JPH06226126A - Crushing device - Google Patents

Abstract

PURPOSE:To obtain a crushing device which can be used in a wide load range or for crushing various types of carbonaceous materials without causing vibration by using each crushing roller of different material which constitutes a roller pivot, and a pivot box acting as a receptacle with engraved slide surface. CONSTITUTION:In a crushing device which crushes a raw material using crushing rollers 6, each crushing roller 6 uses a different material which constitutes a roller pivot 12 and a pivot box 11 acting as a receptacle with an engraved slide surface. For example, in comparison of a case that soft steel is used for a support axial member as a pivot box 11 with a case that a surface-hardened steel is used, the pivot 12 of surface-hardened steel gives a wider crushing roller precession, i.e., a wider amplitude. Thus, each crushing roller has a different pendulum behavior, if the different quality of a support axial member as the pivot 12 is used. Consequently, the crushing rollers are activated in the same phase, so that a self-synchronization phenomenon such as amplifying a self-excited vibration is prevented from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration suppressing technology for a roller mill (crushing device) for finely crushing solid fuel such as coal, limestone, cement clinker or various solid raw materials of various chemical products by a rotating table and a crushing roller. In particular, the present invention relates to a pendulum type spindle device in a roller mill having a structure in which a crushing roller is supported from above in a swinging manner.

[0002]

2. Description of the Related Art Even in a coal-fired boiler, low-pollution combustion (low NOx, reduction of unburned matter) and wide-area load operation (change in coal supply amount) are carried out, and accordingly, high-performance pulverized coal machine (mill)
Came to be requested.

As one type of crusher for finely crushing solid fuels typified by coal, cement raw materials such as limestone or new raw materials, a vertical roller mill having a crushing table and a plurality of crushing rollers is used. It has been used and recently it is solidifying its position as one of the representative models.

This type of mill has a disk-shaped grinding table which rotates at a low speed on a horizontal plane which is driven by a motor having a speed reducer at the bottom of a cylindrical housing (container).
A plurality of crushing rollers are provided on the upper surface thereof, which are rotated by being hydraulically or pressurized by springs or the like at positions where the outer peripheral portion is equally divided in the circumferential direction.

These crushing rollers rotate due to the frictional force generated between the crushing roller and the raw material compressed between the rotary table. The crushing raw material supplied from the shout to the center of the table moves to the outer periphery of the table in a spiral shape on the table by centrifugal force, and is crushed by being caught between the crushing race surface of the table and the crushing rollers. To be done.

The hot air sent through the duct is guided to the lower part of the mill housing, and the hot air is blown up from the air throat between the outer peripheral portion of the crushing table and the inner peripheral portion of the mill housing. There is.

The crushed powder particles are dried while rising in the mill housing by the hot air blown from the air throat. The granular material transported to the upper part of the housing falls from the coarse material due to gravity (primary classification), and is pulverized again in the pulverizing section. The slightly fine powder particles passing through the primary classifying section are classified again by a cyclone separator or a rotary separator (rotary classifier) provided on the upper part of the housing. Fine powder having a particle size smaller than a predetermined particle size is conveyed by an air flow and is sent to a pulverized coal burner or a fine powder storage bin in a boiler.

Coarse particles having a predetermined particle size or more that have not penetrated through the classifier fall on the table due to gravity and are returned to the coarse particles by the primary classification or the raw coal (lump coal) just supplied to the mill. Is crushed again with. In this way, pulverization is repeated in the mill to produce fine product powder.

[0009]

For example, when a tire type roller mill is to be operated under a low load, it is vibration of the mill that is a problem in reducing the load. This vibration phenomenon is complicated and its detailed mechanism has not been clarified. However, it is a kind of frictional vibration caused by the slip between the coal bed and the roller (a discontinuity, a non-linear vibration known as a stick-slip motion). Is considered to be. As the type of vibration, it can be said to be a kind of self-excited vibration because the excitation source cannot be identified as sticky and the vibration waveform has a spike shape.

With normal coal, as shown in FIG. 15, this vibration becomes severe during low load operation (conditions in which there is little coal holdup in the mill), but depending on the type of coal, when it is under extremely high load. Can also occur.

FIG. 18 is a sectional view showing a supporting structure of a conventional grinding roller. In this type of roller mill, the crushing roller 1301 is swingably supported via the roller bracket 1307 with the roller pivot 1309 as a spindle. This swinging action is very important. When the crushing roller 1301 bites in a foreign substance that cannot be crushed, such as an iron piece, the crushing roller 1301 can avoid an impact by shaking its head.

The crushing roller 1301 and the crushing race 1
When the 316 wears, the pressing position (crushing roller 130
1 has a function of appropriately changing the positional relationship between the crushing race 1316 and the crushing race 1316.

Generally, during high load crushing, the crushing roller 13
01 almost does not shake his head. As mentioned above,
When the crushing roller 1301 vigorously bites the raw material at the time of starting the mill or increasing the load, the crushing roller 1301 shakes its head, but the movements of the three crushing rollers are not synchronized in this swinging operation.

At this time, the mill vibrates, but since the crushing rollers 1301 are not synchronized, the dominant frequency cannot be specified, and the frequency distribution is broad, that is, what is called forced vibration, which does not hinder the operation of the mill. Absent.

Reference numeral 1302 denotes a roller shaft, 130
3 is a roller rotation axis, 1304 is a roller cross-section center axis, 13
Reference numeral 05 is a vertical axis, 1306 is a seal plate, 1308 is a pivot box, 1310 is a pressing spring, and 13 is a pressing spring.
11 is a spring frame, 1312 is a mill housing, 1313 is a throat vane, 1314 is hot air, 13
Reference numeral 15 is a grinding ring, 1317 is a compressed powder layer, 1318 is a raw material to be ground, 1319 is a rotary table, and 1320 is a rotary shaft.

On the other hand, when the crushing roller vibrates violently under self-excitation, as shown in FIG.
All of them shift laterally outward (β) almost at the same time, and then, as shown in FIG.
It vibrates up and down like (γ). The three grinding rollers are
It vibrates up and down together (in phase) synchronously. When a certain crushing roller 1101 causes a lateral displacement-like swinging motion (β) and vertical vibration (γ) is generated in the crushing roller 1101, this motion causes the integrated pressure frame or table or the powder layer on it to move. It is transmitted and propagates to other grinding rollers. This is the cause of the in-phase vibration of the crushing roller 1101.

In the drawing, 1102 is a roller pivot, 1103 is a vertical axis, 1104 is a central axis of a cross section, and 110 is a central axis.
5 is a roller rotation center axis, 1106 is a rotary table, 11
Reference numeral 07 is a crushing ring, 1108 is a crushing race, 1109 is a compressed powder layer, 1110 is a raw material, 1111 is a table rotating shaft.

From the above, in order to suppress the vibration of the mill by devising the hardware of the crushing section, it is essential that the three crushing rollers move synchronously, that is, prevent the same phase movement. It turns out that

Based on the above idea, the object of the present invention is to prevent a crushing roller from oscillating its neck in a synchronized manner or to prevent a vertical oscillating motion so that it can be used in a wide area load or in a multi-carbon type without causing vibration. To provide a pendulum type spindle device for a crushing roller of a roller mill (crushing device) that enables the above operation.

[0020]

In order to solve the above problems, in order to create a state in which the oscillating motions of the crushing rollers cancel each other when vibration occurs, the roller mill according to the present invention has the following features. The configuration like this is adopted.

First, a crushing load is transmitted to the crushing roller, and a roller pivot serving as a main shaft of the swinging motion of the crushing roller,
At least one of the material and the structure (shape) of the pivot box forming the roller pivot storage case and forming the sliding surface of the roller pivot is changed in the same mill.

By doing so, the sliding friction state between the surface of the roller pivot and the surface of the pivot box becomes different, so that the period and amplitude at the time of swinging change for each crushing roller. For example, when different materials are used for the roller pivot and the pivot box, one crushing roller uses normal carbon steel as it is in the machined state, while the other crushing roller uses induction hardening tempering or shot peening. The hardness of the surface layer is increased.

On the other hand, when the structures of the roller pivots and the pivot boxes are made different, one crushing roller has a cylindrical shape, while the other crushing rollers have a stepped structure or a split type structure. The apparent projected area with respect to the pivot box is different for each grinding roller.

[0024]

First, consider the case where ordinary mild steel is used for the roller pivot member and the pivot box member into which the roller pivot member is inserted. Under the condition that a load is applied, the apparent contact area increases (according to Hertz's theory of elasticity), but therefore the apparent peak stress (peak of surface pressure) decreases.

On the other hand, when a steel material subjected to a surface hardening and tempering treatment is used as the material of the roller pivot and the pivot box, the contact deformation surface due to elasticity is small and the apparent peak stress (peak surface pressure) is a condition under which mild steel is used. Will be larger than.

Considering the contact deformation amount of both steel materials to be used and the apparent surface pressure, the sum of the contact surface pressures acting at the time of swinging, that is, the shearing force should be the same, but a softer material is used. The roller pivot will be more difficult to roll if it is present. This is probably because microscopic contact such as surface abrasion marks caused by the softness is also involved.

Therefore, for example, comparing the case of using mild steel for the pivot shaft member as the pivot and the case of using surface-hardened steel, the oscillating motion of the crushing roller is greater for the surface-hardened steel. It is considered to be larger, that is, the amplitude becomes larger.

On the other hand, when a roller pivot having a step and a pivot box having a slot (groove) corresponding to the protrusion of the roller pivot are combined (described later as an example), especially when a surface-hardening material is used for these. Since the contact deformation portion is reduced, the roller pivot is more likely to roll.

On the other hand, when the roller pivot is composed of a stepped portion and a central shaft portion (this will also be described later as an embodiment), the contact portion becomes complicated, and the contact and sliding behavior of the roller pivot is complicated. Becomes more complicated. Specifically, since the number of sliding points increases, the roller pivot can roll more easily.

As described above, if the support shaft member centering on the roller pivots having different rolling states is used for each roller bracket in the roller mill, the pendulum-like behaviors of the respective crushing rollers are different from each other. It becomes possible to prevent the occurrence of the self-synchronization phenomenon in which the grinding rollers move in the same phase and are amplified to self-excited vibration. Even if one crushing roller causes a swinging motion and is applied, the other crushing rollers do not follow it because the resistance of the swinging support shaft is different.

Therefore, the swinging motion of a grinding roller is
It will be canceled by the independent movement of the other grinding rollers. In this way, the self-synchronization phenomenon that occurs in the grinding roller quickly self-damps.

With the above operation, the roller mill can be operated stably and quietly without causing severe self-excited vibration even in low load operation or multi-carbon type operation.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing a structure of a roller mill equipped with a crushing roller utilizing a pendulum type support shaft according to the present invention as a sectional view passing through a central axis.

The crushing section of this roller mill is roughly constituted by the crushing roller 6 and the rotary table 3 which are the main elements. Since the features of the present invention relate to the structure of the member that supports the crushing roller, this will be described first.

As shown in FIGS. 1 and 2, in the roller mill to which the present invention is applied, the crushing roller 6 is provided above the roller bracket 7 which supports the crushing roller 6 from the rear side to the upper side. Roller pivot 1
It is supported so that a swinging motion or a pendulum motion is possible around the shaft 2 as a spindle. The roller pivot 12 serves not only as a pendulum-like rotating shaft, but also as a transmission point of the pressing force 18 from above to the roller blast 7 and the crushing roller 6.

In the present invention, the static and dynamic friction states between the roller pivot 12 and the pivot box 11 are made different for each crushing roller, and the period and amplitude of the pendulum swinging operation are made different for each roller.

As shown in FIG. 2, for the roller bracket 7 corresponding to a certain crushing roller, a cylindrical roller-shaped steel roller pivot 12a (without heat treatment or hardening treatment) is used. There is. A roller bracket 7 corresponding to another crushing roller is equipped with a cylindrical roller pivot 12b whose surface layer is shot peened after induction hardening. Among the three crushing rollers, the remaining roller pivots for the crushing roller are steel roller pivots 12c having slot-like steps and surface hardening and tempering treatment.

1 is a raw material, 2 is a raw material supply pipe (center shout), 4 is a crushing ring, 5 is a crushing race, 8 is a roller rotating shaft, 9 is a vertical shaft, 10 is a central axis of a cross section, 13 is hot air. , 14 is a throat vane, 15 is a seal ring, 1
6 is a housing, 17 is a pressure frame, 19 is a rotary classifier, 20 is a dam ring, and 21 is a product fine powder discharge duct.

FIG. 3 shows a state in which the cylindrical roller pivot 301 is mounted as a cross-sectional view from the lateral direction.

FIG. 4 shows a state in which the roller pivot 301 is mounted in the pivot box 302 as a view from above. In this way, the cylindrical roller pivot 301 is
It is mounted in a pivot box 302 in which a cylindrical groove having a slightly larger diameter corresponding to the roller pivot 301 is engraved.

In addition, 301a is a central axis of the roller pivot, 303 is a pressure frame, 304 is a roller bracket, 305 is a crushing roller, 306 is a seal plate, 3
Reference numeral 07 is a vertical axis, 308 is a sectional center axis, and 309 is a rotation center axis.

FIG. 5 shows a modified application example of the cylindrical roller pivot, in which the roller pivot is divided into three parts in the axial direction. If the split type is used in this way, when torque is generated in the roller pivots, the rotating operation of the split roller pivots 310a, 310b, and 310c will be slightly different due to the friction between the split surfaces of the split roller pivots. Compared to the case of using a columnar structure, it is less likely to slip.

Incidentally, these divided roller pivots 310
When a, 310b, and 310c are pushed into the groove of the pivot box with a small tolerance, it becomes difficult to rotate, and the pendulum-like operation of the crushing roller becomes unnatural, so that a minute gap 331 is provided.

6 and 7, the structure of the roller pivot 401 with steps is shown in a horizontal section and a vertical sectional view of the roller pivot with respect to the rotation axis 402 and the rotation axis 4, respectively.
Shown as a parallel cross-section through 02. The shape of the roller pivot 401 is basically cylindrical, but two metal contact portions (406) with the pivot box project as a step. Corresponding to the metal contact portion 406 protruding as the step, the pivot box also has a structure (403) with a slot (groove).

404 is a roller bracket and 405
Is a pressure frame, and 407 is a metal contact portion of the pivot box.

In the example shown in FIG. 8, the roller pivot shaft 40 is provided.
The outer peripheral parts 410a and 410b of the pivots divided around 8 are mounted so as to be combined to form a roller pivot. In such a structure, the rotation sliding surface when torque is generated has the metal contact portion 412 of the pivot, the pivot outer peripheral member 410a (or 410).
b) and the contact surface of the roller pivot shaft 408 and the mating surface 415 of the pivot outer peripheral members 410a and 410b.

Reference numeral 411 is a pivot box with a slot (groove), 413 is a pressure frame, and 414 is a roller bracket.

The overall structure of a roller mill equipped with a crushing roller using the pendulum type spindle device according to the present invention will be further described with reference to FIG.

The raw material 1 is supplied from a raw material supply pipe (center shout) 2 located on the central axis of the upper part of the mill, and drops onto a rotary table 3 rotating at the lower part of the mill. Centrifugal force acts on the raw material on the rotary table 3, and the raw material is fed onto the crushing ring 4 on the outer periphery of the rotary table 3.
Is crushed by the crushing roller 6 on the crushing race 5 which is engraved on the upper surface of and has a substantially arc-shaped cross section. As described above, in this embodiment, each crushing roller 6 uses a member composed of the pivot box 12 having a different structure or material and the pivot box 11 having a different shape or material as a fulcrum of the pendulum motion. Is supported. This fulcrum also has an important role as a crushing load transmission point.

If the structure and material of the roller pivot 12 is different for each roller, the frictional state (dynamic friction coefficient or static friction coefficient) with the sliding surface of the pivot box 11 is different, so the characteristics of the pendulum motion of the crushing roller 6 (cycle and amplitude). Also changes with each roller.

By doing so, the occurrence of the in-phase operation of the crushing roller 6 can be prevented. The pulverized powder is penetrated between the throat vanes 14 and dried by the hot air 13 blown into the mill while being transported to the upper side of the mill. The coarse particles fall on the rotary table 3 due to gravity (primary classification), and are crushed again in the crushing section.

The particles passing through the primary classifying portion are centrifugally classified by the rotary classifier 19 (secondary classification). The relatively coarse particles penetrate between the blades of the rotary classifier 19 and are discharged from the product fine powder discharge duct 21 as product fine powder. In the case of coal, is it sent directly to the pulverized coal burner (hot air 13
Becomes primary air for combustion) or is collected in a storage bin.

Next, as a result of the operation and vibration characteristics of the crushing roller, the effect produced by using the pendulum type spindle device according to the present invention will be described.

As described above, when the roller pivot made of non-heat treated mild steel is used, the local elastic deformation is large when a load is applied, and the total apparent contact surface pressure, that is, the shearing force is the same. Slip rotation is less likely to occur. On the other hand, when the roller pivot is made of the steel material that has been subjected to the surface hardening and tempering treatment, on the contrary, slip rotation is less likely to occur.

The difference in the swinging (pendulum) operation of the crushing roller will be described by taking the difference in the material of the roller pivot as an example.

FIG. 9 shows an example in which the roller pivot 502 subjected to the surface hardening and tempering treatment is used, and the swinging motion (α) of the crushing roller 501 is larger than that in the example of FIG. 10 described later. Here, "getting bigger" means
This means that the swing amplitude (distance in the lateral shift direction) is relatively “large”, and the cycle of this operation also becomes long.

On the other hand, in the crushing roller 50 shown in FIG.
The swinging motion (α) is smaller in both amplitude and period than in the example of FIG. 9. In this way, if the oscillating (pendulum) operation is different for each crushing roller 501, the crushing roller 50
When 1 shakes its head synchronously and further oscillates vertically, the intense self-excited vibration as a self-synchronization phenomenon is suppressed.

Even if one crushing roller 501 momentarily shakes its head, the other crushing rollers have different friction characteristics of the roller pivot. It becomes a vine. In such a case, the swinging motions of the two crushing rollers 501 are not synchronized with each other, and the two crushing rollers 501 cancel each other.

Again, this effect is achieved by the grinding roller 50.
This is caused by the fact that the crushing roller 501 has different sliding frictional characteristics in the supporting shaft portion, that is, in the roller pivot, for each crushing roller 501. In other words, the pendulum motions of the crushing rollers 501 cancel each other out, so that even if a self-synchronization phenomenon of the crushing rollers 501 occurs, the supporting member of the crushing rollers 501 has a function of quickly attenuating. It will be

503 is a vertical axis, 504 is a sectional center axis, 505 is a rotary axis, 506 is a rotary table, 507 is a crushing ring, 508 is a crushing race, and 509 is a central axis of the rotary table.

FIG. 11 summarizes the change in the amplitude of vibration with respect to the coal holdup in the mill and compares the embodiment of the present invention with the prior art.

The amplitude δoc on the vertical axis is made dimensionless by dividing by the amplitude δoc ^* when the crushing roller and the crushing race are metal-touched in idle rotation. On the other hand, the hold-up W on the horizontal axis is made dimensionless by dividing by the hold-up W ^* when the mill is operated at the rated coal feed rate.

The results of this experiment were obtained when crushing coal, which is liable to cause comparatively violent vibration due to the influence of coal quality. In the prior art, the low load range (W / W ^* ≤
0.38), the amplitude was remarkably large, whereas it was proved that the roller mill equipped with the crushing roller provided with the pendulum type spindle device according to the present invention can significantly reduce the amplitude. Even in the case of the embodiment of the present invention, the amplitude becomes slightly larger in the vicinity of W / W ^* ≦ 0.38 than other hold-up conditions, but this vibration is a self-excited vibration having a self-amplifying characteristic. No, it is a type of forced vibration.

FIG. 12 is a summary of the results when using coal that is not so violent even when the roller mill vibrates. Also in this example, it can be seen that the amplitude can be reduced by embodying the present invention. In this example, the effect of reducing the forced vibration under the low-load operation condition is recognized.

FIG. 13 shows a change in the product fine powder particle size q with respect to the coal supply amount Qc. The particle size q on the vertical axis is the standard fine particle size q in the conventional mill when the rated coal feed rate is Qc ^*.
Divided by ^* and expressed as a relative value. Qc on the horizontal axis
Is also made dimensionless by dividing by Qc ^* .

Generally, the grain size q decreases with an increase in the coal supply amount Qc. In the examples according to the present invention, it was found that the fine particle size of the product is almost the same as the particle size in the conventional roller mill. That is, it was proved that the spindle structure of the crushing roller as embodied in the present invention does not significantly affect the crushing performance (at least does not reduce the crushing performance).

From the above, it was confirmed that by embodying the present invention, it is possible to prevent the occurrence of self-excited vibration or reduce the forced vibration without sacrificing the grinding performance.

Since the oscillating state of each crushing roller is different, the wear state of the crushing roller is different, which may hinder the crushing performance and the stable operation of the mill, but as shown in FIG. In addition, it has been confirmed that the amount of wear is almost the same for all the crushing rollers, and that the amount is not so large as compared with the prior art. However, the shape of the worn portion is slightly different for each grinding roller. In particular, if vibration (forced vibration) during rotation where the grinding roller and the grinding race are metal-touched is a problem due to such uneven wear shape, the grinding roller position should be changed alternately. Will be solved by.

The roller mill on which the pendulum type spindle device having the structure according to the present invention is mounted is not limited to the mill for coal-fired boilers described as a specific example, but (1) a mill for oil coke, which is the same solid fuel, (2) Mill for finely grinding limestone for desulfurization, (3) Mill for finely grinding steel slag, non-ferrous slag, (4) Mill for cement finishing, finely milling cement clinker, (5) Various chemistry It can be applied almost as it is to a mill for pulverizing raw materials of products.

[0070]

The effects of mounting the pendulum type spindle device embodying the present invention on the roller mill are summarized as follows.

(1) Vibration of the mill due to the slip of the roller mill can be prevented. This improves the durability of various peripheral devices including the mill itself. In addition, the reliability of the entire thermal power plant is increased.

(2) Low load operation is possible, and the operation load limit of the mill can be further reduced. This expands the operation range of the boiler. Since coal combustion can be performed in the low load operation range, the consumption of fuel oil for auxiliary combustion can be reduced. Therefore, the entire thermal power plant can be operated more economically.

(3) Vibration can be suppressed even under a wide-range load operating condition of the rotary classifier accompanying the high-speed load following operation. As a result, the responsiveness of the boiler can be significantly improved.

(4) Vibration-free operation is possible even for coal that is prone to violent vibration, coal that easily adheres to rollers or races, or coal that has a high calorific value per unit weight and tends to operate with a low load on the mill. become. In this way, the range of coal applicable to thermal power plants is greatly expanded.

(5) Vibration can also be suppressed by controlling the pressing force and the rotation speed of the table and the rotary classifier. However, the pressurizing mechanism also becomes expensive, and a large motor model must be used under conditions of low efficiency.
Further, although the control system becomes complicated, the present invention is a method of suppressing the vibration by devising only the hardware of the crushing section, which is very advantageous from the viewpoint of total cost.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a roller mill equipped with a pendulum type spindle device according to the present invention.

FIG. 2 is a BB line view of FIG.

FIG. 3 is a configuration diagram of a spindle device.

FIG. 4 is a view taken along the line α-α ′ of FIG.

FIG. 5 is an α- of FIG. 3 according to a modified application example of a roller pivot.
FIG.

FIG. 6 is a configuration diagram of another spindle device.

7 is a view as seen from the direction AA of FIG.

FIG. 8 is a cross-sectional view showing a modified example of the roller pivot.

FIG. 9 is a schematic diagram showing a swinging operation of the roller pivot when the swinging amount is large.

FIG. 10 is a schematic diagram showing a swinging operation of the roller pivot when the swinging amount is small.

FIG. 11 is a comparative characteristic diagram showing changes in the amplitude of vibration with respect to a coal holdup in the mill.

FIG. 12 is a comparative characteristic diagram showing changes in the amplitude of vibration with respect to a coal holdup in the case of coal that is less likely to cause vibration.

FIG. 13 is a comparative characteristic diagram showing a change in the product fine powder particle size with respect to the coal supply amount.

FIG. 14 is a comparative characteristic diagram of relative wear amount.

FIG. 15 is a comparative characteristic diagram showing changes in the amplitude of vibration with respect to a coal holdup in a conventional mill.

FIG. 16 is a schematic diagram showing a state of self-excited vibration of a conventional crushing roller.

FIG. 17 is a schematic diagram showing a state of self-excited vibration of a conventional crushing roller.

FIG. 18 is a configuration diagram of a support shaft portion of a roller in a conventional roller mill.

[Explanation of reference numerals] 1 raw material 2 raw material supply pipe 3 rotary table 4 crushing ring 5 crushing race 6 crushing roller 7 roller bracket 8 roller rotary shaft 9 vertical shaft 10 cross-section center shaft 11 pivot box 12 roller roller 13 hot air 14 throat vane 15 seal ring 16 Housing 17 Pressurizing frame 18 Pressure 19 Rotating classifier 20 Dam ring 21 Product dust discharge duct

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hiroaki Kanemoto 6-9 Takaracho, Kure-shi, Hiroshima Babkotuku Hitachi Co., Ltd. Kure Factory (72) Yoshinori Taoka 6-9 Takaracho, Kure-shi, Hiroshima Babkotsu Hitachi Stock Company Kure Factory (72) Inventor Tadashi Hasegawa 6-9 Takaracho, Kure City, Hiroshima Prefecture Babkotuku Hitachi Co., Ltd. Kure Factory (72) Inventor Hiroshi Yuasa 6-9 Takaracho, Kure City, Hiroshima Prefecture Babkotuku Hitachi Co., Ltd. Kure Factory

Claims (5)

[Claims] 1. A rotary table which rotates around a vertical axis on a horizontal plane, and a rotary frame which is held on a pressurizing frame via a roller pivot as a load transmitting point and a pendulum-like supporting shaft, and is provided on the outer peripheral upper surface of the rotary table. In a crushing device for crushing a raw material by using a plurality of crushing rollers that rotate in a state where the surface is pressed, the material forming the roller pivot and the pivot box serving as a receiving seat having the sliding surface of the roller pivot engraved,
A crushing device characterized by being different for each crushing roller. 2. A rotary table which rotates around a vertical axis on a horizontal plane, and a rotary frame which is held on a pressurizing frame via a roller pivot as a load transmitting point and a pivot for pendulum movement, and is provided on the upper surface of the outer peripheral side of the rotary table. A crushing device for crushing a raw material using a plurality of crushing rollers that rotate while pressing surfaces thereof, characterized in that the shape of the roller pivot and the pivot box are different for each crushing roller. 3. The crushing device according to claim 2, wherein the roller pivot is configured as a divided body. 4. The crushing device according to claim 2, wherein the roller pivot and the pivot box have a stepped structure. 5. The neck according to claim 1, wherein a roller pivot or a pivot box having a different structure is applied to each of the plurality of grinding rollers in the same roller mill, and the roller pivot serves as a spindle in the same roller mill. A crushing device characterized in that a pendulum type spindle device of a crushing roller is configured so that the friction state of the swing is different.