JPH03232543A - Vertical type grinder - Google Patents

Abstract

PURPOSE:To smoothen the layer thickness of a raw material and to reduce vibration by arranging an auxiliary roller on the upper face of the outer circumferential part of a rotary table between the grinding rollers and also providing a pressing means. CONSTITUTION:A raw material is supplied on the upper face of the central part of a rotary table 3A from a chute for introducing the raw material. This raw material is moved to the outer circumferential side of a rotary table while drawing a swirly locus on the rotary table 3A. The raw material pulverized by the grinding rollers is put together with the large parts of the moved raw material. These are introduced into the gap between an auxiliary roller 20 and the upper face of the rotary table 3A as a condensational and rarefactional layer 40. While the auxiliary roller 20 is rotated so as to be raised by the layer of the raw material, it compresses the layer 40 between the circumferential face and the upper face of the rotary table 3A to form a compact layer 30. This compact layer 30 reaches the biting sides 4A of the grinding rollers 4. Stable operation is enabled by imparting high pressing force to the grinding rollers 4.

Description

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

[Prior Art] As a type of pulverizer that finely pulverizes raw materials such as limestone, slag, and cement raw materials into powder, there is a vertical pulverizer 1 equipped with a rotating table and pulverizing rollers, as shown in FIG. is widely used. 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 pivotally supported by a shaft 6 on a casing 15. 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 peripheral edge of the rotary table 3A to adjust the raw material bed pressure; 14 is an annular space passage for gas blowing around the rotary table 3A; and 13 is a rotary separator for classifying the raw material crushed by the blades 13A.

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 shoe 17 is subjected to centrifugal force in the radial direction of the table due to the rotation of the rotary table 3A, and as it 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 a seventh roller is in pressure contact with this outer peripheral part and rotates, the raw material with a spiral line 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.

[Problems 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. It is normal for it to be swept away into the annular space. 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 materials to be crushed that have been swept into the annular space, those with small particle diameters will be scattered again, increasing the load applied to the separator and easily resulting in a decrease in classification efficiency. As the objects are swept away, the ventilation pressure loss in 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.

Therefore, as a countermeasure when large vibrations occur, the table's weir height (dam ring height) is adjusted to change the vibration frequency of the raw material layer in the crushing section and move it away from the resonance region.
It is conceivable to change the grinding pressure and table rotation speed by manipulating the table rotation speed, but making the drive device of the one-turn table variable would be unfeasible because the equipment cost would be excessive, 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 replace the internal parts.Also, changing the grinding pressure has the disadvantage that the product particle size changes from the desired one, which ultimately reduces the mill throughput. In reality, the company had to deal with this issue by increasing the number of employees, which was jeopardizing 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 fine pulverization or ultra-fine pulverization than in medium pulverization regions.

Therefore, an auxiliary roller is installed on the rotating table between the crushing rollers, and a certain force is applied in advance to the raw material layer that is bitten by the crushing rollers to compact it and remove the air present between the raw material particles. By supplying the powder to the grinding rollers in a constant layer thickness, efficient grinding was achieved, and at the same time, the vibration value was drastically reduced, allowing stable operation to continue.

However, if the amount of the crushed raw material layer that enters the auxiliary roller changes over time, even if the auxiliary roller is pressed with a constant force, the raw material layer compacted by the auxiliary roller will be deaerated, but the layer The thickness changes from time to time, and there is a problem in that when the thickness is supplied to a crushing roller to perform a crushing action, the vibration value becomes high, and some measure has been required to prevent this.

[Means for Solving the Problems] In order to achieve the above object, the vertical crusher of the present invention has a plurality of rotatable crushing rollers disposed on the upper surface of the outer periphery of the rotary table, and the rollers are supplied to the center of the rotary table. In a vertical crusher that applies a predetermined crushing pressure to a crushing roller and crushes the raw material between the top surface of a rotary table and the circumferential surface of the crushing roller, the crushed raw material is crushed on the top surface of the outer periphery of the rotary table between the crushing roller and the crushing roller. A rotatable auxiliary roller that compresses the raw material bitten by the roller on its circumferential surface is disposed, and a pressing means for pressing the auxiliary roller against the upper surface of the rotary table with arbitrary force is provided, and inside the auxiliary roller A cylindrical or substantially conical elastic member is embedded concentrically with the auxiliary roller rotation axis.

[Operation] The raw material supplied from the raw material input chute to the upper surface of the center of the rotary table traces 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 connects the auxiliary roller and the rotary table. When the raw material particles flow into the space between the auxiliary rollers, 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 deaeration occurs.At the same time, each compressed raw material particle is It is brought into a dense state and becomes a so-called consolidated layer. The compacted layer that has been deaerated and compacted 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 raw material particles, which are crushed by the crushing roller and flowed as a coarse and dense layer, are discharged from the anti-biting side of the crushing roller and are subjected to similar degassing and compaction effects again by this auxiliary roller. It is bitten by the crushing roller located at the top and is efficiently crushed. Unlike the crushing roller, the pressing force of the auxiliary roller toward the upper surface of the rotary table does not contribute to crushing, but rather compresses the raw material particles to form a layer with dense interparticles, which is sometimes referred to as consolidation. ) is formed (approximately 1/20th the force of the crushing roller), 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 and vibrated. However, in spite of this, the layer thickness may suddenly change due to some reason, and as a result, the mill vibration may suddenly become intense.

In the vertical crusher of the present invention, as a countermeasure to the above-mentioned problem, a cylindrical or conical elastic member is embedded inside the auxiliary roller, so that the amount of raw material entering the auxiliary roller changes from time to time in a wave-like manner. As a result, even if the thickness of the raw material layer changes, the elastic member will remain glued.

9.7 The thickness of the raw material layer in the consolidated layer after passing through the auxiliary roller can be leveled and changed into a gentle waveform due to the action 9.7, so by making the thickness of the raw material layer more uniform than before it flows into the auxiliary roller, , it is possible to suppress the increase in vibration due to rapid changes in layer thickness and reduce the vibration value.

In addition, the pressing force applied to the compaction layer of the powder, that is, the compaction force, is changed in response to the change in the pulverizability of the raw material over a relatively long period of time as described above, as well as the product particle size and the tension of the grinding roller. There is a relationship between This is one of the driving operation requirements.

In addition, the shape of the auxiliary roller can be approximately gear-shaped with grooves on the outer circumferential surface, petal-shaped, or may have a structure with many protrusions on the outer circumferential surface, making it easier to crush the raw material. In addition, it is possible to form a stable compacted layer by being reliably bitten.

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

1 to 3 are for explaining one embodiment of the present invention, and FIG. 4 is a cross-sectional view showing the shape of the auxiliary roller of the present invention, and FIG. 4(A) is a vertical cross-sectional view. Front view, Figure 4 (B)
Hat! s4(A) is a cross-sectional view of M-Ma, FIG. 5 shows the shape of another auxiliary roller, FIG. 5(A) is a longitudinal sectional view, and FIG. 5(CB) is a cross-sectional view of FIG. 5(A). A cross-sectional view taken along the line N-N is shown.

First, the present invention will be explained in detail 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 the 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 the figure, the same parts as in FIG. 6 are denoted by 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.
0 is placed. As shown in FIG. 3, the auxiliary roller 20 is rotatably supported on a roller shaft 25 fixed to the tip of a substantially U-shaped arm 21 that is rotatably supported on the casing 15 by a shaft 23. Has been installed. A piston rod 22a of a hydraulic cylinder 22 is supported and connected to the lower end of the arm 21.
A compressive force is applied to the raw material layer by applying a constant hydraulic pressure to the rod end chamber 22b of No. 2. The end of the hydraulic cylinder 22 on the side opposite to the piston rod is connected to the casing 15.
It is rotatably supported on the shaft. 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. In addition, an accumulator is connected to this hydraulic line, and the hydraulic cylinder 2
The pressure in the rod end chamber 22b of No. 2 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.

An auxiliary roller 20 and a rotary table 3 are installed at the bottom of the arm 21.
A gap adjuster 24 is provided to adjust and set the gap between the upper surface of
The screw shaft 24a is screwed into the screw hole of 4b and supported, and by bringing the tip of the screw shaft 24a into contact with the side end of the arm 21, the auxiliary roller 20 and the rotary table 3
It is configured so that the gap between it and the top surface of A 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.

The inside of the auxiliary roller contains rubber, springs, and synthetic resin.
A cylindrical member made of an elastic member 20b such as a foamed molded product is embedded between the rotating shaft 20c and the outer skin 20a (see Fig. 4(A)).
), (B)), or as shown in FIGS.
are fastened with bolts.

Next, the operation of one embodiment of such a configuration will be described.

The raw material supplied from the raw material input shoe 17 to the upper surface of the central part of the rotary table 3A receives the centrifugal force of the rotary table 3A, moves in a spiral trajectory on the rotary table 3A toward the outer circumference of the rotary table, and moves to the outer circumference of the rotary table. As shown in Figure (B), most of the raw materials and the raw materials that have already been crushed and made into fine powder by the crushing roller 4 are combined to form a coarse and dense layer 4.
0 flows into the gap between the auxiliary roller 20 and the top surface of the rotary table 3A, and while the auxiliary roller 20 rotates while being slightly lifted by the raw material layer, this coarse and dense layer flows between its peripheral surface and the top surface of the rotary table 3A. 40 is compressed to form a 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 sill 22, a low pressure that imparts 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 needs to be much smaller than the crushing force of the crushing roller 4, and if its own weight is sufficient, there is no need to apply hydraulic pressure. It varies depending on the size of the surface and the degree of attached moisture.
For example, if the raw material particle size 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 discharged from B, causing them to fly up and become separated from each other, and are mixed with the new raw material supplied from the raw material input shoe 17, forming a dense layer 40. This coarse and dense layer 40 is subjected to the same compaction action as described above by the auxiliary roller 20 located next, and is then reliably bitten and crushed by the crushing roller 4 located on the rotational direction side of the rotary table 3A, thereby producing a product. Since the auxiliary roller 20 is positioned close to the biting side 4A of the crushing roller 4, the compacted layer 30 that comes out of the auxiliary roller 20 becomes closer to the grain size and is removed from the raw material input shoe 17 to the rotary table. Since the amount of new raw material supplied onto the layer 3A is reduced, the consolidated state is less likely to be disturbed, the consolidated layer 30 is stabilized, and it is more reliably bitten into the crushing roller 4. Note that in this embodiment, the auxiliary roller 20
Although we have explained the case where the diameter of
The diameter may be small; on the other hand, if the particle size of the raw material particles is large, the diameter is increased to a size that can provide a consolidation effect according to the particle size of the raw material particles.

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 since it is used to compact the raw material particles, if this gap is too small, the raw material particle layer may become disordered. For example, the raw material particle size is 5 mm or less, and the crushing roller 4 is placed in a relatively large gap so that the raw material particle size is 5 mm or less and is smoothly bitten by the auxiliary roller 20.
When the gap between the auxiliary roller 20 and the rotary table 3A is 5 to 10 mm, the gap between the auxiliary roller 20 and the rotary table 3A is set to 40 to 60 mm.

Note that if the auxiliary roller is placed closer to the raw material discharge side 4B of the crushing roller 4, the raw material crushed by the crushing roller 4 can be more intensively compacted and then bitten into the next crushing roller 4. can.

For some reason, the amount of raw material entering the auxiliary roller fluctuates from time to time, and as a result, the thickness of the consolidated layer formed by the auxiliary roller fluctuates from time to time, resulting in a consolidated layer whose thickness changes in an uneven wave pattern. Even in cases where the crushing roller is bitten by the crushing roller and violently moves up and down, the vibration value of the crusher increases rapidly and stable operation is impaired, the elastic member of the present invention can be used instead of the steel auxiliary roller. When using an auxiliary roller embedded with It absorbs and relaxes the material, changing the aforementioned abrupt waveform into a gentle waveform compaction layer of raw material, which is then supplied to the downstream crushing roller. Therefore, the increase in vibration value is kept to a small extent and stable operation can be continued.

[Effects 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, thereby forming a compacted layer with the particles in a dense state. In addition, it is equipped with means for pressing the auxiliary roller against the top surface of the rotary table, and has a structure in which an elastic member is embedded inside the auxiliary roller, so that stable operation can be achieved by suppressing increases in vibration values. Furthermore, 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.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention,
Fig. 1 (A) is a plan layout diagram of the crushing roller and the auxiliary roller;
Fig. 1 (B) is a front development view of Fig. 1 (A), 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 a cross-sectional view showing the shape of the auxiliary roller of the present invention, FIG. 4(A) is a longitudinal cross-sectional view, and FIG. 4(B) is a cross-sectional view taken along line M-M in FIG. 4(A). , FIG. 5 is a sectional view showing another embodiment of the auxiliary roller of the present invention, FIG. 5(A) is a longitudinal sectional view, and FIG. 5(B) is a NN view of FIG. 5(A). FIG. FIG. 6 is a longitudinal sectional view of a conventional vertical crusher. 1... Vertical crusher, 3A... Rotating table, 4... Grinding roller, 4A... Raw material biting side, 4B... Raw material discharge side, 17... ... Raw material input chute, 0... Auxiliary roller, 20a.
... Outer skin, Ob... Elastic member, 20c... Rotating shaft. Od...Press plate, 21...Arm, 2
... Hydraulic cylinder, 4 ... Gap adjuster, 0 ... 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 arranged 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 bitten into the crushing roller with its circumferential surface. , and a pressing means for pressing the auxiliary roller against the upper surface of the rotary table with arbitrary force is provided, and a cylindrical or substantially conical elastic member is embedded inside the auxiliary roller concentrically with the rotation axis of the auxiliary roller. A vertical crusher characterized by: