JP2010274189A - Vertical crusher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent abnormal vibration and the like caused by air staying in a large amount between a raw material layer and an auxiliary roller, upon minutely crushing a raw material by a vertical crusher. <P>SOLUTION: There is disclosed a vertical crusher that crushes a raw material disposed on a rotary table subsequent to degassing the same by an auxiliary roller, which auxiliary roller includes a plurality of grooves each extending from the smaller diameter side to the larger diameter side of the auxiliary roller. The end part of each of the grooves facing the larger diameter side is rounded and closed midway in a form of a circular arc, and each of the grooves facing the smaller diameter side is extended to the end part of the auxiliary roller while gradually reducing its width, with a gap for a gas to escape therethrough formed thereon at the end part thereof. By virtue of the structure as described above, air generated in a large amount upon compressing the raw material layer during operation is introduced into the plurality of grooves, and subsequently can quickly and efficiently be discharged through the gap formed on each of the grooves at the end part of the smaller diameter side of the auxiliary roller through which a gas can easily flow. Thus unlike a prior art technique, air does not stay in a large amount between the raw material layer and the auxiliary roller, so that abnormal vibration is prevented from arising. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention mainly relates to a vertical crusher suitable for crushing coal, oil coke, slag, clinker, limestone, other inorganic raw materials, and organic raw materials such as biomass, and in particular, when pulverizing the raw materials. The present invention relates to a suitable vertical grinder.

Conventionally, a crusher called a vertical crusher (sometimes called a vertical mill or a vertical roller mill) has been widely used as an apparatus for crushing coal or the like.
Here, the vertical crusher has an excellent characteristic that the raw material can be finely pulverized efficiently, but has a problem that abnormal vibration occurs depending on the type of raw material and the pulverization conditions. It was. Since the abnormal vibration generated in the vertical crusher is induced by various causes, it is necessary to take various measures according to the cause of the vibration. Therefore, many countermeasures for preventing abnormal vibration have been proposed for vertical crushers.

For example, as a situation where abnormal vibration is likely to occur, a case is known in which the raw material is repeatedly pulverized in the machine in order to finely pulverize the raw material.
This is because when the raw material is finely pulverized, it is necessary to repeatedly pulverize the raw material in a vertical pulverizer. The raw material that is repeatedly pulverized in the machine is called a circulating raw material, but the particle size of the circulating raw material is naturally smaller than the raw material before pulverization newly input to the vertical crusher.

The above-mentioned circulating raw material particles become smaller as the finer product is obtained, but the finer particles are entrained with a larger amount of air.
If the raw material is pulverized, the amount of the circulating raw material increases, so the raw material layer on the rotary table contains a large amount of fine raw material with a small particle size and a high porosity, so-called bulky state (as bulk density) Is low).

Since the bulky raw material layer described above contains a large amount of air, the pulverizing roller or the like is in a slippery state, and apparently, the friction coefficient of the raw material layer becomes small and slippery.
Therefore, if a bulky raw material layer is pulverized at once by the pulverizing roller, the pulverizing roller slips and slips on the raw material layer on the rotary table, and the rotation of the pulverizing roller becomes irregular, There was a problem that abnormal vibration occurred.

As one method for preventing abnormal vibration, a conventional technique disclosed in Patent Document 1 is known. The prior art disclosed in Patent Document 1 is a technique in which a raw material layer on a rotary table is degassed using an auxiliary roller, and once compacted, the raw material is efficiently caught in the grinding roller.

Japanese Patent Laid-Open No. 2-174946

Here, as in the prior art disclosed in Patent Document 1, the method of pulverizing the material layer compacted by the auxiliary roller with the pulverization roller can be expected to have a certain effect in terms of improving the pulverization efficiency.
However, even in the prior art disclosed in Patent Document 1, the bulky raw material layer at the time of compaction with the auxiliary roller does not change in that it contains a large amount of air and is slippery.
The pressure that pushes the raw material layer with the auxiliary roller is smaller than the pressure with which the raw material layer is crushed with the crushing roller. If the roller is rapidly consolidated, the air in the raw material layer is deaerated at once, and a large amount of air is interposed between the raw material layer and the auxiliary roller. As a result, there is a problem that a large amount of air stays between the raw material layer and the auxiliary roller, and the auxiliary roller and the raw material layer slip greatly to generate vibration. Therefore, there is a limit to consolidating the raw material layer with the auxiliary roller, and care must be taken not to interpose a large amount of air between the raw material layer and the auxiliary roller.

  The present invention has been made in view of the problems described above, and relates to a vertical crusher suitable for efficiently pulverizing raw materials.

In order to achieve the above object, a vertical crusher according to the present invention comprises:
(1) A vertical crusher in which a rotatable crushing roller and a conical auxiliary roller are arranged on a rotary table, and the raw material charged on the rotary table is deaerated by the auxiliary roller and then crushed by the crushing roller. The auxiliary roller includes a plurality of rows of groove portions extending from the small diameter side to the large diameter side of the auxiliary roller, and an end portion of the groove portion toward the large diameter side of the auxiliary roller is an end on the large diameter side of the auxiliary roller. The end of the groove toward the small-diameter side of the auxiliary roller reaches the end of the small-diameter side of the auxiliary roller so that the gas introduced into the groove can escape. A gap was formed.

(2) In the vertical crusher according to (1), the cross-sectional area of the plurality of rows of grooves is reduced from the large diameter side to the small diameter side of the auxiliary roller.

(3) In the vertical crusher according to (2), with respect to the shape of the groove portion, the end portion of the groove toward the large diameter side of the auxiliary roller is rounded and closed in a circular arc shape, and The groove width is reduced from the diameter side toward the small diameter side.

(4) In the vertical crusher according to any one of (1) to (3), the size of the center diameter of the auxiliary roller is made larger than the size of the center diameter of the crushing roller.

  In the present invention, when the raw material layer is degassed by the auxiliary roller during operation of the vertical crusher, a large amount of air generated when the raw material layer is consolidated is put into the groove portion, and then the gas flow It can be quickly and efficiently discharged from the gap in the groove provided at the small diameter end of the auxiliary roller. Therefore, unlike the prior art, since a large amount of air does not stay between the raw material layer and the auxiliary roller, abnormal vibration is suppressed.

  In addition, by reducing the passage cross-sectional area of the groove portion from the large-diameter side of the auxiliary roller toward the small-diameter side, air can be blown out from the groove at a higher jetting speed, and the raw material covering the groove portion is blown off. And, it has an excellent effect that air is discharged quickly.

  In addition, if the size of the center diameter of the auxiliary roller is made larger than the size of the center diameter of the grinding roller, the width of the compacted portion by the auxiliary roller is increased, so that a sudden volume change of the raw material layer can be avoided and vibration can be further suppressed. The target increases.

It is a figure explaining arrangement | positioning of the crushing roller and auxiliary | assistant roller of a vertical grinder related to this embodiment. It is a figure explaining the whole structure outline of a vertical crusher in connection with this embodiment. It is a figure explaining the structure and arrangement | sequence of a groove part of an auxiliary roller in connection with this embodiment. It is principal part sectional drawing explaining the arrangement | sequence and shape of the groove part which were related to this embodiment and was provided in the auxiliary roller. It is a figure which illustrates notionally the shape of the groove part of an auxiliary roller in connection with this embodiment. It is a figure which illustrates notionally the shape of the groove part of an auxiliary roller in connection with other embodiment by this invention. It is a figure which illustrates notionally the behavior which concerns on this embodiment and discharges air from the groove part of an auxiliary roller. It is a figure which illustrates notionally the consolidation behavior of the raw material layer by an auxiliary roller in connection with this embodiment.

Hereinafter, a preferred example of an embodiment according to the present invention will be described in detail with reference to the drawings.
1 to 8 relate to an embodiment of the present invention, FIG. 1 is a diagram for explaining the arrangement of auxiliary rollers and crushing rollers and the arrangement of grooves provided in the auxiliary rollers, and FIG. 2 is an overall configuration of a vertical crusher. FIG. FIG. 3 is a diagram for explaining the structure of the auxiliary roller and the arrangement of the grooves, and FIGS. 4 and 5 are diagrams for explaining the shape of the groove and the arrangement of the auxiliary roller. FIG. 6 is a diagram for explaining a groove shape according to another embodiment of the present invention. FIG. 7 is a diagram conceptually illustrating the behavior of discharging air from the groove portion of the auxiliary roller. FIG. 8 is a view for conceptually explaining the consolidation behavior of the raw material layer by the auxiliary roller.

Hereinafter, the preferable structure of the vertical crusher 1 by this embodiment is demonstrated.
The vertical crusher 1 used in the present embodiment is driven by a casing 1B and 1A that form an outline of the vertical crusher 1, a speed reducer 2B installed at the lower part of the vertical crusher 1, as shown in FIG. A rotary table 2 driven by a motor 2M, a conical crushing roller 3 and an auxiliary roller 5 are provided. The vertical crusher 1 used in the present embodiment includes an inverter power supply as a driving power source for the drive motor 2M, and a variable speed vertical crusher in which the rotation speed of the rotary table can be arbitrarily changed during operation. Machine 1.

In the vertical crusher 1 shown in FIG. 2, a gas supply port 33 for introducing a gas is provided below the rotary table 2, and an upper intake for taking out the product together with the gas is further provided above the rotary table. An outlet 39 is provided.
The vertical crusher 1 according to the embodiment shown in FIG. 2 includes a rotary classifier 14 above the rotary table 2, and is disposed above the rotary table 2 as a classification mechanism of the classifier 14. The rotating classifying blade 14A is driven by a drive motor (not shown) installed at the top of the vertical crusher 1 so as to rotate freely.

The vertical crusher 1 shown in FIG. 2 passes through the classifier 14 from below the rotary table 2 by introducing gas (air in this embodiment) from the gas supply port 33 during operation by the above-described configuration. Thus, a gas flow that flows to the upper outlet 39 is generated.
The raw material pulverized on the turntable 2 is blown up by the gas and rises in the casing and flows in the direction of the classifier 14, but the raw material having a large diameter and a large weight cannot reach the classifier 14, Alternatively, by falling without being able to pass, it becomes a circulating raw material pulverized again in the vertical crusher 1. The raw material having a small diameter that has passed through the classifier 14 is taken out as a product from the upper outlet 39.

Here, in the present embodiment, as shown in FIG. 1, a plurality of (two in the present embodiment) the crushing rollers 3 are arranged on the upper surface of the rotary table 2 (sometimes referred to as the rotary table upper surface 2A). Thus, it is configured to be pressed in the direction of the rotary table 2. In addition, the crushing roller 3 is driven to rotate via the raw material with respect to the rotary table 2 when the rotary table 2 rotates.

In the present embodiment, a plurality (two in the present embodiment) of auxiliary rollers 5 are arranged on the upper surface of the rotary table 2 so as to be pressed in the direction of the rotary table 2. The roller 5 is rotated by being driven by the rotation table 2 through the raw material as the rotation table 2 rotates. The crushing rollers 3 are arranged on the rotary table 2 so that the two are opposed to the outer peripheral portion thereof, and the auxiliary rollers 5 are arranged so that the phase of the crushing rollers 3 is shifted by 90 degrees. Two are arranged.

Here, as shown in FIG. 3, in the present embodiment, the auxiliary roller 5 is a conical roller of a truncated cone type whose diameter decreases toward the center side of the rotary table, and is on the center side of the rotary table. The small diameter portion of the roller is disposed on the outer peripheral side, and the large diameter portion of the roller is disposed on the outer peripheral side.
The auxiliary roller 5 in the present embodiment has a plurality of grooves M extending in the roller width direction of the auxiliary roller 5 (the width direction of the rolling surface of the auxiliary roller 5).
For reference, in FIG. 3, the auxiliary roller 5 is described with the dimension in the roller width direction as the roller width dimension L and the roller diameter dimension at the center in the roller width direction as the roller center diameter dimension D.

Further, in order to explain the shape of the groove M described above, FIG. 5 conceptually shows a developed view of the surface portion of the auxiliary roller 5.
As can be seen from the outline view of the A part in FIG. 5, a plurality of groove parts M extending in the width direction of the auxiliary roller 5 are arranged at regular intervals. In FIG. 5, the shape of the groove M extends from the large diameter side of the auxiliary roller 5 toward the small diameter side, and the end of the large diameter side of the groove reaches the large diameter side end of the auxiliary roller 5. However, the end of the small diameter side groove portion M is grooved to the small diameter side end portion of the auxiliary roller 5 to form a gap through which gas escapes. ing.

Next, FIG. 4 shows the cross-sectional shape of the groove. As is apparent from the cross-sectional view shown in FIG. 4, a groove with a depth of several millimeters is formed on the end of the groove portion M on the small diameter side of the auxiliary roller 5, and the groove portion having a depth dimension (h1) is used. A gap is formed to secure a gap for gas to escape. Further, in the vicinity of the central portion of the groove portion M in the roller width direction, a groove portion having a depth dimension (h2) is processed by cutting deeper than that, and further. The end of the groove toward the roller large diameter side was gradually shallowed before reaching the end of the roller large diameter side to stop the groove processing.

In addition, if the groove depth dimension h1 of the end necessary for the gas provided at the small-diameter side end of the auxiliary roller 5 to escape is described, if it is too small, the gap for discharging becomes too small and the groove The gas in M cannot be exhausted sufficiently. On the other hand, if the dimension is too large, the gas velocity at the time of discharge becomes slow, and it becomes difficult to eject the gas in the raw material layer. As a result, the gas discharge becomes worse. Accordingly, the groove depth dimension h1 is preferably in the range of 1 mm or more and less than 10 mm.

In addition, the 2nd shape of the groove part by this embodiment was shown in FIG.
In FIG. 6, the shape of the groove portion M is reduced from the large-diameter side of the auxiliary roller 5 toward the small-diameter side, and the end on the large-diameter side is rounded and closed, and the groove portion M on the small-diameter side is closed. The end reaches the end on the small diameter side of the auxiliary roller 5 and forms a gap for gas to escape.

In addition, the embodiment shown in FIG. 6 and the embodiment shown in FIG.
Here, the embodiment of FIG. 6 is characterized in that the cross-sectional area of the groove portion is reduced from the large diameter side of the auxiliary roller 5 toward the small diameter side.
As apparent from FIG. 6, the shape of the groove portion M is reduced from the large diameter side to the small diameter side of the auxiliary roller 5, and the depth of the groove portion is substantially uniform near the center in the width direction. The part is shallow.

If the amount of gas does not change, the speed at which the gas flows in the groove is affected by the shape of the groove, and basically the gas speed increases as the passage cross-sectional area of the groove through which the gas flows decreases.
The passage cross-sectional area of the groove in the embodiment shown in FIG. 6 is obtained by multiplying the width of the groove (groove dimension in the direction orthogonal to the roller width direction) shown in the A surface development drawing of the roller by the groove depth. It will be what (does).
As described above, when the gas velocity at the time of discharge becomes slow, the gas discharge becomes worse. Therefore, the faster the speed of the gas ejected from the end of the groove, the better. The embodiment shown in FIG. 6 is one of the particularly preferred embodiments in that the passage cross-sectional area can be reduced to increase the speed of the exhausted gas.

Furthermore, in this embodiment, as shown in FIG. 1, the size of the auxiliary roller 5 is made larger than that of the crushing roller 3. Although the configuration of the auxiliary roller 5 is conceptually shown in FIG. 3, in the present embodiment, the center diameter dimension D of the auxiliary roller 5 (the diameter dimension of the center portion in the width direction of the rolling surface of the auxiliary roller 5) It was about 1.2 times the center shape dimension.

The auxiliary roller 5 is not a roller for pulverizing the raw material. Therefore, normally, the auxiliary roller 5 is designed such that the roller width dimension L is the same as the roller width dimension of the grinding roller 3 and the roller center diameter dimension D is smaller than the center diameter dimension of the grinding roller.
This is based on the idea that the material layer to be crushed by the crushing roller 3 can be consolidated by the auxiliary roller 5 as long as the auxiliary roller 5 and the crushing roller 3 have the same roller width.
Therefore, conventionally, it has been considered that even if the center diameter dimension D of the auxiliary roller 5 is smaller than the center diameter dimension of the crushing roller 3, the function as the auxiliary roller 5 is sufficiently achieved.
As a result, in order to reduce the cost, the auxiliary roller 5 is generally made with a smaller roller center diameter than the grinding roller.
In some cases, the roller made as the crushing roller 3 can be used as it is and used as the auxiliary roller 5, but even in that case, the auxiliary roller 3 and the crushing roller 5 have only the same diameter.

However, although details will be described later, when the applicant consolidates the bulky material layer with the auxiliary roller 5, not only the width dimension L of the auxiliary roller 5 described above but also the size of the center diameter dimension D is: Since it has been found that the effect of consolidation is greatly affected, the center diameter dimension D of the auxiliary roller 5 is deliberately larger than that of the grinding roller 3.

  In addition, the model | type of the vertical crusher 1 which can be used for this embodiment is not restricted to what was mentioned above, Of course, it can change without deviating from the technical idea of this invention.

Hereinafter, a preferable example of the operation method of the vertical crusher 1 according to the present embodiment will be described.
The raw material (in this embodiment, coal) input to the raw material input port 35 of the vertical crusher 1 is input to the vicinity of the center of the rotary table via the raw material input chute 13 while drawing a spiral trajectory, Move to the outer periphery of the rotary table.
The raw material charged on the rotary table is combined with the circulating raw material, which will be described later, on the rotary table 2, and most of the raw material is compressed by the auxiliary roller 5 and degassed. It is bitten in between and crushed.
Then, the raw material caught by the rotary table 2 and the pulverizing roller 3 passes over the dam ring 15 provided around the outer edge of the rotary table 2, and the gap between the outer peripheral portion of the upper surface 2 of the rotary table and the casing. To the annular passage 30 (sometimes referred to as the annular space 30).

The raw material that has reached the annular passage 30 is blown up by the gas and rises in the casing and tends to flow in the direction of the rotary separator 14, but the raw material having a large diameter and a large weight can reach the separator 14. By falling without being able to pass through the separator 14 or not, it becomes a circulating raw material that is circulated and repeatedly pulverized in the vertical crusher 1.
And when pulverizing a raw material, the ratio of a circulating raw material becomes large in the vertical crusher 1, and a bulky raw material layer is formed.

The circulating raw material is repeatedly supplied onto the rotary table until it has a predetermined particle size and discharged outside the apparatus, and after being compressed by the auxiliary roller 5 and deaerated, the rotary table 2 and the grinding roller 3 are supplied. And is crushed. On the other hand, the raw material pulverized small to a predetermined particle diameter reaches the separator 14 and passes therethrough, and is taken out from the upper outlet 39 as a pulverized product.

Here, in the present embodiment, the raw material put on the rotary table 2 is deaerated by the auxiliary roller 5 and then pulverized by the pulverizing roller 3. A groove M for venting gas is formed in the auxiliary roller 5. ing. Accordingly, a large amount of air generated when the raw material layer is consolidated can be quickly discharged from the end portion of the groove portion M on the small diameter side of the auxiliary roller 5 after entering the groove portion M.

In the present embodiment, when the raw material layer is degassed by the auxiliary roller 5, the degassed air is ejected from the end portion on the small diameter side of the auxiliary roller 5 toward the center side of the rotary table. . Usually, in the crushing roller or the like of the vertical crusher 1, the roller small-diameter side requires less work than the roller large-diameter side. In other words, the smaller diameter side of the roller is weaker with respect to the grinding roller and the raw material layer, and as a result, the gas in the groove tends to flow.
This is also true for the auxiliary roller 5, and discharging the gas from the end on the small diameter side where the area between the roller and the raw material layer is weak has the advantage that the air discharging effect is higher.
In the present embodiment, for the reasons described above, a large amount of air does not stay between the raw material layer and the auxiliary roller as in the prior art, so that abnormal vibration is suppressed.

  Further, in the embodiment shown in FIG. 6, with respect to the shape of the groove portion M, the flow of gas can be narrowed from the large diameter side to the small diameter side of the auxiliary roller 5, and the gas exhaust speed can be increased. As a result, since the speed of the gas discharged from the narrow groove formed at the end portion on the small diameter side is higher than that in the above-described embodiment, there is an excellent effect that air is discharged more quickly.

For reference, if there is no difference in the height of the raw material layer before and after the auxiliary roller 5, the portion where the auxiliary roller 5 compacts the raw material layer during operation connects the lowest point of the auxiliary roller 5. Since the line segment is a single line (a single line extending across the roller in the width direction), for example, the size of the consolidated portion does not change greatly regardless of whether the center diameter D is large or small. In the prior art, the center diameter dimension D of the auxiliary roller 5 is made small based on such a concept.

However, if the raw material is actually compacted by the auxiliary roller 5, there will be a large difference in the height of the raw material layer before and after being bitten by the auxiliary roller 5. If the height of the raw material layer is different before and after being bitten by the auxiliary roller 5, the larger the central diameter D, the wider the line segment of the above-described consolidated portion. More specifically, the width dimension of the consolidation portion (one line segment extending across the above-described roller in the width direction) becomes wider.
In other words, when the raw material layer is bulky, the larger the auxiliary roller 5 is, the more raw material layer portions can be bitten at a time.

FIG. 8 shows the relationship of the width dimension X of the consolidated portion of the raw material layer to the center diameter dimension D.
When the height of the raw material layer is changed before and after the auxiliary roller 5 (the front dimension is T1 and the rear dimension is T2), if the center diameter dimension of the auxiliary roller 5 is D1> D2, the width dimension of the consolidated portion is X1> X2. If the amount of change in the height dimension of the raw material layer is the same before and after the auxiliary roller 5, the center diameter dimension D1 having a larger width dimension X1 of the consolidated portion shows a more gradual volume change. become. In particular, when the raw material is finely pulverized, the bulky raw material layer is consolidated, so that the difference in height of the raw material layer is large before and after the auxiliary roller 5, and by increasing the central diameter D, the consolidated portion Since the width of is increased, a sudden volume change of the raw material layer can be avoided.
Therefore, according to the vertical crusher 1 of the present embodiment, the sudden change in volume can be reduced even for the auxiliary roller 5, and as a result, the volume can be changed gradually. Since air is gradually deaerated and slipping between the auxiliary roller 5 and the raw material layer can be suppressed, it is effective in suppressing vibrations and hardly causes abnormal vibrations.

As described above, the vertical pulverizer according to the present invention has a feature that vibration is less likely to occur during fine pulverization compared to the prior art, so it is used as a pulverizer that is particularly suitable for pulverizing raw materials. it can.

DESCRIPTION OF SYMBOLS 1 Vertical crusher 2 Rotary table 3 Crushing roller 5 Auxiliary roller 14 Classifier 15 Dam ring 35 Raw material inlet 39 Upper outlet D Roller center diameter dimension L Roller width direction dimension T Raw material layer thickness M Groove part

Claims (4)

A vertical crusher in which a rotatable crushing roller and a conical auxiliary roller are arranged on a rotary table, and the raw material charged on the rotary table is degassed by the auxiliary roller and then crushed by the crushing roller,
The auxiliary roller has a plurality of grooves extending from the small diameter side to the large diameter side of the auxiliary roller, and the end of the groove toward the large diameter side of the auxiliary roller reaches the end of the auxiliary roller on the large diameter side. Without being closed,
The vertical crushing characterized in that the end of the groove toward the small diameter side of the auxiliary roller reaches the end of the small diameter side of the auxiliary roller to form a gap for the gas introduced into the groove to escape. Machine. 2. The vertical crusher according to claim 1, wherein a passage cross-sectional area of the plurality of rows of grooves is reduced from a large diameter side to a small diameter side of the auxiliary roller.   Regarding the shape of the groove portion, the end portion of the groove toward the large-diameter side of the auxiliary roller is rounded and closed in an arc shape, and the groove width decreases from the large-diameter side of the auxiliary roller toward the small-diameter side. The vertical crusher according to claim 2, wherein The vertical crusher according to any one of claims 1 to 2, wherein a dimension of a center diameter of the auxiliary roller is larger than a dimension of a center diameter of the crushing roller.

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