JP2001046897A - Milling apparatus of cement clinker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cement clinker milling apparatus possible to adjust the particle size distribution of a cement product and to improve milling efficiency without enlarging the constitution. SOLUTION: The milled product produced by milling cement clinker by a vertical type roller mill is transported upward by a bucket elevator 23, supplied to a fluidized bed type classification apparatus 26 to be roughly classified to approximately fine powder and the remaining coarse particle-containing milled matter, and then only the approximately fine powder is supplied to a separator to be classified to a fine powder and a coarse powder and then the fine powder is taken out as a cement product and the coarse powder is turn back again to the vertical type roller mill after being mixed with the remaining coarse particle-containing milled matter classified by the fluidized bed type classification apparatus 26. In such a manner, the load to the air current type classification apparatus 27 is lessened to make the apparatus 27 possible to be miniaturized and, at the same time, the particle size constitution of the cement product is made adjustable by adjusting the amount of the remaining milled matter bypassing the fluidized-bed type sieving apparatus 26 to improve the quality of the cement product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved cement clinker crushing apparatus for crushing a cement clinker as a crushing material to produce a cement product as a crushed material by a closed circuit crushing system having a vertical roller mill. .

[0002]

2. Description of the Related Art FIG. 5 is a system diagram showing a typical prior art cement clinker crushing apparatus 1. This prior art is disclosed in Japanese Patent Application Laid-Open No. 9-276727.
The conventional cement clinker crushing apparatus 1 includes a vertical roller mill 2 for crushing the cement clinker, a bucket elevator 3 for transporting the crushed material crushed by the vertical roller mill 2 upward, and the bucket elevator 3. A distribution damper 4 that divides the cement clinker transported upward, returns a part of the divided cement clinker to the vertical roller mill 2, and converts the crushed material guided by the distribution damper 4 into fine powder and coarse powder according to the particle size. And a separator 5 for returning the coarse powder to the vertical roller mill 2 and a refined powder classified by the separator 5,
The dust collector 6 is realized by a bag filter or the like and captures fine powder transported by air from the separator 5 to take out cement as a product. The dust collector 6 has a suction fan 7 for introducing a suction force to the dust collector 6.

The vertical roller mill 2 has a structure without a separator, and a table 9 is provided below a housing 8 with a motor 11 around a vertical rotation axis 10.
It is rotationally driven by the rotational force from. The raw material cement clinker is supplied to a raw material input chute 13 of the vertical roller mill 2 as shown by an arrow
It is crushed and crushed by the rollers 14 above. Substantially all of the pulverized product is discharged from the discharge chute 15 below the table 9 and transported to a position above the separator 5 by the bucket elevator 3. The fine powder classified by the separator 5 is collected by the dust collector 6, and the air is radiated by the suction fan 7, so that only the fine powder, which is a product, is taken out.

[0004]

In the above prior art, the crushed material pulverized by the vertical roller mill is sorted by the distribution damper 4, and a part thereof is guided to the separator 5 and refined according to the particle size. And coarse powder are separated and the fine powder is taken out as a product.
And is again transported upward by the bucket elevator 3 and distributed to the separator 5 and the vertical roller mill 2 by the distribution damper 4, thus forming a closed-circuit grinding system. The flow distribution of the product can be controlled by adjusting the distribution of the separator 5 and the vertical roller mill 2 by the use of 4, so that the quality of the cement product can be adjusted optimally. Vertical roller mill 2
The crushed product contains 20 to 30% by weight of particles having a large particle size of about 2 to 13 mm. On the other hand, the particle size of the fine powder classified as a cement product is a fine powder of approximately 60 μm or less.
Classifying particles having a large particle size of about 13 mm by the separator 5 is not only meaningless, but also
(A) The amount of treatment in the separator 5 increases, and the separator 5 must be enlarged. (B) Classification performance is increased because 20 to 30% by weight of particles having a large particle size is contained as described above. And (c) the power required for classification of the separator 5 increases, and (d)
Has a problem that the inside wear is significantly increased and the durability of the separator 5 is reduced.

In order to solve such problems (a) to (d), for example, as shown in Japanese Utility Model Application Laid-Open No. Sho 61-15045, a crushed product pulverized by a vertical roller mill is charged into a separator. Before doing so, the coarse particles and fine particles are separated by a coarse particle separator, also called a vibrating sieve, and the coarse particles are returned to a vertical roller mill, and only the fine particles are charged into the separator. Problems arise. That is, (e) coarse particles directly returned to the vertical roller mill by bypassing the separator are coarse meshes of a sieve mesh, for example, coarse particles of about 5 mm or more, and this particle size is a cement clinker which is a newly supplied raw material. Rather, it is not possible to freely control the amount returned to the vertical roller mill and the amount returned to the vertical roller mill, so it is not possible to adjust the particle size composition of the cement, and the particle size distribution width specific to cement in the vertical roller mill is very narrow. (F) The circulation rate of such a closed-circuit pulverizing system (= coarse-grain / fine-grain) is very large, 10 to 15, so that the throughput of the coarse-grain separator is small. In the case of an enormous amount, for example, an average crushing amount of 100 t / h of the crushing equipment in the cement crushing, the processing amount of the coarse particle separator is the same as that of the conventional technology disclosed in Japanese Utility Model Laid-Open No. 61-15045. , 100t / h × (11~1
6) = 1100-1600 t / h. When the opening capacity of the coarse particle separator is 5 mm, the coarse particle separator has a processing capacity of 20 to 30 t / h / m ^2.
, The required processing area is about 40 to 80 m ² ,
In practice, it is not feasible.

(G) Although the required processing area of the coarse particle separator is enormous, the separator has a particle size of 5 m.
As a result, a sufficient effect cannot be expected for improving the classification performance and abnormal wear of the separator. It is also conceivable to reduce the size of the sieve of the coarse-grain separator in order to improve the classifying performance and abnormal wear.However, if the size of the sieve is reduced in this way, the coarse-grain separator can be used. It has to be larger, making it less practically feasible.

(H) In addition, the life of the sieve net used for the coarse particle separator is expected to be about one month by analogy with similar equipment, and frequent maintenance is required, thereby lowering the operation efficiency and There is a problem that operation cost is high and economic efficiency is poor.

An object of the present invention is to provide a cement clinker pulverizing apparatus which can reduce the size of the structure, adjust the particle size distribution of a cement product, and improve the pulverizing efficiency.

[0009]

SUMMARY OF THE INVENTION The present invention provides a vertical roller mill for pulverizing cement clinker, a first transport means for transporting the crushed material pulverized by the vertical roller mill upward, and a first transport means. A fluidized bed classifier that fluidizes the granulated material supplied from above, removes roughly fine powder from the upper outlet, and removes the remaining granulated material from the lower outlet and roughly classifies the fluidized bed. A separator that classifies the roughly fine powder supplied from the type classifier into a fine powder and a coarse powder, and a coarse product classified by the separator with the remaining crushed product roughly classified by the fluidized bed classifier. A cement clinker crushing device, comprising: a second transport means for returning the powder to the vertical roller mill together with the powder.

According to the present invention, the raw material cement clinker is charged as a crushing material into a vertical roll mill,
Pulverized by actions such as crushing and grinding. The crushed material pulverized by the vertical roll mill is transported upward by the first transport means, and is roughly classified by a fluidized bed classifier. This fluidized bed classifier has lower performance of separating coarse and fine powders than a general airflow classifier such as the separator, and the classification particle size distribution is relatively ambiguous. Therefore, the classification in the fluidized bed classifier is not a general classification concept of the above-described airflow classifier or the like, "classification into fine powder and coarse powder", but "crushing of fine powder and residual powder". In the present invention, this latter operation of "separating into fine powder and the remaining crushed material" is referred to as "coarse classification" (hereinafter the same).

In such a fluidized bed classifier,
The granulated material supplied from above by the first transport means is fluidized on the dispersion plate by an air flow to form a fluidized bed. In the upper part of this fluidized bed, relatively small-mass fine powder flows, and in the lower part, large-mass coarse particles mainly flow. However, the coarse-grained fluidized bed in the lower part contains some fine powder. I have. Therefore, fine powder is generally taken out from the upper outlet, and the remaining crushed material, that is, powder containing mainly fine particles, mainly coarse particles, is taken out from the lower outlet. The crushed material supplied from the first transport means is roughly classified.

The roughly fine powder taken out from the upper outlet of the fluidized bed classifier is supplied to a separator and classified into fine powder and coarse powder, and the fine powder is provided with a dust filter provided with a bag filter or the like. Collected and removed as product. The coarse powder classified by the separator and the remaining crushed material roughly classified by the fluidized bed classifier are returned to the vertical roller mill by the second transport means.

[0013] In this manner, the separator can be made so as not to contain the remaining crushed material mainly composed of coarse particles from which fine powder has been removed by the fluidized bed classifier. , At least 2-3
About 20% by weight or more of coarse particles having a particle diameter of not less than mm can be removed. Therefore, only powders suitable for classification by the separator are supplied, whereby the size of the separator can be reduced. In addition, since interference of the coarse particles with the fine powder in the separator can be eliminated, the fine powder can be efficiently collected, thereby improving the classification efficiency of the separator. Further, since the coarse particles having a particle diameter of at least 2 to 3 mm are not supplied to the separator, the wear of the separator can be remarkably reduced, and the durability of the separator is improved.

Further, as described above, the remaining crushed material returned from the fluidized bed type classifier to the vertical roller mill by bypassing the separator contains coarse particles and some fine powder. By adjusting the amount of supply to the vertical roller mill or the distribution of coarse particles and fine powder in the remaining crushed product, it is possible to control the particle size composition of the fine powder, thereby the required cement product The particle size distribution can be controlled, and the quality of the product can be improved. Moreover, since the fluidized bed classifier has a processing capacity of, for example, about 250 t / h per 1 m ² ,
It is not necessary to use a fluidized bed type classifier having an excessively large processing capacity, whereby the configuration is not enlarged, the operation cost is low, and the economic efficiency can be improved.

In the invention, it is preferable that the second transport means includes discharge amount adjusting means for adjusting the discharge amount of the remaining crushed material discharged from the lower discharge port of the fluidized bed classifier. Features.

According to the present invention, the second transport means includes a discharge amount adjusting means, and the discharge amount adjusting means discharges the remaining crushed material discharged from the lower outlet of the fluidized bed classifier. Adjust the volume. By increasing the discharge amount of the remaining crushed material discharged from the lower discharge port of the fluidized bed classifier by such a discharge amount adjusting means, the amount of fine powder returned to the vertical roller mill increases, and as a result, the vertical Since the compounding ratio of the fine powder in the pulverized product of the mold roller mill increases, the width of the particle size distribution of the fine powder classified by the separator can be increased. Conversely, when the amount of discharge by the discharge amount adjusting means is reduced, the amount of fine powder returned to the vertical roller mill is reduced, so that the amount of fine powder in the crushed product of the vertical roller mill is also reduced, and the fineness classified by the separator is reduced. The mixing ratio of the fine powder in the powder is reduced, and the width of the particle size distribution of the fine powder can be narrowed.

In this way, the discharge amount adjusting means
Desirable particle size distribution of fine powder taken out as fine powder from separator by adjusting the feed rate of the remaining crushed material mainly containing coarse particles from the lower outlet of fluidized bed classifier to vertical roller mill Thus, it is possible to easily adjust the configuration to a desired configuration, and to easily produce a cement product having a target particle size configuration with a simple configuration.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a system diagram showing a cement clinker crushing apparatus 21 according to an embodiment of the present invention.
The cement clinker crushing device 21 of the present embodiment includes a vertical roller mill 22 for crushing the cement clinker input as a raw material, and a first transport for transporting the crushed material crushed by the vertical roller mill 22 upward. The bucket elevator 23 as a means and the crushed material supplied from above by the bucket elevator 23 are fluidized, and roughly fine powder is taken out from the upper outlet 24, and the remaining crushed material is taken out from the lower outlet 25. Bed type classifier 2 for coarse classification
6, an air flow classifier 27 which is a separator for classifying the roughly fine powder supplied from the fluidized bed classifier 26 into a fine powder and a coarse powder, and a lower outlet of the fluidized bed classifier 26 Screw conveyor 28 which is a discharge amount adjusting means for adjusting the discharge amount of the remaining crushed material discharged from
And a part of the second transport means for returning the remaining crushed material roughly classified by the fluidized-bed classifier 26 to the vertical roller mill 22 together with the coarse powder classified by the airflow classifier 27. The bypass transport path 29, the fines classified by the pneumatic classifier 27 are guided by pneumatic transport, and a dust collector 30 realized by, for example, a bag filter that collects the fines, and a suction force applied to the dust collector 30. And a suction fan 31 to be introduced.

The vertical roller mill 22 has a table 38 which is driven to rotate about a vertical rotation axis 37 below a housing 36 thereof, and is arranged on a peripheral portion of the table 38 at intervals in the circumferential direction. A plurality of rollers 3 driven by rotation about the vertical axis of rotation 37
9, a rotary drive source 41 having a motor 40 for driving the table 38 to rotate about a vertical rotation axis 37, and a cement clinker, which is provided in the upper center of the housing 36 and is a raw material, is supplied to the table 38 by feeding it. It has a raw material charging chute 42 and a dust discharge port 43 that is provided near the upper peripheral portion of the housing 36 and discharges dust generated by crushing of the cement clinker in the housing 36.

The cement clinker supplied to the table 38 from the raw material input chute 42 is
Each of the rollers 39 driven by the rotation of the table 38 about the vertical rotation axis 37 crushes and crushes the table. Substantially all of the crushed crushed material is discharged out of the machine from below the table 38, guided to the intake 45 provided at the lower part of the bucket elevator 23 by the first chute 44, and provided with a plurality of Buckets are sequentially charged into the buckets and transported upward, and the bucket elevators 23
Is discharged to a second chute 47 from an outlet 46 provided at the upper part of the hopper.

The crushed material discharged from the bucket elevator 23 to the second chute 47 in this way is introduced into the fluidized bed classifier 26 from above, and is blown up from below by a roots blower 48 through a dispersion plate (not shown). Fluidized by the air flow, as described above, the roughly fine powder is taken out from the upper outlet 24, and the remaining pulverized matter including coarse particles is taken out from the lower outlet 25, and thus the second chute is discharged from the bucket elevator 23. The pulverized material supplied via the pipe 47 is roughly classified. The flow rate of the compressed air supplied from the roots blower 48 is selected to be, for example, about 90 m ³ / min in equipment having a pulverization amount of 100 t / h.
This flow rate is not limited to this, and the fluidized state of the fluidized bed is affected by many factors such as the particle size of the injected granules, physical characteristics, structure of the dispersion plate, and physical properties of the compressed air. Therefore, it is optimally determined according to these factors.

The roughly fine powder taken out from the upper outlet 24 of the fluidized-bed classifier 26 is supplied to the air-flow classifier 27 from above by a third chute 49.
Also connected to this upper part is an air flow transport pipe 55 that guides the fine powder and suction power to the dust collector 30 to form an air flow transport path. The air classifier 27 is also supplied with, for example, normal-temperature cooling air from a blower 50, and the extraction chutes 51, 52 and the air chute 51, 52 for preventing the fluidized bed classifier 26 and the vertical roller mill 22 from generating dust. The fine powder conveyed by airflow is supplied from a bleeding / merging chute 53 which joins and supplies the fine powders guided by these chutes 51 and 52, and is classified by the airflow classifier 27. The fluidized bed classifier 26 and the vertical The generation of dust in the mold roller mill 21 is prevented.

FIG. 2 shows a fluidized bed classifier 2 shown in FIG.
6 is a cross-sectional view showing a specific configuration of FIG. The fluidized bed type classifier 26 has a substantially rectangular parallelepiped hollow casing 61.
A dispersion plate 62 in which a number of through holes are formed is provided, and partitions the space in the casing 61 into an upper flow chamber 63 and a lower air chamber 64. The dispersing plate 62 is formed so as to be inclined so that an inner region is lower than a peripheral portion. The air chamber 64 is divided into a first air chamber 66 and a second air chamber 67 by a partition plate 65, and air is individually supplied to the air chambers 66 and 67 from the first and second air introduction ports 68 and 69. be introduced. Above the first air chamber 66, the bleed duct 7
0 is formed, and the bleed duct 70 communicates with the flow chamber 63. Each air chamber 66, 67 from each air inlet 68, 69
The air introduced into the air extraction duct 70 is extracted from the air extraction duct 70, and is supplied from the air extraction chute 51 connected to the air extraction duct 70 to the air flow classifier 27 via the air extraction merge chute 53 to collect fine powder.

The lower part where the upper surface of the dispersion plate 62 is the lowest is connected to the coarse powder discharge chute 73 and opened.
Further, the casing 61 is provided with a crushed material supply port 74 to which crushed material is supplied from the bucket elevator 23 via the second chute 47, and one side of the side wall of the side wall where the crushed material supply port 74 is opened. On the other side opposite to the part, a fine powder discharge chute 75 is provided so as to open in a region as an upper portion above the opening region of the coarse powder discharge chute 73 of the dispersion plate 62.

The partition plate 65 includes a coarse powder discharging chute 73.
Is provided on the outside. The second air chamber 67 is supplied with air at a flow rate necessary for fluidizing the crushed material supplied from the crushed material supply port 74 from the second air introduction port 69. The second air inlet 69 has a roots blower 48.
From the air supply. Air is supplied from the first air inlet 68 to the first air chamber 68 at a flow rate necessary for jetting air from the through-holes of the dispersion plate 62 at a flow rate at which coarse powder does not enter the fine powder discharge chute 75. Then, the air from the roots blower 48 is branched and supplied to the first air inlet 68.

The fine powder discharge chute 7 of the casing 61
Below the other side where the 5 is provided, an inclined portion 77 that is inclined inward and downward is formed. Of the crushed material soared upward by the air flow ejected from the dispersing plate 62, particles larger than coarse powder are used to form a drool in the upward flow due to the inclined portion 77 and generate a stall region. Of the fine powder discharge chute 75
It is possible to prevent or reduce the amount of the fine powder and the remaining crushed product by roughly mixing and preventing the mixture from being discharged into the internal air flow and being discharged.

Next, the operation of the crusher 21 will be described. Substantially all of the cement clinker crushed by the vertical roller mill 22 is taken out from below the vertical roller mill 22 and supplied to the inlet 45 of the bucket elevator 23 by the first chute 44. The bucket elevator 23 transports the crushed material supplied to the inlet 45 upward, discharges the crushed material from the outlet 46 to the second chute 47, and supplies the crushed material to the fluidized bed classifier 26 from above via the second chute 47. Is done.

In this fluidized bed classifier 26, 2-3 mm
It is roughly classified into a fine powder having the following particle size and a crushed product containing the remaining coarse particles. In the fluidized bed classifier 26, the first and second air chambers 66 and 67 below the dispersion plate 62
Air is individually supplied at an optimum flow rate from the roots blower 48, and in a region below the crushed material supply port 74 of the dispersion plate 62,
The crushed material on the dispersion plate 62 is fluidized by air ejected from the through holes 71a of the dispersion plate 62 at a flow rate suitable for fluidization. In the region of the dispersion plate 62 on the side of the fine powder discharge chute 75, the flow velocity of the air ejected upward from the through holes 71b of the dispersion plate 62 in this region is ejected from the through holes 71a in the region of the pulverized material supply port 74 side. Because it is set lower than the flow rate of air, coarse particles having a large mass flow at a relatively low position in the fluidized bed, and fine powder and fine powder having a small mass flow at a relatively high position in the fluidized bed. Fluidized.

In this way, the particle size distribution is changed from coarse to fine from the region below the granulated material supply port 74 to the region near the fine powder discharge chute 75 in one fluidized bed with the partition plate 65 as a substantially boundary. In general, only fine powder can be removed from the fine powder discharge chute 75, and the remaining pulverized material including coarse particles can be removed from the coarse powder discharge chute 73 and roughly classified.

The remaining crushed material taken out from the coarse powder discharge chute 73 of the fluidized bed classifier 26 as described above is discharged to the fourth chute 54 at a predetermined flow rate by the screw conveyor 28, and the raw materials are charged. The raw material is mixed with the raw material cement clinker fed through the chute 42 and supplied to the vertical roller mill 22 again.

The roughly fine powder discharged from the fine powder discharge chute 75 of the fluidized bed classifier 26 is supplied from above to the airflow classifier 27 by the third chute 49. In the air-flow classifier 27, as described above, in the fluidized-bed classifier 26, a crushed product containing a relatively large mass of coarse powder, coarse particles, and some fine powder mixed from the coarse powder discharge chute 73, specifically, Since particles having a particle size of 2-3 mm or more are removed by about 20% by weight or more, the amount of the crushed material to be classified by the air-flow classifier 27 can be reduced, and therefore, undesirably. High classification efficiency can be achieved by the small airflow classifier 27 without requiring a large empty tower area.

The fine powder classified in the air-flow classifier 27 is transported by airflow through the airflow transport pipe 55 and guided to the dust collector 30, where only the particles are collected by the bag filter and taken out as a product. In this way, in order to pneumatically transport and guide the fine powder to the dust collector 30 by the pneumatic transport pipe 55, the suction capacity of the suction fan 31 is 100t /.
h, for example, 2500 m ³ / mi
n is selected.

The coarse powder classified by the air-flow classifier 27 is discharged from a fifth chute 56 connected to an intermediate position of the fourth chute 54, and is restricted in the fourth chute 54 by the screw conveyor 28. At the predetermined flow rate, and is supplied to the vertical roller mill 22 from the raw material charging chute 42 and pulverized again.

Thus, the vertical roller mill 22 and the first
A portion 57 of the chute 44, the bucket elevator 23, the second chute 47, the third chute 49, the airflow type classifier 27, the fifth chute 56, and the fourth chute 54 on the downstream side of the connection position of the fifth chute 56; Shooting chute 4
The first closed-circuit pulverizing route is constituted by a portion 58 downstream of the connection position of the second chute 54.
The vertical roller mill 22, the first chute 44, the bucket elevator 23, the second chute 47, the fluidized bed classifier 2
6, the screw conveyor 28, the fourth chute 54, and the downstream portion 58 of the raw material charging chute 42 constitute a second closed circuit pulverizing route.

In the first and second closed-circuit pulverizing routes, the second transportation including the fourth chute 54, the portion 58 of the raw material input chute 42, the fifth chute 56, and the screw conveyor 28 is performed. The fourth chute 54 excluding the screw conveyor 28 and the portion 58 of the raw material charging chute 42 constitute the bypass transport path 29.

As described above, of the crushed material supplied to the airflow classifier 27, the remaining crushed material excluding the roughly fine powder is
It is diverted by the screw conveyor 28 and the fourth chute 54 and guided to the vertical roller mill 22, and is crushed by the crushing device 21 that uses the first and second closed-circuit crushing routes together.
The structure can be reduced in size, the particle size distribution of the cement product can be adjusted, and the pulverization efficiency can be improved. Moreover,
Among the crushed materials supplied to the airflow classifier as described above,
Coarse particles having a particle size of at least a few mm or more
Weight percent or more can be removed.
The abrasion of a member that the crushed material such as the casing 61 and the dispersion plate 62 abuts or slides on can be remarkably reduced, and the durability of the airflow classifier 27 can be improved.

Further, when the flow distribution width of the cement product is narrow, the number of revolutions of the screw conveyor 28 is increased to increase the transport amount, and the flow rate of the crushed material that bypasses the airflow classifier 27 is increased. This bypass crushed material includes
As described above, since a considerable amount of fine powder is contained in addition to the coarse particles, the amount of fine powder further increases by increasing the transport amount, and the amount of fine powder in the crushed material taken out from the vertical roller mill 22 increases. However, this increases the amount of fine powder in the cement product, and can change the particle size distribution of the cement product to a wide range. When the particle size distribution of the cement product is wide, the rotation speed of the screw conveyor 28 described above is reduced, and the flow rate of the crushed material that bypasses the air-flow type classifier 27 is reduced. The amount of fines decreases. As a result, the amount of fine powder in the crushed material taken out from the vertical roller mill 22 decreases, the amount of fine powder in the cement product decreases, the width of the particle size distribution of the cement product can change to a narrow side, and the particle size of the cement product decreases. The distribution can be improved.

Further, the particle size of the roughly fine powder taken out from the discharge port 24 on the upper part of the fluidized bed classifier 26 is adjusted by adjusting the amount of air blown by the roots blower 48 to each of the through holes 71a, 7a of the dispersion plate 62.
The flow velocity of the air blown up from 1b can be changed, and can be changed according to the wind speed in the tower of the fluidized bed. The fluidized bed classifier 26 can practically take out fine powder and fine powder having a particle size of 2 to 3 mm or less. Therefore, in another embodiment of the present embodiment, the screw conveyor 2
A configuration in which 8 is omitted is also possible.

Further, since the fluidized bed classifier 26 has a large processing capacity, unlike the conventional technique disclosed in the above-mentioned Japanese Utility Model Application Laid-Open No. Sho 61-15045, it requires an unnecessarily large processing area for classification. Instead, the fluidized bed classifier 26 can be downsized, and therefore the entire configuration of the pulverizing device 21 can be downsized. In addition, the above-mentioned Japanese Utility Model Application No. 61-15045
No vibration sieve is used as in the prior art disclosed in Japanese Unexamined Patent Application Publication No. 2000-146, so that frequent maintenance is not required, the driving power is minute, the operating cost is low, and the economic efficiency is improved. Can be.

FIG. 3 is a system diagram showing a cement clinker crushing apparatus 21a according to another embodiment of the present invention. Note that the same reference numerals are given to portions corresponding to the above-described embodiment, and description thereof will be omitted to avoid duplication. In the cement clinker pulverizer 21a of the present embodiment, a cyclone separator 81 is used instead of the airflow classifier 27. The cyclone separator 81 includes a classifier 82
The upper part of the classifier 81 is realized by a Wedada type cyclone air separator having a plurality of cyclones 83 provided in the circumferential direction. The pulverized material supplied from the upper center of the classifier 82 through the third chute 49 is dispersed by the centrifugal force on the dispersion plate, and the fine powder is dispersed by the swirling upward flow generated by the upper fan and the lower fixed blade. Ascending, the coarse powder falls down and is thus classified. The fine powder that has risen is individually collected by each cyclone 83 and discharged from the sixth chute 85 as a product.

Classification air is supplied to the classifier 82 by a blower 86, and the air is discharged from the upper part of each cyclone 83 and returns to the blower 86. The air is accelerated by the blower 86 and supplied to the classifier 82 again. Used in circulation. A part of the air circulated and used as described above is guided to the dust collector 30 to capture fine powder, and the captured fine powder passes through the seventh chute 87 and the sixth chute 8.
It merges with the fine powder in 6 and is discharged as a product.

As described above, the collection of the fine powder is performed individually by the plurality of cyclones 83 provided outside the classifier 82, so that the capacity can be increased with high classification performance. In addition, since the air is circulated and used by the blower 86, it is not necessary to take in much air from the outside, so that the temperature of the product is prevented from lowering due to the taking in of external air.

FIG. 4 is a system diagram showing a cement clinker crushing apparatus 21b according to still another embodiment of the present invention. Cement clinker crushing apparatus 21b of the present embodiment
, A rotary feeder 82 is provided in place of the screw conveyor 28. Such a rotary feeder 82 adjusts the rotation speed of a motor (not shown) to adjust the discharge amount of the remaining crushed material discharged from the lower outlet 25 of the fluidized bed classifier 26 to the fourth chute 54. The screw conveyor 28
The same effect can be obtained. Note that the same reference numerals are given to portions corresponding to the above-described embodiment, and description thereof will be omitted to avoid duplication.

[0044]

According to the present invention, the separator is supplied from the fluidized bed classifier so that the remaining crushed material including coarse particles coarsely classified by the fluidized bed classifier is not supplied to the separator. Since the roughly fine powder is classified into the fine powder and the coarse powder, the structure of the separator can be reduced, and the performance of the separator can be reduced in size and simplified. Further, the interference of the coarse particles contained in the remaining pulverized material in the separator with the fine powder is eliminated, so that the classification efficiency of the separator can be improved. Further, since no coarse particles are supplied to the separator, the wear of the separator can be remarkably reduced, and the durability is improved.

The remaining crushed material which is returned from the fluidized bed classifier to the vertical roller mill by bypassing without a separator is not only coarse but also contains some fine powder. By adjusting the amount of air to remove, the height of the upper outlet for removing the fine powder and other factors that change the classification characteristics, the amount of the remaining crushed product returned to the vertical roller mill was adjusted, The particle size composition of the product can be adjusted, whereby a cement product having an optimum particle size composition can be stably obtained.

The processing capacity of the fluidized bed classifier is
For example, since it is as large as about 250 t / h per 1 m ^2, it is not necessary to use an excessively large fluidized bed classifier, and desired coarse classification can be performed with a small facility, and the economic efficiency can be improved.

Further, according to the present invention, the second transport means includes a discharge amount adjusting means, and the remaining amount of the crushed material discharged from the lower outlet of the fluidized bed classifier by the discharge amount adjusting means. Adjust emissions. By increasing the discharge amount of the remaining crushed material discharged from the lower discharge port of the fluidized bed classifier by such a discharge amount adjusting means, the amount of fine powder returned to the vertical roller mill increases, and as a result, the vertical Since the compounding ratio of the fine powder in the pulverized product of the mold roller mill increases, the width of the particle size distribution of the fine powder classified by the separator can be increased. Conversely, when the amount of discharge by the discharge amount adjusting means is reduced, the amount of fine powder returned to the vertical roller mill is reduced, so that the amount of fine powder in the crushed product of the vertical roller mill is also reduced, and the fineness classified by the separator is reduced. The mixing ratio of the fine powder in the powder is reduced, and the width of the particle size distribution of the fine powder can be narrowed.

As described above, by the discharge amount adjusting means,
Desirable particle size distribution of fine powder taken out as fine powder from separator by adjusting the feed rate of the remaining crushed material mainly containing coarse particles from the lower outlet of fluidized bed classifier to vertical roller mill Thus, it is possible to easily adjust the configuration to a desired configuration, and to easily produce a cement product having a target particle size configuration with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a system diagram illustrating a cement clinker crushing apparatus 21 according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a specific configuration of the fluidized bed classifier 26 shown in FIG.

FIG. 3 is a system diagram showing a cement clinker crushing apparatus 21a according to another embodiment of the present invention.

FIG. 4 is a system diagram showing a cement clinker crushing apparatus 21b according to still another embodiment of the present invention.

FIG. 5 is a system diagram showing a typical prior art cement clinker crushing apparatus 1.

[Explanation of symbols]

 21, 21a, 21b Crusher 22 Vertical roller mill 23 Bucket elevator 24 Upper discharge port 25 Lower discharge port 26 Fluidized bed classifier 27 Air flow classifier 28 Screw conveyor 29 Bypass transport path 30 Dust collector 31 Suction fan 42 Raw material input Chute 44 First chute 47 Second chute 49 Third chute 51,52 Extraction chute 53 Extraction confluence chute 54 Fourth chute 55 Air flow transport pipe 56 Fifth chute 61 Casing 62 Dispersion plate 63 Flow chamber 64 Air chamber 65 Partition plate 81 Cyclone Separator 82 Rotary feeder

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Ueda 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe City, Hyogo Prefecture Inside the Kobe Plant of Kawasaki Heavy Industries, Ltd. 3-1-1, Kawasaki Heavy Industries, Ltd. Kobe Plant (72) Inventor Kansaburo Sudo 3-8-1, Nishikanda, Chiyoda-ku, Tokyo Taiheiyo Cement Co., Ltd. F-term (reference) 4D021 FA09 FA22 FA26 FA26 GA03 GA08 GA12 GA13 GA27 GB03 HA01 HA10 4D063 EE09 EE13 GA10 GB02 GC16 GC36 GD04 4D067 EE50

Claims (2)

[Claims] 1. A vertical roller mill for crushing a cement clinker, a first transport means for transporting crushed material crushed by the vertical roller mill upward, and a crushing material supplied from above by the first transport means. The fluidized material is fluidized, the roughly fine powder is taken out from the upper outlet, and the remaining crushed material is taken out from the lower outlet and roughly classified, and the fluidized bed classifier is supplied from the fluidized bed classifier. A separator that classifies the roughly fine powder into a fine powder and a coarse powder, and the remaining crushed material roughly classified by the fluidized bed classifier is returned to the vertical roller mill together with the coarse powder classified by the separator. An apparatus for pulverizing a cement clinker, comprising: a second transportation means. 2. The method according to claim 1, wherein the second transporting means includes a discharge amount adjusting means for adjusting an amount of the remaining crushed material discharged from an outlet at a lower portion of the fluidized bed classifier. An apparatus for crushing a cement clinker according to claim 1.