JPH03154652A - Vertical pulverizing mill - Google Patents

Abstract

PURPOSE:To achieve continuously long period stable operation by providing an auxiliary roller on the upper surface of outer periphery of a rotary table to compress with its circumferential surface a layer of raw material to be pressed by a grinding roller and providing a pressing means to press the auxiliary roller against the rotary table under optional force. CONSTITUTION:A plurality of grinding rollers 4 are disposed rotatably on the upper surface of outer periphery of a rotary table 3A so that raw material fed to the central region of the table 3A is ground between the upper surface of the table 3A and the circumferential surfaces of the rollers 4, while predetermined grinding pressure is applied to the rollers 4. And, an auxiliary roller 20 is provided rotatably on the upper surface of outer periphery of the table 3A between the rollers 4 and 4 to compress with its circumferential surface a layer of the raw materiel to be pressed by the rollers 4. A boss, which supports therein a rotation axis 25 of the roller 20, is pivotally supported by a pin 23 and the roller 20 is pressed against the upper surface of the table 3A under optional force by means of a pressing means comprising an arm 21, hydraulic cylinder 22, etc. As a result, a long period stable operation can continuously be performed, resulting in improved productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vertical pulverizer that pulverizes raw materials such as limestone, slag, and cement raw materials through cooperation between a rotating table and pulverizing rollers.

[Conventional technology]

As a type of pulverizer that finely grinds raw materials such as limestone, slag, and cement raw materials into powder, a vertical pulverizer 1 equipped with a rotary table and pulverizing rollers is widely used, as shown in Fig. 5. There is. This type of crusher includes a disc-shaped rotary table 3A that is driven by a motor 2A and a reducer 2 to rotate at a low speed in the lower part of a cylindrical casing 15, and a hydraulic pressure installed at a portion that equally divides the outer periphery of the upper surface in the circumferential direction. The crushing roller 4 is provided with a plurality of crushing rollers 4 that are pressed against each other and rotated as a result of rotation.

The crushing roller 4 is connected to a piston rod 10 of a hydraulic cylinder 9 via an arm 5 and an arm 7 that are rotatably supported on a casing 15 by a shaft 6. By operating the hydraulic cylinder 9, the crushing roller 4 is 4 is pressed onto the rotary table 3A to apply crushing pressure to the raw material.

3B is a dam ring provided on the outer periphery of the rotary table 3A to adjust the raw material layer pressure; 14 is an annular space passage around the rotary table 3A for blowing up gas; 13 is a rotary separator for classifying the raw material crushed by the blades ml 3A; 16 is an outlet for taking out the product together with the gas, and 17 is a raw material input chute.

In such a vertical crusher, the raw material supplied to the center of the rotary table by the raw material input chute 17 receives centrifugal force in the radial direction of the table as it rotates to the rotary table 3 and slides on the rotary table 3A. It receives a rotational force from the rotary table 3A, slides between it and the rotary table 3A, and rotates somewhat slower than the rotation speed of the rotary table 3A.

The above two forces, that is, the forces in the radial direction and the force in the rotational direction are combined, and the raw material moves to the outer circumference of the rotary table 3A while drawing a spiral trajectory on the rotary table 3A. Since the roller is in pressure contact with this outer peripheral part and rotates, the raw material drawing a vortex enters between the crushing roller 4 and the rotary table 3A from a direction forming a certain angle with the roller axis direction and is bitten. crushed and crushed.

On the other hand, air is supplied to the base of the casing 15 by a duct.
Alternatively, gas such as hot air is introduced, and as this gas blows up from the annular space 14 between the outer peripheral surface of the rotary table 3A and the inner peripheral surface of the casing, the crushed fine powder is entrained in the gas. and rise inside the casing 15,
A classification action is performed by the blades 13A of the separator 13 located at the top, and products with a predetermined particle size are discharged from the discharge port 16 together with gas and sent to the next process.

[Problem to be solved by the invention]

In the conventional vertical crusher as described above, a considerable amount of the material to be crushed that reaches the biting side of the rollers on the table is not bitten by the rollers and is swept away into the annular space. is normal. Among the materials to be crushed that are pushed into the annular space on the biting side of the rollers, those with large particle sizes become waste stones and fall through the annular space, increasing the amount of waste stones and increasing the amount of processing work. let Also,
Among the objects to be crushed that have been swept into the annular space, those with small particle sizes are scattered again, which increases the load applied to the separator and tends to cause a decrease in classification efficiency. Furthermore, by forcing a large amount of material to be crushed into the annular space, the ventilation pressure loss of the annular space increases, thereby increasing the fan power.

In this way, in order to blow up and circulate the overflow granules, a crusher requires air blowing equipment with an air volume several times the required air volume, and the increased circulation volume requires a large air volume and pressure, which increases equipment costs. Not only does this significantly increase power consumption, but also, especially when ultrafinely pulverizing raw materials with relatively poor physical properties, mill vibrations often occur, and the vibration value (amplitude) is particularly high. In severe cases, equipment may be damaged or become inoperable, forcing the company to suspend operations.

For this reason, as a countermeasure when large vibrations occur, in order to change the frequency of the vibration of the raw material layer in the crushing section and move it away from the resonance area, the table's weir height (dam ring height)
It is conceivable to change the grinding pressure and table rotation speed by manipulating the rotary table drive device, but making the drive device of the rotary table variable would be unfeasible due to excessive equipment costs, and the table weir height (dam ring In order to change the grinder height, it is necessary to stop the operation of the grinder and carry out internal work.Also, changing the grinding pressure has the disadvantage that the product particle size changes from the desired one.
In the end, the actual situation was to reduce the mill throughput, which undermined a stable production plan. Therefore, even if mill vibration occurs, it is possible to change the frequency of the pulverized raw material layer to reduce the vibration amplitude and quickly return to the normal stable operating state with low vibration without significantly reducing the mill throughput. There was a need for means. These vibrations tended to occur more frequently in the finely pulverized or ultrafine pulverized region than in the medium pulverized region.

[Means to solve the problem]

In order to achieve the above object, the vertical crusher of the present invention has a plurality of rotatable crushing rollers arranged on the upper surface of the outer periphery of a rotary table, and the raw material supplied to the center of the rotary table is crushed by the crushing rollers in a predetermined manner. In a vertical crusher that applies pressure to crush between the top surface of a rotary table and the circumferential surface of a crushing roller, a layer of raw material to be bitten by the crushing roller is placed on the top surface of the outer circumference of the rotary table between the crushing roller and the crushing roller. A press that includes a rotatable auxiliary roller that is compressed on its peripheral surface, a boss that supports the rotating shaft of the auxiliary roller is swingably supported by a pin, and the auxiliary roller is pressed against the top surface of the rotary table with arbitrary force. The structure has a means.

[For production]

The raw material supplied from the raw material input chute to the upper surface of the center of the rotary table draws a spiral trajectory on the rotary table, moves toward the outer circumference of the rotary table, reaches the biting side of the auxiliary roller, and is passed between the auxiliary roller and the rotary table. When the raw material particles flow into the water, the auxiliary roller rotates and compresses the raw material particles with the required pressing force on its circumferential surface, and the gas between the particles is removed and degassing occurs, and at the same time, each compressed raw material particle becomes dense. This is called a consolidated layer. The compacted layer that has undergone this degassing and compaction action reaches the biting side of the crushing roller by the rotation of the rotary table, is pressed against the rotary table with a high pressing force, and is bitten by the driven crushing roller, resulting in continuous crushing. . In addition, the so-called loose pieces that are crushed by the crushing roller and released from the non-biting side of the crushing roller,
The raw material particles flowing as a coarse and dense layer are again subjected to similar degassing and compaction effects by this auxiliary roller, and then bitten into the next crushing roller and efficiently crushed. Unlike the crushing roller, the pressing force of the auxiliary roller toward the top of the rotary table does not contribute to crushing, but rather compresses the raw material particles and forms a layer with dense particles, the so-called consolidation layer (hereinafter, such a layer). This force is sufficient to form a pulverizing effect (sometimes referred to as consolidation), and is much smaller than the pressing force of the crushing roller.

If the above-mentioned auxiliary roller is arranged close to the raw material biting side of the crushing roller, the new raw material from the raw material input chute guided to the outer periphery of the rotary table will be difficult to flow into the raw material biting side of the crushing roller, and the auxiliary roller will Since the proportion of the material flowing into the raw material biting side increases, the compacted layer in which the raw material particles are compressed by the auxiliary roller and made dense is less likely to be disturbed by the new raw material, and the biting into the crushing roller is more reliably performed. . Of course, the raw material crushed by the previous crushing roller and the new raw material are consolidated together by this auxiliary roller.

At the same time, by forming a consolidated layer with a constant thickness using an auxiliary roller, the natural frequency of the raw material layer is kept constant.
The second main function of the auxiliary roller is to reduce vibrations.

In this way, the powder layer (consolidated layer) compacted by the auxiliary roller is efficiently pulverized by the crushing roller disposed after the auxiliary roller, and the raw material layer is kept at a constant height to prevent vibration. Despite this, for some reason, the layer thickness increased, and as a result, the mill vibrations suddenly became more intense.

In the vertical crusher of the present invention, as a countermeasure to the above-mentioned problem, an auxiliary roller is provided, and in order to ensure that the powder bitten into the crushing roller by this auxiliary roller becomes a compacted layer, the rotation of the auxiliary roller is The boss supporting the shaft is supported by a pin so that it can swing, and a pressing means is provided to press the auxiliary roller against the top surface of the rotary table with arbitrary force. In response to the increase in vibration value caused by changes in the thickness of the consolidated layer and the increase in the layer thickness of the consolidated layer, the vibration value can be reduced by increasing the pressing force to suppress the increase in the consolidated layer thickness and maintain it at a constant thickness. .

In addition, the pressing force applied to the compaction layer of powder, that is, the compaction force, is changed in accordance with the above-mentioned changes in the pulverizability of the raw material, as well as depending on the product particle size, the tension of the grinding roller, and the height of the dam ring. are also related, and when these change, it is possible to change the pressing force of the auxiliary roller accordingly and suppress the increase in vibration value to some extent, so the pressing force of the auxiliary roller is considered as one of the operational requirements. Become.

In addition, when foreign matter that cannot be crushed is mixed into the raw material and passes through the auxiliary roller, the auxiliary roller is urged by a pressing means to apply a pressing force, so unreasonable force is applied to the auxiliary roller and the equipment The auxiliary roller rotates around the pin fulcrum mouth and rises to pass these foreign objects so as not to damage them.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

1 to 3 illustrate a first embodiment of the present invention, and FIG. 4 illustrates another different embodiment.

First, a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

In FIG. 1, FIG. 1(A) is a plan view showing the arrangement of the crushing roller and auxiliary roller on the rotary table, FIG. 1(B) is a front development view of FIG. 1<A), and FIG. The figure is a perspective view showing the entire vertical crusher, and FIG. 3 is a side view of the auxiliary roller attachment part. In addition, in the figure, the same parts as in FIG. 5 are given the same reference numerals, and the explanation thereof will be omitted.

As shown in FIGS. 1 and 2, two crushing rollers 4 are arranged on the upper surface of the outer peripheral part of the rotary table 3A at symmetrical positions with respect to the center of the rotary table 3A.
An auxiliary roller 2 having a diameter smaller than that of the crushing roller 4 is located on the upper surface of the outer peripheral part of the rotary table 3A between the crushing roller 4 and the crushing roller 4 at a position close to the raw material biting side 4A of each crushing roller 4.
o is placed. As shown in FIG. 3, this auxiliary roller 20 is rotatably supported by a roller shaft 25 fixed to the tip of a substantially U-shaped arm 2I which is rotatably supported by a shaft 23 on the casing 15. installed.

A piston rod 22a of a hydraulic cylinder 22 is supported and connected to the lower end of the arm 21, and a constant pressure of hydraulic pressure is applied to the rod end chamber 22b of the hydraulic cylinder 22 to apply compressive force to the layer of raw material. Hydraulic cylinder 2
The end portion of the piston rod 2 on the side opposite to the piston rod is rotatably supported by the casing 15. Note that this compression force is achieved by adjusting the oil pressure with a pressure regulating valve (not shown) attached to a hydraulic line connected to the rod end chamber 22b of the hydraulic cylinder 22. Further, an achi emulator is connected to this hydraulic line, and the rod end chamber 22b of the hydraulic cylinder 22 is maintained at a constant pressure. By expanding and contracting the piston rod 22a of the hydraulic cylinder 22, the arm 21 is rotated about the shaft 23, and the auxiliary roller 20 moves up and down. At the bottom of the arm 21, there is a device for adjusting the gap between the auxiliary roller 20 and the top surface of the rotary table 3A.
A gap adjuster 24 for setting is provided, and the gap adjuster 24 is fixed to the casing 15 and has a screw hole screwed into a base 24b, and is supported by being screwed into the screw hole of this base 24b. By bringing the tip of the screw shaft 24a into contact with the side end of the arm 21, the gap between the auxiliary roller 20 and the upper surface of the rotary table 3A can be set.

Note that if the weight of the auxiliary roller 20 is sufficient as the compressive force for the layer of raw material, the hydraulic cylinder 22 is left free.

Next, the operation of the first embodiment having such a configuration will be explained.

The raw material supplied from the raw material input chute 17 to the upper surface of the central part of the rotary table 3A is subjected to the centrifugal force of the rotary table 3A, and moves toward the outer circumference of the rotary table while drawing a spiral trajectory on the rotary table 3A. As shown in (B), most of the raw materials and the raw materials that have already been crushed and powdered by the crushing roller 4 are combined to form a coarse and dense layer 4.
The auxiliary roller 20 rotates as it is slightly lifted by the raw material layer, and the coarse and dense particles flow into the gap between the auxiliary roller 20 and the top surface of the rotary table 3A. Layer 40 is compressed into consolidated layer 30. This compacted layer 30 reaches the biting side 4A of the crushing roller 4 due to the rotation of the rotary table 3A, and here, the raw material particles are not scattered but are formed into a compacted layer in a dense state, so that the crushing roller 4 is Even if a pressing force as a high crushing force is applied and a narrow gap is provided between the top surface of the rotary table 3A and the top surface of the rotary table 3A in order to obtain a predetermined product particle size, biting into the crushing roller 4 becomes more reliable. The proportion (amount) of the raw material that is scraped by the crushing roller 4 and flows through the side of the crushing roller 4 without being bitten by the crushing roller 4 is reduced. This improves the pulverization efficiency. In addition, the first
In the figure (A), F indicates the movement trajectory of the raw material particles, C indicates the biting part (pulverization part) between the roller and the rotary table 3A, and only the right half of the figure shows the movement trajectory of the raw material particles. .

At this time, the auxiliary roller 20 compresses the particles of the raw material to purge the interparticle gas and increase the density of the layer between the particles.
By adjusting the oil pressure of the hydraulic cylinder 22, a low pressure that provides a so-called compaction effect and does not contribute to pulverization of the raw material is provided. The pressing force of this auxiliary roller 20 is applied to the screw shaft 24 when the raw material is inserted into the gap between the auxiliary roller 20 and the rotary table 3A.
The force is such that the auxiliary roller 20 is lifted slightly higher than the height of the auxiliary roller 20 regulated by a.

The pressing force of this auxiliary roller 20 may be much smaller than the pressing force as the crushing force of the crushing roller 4, and if its own weight is sufficient, there is no need to apply hydraulic pressure. The pressing force of this auxiliary roller varies depending on the size of the raw material particles and the degree of adhering moisture; for example, when the raw material particle diameter is small, the pressing force may be small.

The raw material that has been bitten by the crushing roller 4 and crushed into small pieces is subjected to compressive force in the narrow gap between the crushing roller 4 and the rotary table 3A, and then receives the rotational force of the rotary table 3A and the crushing roller 4. , the raw material discharge side 4 of the crushing roller 4
The particles are vigorously ejected from B and fly up, causing the particles to become separated from each other, and are mixed with the new raw material supplied from the raw material input chute 17 to form a dense layer 40. The coarse and dense layer 40 is subjected to the same compaction effect as described above by the auxiliary roller 20 located next, and is further bitten and crushed by the crushing roller 4 located on the rotational direction side of the rotary table 3A, thereby reducing the product particle size. It's getting closer. Then, the compacted layer 30 that has come out from the auxiliary roller 20 is compressed by the auxiliary roller 20 on the biting side 4 of the crushing roller 4.
Since it is located close to A, the amount of new raw material supplied from the raw material input chute 17 onto the rotary table 3A is reduced, so that the consolidated state is less likely to be disturbed, and the compacted layer 30 is stabilized, and the crushing roller 4 It will definitely get caught. In this embodiment, the diameter of the auxiliary roller 20 is smaller than the diameter of the crushing roller 4.
- When the particle size of the raw material particles for boat fishing is small, the diameter of the auxiliary roller 20 may be small; on the other hand, when the particle size of the raw material particles is large, the diameter should be increased to match the particle size of the raw material particles. The size should be set so that the compaction effect can be applied accordingly.

Further, the gap between the auxiliary roller 20 and the upper surface of the rotary table 3A is set by inserting and removing the screw shaft 24a of the gap adjuster 24. This gap is made larger when the raw material particle size is large, and made smaller when it is small, but the purpose of consolidating the raw material particle layer is that if this gap is too small, the raw material particle layer becomes For example, the raw material particle size is 51 m or less, and the crushing roller 4 is placed in a relatively large gap so that it can be smoothly bitten by the auxiliary roller 20 without being disturbed.
When the gap between the auxiliary roller 20 and the rotary table 3A is 5 to 1011 mm, the gap between the auxiliary roller 20 and the rotary table 3A is set to 40 to 60 wm.

Next, a second embodiment, which is different from the first embodiment shown in FIGS. 1 to 3, regarding the swing mechanism and pressing means of the auxiliary roller will be described based on FIG. 4.

This embodiment is similar to the bottle fulcrum 23 of the auxiliary roller in the first embodiment.
is located outside the crusher, whereas the bin fulcrum 23
is provided in the crusher, and a boss 26 that supports the rotating shaft 25 of the auxiliary roller 20 is swingably held by a bin fulcrum 23 of a support 23a that projects from the inner surface of the casing 15. A lever 26a provided at the top of the boss 26 is connected by a pin fulcrum 27 to a rond 28 which is biased toward the inside of the crusher by a compression coil spring 29 enclosed in a spring hook 29a, so that the lever 26a is always connected to the bin fulcrum 23. The auxiliary roller 20 is pressed counterclockwise around the center via the boss 26 against the upper surface of the rotary table 3A. Compression coil spring 29
The biasing force is applied to the nut 29b screwed into the threaded portion of the iron 28.
, 29c. 28a is a cushioning elastic body made of rubber or synthetic resin. 26b is an extensible pipe for greasing. The spring pressing means shown in FIG. 4 may be a hydraulic cylinder and may be operated remotely.

As mentioned above, in both the first embodiment shown in FIGS. 1 to 3 and the second embodiment shown in FIG. Even if a piece of iron (2, wood, etc.) gets mixed in and passes through the auxiliary roller, it can temporarily rotate upward to the pin fulcrum opening, thereby alleviating the impact on the auxiliary roller and other equipment.

〔Effect of the invention〕

As is clear from the above explanation, in the present invention, the raw material particles are compressed by the auxiliary roller to degas the gas existing between the particles, and it is possible to form a compacted layer in which the particles are in a dense state, and Since a means for pressing the auxiliary roller against the upper surface of the rotary table is provided, even if the vibration value increases due to some change in the grinding conditions, the vibration value can be reduced by changing the pressing force of the auxiliary roller. Therefore, long-term continuous stable operation can be continued and productivity can be improved.

In addition, even if foreign matter gets mixed into the raw material layer, the auxiliary roller rotates upward at the pin fulcrum to cushion the impact and prevent damage to the equipment.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, FIG. 1(A) is a plan layout diagram of a crushing roller and an auxiliary roller, and FIG. 1(B) is a plan view of a crushing roller and an auxiliary roller. ), FIG. 2 is an overall perspective view of the crusher, FIG. 3 is a side view of the auxiliary roller attachment part, FIG. 4 is an enlarged vertical sectional view of the main part showing the second embodiment of the present invention, and FIG. The figure is an overall vertical sectional view of a conventional vertical crusher. 1... Vertical crusher, 3A... Rotary table, 4
... Grinding roller, 4A... Raw material biting side, 4B.
...Raw material discharge side, 17...Raw material input chute, 20
...Auxiliary roller, 21...Arm, 22...
- Hydraulic cylinder, 23... Bottle fulcrum, 24... Gap adjuster, 28... Rondo, 29... Compression coil spring, 30... Consolidated layer, 40... Dense layer.

Claims (1)

[Claims] (1) A plurality of rotatable crushing rollers are arranged on the upper surface of the outer periphery of the rotary table, and a predetermined crushing pressure is applied to the raw material supplied to the center of the rotary table to the crushing rollers, and the raw material is crushed between the upper surface of the rotary table and the circumferential surface of the crushing rollers. In the vertical crusher, a rotatable auxiliary roller is disposed on the upper surface of the outer periphery of the rotary table between the crushing roller and the crushing roller, and the rotatable auxiliary roller compresses the layer of raw material caught in the crushing roller with its circumferential surface. , a boss supporting the rotational shaft of the auxiliary roller is swingably supported by a pin, and
A vertical crusher characterized in that a pressing means is provided for pressing the auxiliary roller against the upper surface of the rotary table with an arbitrary force.