supply pipe (22a), and is dispersed around the fixed separator plate (14) by the rotation. The particles are then dropped and classified into coarse particles descending by their own weight and powder (medium particles and fine particles) accompanying the upward flow by the upward flow of air supplied from the air introduction pipe (22c). It can discharge | emit from a coarse grain chute | shoot (22b). Further, the powder accompanying the upward flow is rectified by the fixed vane (14a) of the fixed separator plate (14), becomes a swirling flow by the rotation of the rotating vane (12a), and the fine particles are caused to flow by the action of centrifugal force. The intermediate particles are taken out to the outside through the fine powder duct (18), and the intermediate particles descend on the outside of the rotary vane and are discharged to the outside through the intermediate particle chute (20). Therefore, with this configuration, the powder can be classified into fine particles, medium particles, and coarse particles.
Further, according to the configuration of the present invention, the rotary rotor (12) and the rotary dispersion plate (16) can be independently driven to rotate, so that the powder supplied by rotating the rotary dispersion plate at a relatively low speed is uniform. The particle size of the fine particles can be adjusted by rotating the rotating rotor at a relatively high speed.
[0010]
Furthermore, according to a preferred embodiment of the present invention, the coarse chute (22b) is formed in a taper shape whose diameter gradually decreases downward, and the air introduction pipe (22c) is provided at an intermediate portion of the coarse chute. Is formed. With this configuration, the upward flow in the coarse chutes can be strengthened downward and the coarse particles can be effectively classified.
[0011]
Further, according to the present invention, the preliminary pulverizer (3) having a rotary table and a pulverizing roller and pulverizing the raw material, and the above-mentioned method for classifying the powder into fine particles, coarse particles and intermediate intermediate powder by the flow of air flow An air classifier (10) and a mechanical transport means (4) for transporting the powder pulverized by the preliminary pulverizer to the air classifier, the fine particles classified by the air classifier are collected as products, and coarse particles A fine powder production facility is provided that is recycled to a pre-pulverizer.
[0012]
According to the configuration of the present invention, since the preliminary pulverizer (3) having a rotary table and a pulverizing roller is used to pulverize the raw material, the pulverization efficiency is high, and the powder pulverized by the preliminary pulverizer is transported to the air classifier. Since the mechanical transportation means (4) is used, the transportation efficiency is high. Further, in the present invention, the air classification device (10) for classifying the powder into fine particles, coarse particles and intermediate intermediate powder by the flow of air flow is provided, so that the classification efficiency can be improved and the classification is performed. Since the classified fine particles are collected as a product and the coarse particles are recycled to the preliminary pulverizer, the pulverization efficiency of the preliminary pulverizer and the transport efficiency of the mechanical transportation means can be further increased.
[0013]
According to a preferred embodiment of the present invention, a ball mill (6) is further provided, and medium grains classified by an air classifier are supplied. With this configuration, the pulverization efficiency in the ball mill can also be increased by supplying the ball mill with the intermediate particles obtained by classifying the fine powder as a product with the air classifier.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.
FIG. 1 is a cross-sectional view of an air classifier according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. As shown in FIGS. 1 and 2, the air classification device 10 of the present invention includes a hollow cylindrical rotary rotor 12, a hollow cylindrical fixed separator plate 14, a rotary dispersion plate 16, a fine powder duct 18, a medium grain chute 20, and It consists of a casing 22.
[0015]
The rotary rotor 12 is rotationally driven by a driving device (not shown) around a vertical axis Z. Further, the rotary rotor 12 has a plurality of rotary vanes 12a arranged at intervals in the circumferential direction as shown in FIG. The fixed separator plate 14 is fixed concentrically around the rotary rotor 12. Moreover, as shown in FIG. 2, it has the some fixed vane 14a arrange | positioned at intervals in the circumferential direction. In this example, the rotary vane 12a and the fixed vane 14a are flat plates inclined in the same direction, and the rotary rotor 12 rotates (rotates counterclockwise in the figure) in the direction of the air flow that has passed through the fixed vane 14a. It smoothly passes between the rotary vanes 12 a and flows into the rotary rotor 12. Each vane 12a, 14a may have an airfoil shape or other shapes.
[0016]
The fine powder duct 18 communicates the inside of the rotary rotor 12 with the outside. In addition, in this figure, although the fine powder duct 18 is located under the rotary rotor 12, this invention is not limited to this, You may provide above the rotary rotor 12. FIG.
The medium grain chute 20 is provided below the fixed separator plate 14 and communicates with the rotary rotor 12 to the outside. As shown in FIG. 1, the middle grain chute 20 is preferably formed in a tapered shape at the lower side so that coarse grains fall smoothly.
With the configuration described above, the air flow introduced from the outside is rectified by the fixed vane 14a of the fixed separator plate 14, a swirl flow is formed by the rotation of the rotating vane 12a, and fine particles and medium particles are classified by the action of centrifugal force. The fine powder duct 18 and the medium grain chute 20 can each be taken out to the outside.
[0017]
The casing 22 is an airtight container that surrounds the rotary dispersion plate 16, the fixed separator plate 14, and the medium grain chute 20 with a space therebetween. The casing 22 includes a powder supply pipe 22a for supplying powder onto the rotary dispersion plate 16, a coarse chute 22b for discharging coarse grains, and an air introduction pipe 22c for introducing air. Yes. In this example, the coarse grain chute 22b is formed in a tapered shape whose diameter gradually decreases downward. An air introduction pipe 22c is provided in the middle part of the coarse chute 22b.
The rotation dispersion plate 16 is rotationally driven independently by a driving device (not shown) coaxially with the rotary rotor 12. The rotation dispersion plate 16 is formed so as to close the upper part of the fixed separator plate.
With this configuration, the preliminarily pulverized powder is supplied onto the rotary dispersion plate 16 via the powder supply pipe 22a, and is dispersed and dropped around the fixed separator plate 14 by the rotation, and supplied from the air introduction pipe 22c. By the upward flow of air, it is classified into coarse particles descending under their own weight and powder (medium particles and fine particles) accompanying the upward flow, and the coarse particles can be discharged from the coarse particle chute 22b.
[0018]
Furthermore, according to the configuration of the present invention described above, the rotary rotor 12 and the rotary dispersion plate 16 can be independently driven to rotate, so that the powder supplied by rotating the rotary dispersion plate 16 at a relatively low speed can be uniformly distributed. The particles can be dispersed so as to spread gently, and conversely, the rotating rotor 12 can be rotated at a relatively high speed to adjust the particle size of the fine particles.
[0019]
FIG. 3 is an overall configuration diagram of the fine powder production facility according to the present invention. As shown in this figure, the fine powder production facility of the present invention includes a preliminary pulverizer 3 having a rotary table and a pulverizing roller to pulverize the raw material, fine particles, coarse particles and intermediate particles between them by the flow of air flow. An air classifier 10 for classifying into powder, a mechanical transport means 4 for transporting the powder pulverized by the preliminary pulverizer to the air classifier, and a ball mill 6, and recovering fine particles classified by the air classifier 10 as a product The coarse particles are recycled to the preliminary pulverizer 3 and the intermediate particles classified by the air classifier 10 are supplied to the ball mill 6.
[0020]
With this configuration, since the preliminary pulverizer 3 having a rotary table and a pulverizing roller is used to pulverize the raw material, the pulverization efficiency is high, and mechanical transport means 4 for transporting the powder pulverized by the preliminary pulverizer 3 to the air classifier 10. (For example, a bucket elevator or a belt conveyor) is used, so that the transportation efficiency is high. Further, in the present invention, the air classification device 10 for classifying the powder into fine particles, coarse particles, and intermediate intermediate powder by the flow of air flow is provided, so that the classification efficiency can be improved, and the classified fine particles Since it is recovered as a product and the coarse particles are recycled to the preliminary pulverizer 3, the pulverization efficiency of the preliminary pulverizer 3 and the transport efficiency of the mechanical transport means can be further increased. Furthermore, the grinding efficiency in the ball mill 6 can be improved by providing the ball mill 6 with the intermediate particles classified by the air classifier 10 to the ball mill.
[0021]
Examples of the present invention will be described below.
FIG. 4 is an example of the fine powder production facility of the present invention, and shows actual measurement values of the entire material balance. As can be seen from this figure, 30 t / h of fine particles are separated from the raw material of 126 t / h by the air classifier 10 of the present invention, thereby reducing the load on the ball mill 6. Further, the obtained fine particles were of good quality having a specific surface area of 3200 cm ² / g or more. Further, it was found that about 500 cm ² / g medium grains were supplied to the ball mill 6 and the grinding efficiency in the ball mill 6 could be increased.
[0022]
FIG. 5 shows an embodiment of the air classifier of the present invention, and shows the particle size distribution of the powder before and after classification. In this example, the rotating rotor 12 having a diameter of about 2300 mm is rotated at a high speed of about 18 to 180 rpm, and the rotating dispersion plate 16 having a diameter of about 3000 mm is rotated at a low speed of about 7.5 to 30 rpm.
FIG. 5 shows that the pre-ground powder A can be effectively classified into coarse particles B, medium particles C, and fine particles D by the air classifier of the present invention. Moreover, the obtained product (fine powder D) is very fine and fine, with 92% passing through 44 μm, and its distribution is sharp.
[0023]
In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.
[0024]
【The invention's effect】
As described above, in the air classification device of the present invention, the rotary rotor 12 and the rotary dispersion plate 16 can be independently rotated, so that the powder supplied by rotating the rotary dispersion plate at a relatively low speed can be uniformly distributed. The particles can be dispersed so as to spread gently, and conversely, the rotating rotor can be rotated at a relatively high speed to adjust the particle size of the fine particles.
In addition, the fine powder production facility of the present invention uses the preliminary pulverizer 3 so that the pulverization efficiency is high. Since the mechanical transportation means 4 is used, the transportation efficiency is high. Further, since the air classification device 10 is provided, the classification efficiency is improved. Since the classified fine particles can be collected as a product and the coarse particles are recycled to the preliminary pulverizer, the stable operation of the preliminary pulverizer and the pulverization efficiency of the ball mill 6 can be increased.
[0025]
Therefore, the air classification apparatus of the present invention and the fine powder production equipment using the air classification apparatus are capable of efficiently classifying powder into fine powder, medium powder and coarse powder, and not only the classification efficiency using the air classification apparatus. It has excellent effects such as further improving the pulverization efficiency and the transportation efficiency.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an air classifier according to the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is an overall configuration diagram of a fine powder production facility according to the present invention.
FIG. 4 is an embodiment of the fine powder production facility of the present invention.
FIG. 5 is an embodiment of the air classifier of the present invention.
FIG. 6 is a schematic view of a vertical mill.
FIG. 7 is an overall configuration diagram of a conventional fine powder production facility.
[Explanation of symbols]
1 Crusher 2 Coarse Grain Separator 3 Preliminary Crusher 4, 4a, 4b Mechanical transportation means (bucket elevator)
5 Vibrating sieve 6 Ball mill 7 Air separator 10 Air classifier 12 Rotating rotor 12a Rotating vane 14 Fixed separator plate 14a Fixed vane 16 Rotating dispersion plate 18 Fine powder duct 20 Medium grain chute 22 Casing 22a Powder supply pipe 22b Coarse grain chute 22c Air introduction tube

Claims (5)

A hollow cylindrical rotary rotor (12) having a plurality of rotary vanes (12a) which are rotationally driven about a vertical axis Z and spaced apart in the circumferential direction, and are concentrically fixed around the rotary rotor. And a hollow cylindrical fixed separator plate (14) having a plurality of fixed vanes (14a) arranged at intervals in the circumferential direction, and rotational dispersion that is rotationally driven coaxially with the rotary rotor and closes the upper portion of the fixed separator plate A plate (16), the rotating dispersion plate is rotated at a relatively low speed, the supplied powder is dispersed so as to spread gently and gently, and the rotating rotor is rotated at a relatively high speed to form fine particles. Adjust the grain size of
Each rotary vane and each fixed vane has a front end in the rotational direction of the rotary rotor and a rear end in the rotational direction,
The rotating vanes and the fixed vanes extend obliquely from the rotating direction to the same side and extend from the leading end to the trailing end so that the leading end is closer to the rotating shaft of the rotating rotor than the trailing end. ,
An air classification device characterized in that an air flow passes between a plurality of stationary vanes and then passes between a plurality of rotating vanes so as to be directed toward the rotating shaft .   A fine powder duct (18) communicating with the inside of the rotating rotor (12) to the outside, a medium-sized chute (20) provided below the fixed separator plate (14) and communicating with the rotating rotor, and a rotation The dispersion plate, the fixed separator plate and the medium grain chute are surrounded at intervals, and a powder supply pipe (22a) for supplying powder on the rotating dispersion plate, a coarse chute (22b) for discharging coarse particles, and air are introduced. The air classification device according to claim 1, further comprising: a hollow cylindrical casing (22) having an air introduction pipe (22c).   The coarse grain chute (22b) is formed in a tapered shape whose diameter gradually decreases downward, and the air introduction pipe (22c) is formed in an intermediate part of the coarse grain chute. Item 3. The air classification device according to Item 2.   A preliminary pulverizer (3) having a rotary table and a pulverizing roller for pulverizing the raw material, and an air classifier according to claim 1, wherein the powder is classified into fine particles, coarse particles and intermediate intermediate powder by the flow of air. (10) and mechanical transport means (4) for transporting the powder pulverized by the preliminary pulverizer to the air classifier, the fine particles classified by the air classifier are recovered as products, and the coarse particles are preliminarily pulverized. Fine powder manufacturing equipment characterized by recycling to a machine.   The fine powder production facility according to claim 4, further comprising a ball mill (6), and supplying the intermediate particles classified by the air classifier.

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