JP5397754B2 - Vertical crusher - Google Patents

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. A measuring device for measuring the vibration of the vertical crusher, a storage device for storing the allowable limit value of vibration, and the vibration value measured by the measuring device is the allowable limit value of vibration stored in the storage device in advance. The number of rotations of the rotary table is decelerated when the auxiliary roller is exceeded, and a plurality of grooves extending in the width direction are arranged on the auxiliary roller, and gaps for allowing gas to escape at both ends of the grooves In addition, the depth dimension of the groove near the center in the width direction of the roller is configured to be larger than the depth dimension of both ends of the groove part .

The present invention relates to a vertical pulverizer that is deaerated by an auxiliary roller and then pulverized by a pulverizing roller. The rotation speed of the rotary table is reduced.
According to the above-described configuration, the present invention can prevent a slip generated between the raw material layer and the auxiliary roller and suppress the occurrence of vibration.

Further, by arranging a plurality of rows of groove portions extending in the width direction on the auxiliary roller, ensuring a gap for gas to escape at both ends of the groove portion, and the depth dimension of the groove portion near the center in the width direction of the roller, By configuring so as to be larger than the depth dimension of both ends of the groove portion, a large amount of air generated when the raw material layer is consolidated is put into the groove portion, and then promptly from both ends of the groove portion. It can be discharged. 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.

It is a figure explaining the whole structure of a vertical grinder related to this embodiment. It is a figure explaining the roller arrangement | positioning of a vertical grinder related to this embodiment. It is a figure explaining the auxiliary roller structure 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 arrangement | sequence and shape of the groove part of an auxiliary roller concerning 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. The relationship between the speed of the raw material layer and the roller and the coefficient of friction is shown.

Hereinafter, an example of a preferred embodiment of the present invention will be described in detail with reference to the drawings.
1 to 5 relate to the present embodiment, and FIG. 1 is a conceptual diagram illustrating the overall configuration of a vertical crusher. FIG. 2 is a diagram for explaining the arrangement of the auxiliary roller and the crushing roller and the arrangement of the groove portions provided in the auxiliary roller. FIG. 3 is a diagram for explaining the structure of the auxiliary roller and the arrangement of the groove portions. 4 and 5 are diagrams for explaining the arrangement and shape of the grooves of the auxiliary roller. FIG. 6 is a diagram for conceptually explaining the consolidation behavior of the raw material layer by the auxiliary roller. FIG. 7 shows the relationship between the speed and the friction coefficient for the raw material layer and the roller.

Hereinafter, the preferable structure of the vertical crusher 1 by this invention is demonstrated.
The vertical pulverizer 1 used in the present embodiment is driven by a casing 1B and 1A that form the outline of the vertical pulverizer 1, a speed reducer 2B installed at the lower portion of the vertical pulverizer 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. Further, the vertical crusher 1 of the embodiment shown in FIG. 1 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 on the top of the vertical crusher 1 so as to rotate freely.

Here, in the present embodiment, as shown in FIG. 1, the vibration sensor S1 for measuring the vibration value of the vertical crusher 1 is provided, and the control panel 50 is provided.
The control panel 50 includes a control device 50A and a storage device 50B. The control device 50 stores a predetermined vibration value as a set value in the storage device 50B and receives a vibration value transmitted from the vibration sensor S1. It is configured as follows.
During the operation of the vertical crusher 1, the vibration value set and stored in the storage device 50B and the vibration value measured by the vibration sensor S1 are compared by the control device 50A, and the vibration value set in advance is measured. When the vibration value is reached, a signal for decelerating the rotational speed is transmitted from the control device 50A to the electric motor 2M.
In the present embodiment, the vibration value of the limit size allowed while the vertical crusher 1 is in operation is determined as the allowable limit vibration value and stored in advance in the storage device 50B as a set value.

In the vertical crusher 1 shown in FIG. 1, a gas supply port 33 for introducing a gas is provided below the rotary table 2, and an upper outlet 39 for taking out the product together with the gas above the rotary table. Is provided.
The vertical crusher 1 shown in FIG. 1 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 is circulated in the vertical crusher 1 and becomes a circulating raw material that is pulverized again. 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. 2, 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. 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 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 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, the vicinity of the roller center of the groove M is grooved 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, and 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.

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) is the crushing roller 3. About 1.2 times the center shape dimension of

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 compaction 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.
In the present embodiment, before operation, the vibration value of the limit size allowed by the vertical crusher 1 is set and stored in the storage device 50B of the control panel 50 as the allowable limit vibration value.
When the operation is started, 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 to form a spiral shape. While drawing the 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 compacted by the auxiliary roller 5 and degassed. It is bitten 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 this embodiment, the vibration value of the vertical crusher 1 is always measured by the vibration sensor S1. While the vertical crusher 1 is being controlled (during control operation), the control panel 50 compares the allowable vibration limit value set in the storage device 50B with the measured vibration value, and sets the pre-set allowable limit value. When the measured vibration value reaches the value, a signal for decelerating the rotation speed is transmitted to the electric motor 2M.
When the rotational speed of the rotary table is reduced by the signal from the control panel 50, the friction coefficient between the auxiliary roller 5 and the raw material layer increases as shown in FIG. 7, and as a result, the auxiliary roller 5 and the raw material are increased. The layer is less likely to slip.
According to the above-described configuration, the present invention can prevent a slip generated between the raw material layer and the auxiliary roller and suppress the occurrence of vibration.

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. A groove M for venting gas is formed in the auxiliary roller 5. ing. 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 5, abnormal vibration is suppressed.

In particular, in this embodiment, the depth of both ends of the groove portion is made shallower, and the both end portions are formed to be deeply recessed in the vicinity of the center in the width direction of the roller tire.
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, and the introduced large amount of air is formed at both ends. It is configured to discharge at once from the shallow groove.
As a result, the speed of the air discharged from the shallow grooves formed at both ends can be increased as compared with the prior art, so even if both ends of the groove M are buried in the raw material layer, the air is discharged. The raw material which covered the groove part M can be blown off by the momentum of air, As a result, it has the outstanding effect that discharge | emission of air is performed rapidly.

Further, 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 consolidates the raw material layer during operation is a line segment connecting the lowest point of the auxiliary roller 5 ( 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 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 is avoided, which is effective.
In the vertical crusher 1 of the present embodiment, the sudden change in volume is reduced and the change in volume is gradual with respect to the auxiliary roller 5 as well, so that abnormal vibration hardly occurs.

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 T Raw material layer thickness D Roller center diameter dimension L Roller width direction dimension M Groove part

Claims (1)

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,
A measuring device for measuring the vibration of the vertical crusher and a storage device for storing the allowable limit value of vibration are provided, and the vibration value measured by the measuring device exceeds the allowable limit value of vibration stored in the storage device in advance. when the, characterized by decelerating the rotational speed of the rotary table,
The auxiliary roller is provided with a plurality of rows of grooves extending in the width direction to form a gap for gas to escape at both ends of the groove, and the depth dimension of the groove near the center in the width direction of the roller is: A vertical crusher formed so as to be larger than the depth of both ends of the groove .

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