JP2010274188A - 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 extending in the width direction thereof with the depth of the grooves at their both end parts made shorter than the depth of the grooves in the vicinity of the central part in the width direction of the auxiliary roller. 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 be discharged through the both end parts of the grooves. Thus unlike a prior art technique, air does not stay in a large amount between the raw material layer and the auxiliary roller, and thus abnormal vibration is prevented from arising. The depth of the grooves at the both end parts thereof is made to be within a range of from 1 to 10 mm, and hence air present in the grooves can quickly be discharged. <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 an auxiliary roller are arranged on a rotary table, and the raw material put on the rotary table is deaerated by the auxiliary roller and then crushed by the crushing roller. The auxiliary roller is provided with a plurality of rows of groove portions extending in the roller width direction, and the groove depth size at both ends of the groove portion is smaller than the groove depth size near the center in the roller width direction.

(2) In the vertical crusher according to (1), the groove depth dimension at both ends of the groove is in the range of 1 mm to 10 mm.

(3) In the vertical crusher according to (1) or (2), the size of the center diameter of the auxiliary roller is larger than the size of the center diameter of the crushing roller.

According to 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 groove portion Can be quickly discharged from both ends.
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, the air in a groove part can be rapidly discharged | emitted by setting it as the range of 1 mm-10 mm about the depth dimension of the both ends of the said groove part.

  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 shape of the groove part provided in the 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 this embodiment. 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 5 relate to a preferred example of the present embodiment. 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. FIG. It is a conceptual diagram explaining a structure. 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 arrangement and shape of the groove of the auxiliary roller. FIG. 6 is a diagram 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, and extends in the roller width direction of the auxiliary roller 5 (the width direction of the rolling surface of the auxiliary roller 5). The groove part M of the book is processed. 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 aforementioned groove portion, FIG. 5 conceptually shows a developed view of the surface portion of the auxiliary roller 5. As can be seen from the external view of part A in FIG. 5, a plurality of grooves M extending in the width direction of the auxiliary roller 5 are arranged at regular intervals.

In the present embodiment, the shape of the groove portion M described above is characterized, and a gap for gas to escape is secured at both ends of the groove portion M, and the depth dimension of the groove portion M near the center in the roller width direction is as follows. It is processed to be larger than the depth dimension at both ends of the groove M.
FIG. 4 shows a cross-sectional shape of the groove M. The groove part M is formed so as to extend in the width direction of the roller and cross the roller, and both ends of the groove part M are grooved with a groove depth dimension (h1) of several millimeters in depth. In addition to ensuring a gap for the gas that has entered the groove M to escape, as for the groove center M, the vicinity of the roller center is deeper than both ends (depth dimension: h2). Yes.

Here, the groove depth dimension h1 at the end necessary for gas to escape will be described. If it is too small, the gap for discharging becomes too small and the air in the groove M is sufficiently discharged. I can't. 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. Therefore, the groove depth dimension h1 is preferably in the range of 1 mm or more and less than 10 mm.

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 whose main purpose is to pulverize 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 grinding roller 3 passes over the dam ring 15 provided around the outer edge of the rotary table 2 and passes through the gap between the outer peripheral portion of the rotary table 2 and the casing. It goes to a certain annular passage 30 (sometimes referred to as an 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. It cannot fall or cannot pass through the separator 14 and falls. The dropped raw material becomes a circulating raw material that is circulated in the vertical crusher 1 and repeatedly pulverized. When the raw material is finely pulverized, the ratio of the circulating raw material is increased in the vertical pulverizer 1, and a bulky raw material layer is formed.

The circulating raw material is repeatedly supplied onto the rotary table, compressed by the auxiliary roller 5 and deaerated until it is discharged to the outside with a predetermined particle size, and then the rotary table 2 and the pulverizing roller 3. 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 this embodiment, the raw material put on the rotary table is degassed by the auxiliary roller 5 and then pulverized by the pulverizing roller 3. The auxiliary roller 5 is provided with a groove portion M for venting gas. is doing.
Therefore, a large amount of air generated when the raw material layer is consolidated can be quickly discharged from both ends of the groove portion M after entering the groove portion M. 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 particular, in the present embodiment, the depths of both ends of the groove M are made shallower, and the vicinity of the center in the roller width direction is formed deeper than both ends.
Therefore, the vertical crusher 1 in the present embodiment can introduce a large amount of air near the center of the deeply formed groove M when the raw material is degassed. It is the structure which can discharge | emit at once from the shallow groove part M formed in this.
As a result, the speed of the air discharged from the shallow grooves M formed at both ends can be increased as compared with the prior art, so that even if both ends of the grooves M are buried in the raw material layer, the discharged air The raw material covering the groove M can be blown away by the momentum of the speed, and as a result, the air that has entered the groove M is quickly discharged.

Here, 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 it is a line segment (a single line extending across the roller in the width direction), for example, even if the center diameter D is large or small, there is no significant change in the size of the consolidated portion. 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. 6 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 dimension in the height direction 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. .
In particular, when the raw material is finely pulverized, the bulky raw material layer is consolidated, so that there is a large difference in the height of the raw material layer before and after the auxiliary roller 5. Since the width of the portion can be 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 auxiliary roller 5 can also moderate the volume change by relaxing the sudden volume change. As a result, the air in the raw material layer Since the deaeration is performed slowly and the slip between the auxiliary roller 5 and the raw material layer can be suppressed, it is effective for suppressing vibration.

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 input port 39 Upper outlet D Roller center diameter dimension L Roller tire width direction dimension T Raw material layer thickness M Groove part

Claims (3)

A vertical pulverizer in which a rotatable pulverizing roller and an 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 pulverized by the pulverizing roller,
The auxiliary roller includes a plurality of rows of groove portions extending in the roller width direction, and the groove depth size at both ends of the groove portion is smaller than the groove depth size near the center in the roller width direction. A vertical crusher.   The vertical crusher according to claim 1, wherein a groove depth dimension at both ends of the groove part is in a range of 1 mm to 10 mm. The vertical crusher according to claim 1 or 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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