JPH10230180A - Method and apparatus for grinding cement clinker by vertical roller mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable stable operation by suppressing the vibration of a vertical roller mill. SOLUTION: A vertical roller mill 11 has a classifier 37 not built therein and the substantially total amt. of ground matter to be ground is taken out of the lower part of a table 13 to be transported to the classifier 37 by a bucket elevator 38 and the crude powder classified by the classifier 37 is returned to the vertical roller mill 11. A liquid, for example, only water or a mixture of water and diethylene glycol is sprinkled only to a grinding region outside a position where the relative speed of the table 13 and the roller 16 is zero in the radius direction of the table 13 in an amt. of 0.5-3% with respect to the matter to be ground. By this constitution, the matter to be ground is certainly bitten in the gap between the table 13 and the roller 16 to form a ground layer and, therefore, vibration is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for pulverizing cement clinker by a vertical roller mill in which a step of pulverizing an object to be pulverized such as a cement clinker and a cement raw material and taking out the product is performed by a vertical roller mill.

[0002]

2. Description of the Related Art FIG. 28 shows a conventional vertical roller mill used for crushing an object to be crushed such as a cement clinker and a cement raw material into a product. The vertical roller mill 1 is of a so-called built-in separator type. A table 3 that is rotated around a vertical axis is provided in a housing 2, and is driven to rotate by a motor 4. A plurality of rollers 5 are pressed on the table 3. In the housing 2, a classifier 6 is provided above the table 3 and the rollers 5. The material to be crushed loaded from the raw material chute 7 is crushed and crushed between the table 3 and the roller 5. Air is guided from below into a gap 8, which is a nozzle between the outer peripheral surface of the table 3 and the inner peripheral surface of the housing 2, and the material to be crushed is blown up by an air flow 9. The blown-up material to be crushed is classified by the classifier 6, and the fine powder is flown as a product from the pipeline 10 as a product. As indicated by the arrow 11, the coarse powder is returned to the table 3 again, crushed and circulated.

In this prior art, the material to be ground is charged from a raw material chute 7 having a circulation ratio of the material to be ground (grinding opportunity ratio, that is, a circulating flow rate of coarse powder returned from the classifier 6 to the center of the table 3). (Ratio to the flow rate) is said to be 1000% or more, whereby the coarse powder is immediately returned to the table 3 and reground. Therefore, for example, for a grinding flow rate of 100 ton / hour of the material to be ground, 1000 to
More than n / hour objects to be ground are transported by air flow.

Another problem with the conventional vertical roller mill shown in FIG. 28 is that the product obtained from the conduit 10 has a narrow particle size distribution. In the grinding of cement clinker, the particle size distribution of the product occupies an important weight for the product quality. In the prior art, it is difficult to freely control this particle size distribution.

In the conventional vertical roller mill shown in FIG.
Since the ratio of the amount of generated fine powder is small, the obtained product has more intermediate particles than the product obtained by the tube mill.
Therefore, n in the Rosin-Rammler diagram
The product has a large value and a narrow particle size distribution. Cement products with a narrow particle size distribution result in an increase in the standard soft water content and an increase in the unit water content in concrete tests, resulting in poor quality.

Still another problem of the conventional vertical roller mill shown in FIG. 28 is that the power of the fan by air sweep, that is, the air flow conveyance is very large. In order to classify the material to be crushed by the classifier 6 provided in the housing 2, the material to be crushed between the table 3 and the roller 5 is introduced from below the table 3 through the gap 8. It must be blown up by a large flow of air and transported to the classifier 6 by air flow. Therefore, FIG.
The pressure loss in the vertical roller mill shown in FIG. 8 is very large, and the fan power and the fan power consumption for this are very large.

A further problem with the conventional vertical roller mill shown in FIG. 28 is that the product temperature becomes too low. This prior art has a structure in which the entire amount of air required for airflow conveyance of a material to be ground is taken in with cold air at room temperature. Therefore, the cooling performance is large, and the temperature of the object to be ground is lowered. The material to be ground includes gypsum together with cement clinker. This gypsum becomes a cement product as gypsum by the decrease in temperature. Usually, it is preferable that the water of crystallization of gypsum becomes hemihydrate gypsum or anhydrous gypsum during the pulverization process. In the prior art, the problem of cement false setting due to gypsum dihydrate can occur. In order to solve this problem, equipment for taking in hot air from the outside is required, or equipment for circulating exhaust air from a fan is required. Therefore, a large capital investment is required, and the equipment cost increases.

[0008] In order to solve this problem, the present applicant has previously proposed a new configuration for grinding a cement clinker by a vertical roller mill. With this proposed technology,
Using a vertical roller mill without a built-in classifier, take out substantially all of the pulverized material pulverized by the vertical roller mill from under the table, and install it outside the vertical roller mill by mechanical transportation such as a bucket elevator. The coarse powder classified by the classifier is returned to the vertical roller mill together with a new material to be crushed and circulated. In this configuration, the circulation ratio is chosen to be smaller than in the prior art. As a result, the mechanical transportation means and the classifier are reduced in size and equipment costs are reduced, and the power consumption for circulating transportation and the power consumption for classification are reduced.
Improve the power saving effect.

In this proposed technique, the amount of material to be ground on the table of the vertical roller mill is significantly smaller than that of the prior art vertical roller mill having a circulation ratio of 1000% or more as described above with reference to FIG. . Therefore, it is difficult to form a pulverized layer between the table 3 and the roller 5.

In the prior art vertical roller mill shown in FIG. 28, a liquid is added to the material to be ground to be charged into the raw material chute 7 in order to prevent vibration (for example, see Japanese Unexamined Patent Publication No.
3-159241, Tokuhei 7-64603). This figure 2
In the prior art of No. 8, the pulverized material pulverized by the roller 5 is blown out of a wind box below the table 3 at a high speed from a gap 8 between the outer peripheral surface of the table 3 and the inner peripheral surface of the housing 2. It is carried to the airflow and carried to the upper classifier 6, where it is classified into a fine powder product and a coarse powder. The fine powder is transported out of the machine from the pipe 10 by airflow to be a product. The coarse powder is returned to the center of the table 3 again, and is crushed again by the rollers 5.

On the table 3, all the crushed objects scattered from the outer peripheral portion of the table are not carried to the classifier 6. In the gap 8, the airflow velocity is, for example, 30 m /
Although it is not less than s, it decreases to several m / s near the upper part of the gap 8. Therefore, the crushed material blown up by the high-speed airflow in the gap 8 is subjected to the low-speed airflow immediately thereafter, and the untransportable coarse particles are separated by the classifier 6.
Without being conveyed to the table 3 by air flow, they are sequentially dropped on the table 3 and re-crushed by the rollers 5.

Therefore, in the prior art shown in FIG. 28, the coarse particles are blown back by the airflow to the vicinity of the outer peripheral portion of the table 3 rather than the central portion of the table 3, so that a large amount of the coarse particles are present. That is, the object to be crushed falls and exists more in the grinding area than in the compression and crushing area. Therefore, the amount of the raw material existing in the grinding area on the table 3 is naturally larger than the amount of the raw material in the compression and crushing area. Therefore, a sufficient amount of the raw material is caught between the table 3 and the roller 5 in the grinding region as compared with the compression and grinding region. Therefore, in the prior art, the vibration of the vertical roller mill can be effectively suppressed by adding the liquid to the material to be ground supplied to the raw material chute 7 in advance.

However, in the above-mentioned proposed technique, even if the above-mentioned liquid is added to the material to be ground supplied from the raw material chute 7 to the vertical roller mill as it is, the effect of suppressing the vibration is small and unstable. It became operation.

The inventor of the present invention has considered the reason why the vibration suppression effect is small even if a liquid is added to the material to be pulverized to be charged into the vertical roller mill in the above-mentioned proposed technology. One of the reasons is that the amount of material to be ground on the table of the vertical roller mill in the above-mentioned proposed technology is larger than that of the prior art vertical roller mill described with reference to FIG. This is because it has been greatly reduced. Another one of the reasons
First, the vertical roller mill incorporating the classifier 6 described with reference to FIG. 28 and the vertical roller mill in which the above-described proposed classifier is externally installed, have a gap between the table and the rollers. Raw material biting conditions are different, and in the above-described proposed vertical roller mill, the entire amount of the crushed raw material is discharged, and a large amount of coarse powder is blown back to the vicinity of the outer peripheral portion of the table by an air current, and a large amount is present. Therefore, as the area on the table where the raw material diffuses becomes larger in the radially outward direction, and the particle diffusion rate increases, the thickness of the raw material layer on the table becomes thinner. .

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the power consumption, to improve the product quality of cement, and to prevent the problem of cement false setting due to gypsum moisture. Not only do
An object of the present invention is to provide a method and an apparatus for pulverizing a cement clinker by a vertical roller mill capable of suppressing vibration and maintaining a stable operation while lowering a circulation ratio of a material to be circulated.

[0016]

According to the present invention, a plurality of rollers are arranged at intervals in a circumferential direction on a table rotating around a vertical axis, and a material to be ground supplied to a center portion of the table is formed. , Crushed and crushed by being caught between the table and the roller, and the crushed material thus crushed, substantially all of the crushed material is taken out from under the table, and a vertical roller mill without a classifier is used. The grinding area in which the object to be ground is frictionally ground between the table and the roller outside the position in the radial direction of the table immediately before the position where the relative speed between the table and the roller is zero immediately before the upstream side in the rotation direction of the table. Is a method of pulverizing a cement clinker by a vertical roller mill, wherein a liquid is added only to the cement clinker. Further, the invention is characterized in that the liquid accounts for 0.5 to 3% of the object to be ground.

Therefore, according to the present invention, since the pressure loss of the mill is greatly reduced as compared with the above-mentioned prior art,
The power consumption of the fan can be reduced.

Also, since the type of the classifier can be freely selected, for example, a cyclone collecting type classifier is used, and the classifying means and air supplied to the cyclone are circulated and used to classify the cold air so as to reduce the amount of cold air. There is no need to import. As a result, the temperature of the material to be ground does not become too low, the problem of cement false setting due to gypsum dihydrate described in connection with the above-mentioned prior art is eliminated, and the equipment is simplified.

In the present invention, the type of classifier can be selected, so that the temperature problem is solved. That is, it is not necessary to take in cool air by using a classifier as a cyclone collecting type and circulating air, so that the temperature is kept high. In some cases, the product must be cooled.

According to the present invention, a liquid of, for example, 3% or less of the material to be ground is added only to the grinding region, thereby suppressing the vibration of the vertical roller mill, enabling a stable operation and greatly Thus, it is possible to improve the pulverization efficiency and further improve the narrowness of the particle size configuration width, which is a problem of the vertical roller mill for pulverizing the cement clinker, thereby improving the product quality.

According to the present invention, the liquid is added to the material to be ground on the table immediately before the roller bites only in the region radially outward of the table from the vicinity of the center of the roller width, which is the grinding region. By spraying and spraying water, the operation of the vertical roller mill can be stabilized under a lower circulation ratio than the prior art shown in FIG. 28, and in addition, the pulverization efficiency can be improved and the quality of cement products can be improved.

In the grinding region, the peripheral speed difference between the table and the outer peripheral surface of the roller is large, so that friction grinding is performed. In order to perform a stable operation in this grinding region, the state of biting of the object to be ground by the table and the roller is always kept the same, and the compacted raw material layer at the time of grinding by the pressure of the roller is formed stably. It is very important to. In addition, in order to obtain high-quality products by increasing the ratio of the amount of fine powder generated and the high crushing efficiency, the pressure of the roller must effectively act as a sufficiently effective crushing pressure on the material to be crushed in the grinding region. It is important to be able to. For this purpose, a sufficient amount of the material to be ground must be present in the grinding area.

[0023] Among the annular regions where the rollers on the table are pressed, in the compression and crushing region radially inward of the grinding region, the difference in the peripheral speed between the table and the outer peripheral surface of the roller, that is, the compression and crushing region where the relative slip is small. Is formed. In the vertical roller mill according to the present invention, since the amount of the crushed material on the table is the same in the compression crushing region and the grinding region, the crushed material is spread on the table as it goes radially outward of the table. As the area of the raw material increases and the particle diffusion rate increases, the thickness of the raw material layer, which is the object to be ground, on the table decreases. Therefore, in the vertical roller mill according to the present invention, the raw material layer is not formed with a sufficient thickness in the grinding region, and the pulverized layer tends to be formed only in the compression and pulverizing region. When the raw material layer is not formed with a sufficient thickness in the grinding region, large vibrations are generated in the vertical roller mill, resulting in a very unstable operation. Particularly, in a configuration in which the circulation ratio is very small, for example, 300% or less, since the absolute amount of the raw material on the table is significantly reduced as compared with the prior art of FIG. 28, stable operation is continued. Doing so is more difficult.

Therefore, according to the present invention, the liquid is added to the material to be ground only in the grinding area on the table. Therefore, even if the layer thickness of the object to be ground in the grinding region is small as in the present invention, the performance of the object to be ground into the roller can be significantly improved. Therefore, the material to be crushed can be sufficiently compacted in the grinding region, that is, the material to be crushed can be pressed between the table and the roller, and the crushing pressure of the roller can be effectively used as the crushing force. As a result, even when the circulation ratio is 300% or less, the vibration of the vertical roller mill can be effectively suppressed, and the stable operation can be continued.

Further, according to the present invention, since friction grinding can be performed under a sufficient grinding pressure in the grinding region, the ability to generate fine powder is significantly improved. As a result, a desired particle size composition in terms of the quality of the cement product is obtained, and the effect of the pulverizing system to which the present invention is applied can be sufficiently exhibited.

According to the experiment of the present inventor, when a liquid is added only to the compression and pulverization region, the object to be pulverized solidified with the liquid is unstablely adhered to the outer peripheral surface of the roller, and a large vibration is generated. Would. According to the experiment of the present inventors,
If liquid is added not only in the grinding area but also in the grinding area,
Similarly, large vibration occurs. Furthermore, according to the experiment of the present inventor, a large vibration is generated even when the liquid is added in advance to the material to be pulverized to be charged in the center of the table in the vertical roller mill.

According to the concept of the present invention, it has been found that the liquid is supplied only to the milling zone, which, for the first time, reduces the vibration. In addition, the liquid is added immediately before the roller is caught, thereby preventing the added liquid from evaporating and disappearing before being caught by the roller due to the raw material holding heat.

The liquid is selected from 0.5 to 3% of the material to be ground. If the liquid content exceeds 3%, a chemical reaction of the cement clinker occurs, which may cause pseudo-caking. 0.5 liquid
%, There is no effect of preventing vibration. This liquid is preferably chosen to be about 1-2% of the material to be ground.

The liquid may be, for example, water alone, but may also be a mixture of water and a grinding aid such as diethylene glycol. Diethylene glycol is mixed at a weight ratio of 1/100 to 1/10 of water.

According to the present invention, as described above, in the vertical roller mill according to the present invention, the layer thickness of the material to be ground in the grinding region is such that the circulation ratio is smaller than that in the prior art, and the compression grinding region and the grinding region are different. Are significantly thinner than in the prior art due to the fact that the amounts of raw materials present in each of them are equal. Therefore, even if the prior art of adding a liquid to the material to be ground supplied to the raw material chute 7 in advance is applied to the present invention as it is, the vibration of the vertical roller mill in the present invention cannot be suppressed. The present invention solves this problem as described above.

Further, the present invention provides a classifier for classifying a material to be pulverized by a vertical roller mill to obtain a cement product, and a mechanical transport for transporting at least a part of the material to be pulverized taken out of the vertical roller mill to a classifier. Means are provided.

According to the present invention, the material to be pulverized taken out from under the table of the vertical roller mill is provided by a mechanical transportation means such as a bucket elevator, a screw conveyor, a chain conveyor or the like without using a pneumatic force. And at least a part of the material to be ground is guided to a classifier, where coarse powder is obtained and returned to a vertical roller mill for circulation. The classifier is provided outside the vertical roller mill. The classifier may be a so-called air-flow classifier that uses pneumatic force, but may have a configuration using a sieve or the like, or may have another configuration.

Further, the present invention is characterized in that at least a part of the material to be pulverized taken out of the vertical roller mill is supplied to a tube mill.

According to the present invention, the whole amount of the material to be pulverized taken out from below the table of the vertical roller mill is supplied directly to the next tube mill, or only the coarse powder classified by the classifier is supplied to the tube mill. In addition, coarse powder obtained by classifying the material to be pulverized taken out of the vertical roller mill, or a part thereof is directly returned to the vertical roller mill without passing through a classifier, and the remaining material to be pulverized is supplied to a tube mill. You may do so. Thus, the vertical roller mill without the classifier according to the present invention functions as a pre-pulverizer for the tube mill.

For coarse pulverization, a vertical roller mill has a better pulverization efficiency than a tube mill, and the particle size supplied to the tube mill is small, so that the ball provided in the body of the tube mill is reduced. The size of the pulverization medium, such as the pulverization medium, can be reduced, thereby improving the pulverization efficiency of the tube mill itself. Thus, by combining the vertical roller mill for pre-crushing with the tube mill, the crushing efficiency of the entire system can be improved.

In the tube mill, an object to be pulverized is supplied from one axial end of a body having a substantially horizontal rotation axis, and powder pulverized by a pulverizing medium in the body is supplied to the other end in the axial direction. It is pushed out from the part in the axial direction and discharged.

An air sweep mill may be used instead of the tube mill. This air sweep mill is also provided by a grinding media in the fuselage having a substantially horizontal axis of rotation.
The grinding of the material to be crushed is the same as that of the tube mill described above, but the crushed powder has a configuration in which the crushed powder is conveyed by airflow and discharged from the other end. The term "tube mill" in the above claims also includes such air sweep mills.

Further, according to the present invention, a plurality of rollers are arranged at intervals in a circumferential direction on a table which rotates around a vertical axis, and the material to be pulverized supplied to the center of the table is separated by the table and the rollers. Pulverized and crushed by being interposed between the rollers, and the crushed material thus crushed is substantially entirely removed from below the table, and a vertical roller mill without a classifier is provided. Is located just in front of the table, and only in the grinding area where the object to be ground is frictionally ground between the table and the roller outside the table in the radial direction from the position where the relative speed between the table and the roller is zero. And a nozzle for injecting a liquid of 0.5 to 3% of the material.

According to the present invention, the equipment can be miniaturized, the quality of the cement clinker can be improved, the fan power can be reduced, and the problem of false cement setting of the dihydrate gypsum can be prevented. , Which can further simplify the equipment, which is the same as described above.

Further, the present invention is characterized in that the nozzle has a nozzle hole for ejecting the liquid in a flat shape extending in the radial direction of the table.

Further in accordance with the invention, the liquid ejected from the nozzle holes has a flat, so-called fan-shaped shape extending in the radial direction of the table, so that the number of nozzles is as small as possible so that the liquid is uniformly distributed in the grinding area. The liquid can be sprinkled and added.

Further, the present invention provides a classifier for classifying a material to be pulverized by a vertical roller mill to obtain a cement product, and a mechanical transport means for transporting at least a part of the pulverized material taken out of the vertical roller mill to a classifier. And further characterized by: Further, the present invention is characterized in that the mechanical transport means transports the entire amount of the material to be ground taken out of the vertical roller mill to a classifier. The present invention is further characterized by further comprising a distributing means for transporting a part of the material to be ground transported by the mechanical transport means to the classifier, and for directly transporting the remaining material to be ground back to the vertical roller mill. And

According to the present invention, the entire amount of the material to be pulverized taken out of the vertical roller mill may be transported to the classifier as described in claim 8, but in addition to the above, in particular, as described in claim 9, A part of the material to be pulverized taken from the roller mill is transported to a classifier by a mechanical transport means to obtain coarse powder, and the residual material to be pulverized taken out from the vertical roller mill, together with the coarse powder, a vertical roller mill. May be returned again. In the fine powder product obtained from the classifier according to the configuration of claim 9, fine powder having a relatively small particle size is included, so that the particle size distribution of the product can be widened and the quality of cement can be improved. Useful.

Further, the present invention is characterized by further comprising a tube mill for further pulverizing the pulverized material taken out from the vertical roller mill with a pulverizing medium in a body driven to rotate about a substantially horizontal axis.

According to the present invention, at least a part of the pulverized material taken out from the vertical roller mill is supplied to the tube mill, and the vertical roller mill is used for pre-pulverization, so that the pulverization efficiency of the whole system can be improved. Tube mills include air sweep mills.

[0046]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention. The crusher of the cement clinker basically includes a vertical roller mill 11, a classifier 37 for returning the classified coarse powder to the vertical roller mill 11 and circulating the same, and a pulverized material extracted from the vertical roller mill 11. And a bucket elevator 38 which is a mechanical transport means for transporting to the classifier 37. The fine powder classified by the classifier 37 is conveyed by airflow through a conduit 39, and is filtered by a bag filter 40.
Collected in the product. An attraction fan 41 is connected to the bag filter 40. The coarse powder obtained by classification by the classifier 37 is returned from the raw material chute 27 to the vertical roller mill 11 and circulated through the pipe 46 together with the material to be ground in the pipe 47.

FIG. 2 shows a vertical roller mill 1 shown in FIG.
1 is a simplified longitudinal sectional view of FIG. This vertical roller mill 1
1 has a substantially right cylindrical housing 12. A table 13 having a vertical axis 33 is arranged in the housing 12. The table 13 is driven to rotate by a motor 15 via a speed reducer 14 provided below the table 13.

On the table 13, a plurality of rollers 16 are arranged on the crushing orbit diameter Dφ at intervals in the circumferential direction. The roller 16 has a rotation axis extending in the radial direction of the table 13 and is pivotally supported by an arm 17. Arm 17
Is attached to a support 19 provided at a fixed position by a support 18 having a horizontal axis. The roller 16 and the arm 17 can be retracted around the support shaft 18 as shown by a virtual line 20 to perform maintenance and inspection.

The arm 17 is connected via a pin 23 to a piston rod 22 of a hydraulic cylinder 21 constituting a pressurizing device. The cylinder 21 is moved by the clevis pin 24.
It is connected to a bracket 26 mounted in a fixed position.
By reducing the piston rod 22 of the cylinder 21, the roller 16 can be pressed against the table 13 and pressed against the table 13.

A raw material chute 27 having an axis coinciding with the vertical axis of the table 13 in the housing 12 is provided. An object to be ground such as a cement clinker and a cement raw material is loaded into the raw material chute 27 as indicated by an arrow 28. From the lower part of the chute 27, the material to be ground falls to the center of the table 13 and is supplied.

The material to be pulverized supplied to the center of the table 13 is caught between the roller 16 disposed on the diameter Dφ of the pulverizing action of the table 13 and is pulverized and pulverized in the pulverization area Z of the pulverization path. Is done.

A substantially entire amount of the crushed material moves radially outward of the table 13, passes through a gap between the outer peripheral surface of the table 13 and the inner peripheral surface of the housing 12, and moves downward of the table 13. Falls on an endless annular receiving table 29 provided at the end. The crushed material on the pedestal 29 is moved in the circumferential direction by the scraper 30 fixed to the table 13, and is discharged from the discharge hole 31 of the pedestal 29 to the outlet chute 32.
It is taken out through. The material to be crushed from the outlet chute 32 is guided to the bucket elevator 38 via the pipe 42. The crushed material lifted by the bucket elevator 38 is supplied to the classifier 37 from a pipe 43.

A pipe 44 is connected to the upper part of the housing 12 of the vertical roller mill 11, and connected to a classifier 37.
Dust generation is prevented.

FIG. 3 shows the roller 16 of the vertical roller mill 11.
FIG. 4 is a simplified horizontal sectional view as viewed from above. Roller 16
In this embodiment, a total of three are arranged at equal intervals in the circumferential direction. The direction of rotation of the table 13 is arrow 45
Indicated by

According to the present invention, stable operation can be achieved by suppressing vibrations, the crushing efficiency can be greatly improved, and the narrowness of the particle size configuration of the cement clinker product can be improved to improve the product quality. As shown in FIG. 3, the rotation direction 4 of the table 13 is
Immediately before the upstream side, a nozzle 5 for spraying and spraying the liquid
9 are provided respectively. With this nozzle 59, the liquid is supplied only to the grinding zone Z2 as described later.

The liquid is selected from 0.5 to 3% of the material to be ground. If the liquid content exceeds 3%, a chemical reaction of the cement clinker occurs, which may cause pseudo-caking. 0.5 liquid
%, There is no effect of preventing vibration. This liquid is preferably chosen to be about 1-2% of the material to be ground.

The liquid may be, for example, water alone, but may also be a mixture of water and a grinding aid such as diethylene glycol. Diethylene glycol is mixed at a weight ratio of 1/100 to 1/10 of water.

FIG. 4 is a simplified side view developed in the circumferential direction showing a state in which the raw material layer 48 as the object to be ground on the table 13 is crushed and crushed by the rollers 16. The roller 16 has a hydraulic cylinder 2 as indicated by an arrow 49.
1 acts on the pressing force. The state where the flow rate of the coarse powder supplied from the classifier 47 to the vertical roller mill 11 is large, and thus the circulation ratio is high, is shown in FIG. 4 (1). The state where the ratio is low is shown in FIG. Table 13
The rotation of the arrow 45 causes the roller 16 to rotate as indicated by the arrow 50. As shown in FIG. 4A, when the circulation ratio is high, the layer thickness d1 of the raw material layer 48 is large, and the layer thickness d2 after crushing and pulverization is small, and the difference (=
d1-d2) is large.

On the other hand, in the state of FIG. 4 (2) where the circulation ratio is small, the layer thickness d3 of the raw material layer 48 to be pulverized is smaller than the above-mentioned layer thickness d1 (d3 <d1), The difference with the later layer thickness d4 (= d3-d4) is small. In the state of FIG. 4A, the pressing force acting on the material layer 48 by the roller 16 effectively acts on the material layer 48,
The maximum value Pmax1 is less than the maximum value Pmax2 of the pressing force in the state where the circulation ratio in FIG.
max1 <Pmax2). Therefore, when the circulation ratio is high as shown in FIG. 4A, the energy loss increases, and other energy that does not effectively contribute to the pulverization, ie, the roller 1
6, the rolling resistance, vibration and noise increase, and the crushing efficiency decreases. For this reason, reducing the average surface pressure of the roller 16 to increase the circulation ratio and repeatedly crushing and crushing the material to be crushed results in a high ratio of crushing power consumption and a bad result. Therefore, in the present invention, as shown in FIG. 4B, the average surface pressure of the roller 16 is increased to make the particle diameter after one pulverizing operation smaller.

FIG. 5 is a side view of the roller 16, FIG. 6 is a front view of the roller 16, and FIG. 7 is a plan view of the roller 16. The axis of rotation of roller 16 is indicated by reference numeral 34. A plane 35 parallel to the rotation axis 34 of the roller 16
When the projected area S is S, the projected area S is
When the width of the roller 16 on the projection surface 35 parallel to the rotation axis 24 of No. 6 is a and the diameter of the roller 16 is b, approximately S = a
-It is b. According to the present invention, the average surface pressure of the pressing force of the roller 16 against the table 13 viewed from the projection area S is
It is selected from 10 to 15 kg / cm ² .

FIG. 8 is a graph showing the experimental results of the present inventor. In the configuration shown in FIGS.
7 is a cement clinker, and is a work index (work i) indicating the grindability.
ndex) Wi is 14 to 16 kWh / ton, the table 13 and the roller 16 are made of high chrome cast iron, the width a of the roller 16 is 340 mm, and the diameter b is 90.
0 mmφ, and the crushing orbit diameter Dφ of the table 13 =
1300 mm, and the rotation speed of the table 13 is 45.4.
rpm, and the particle size of the clinker which is the material to be ground newly charged into the raw material chute 27 is 80% pass particle size 25 m
m.

The experimental results shown in FIG. 8 indicate that when the average surface pressure in the projected area of the roller 16 is in the range of 10 to 15 kg / cm ² , the specific crushing power consumption ratio of the motor 15 is relatively small, which is preferable. Average surface pressure is 10 kg / cm ²
If it is less than 1, the specific grinding power consumption ratio is large, and
If it exceeds 5 kg / cm ² , the ratio of the specific grinding power consumption becomes large. The preferable range of the average surface pressure at which the specific grinding power consumption ratio is small is 11 to 14 kg / cm ² , and more preferably the average surface pressure is 11.3 to 13.3 kg / cm ^2.
And most preferably the average surface pressure is 12.2 kg / cm
²

An average surface pressure of 8 kg / c set in the vertical roller mill of the prior art described above with reference to FIG.
It can be seen that in the range of m ² or less, in the configuration of the present invention, the ratio of the specific grinding power consumption is significantly deteriorated.

FIG. 9 is a graph showing another experimental result of the present inventor. In FIG. 9, the table 1 of the roller 16 is shown.
3 shows the relationship between the average surface pressure as viewed from the projection area onto No. 3 and the n value of the Rosin-Lammla diagram. It is understood that the higher the average surface pressure is, the smaller the n value is, that is, the larger the product particle size is, and the better the result is obtained as a cement product. 15k average surface pressure
Even if it is set to a value exceeding g / cm ² , only the energy not contributing to the pulverization is increased, and the pulverization efficiency is rather reduced as described with reference to FIG. If the average surface pressure is set to a value exceeding 15 kg / cm ² , the strength of the vertical roller mill 11 must be increased unnecessarily, which is disadvantageous in cost.

FIG. 10 is a graph showing the relationship between the n value of the rosin-lamellar diagram showing the experimental results of the present inventor and the concrete strength. The n value may be chosen to be about 1.2,
It is preferable to increase the concrete strength, and the n value is set in a range of about 1.1 to 1.3.

FIG. 11 is a graph showing the experimental results of the present inventor. It is a graph which shows the relationship between the n value of a rosin-ramla diagram, and the unit water amount in a concrete test. By setting the n value in the range of about 1.1 to 1.3 as described above, it can be seen that the unit water volume is small and preferable.

Therefore, from FIGS. 10 and 11, it is necessary that the n value be selected in the range of about 1.1 to 1.3. For this purpose, as shown in FIG. The surface pressure is selected according to the invention in the range from 10 to 15 kg / cm ² .

FIG. 12 is a graph showing the relationship between the circulating ratio of the specific grinding raw material and the specific grinding power consumption ratio in an experiment conducted by the present inventor. The line 53 has the average surface pressure of 10 to 15 k.
It shows the characteristics when it is set in the range of g / cm ² . Line 5
4 shows the characteristics when the average surface pressure is set in the range of 7.8 to 10.5 kg / cm ² . From this experimental result, it can be seen that by selecting the circulation ratio to be 100 to 300%, the specific grinding power consumption ratio can be reduced.

As can be seen from FIG. 12, there is a close relationship between the average surface pressure and the circulation ratio. Average surface pressure is 10-1
By selecting the ratio in the range of 5 kg / cm ² , the specific crushing power consumption ratio can be reduced at a low circulation ratio. If the circulation ratio exceeds 300%, the vibration increases, and stable operation is difficult.

From the experimental results shown in FIG. 12, it is better to increase the average surface pressure to make the particle size of the material to be pulverized after one pulverizing operation between the table and the roller smaller. The results are obtained.In contrast, lowering the average surface pressure, increasing the circulation ratio, and repeating the pulverizing operation many times, increases the specific pulverization power consumption and may result in bad results. I understand.

FIG. 13 shows the experimental results of the present inventor.
It is a graph which shows the relationship between a circulation ratio and n value of a Rosin-Lamura diagram. Line 55 in FIG. 13 shows the characteristics when the the average surface pressure 10-15 kg / cm ^2, line 56 shows the characteristic when the average surface pressure 8~10.5kg / cm ^2. By reducing the circulation ratio, n
It can be seen that the value can be reduced, that is, the product particle size can be increased, and the quality as a cement product is improved. If the average surface pressure of 8 kg / cm ² in the prior art described in connection with FIG. 28 described above is applied to the present invention,
Property 56 is obtained, the n value is large, the particle size distribution is narrow, and the quality of the cement product is deteriorated.

FIG. 14 is a side view of the nozzle 59, and FIG.
5 is a longitudinal sectional view of the nozzle 59, and FIG. 16 is a perspective view of the nozzle 59. The nozzle 59 has a tapered screw 6
0 and a spanner engaging portion 61, and a lower portion 62 thereof includes
A nozzle hole 63 is formed. Nozzle 59 taper screw 6
0 is connected to a header 81 extending in the radial direction of the table 13, and the liquid is pumped. The nozzle 59 has a header 81
May be provided in plurality. The outer shape of the lower portion 62 is a right cylindrical shape, and an inverted V-shaped nozzle hole 63 extending perpendicular to the axis 66 and expanding downward is formed. This nozzle hole 63 is
It communicates with a substantially straight cylindrical liquid supply space 64 formed in the nozzle 59. In the lower part of the space 64, a curved portion 65 having a smaller inner diameter as it goes downward is formed.

The nozzle 59 is configured to be symmetrical left and right in FIG. This plane of symmetry is parallel to a vertical plane including the rotation axis 24 of the roller 16 and coincides with or parallel to a radially extending vertical plane including the vertical rotation axis of the table 13.

FIG. 17 is a perspective view showing a state in which the liquid 67 is being ejected from the nozzle 59. The liquid 67 ejected from the nozzle 59 is ejected from the nozzle hole 63 in a flat shape, and is formed in a fan shape. The plane formed by the flatly ejected liquid 67 extends substantially in the radial direction of the table 13 and coincides with the aforementioned plane of symmetry, and coincides with or is parallel to the vertical plane including the rotation axis 34 of the roller 16. By using this type of nozzle 59, a large effect can be obtained with a small amount of water spray.

FIG. 18A is a vertical sectional view of the table 13 in the vertical roller mill 11 and a vertical plane including the vertical rotation axis of the table 13. Outer peripheral surface 70 of roller 16
Is an arc surface centered on a position on the contact center line 71. The contact center line 71 is the rotation axis 34 of the roller 16.
And at a central position equidistant from both axial end surfaces of the roller 16.

The table 13 has an outer peripheral surface 7 of the roller 16.
An arc-shaped concave surface 72 corresponding to 0 is formed.
The surface 72 is formed in an annular shape around the rotation axis of the table 13 so that the distance Δd between the outer peripheral surface 70 of the roller 16 and the surface 72 of the table 13 becomes smaller toward the outside in the radial direction of the table 13. You. An annular projection 73 called a dam ring is formed at a radially outer end of the surface 72. The radially inner end 74 of the annular projection 73 projects toward the front surface 72, that is, radially inward of the table 13, and has a so-called overhang shape.

The crushed and crushed area Z is formed by the outer peripheral surface 70 of the roller 16 and the surface 72 of the table 13. The region Z includes a compression and crushing region Z1 and a grinding region Z2 radially outward from the compression and crushing region Z1.

FIG. 18B shows the table 13 and the roller 1
6 is a view for explaining a crushing operation with No. 6. FIG. The line 75 indicates the peripheral speed of the outer peripheral surface 70 of the roller 16 around the rotation axis 34 along the radial direction of the table 13, and changes so as to protrude upward along the radial direction of the table 13. Line 76
Indicates the distribution of the rotational speed of the table 13 along the radial direction, and is linear. Synchronization point 77 is defined by lines 75 and 76
At the position where the relative speed between the outer peripheral surface 70 of the table 16 and the surface 72 of the table 13 is zero. Radially inward from the synchronization point 77, the surface 72 of the table 13 and the outer peripheral surface 7 of the roller 16 are indicated by hatching 78.
The peripheral speed difference from zero is small, the relative slip is small, and the object to be pulverized is mainly compressed and pulverized.

Outside the synchronous point 77 in the radial direction of the table 13, as shown by a hatched line 79, the peripheral speed difference is larger than in the compression crushing zone Z 1. Here, the crushed material is mainly subjected to friction crushing. . According to the concept of the present invention, the liquid 67 from the nozzle 59 is jetted only to the spray area 80 in the milling zone Z2.

In the vertical roller mill 11 of the present invention, substantially the entire amount of the crushed object is lowered from the gap between the outer peripheral surface 82 of the table 13 and the inner peripheral surface of the housing 12 as described above. Therefore, the amount of the object to be ground on the table 13 is the same in the compression and crushing region Z1 and the grinding region Z2. Therefore, in the grinding zone Z2 which is located radially outward of the compression-grinding zone Z1, the layer thickness of the material to be ground on the table 13 becomes thin. As a result, large vibrations are generated in the vertical roller mill 11, resulting in a very unstable operation. In order to solve this problem, a liquid is added from a nozzle 59 so that the material to be crushed in the grinding zone Z2 having a small layer thickness is transferred to the table 13 and the roller 1.
6, and the crushing pressure of the roller 16 can be effectively used as the crushing force.
Therefore, vibration of the vertical roller mill 11 can be effectively suppressed, and stable operation can be continued. In addition, since friction grinding can be performed under a sufficient grinding pressure in the grinding zone Z2, the ability to generate fine powder is remarkably improved, and a desired particle size composition in terms of quality of the cement product can be obtained.

According to the experiment of the present inventor, when the liquid was added to the compression and crushing zone Z1, large vibrations occurred. It has also been found that large vibrations occur when a liquid is added in advance to the material to be pulverized to be charged into the center of the table 13 in the vertical roller mill 11. Therefore, the liquid is supplied only to the grinding zone Z2.

According to the experiment of the present inventor, FIGS.
According to the present invention, when the liquid is not added, the vibration amplitude of the table 13 of the vertical roller mill 11 is 30 to 50 μm, but according to the present invention, the addition of the liquid of 1 to 2% of the material to be ground is performed according to the present invention. As a result, the vibration amplitude was greatly reduced to 15 to 30 μm, and extremely stable operation became possible. In addition, the power consumption was improved by about 15% compared to when no liquid was added, and the crushing efficiency was greatly improved. It was confirmed that it was possible to achieve.

The experimental results shown in FIGS. 8 to 13 are the results when the liquid was added according to the present invention.

FIG. 19 shows a Rosin-Lamura diagram showing the experimental results of the present inventor. When the liquid is sprayed, the characteristics of the line 84 are obtained.
Was obtained. The horizontal axis in FIG. 19 is the particle diameter Dp of the cement product. The vertical axis represents log ｛log (100 / R, where R (Dp) is a particle larger than the particle diameter Dp, that is, an accumulated oversize output amount, that is, a residual amount (%).
(Dp))｝. The passing amount is logｌｏlog (10
0-R (Dp))}. The slope tanθ in the rosin-lamellar diagram in FIG. 19 is the n value.

In the operation without liquid, as shown by line 85, a product with a large n value = 1.33 and thus a narrow particle size composition was obtained, but by adding liquid, The n value was 1.16, and a product having a significantly wide range of particle size composition could be obtained. A good product having a wide range of particle size composition is obtained by using an n value of 1.1 to 1.2 of a product obtained from a conventionally used tube mill.
And is preferable.

FIG. 20 is a system diagram showing the entire configuration of another embodiment of the present invention. In this embodiment, a part to be ground which is a cement clinker transported by a bucket elevator 38 is partially supplied from a pipe 43 to a classifier 37 by a distribution means 87, and a remaining part to be ground is removed by a pipe. Lead to road 88. The coarse powder obtained from the classifier 37 in the pipe 46 and the material to be pulverized from the pipe 88 are passed through a pipe 89
Then, the raw material chute 27 of the vertical roller mill 11 of the present invention is charged together with a new material to be ground. According to this configuration, the fine powder obtained from the classifier 37 and thus from the bag filter 40 contains fine powder having a relatively small particle size, and the particle size distribution of the product can be broadened. Helps to improve the quality of cement products.

The flow rate of the material to be crushed distributed to the pipe 88 by the distribution means 87 may be about 30% of the flow rate of the material to be crushed sent to the classifier 37 via the pipe 43. Distribution means 87
The pipe 90 that guides the material to be crushed discharged from the bucket elevator 38 is branched into two pipes 43 and 88, and a damper 91 having a horizontal swing axis is provided at the branch position. The configuration may be such that the angle of 91 is changed and adjusted. In this way, the particle size distribution of the product can be controlled more widely and freely.

FIG. 21 is a sectional view of the classifier 37, and FIG.
FIG. 2 is a cross-sectional view taken along line XXII-XXII of FIG. An outer cylinder 94 is connected to an upper portion of the housing 93, and a frusto-conical chute 95 is provided therein. The air extracted from the vertical roller mill 11 through the conduit 44 is taken together with the air taken in from the outside and the outer cylinder 9.
4 is led. The pipe 39 is connected to the upper part of the outer cylinder 94. A pipe 46 for guiding coarse powder to the vertical roller mill 11 is connected to a lower portion of the housing 93. Shoot 9
Below the 5, a dispersion plate 96 is provided. This dispersion plate 9
6, the blade members 97 are fixed at equal intervals in the circumferential direction.

FIG. 23 is a horizontal sectional view showing the dispersion plate 96 and the blade member 97 of FIG. The lower end of the vertical rotation shaft 98 is fixed to the dispersion plate 96. The drive shaft 98 is driven to rotate by a motor 99.

The material to be ground and the air from the conduit 44 are guided into the outer cylinder 94 from below. The object to be ground is the dispersion plate 9
6 and the blade member 97 are swirled and scattered with the airflow, are classified by their centrifugal force and inertia, and the coarse powder is guided to the pipeline 46 from below the housing 93.
The fine powder floats by the airflow, is conveyed by airflow from the pipe line 39 to the bag filter 40, is collected, and becomes a product.

[0091] Instead of the bag filter 40, a cyclone or the like may be used.

FIG. 24 is an overall system diagram of another embodiment of the present invention. This embodiment is similar to the above-described embodiments, and corresponding parts are denoted by the same reference numerals. The raw material chute 27 on the upper part of the vertical roller mill 11 is pulverized by the vertical roller mill 11,
6 and is taken out from below through conduits 32 and 42. The material to be crushed from the vertical roller mill 11 is
Transported by the bucket elevator 38, the classifier 37
It is classified by being guided to a. The coarse powder obtained by classification is
It is supplied to the tube mill 113.

In the tube mill 113, the supply port 11 at one axial end of the body 114 having a substantially horizontal rotation axis is provided.
5, the object to be crushed is lifted along the inner wall by the rotation of the body 114 together with the crushing medium by the crushing medium such as a ball in the body 114, and the rolling of the crushing medium, the collision between the crushing medium at the time of falling, and The pulverization medium is pulverized by receiving an impact force and a frictional force due to mutual contact. From the other end of the body 114 in the axial direction, the crushed material is taken out from the outlet 116 and returned to the bucket elevator 38 via the pipe 117. The upper part of the housing 12 of the vertical roller mill 11, the bucket elevator 38, the classifier 37a, and the tube mill 113 are bled by a suction fan 41 via a bag filter 40.

FIG. 25 is a system diagram showing the entire configuration of another embodiment of the present invention. This embodiment is similar to the above-described embodiment, and corresponding portions are denoted by the same reference numerals. A bucket elevator 38 and a sieving device 122 are provided between the vertical roller mill 11 and a tube mill 121 which is an air sweep mill. Vertical roller mill 11
The material to be pulverized taken out of the pipe line 42 from below is fed into the bucket elevator 38 and transported, and the sieving device 12
2 is supplied.

The sieving device 122 classifies the material to be ground supplied from the supply port 123 by the sieve 124. The coarse powder obtained by classification by the sieving device 122 is supplied to the vertical roller mill 11 via the pipe 46, returned, and pulverized again. Fine powder obtained by classification by the sieving device 122 is passed through a pipe 124 through a tube mill 121.
Supplied to The material to be pulverized by the tube mill 121 is transported by airflow to another classifier 37b via a pipe line 127. The coarse powder classified by the classifier 37b
28 returns to the inlet 115 of the tube mill 121. The fine powder classified by the classifier 37b is taken out from the pipe 129 as a product.

According to this configuration, the sieve device 122 removes large-diameter coarse powder from the material to be pulverized supplied from the vertical mill 11 and is determined by the diameter of the pulverizing medium of the tube mill 121 and the like. An object to be crushed having a particle diameter exceeding the optimum particle size for improving the crushing efficiency of the object to be crushed into the tube mill 121 can be removed, and the crushed object is again crushed by the vertical roller mill 11. Therefore, the diameter of the crushing medium of the tube mill 121 can be further reduced, and the crushing efficiency can be improved.

FIG. 26 is a system diagram showing the overall configuration of still another embodiment of the present invention. Vertical roller mill 11
First, a new material to be ground, which is a cement clinker, passes through the raw material chute 27 and is supplied to the hopper 1 by the quantitative feeder 130.
From 31, a constant weight is cut out and charged per unit time. From below the table 13 of the vertical roller mill 11,
Substantially all of the material to be crushed is withdrawn via lines 32, 42, transported by bucket elevator 38 and guided to distribution means 87. A part of the material to be ground from the vertical roller mill 11 is returned to the vertical roller mill 11 via the pipe 43 by the distribution means 87, and the remaining part is supplied from the pipe 88 to the inlet 115 of the tube mill 113. And distributed.

The material to be pulverized by the pulverizing medium in the tube mill 113 is guided to the classifier 37 a by another bucket elevator 132, and the coarse powder after the classification is passed from the pipe 133 to the tube mill 113. Guided and reground. The fine powder classified by the classifier 37a is taken out from the pipe 107 as a product.

FIG. 27 is a system diagram showing the overall configuration of still another embodiment of the present invention. Portions corresponding to the above-described embodiments are denoted by the same reference numerals. The material to be pulverized taken out below the vertical roller mill 11 is transported by the bucket elevator 38 and guided to the fluidized bed classifier 135. The coarse powder obtained by the classification by the fluidized bed classifier 135 is returned to the vertical roller mill 11 through the pipe 46 and re-ground. The fine powder floating in the airflow in the classifier 135 or the fine powder on the upper part of the fluidized bed is supplied from the pipe 88 to the tube mill 1.
Thirteen inlets 115 are supplied. Tube mill 113
Is supplied from the outlet 116 to the classifier 37a through another bucket elevator 132. The coarse powder classified by the classifier 37a is returned to the tube mill 113 via the pipe 133. Fine powder obtained by classification by the classifier 37a is taken out from the pipe 107 as a product. The classifier 135 may be a sieving device, and may have another configuration.

The present invention can be implemented not only in connection with the above-described embodiments, but also in connection with other configurations.

[0101]

According to the first aspect of the present invention, the vibration of the vertical roller mill can be prevented, the specific power consumption ratio can be reduced, and a good result can be obtained. The operation state can be stably maintained.

Further, according to the present invention, the object to be ground is taken out from below the table of the vertical roller mill and is transported to the classifier by the mechanical transport means, so that the fan power can be reduced.

Depending on the type of classifier, the air flow is circulated by the cyclone and the fan, so that a large amount of air is not required, so that the temperature of the material to be ground does not decrease. This eliminates the problem of false setting of the cement due to gypsum moisture, and eliminates the need for a facility for taking in hot air and a facility for circulating the exhaust air of a large flow exhaust fan as described in connection with the prior art. The equipment is simplified and downsized.

In particular, according to the present invention, stable operation is enabled by adding a liquid only to the milling region, and the crushing efficiency is greatly improved. In the present invention, the narrowness of the particle size configuration width, which is a problem in the vertical roller mill, can be improved, and the product quality can be improved. That is, although the circulation ratio is smaller than that of the prior art, the vibration of the vertical roller mill is effectively suppressed, stable operation is possible, and friction grinding is performed under a sufficient grinding pressure in the grinding region. As a result, the ability to generate fine powder is remarkably improved, and as described above, a desired particle size composition in terms of the product quality of the cement clinker can be obtained.

According to the second aspect of the present invention, it is possible to prevent the chemical reaction of solidifying the cement clinker and effectively prevent the vibration of the vertical roller mill.

According to the third aspect of the present invention, at least a part of the material to be pulverized taken out of the vertical roller mill is transported to the classifier by mechanical transport means, and the coarse powder obtained by the classifier is subjected to vertical molding. It is possible to return to the roller mill, thereby improving the particle size composition of the cement product.

According to the fourth aspect of the present invention, by using a vertical roller mill having excellent crushing efficiency of coarse crushing, and supplying the crushed material roughly crushed by the vertical roller mill to a tube mill, The grinding medium of the mill can be reduced, and the grinding efficiency of the tube mill itself can be improved. Thus, the pulverization efficiency of the entire system in which the vertical roller mill and the tube mill are combined can be improved.

According to the fifth aspect of the present invention, as described above, the size of the equipment is reduced, the product quality of the cement clinker is improved, the fan power is reduced, and the problem of false cementation of the cement due to gypsum moisture occurs. Can be prevented.

According to the sixth aspect of the present invention, the liquid can be uniformly sprayed on the material to be ground only in the grinding area. Therefore, the vibration of the vertical roller mill can be reliably prevented, and the pulverization efficiency can be reliably improved.

According to the seventh and eighth aspects of the present invention, the entire amount of the material to be ground taken out of the vertical roller mill is transported to a classifier, and the coarse powder classified by the classifier is returned to the vertical roller mill. As a result, a product having a particle size configuration equivalent to that of a tube mill can be obtained.

According to the ninth aspect of the present invention, only a part of the material to be ground taken out of the vertical roller mill is transported to a classifier,
The obtained coarse powder is returned to the vertical roller mill together with the remaining material to be crushed from the vertical roller mill and further to be crushed by the distribution means. According to this configuration, the fine powder contained in the material to be pulverized taken out of the vertical roller mill is also returned to the vertical roller mill. By controlling the flow rate of the material to be pulverized to be transported to the classifier and the vertical roller mill directly by the distribution means in this way, the mixing ratio of the fine powder in the product can be arbitrarily adjusted, and has a particle size structure suitable as cement. Products can be obtained.

According to the tenth aspect of the present invention, the vertical roller mill is used for pre-grinding of the tube mill, and the pulverizing efficiency of the entire system in which the vertical roller mill and the tube mill are combined can be improved. become.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a configuration of a vertical roller mill 11.

FIG. 3 is a horizontal sectional view showing a table 13 and a roller 16 of the vertical roller mill 11.

FIG. 4 is a simplified cross-sectional view showing a state in which an object to be crushed 48 on a table 13 is crushed and crushed by the action of a roller 16;

FIG. 5 is a front view showing a state in which the roller 16 is projected on a surface 35 on the table 13 parallel to the rotation axis 34 thereof.

FIG. 6 is a side view showing a state when the roller 16 is projected on a surface 35.

FIG. 7 is a plan view showing a state when the roller 16 is projected on a surface 35.

FIG. 8 is a graph showing the relationship between the average surface pressure of the roller 16 and the specific crushing power consumption ratio, showing the experimental results of the present inventor.

FIG. 9 is a graph showing the relationship between the average surface pressure of the roller 16 and the n value of the Rosin-Rammler diagram according to the experimental results of the present inventor.

FIG. 10 is a graph showing the relationship between the n value of the rosin-lamellar diagram and the concrete strength based on the experimental results of the present inventor.

FIG. 11 is a graph showing a relationship between an n value of a rosin-lamellar diagram and an unit water amount in a concrete test according to an experiment performed by the present inventor.

FIG. 12 is a graph showing the relationship between the circulating ratio of the material to be crushed and the specific crushing power consumption ratio in an experiment conducted by the present inventors.

FIG. 13 is a graph showing the relationship between the circulation ratio of the material to be ground and the n value of the Rosin-Lambert diagram according to the experiment of the present inventor.

14 is a side view of the nozzle 59. FIG.

FIG. 15 is a sectional view of a nozzle 59.

FIG. 16 is a perspective view of a nozzle 59.

FIG. 17 is a perspective view showing a state in which a liquid 67 is ejected by a nozzle 59.

FIG. 18 is a view for explaining the crushing and crushing operation by the table 13 and the rollers 16 in the vertical roller mill 11;

FIG. 19 is a rosin-lamella diagram showing the experimental results of the present inventor.

FIG. 20 is a system diagram showing the overall configuration of another embodiment of the present invention.

FIG. 21 is a longitudinal sectional view showing a configuration of the classifier 37 shown in FIGS. 1 and 20.

FIG. 22 is a simplified horizontal cross-sectional view as viewed from XXII-XXII in FIG. 21.

FIG. 23 shows the dispersion plate 96 and the blade member 9 in the classifier 37.
FIG.

FIG. 24 is a system diagram showing an overall configuration of still another embodiment of the present invention.

FIG. 25 is a system diagram showing an overall configuration of another embodiment of the present invention.

FIG. 26 is a system diagram showing the overall configuration of another embodiment of the present invention.

FIG. 27 is a system diagram showing an overall configuration of still another embodiment of the present invention.

FIG. 28 is a sectional view of the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Vertical roller mill 12 Housing 13 Table 15 Motor 16 Roller 27 Chute 32 Exit chute 37, 37a, 37b Classifier 38 Bucket elevator 40 Bag filter 41 Induction fan 59 Nozzle 63 Nozzle hole 67 Liquid 77 Synchronization point 87 Distributing means 91 Damper 97 Blade Member S Projection area Z Crush and crush area Z1 Compression and crush area Z2 Grinding area

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seisuke Sawamura 3-1-1, Higashi-Kawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries, Ltd. Kobe Plant (72) Inventor Hiroshi Ueda Higashi-Kawasaki, Chuo-ku, Kobe-shi, Hyogo 3-1-1, Kawamachi, Kobe Plant, Kawasaki Heavy Industries, Ltd. (72) Inventor Fuminori Ando 3-1-1, Higashikawasaki-cho, Chuo-ku, Kobe, Hyogo Prefecture, Kobe Plant, Kawasaki Heavy Industries, Ltd. (72) Mitsuaki Murata Tokyo 2-14-1, Nishishinbashi, Minato-ku, Tokyo Chichibu Onoda Co., Ltd. (72) Inventor Akihiko Takayama 2-14-1, Nishi-Shimbashi, Minato-ku, Tokyo Chichibu Onoda, Ltd.

Claims (10)

[Claims] 1. A plurality of rollers are arranged at intervals in a circumferential direction on a table which rotates around a vertical axis, and an object to be ground supplied to the center of the table is placed between the table and the rollers. Pulverize by crushing and crushing, take out substantially all of the crushed material from below the table, and use a vertical roller mill that does not incorporate a classifier, and use a vertical roller mill upstream of each roller in the rotation direction of the table. Immediately before, liquid should be added only to the grinding area where the material to be ground is frictionally ground between the table and the roller outside the table in the radial direction from the position where the relative speed between the table and the roller is zero. A method of pulverizing cement clinker using a vertical roller mill. 2. The method according to claim 1, wherein the liquid is 0.5 to 3% of the material to be ground. 3. A classifier for classifying an object to be pulverized by a vertical roller mill to obtain a cement product, and a mechanical transport means for conveying at least a part of the object to be pulverized taken out of the vertical roller mill to a classifier. The method for pulverizing a cement clinker by a vertical roller mill according to claim 1 or 2, which is provided. 4. The method for pulverizing cement clinker with a vertical roller mill according to claim 1, wherein at least a part of the material to be pulverized taken out of the vertical roller mill is supplied to a tube mill. 5. A plurality of rollers are arranged at intervals in a circumferential direction on a table rotating around a vertical axis, and a material to be ground supplied to a center portion of the table is placed between the table and the rollers. The crushed material is crushed and crushed, and the crushed material thus crushed is substantially entirely taken out from under the table, and a vertical roller mill without a classifier is provided immediately upstream of each roller in the rotation direction of the table. It is located only in the grinding area where the material to be ground is frictionally ground between the table and the roller radially outside the table from the position where the relative speed between the table and the roller is zero. And a nozzle for injecting 5 to 3% of a liquid. 6. The apparatus for crushing a cement clinker by a vertical roller mill according to claim 5, wherein the nozzle has a nozzle hole for jetting the liquid in a flat shape extending in a radial direction of the table. 7. A classifier for classifying a ground product of a vertical roller mill to obtain a cement product, and a mechanical transport means for transporting at least a part of the ground product taken out of the vertical roller mill to a classifier. An apparatus for crushing a cement clinker by a vertical roller mill according to claim 5 or 6, wherein the apparatus comprises: 8. The vertical roller mill according to claim 5, wherein the mechanical transport means transports the entire amount of the material to be ground removed from the vertical roller mill to a classifier. Cement clinker crusher. 9. A distribution means for transporting a part of the material to be crushed transported by the mechanical transport means to a classifier and transporting the remaining material to be crushed directly to a vertical roller mill for return. An apparatus for grinding a cement clinker by a vertical roller mill according to any one of claims 5 to 7. 10. The tube mill according to claim 5, further comprising a tube mill that pulverizes the pulverized material taken out of the vertical roller mill with a pulverizing medium in a body that is driven to rotate about a substantially horizontal axis. Cement clinker crusher with vertical roller mill.