JPH03213156A - Vertical grinder - Google Patents

Abstract

PURPOSE:To reduce a vibration value by providing a press means pressing an auxiliary roller to the upper surface of a turntable by arbitrary force and arranging an air jet nozzle to the upper surface of the turntable between the auxiliary roller and a grinding roller. CONSTITUTION:A plurality of freely rotatable grinding rollers 4 are arranged to the upper surface of the outer peripheral part of a turntable 3A and predetermined grinding pressure is applied to the grinding rollers 4 to grind the raw material supplied to the central part of the turntable 3A between the upper surface of the turntable 3A and the peripheral surfaces of the grinding rollers 4. A freely rotatable auxiliary roller 20 compressing the layer of the raw material forcibly transferred to the grinding rollers 4 by its peripheral surface is arranged to the upper surface of the outer peripheral part of the turntable 3A between the grinding rollers 4 and a press means consisting of an arm 21 and a hydraulic cylinder 22 pressing the auxiliary roller 20 to the upper surface of the turntable 3A by arbitrary force is provided and air jet nozzles 100 are arranged to the upper surface of the turntable 3A between the auxiliary rollers 20 and 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 a pulverizing roller.

[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 l equipped with a rotary table and pulverizing rollers is widely used, as shown in Figure 4. 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 lO of a hydraulic cylinder 9 via an arm 5 and an arm 7 that are swingably 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 13A; 16 17 is a discharge port from which the product is taken out together with the gas, and 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 is rotated as it slides on the rotary table 3A due to the centrifugal force in the radial direction of the table due to the rotation of the rotary table 3A. It receives a rotational force from the 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 roller is in pressure contact with this outer circumferential portion and rotates, the raw material drawing a spiral line enters between the crushing roller 4 and the rotary table 3A from a direction forming a certain angle with the roller axial direction and is bitten. 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 materials to be crushed that have been swept into the annular space, those with small particle diameters are scattered again, so the load applied to the separator becomes heavy (which tends to cause a decrease in classification efficiency. As the material to be crushed is 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. (In particular, when ultrafinely pulverizing raw materials with physical properties that make them relatively difficult to grind, mill vibrations often occur, and the vibration value (amplitude) increases. In particularly large cases, equipment may be damaged or become inoperable, forcing operations to be halted.

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 area.
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. The occurrence of these vibrations was more likely to occur in the finely pulverized or ultra-fine 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 rotatable auxiliary roller that compresses on its peripheral surface is arranged, and a pressing means is provided for pressing the auxiliary roller against the upper surface of the rotary table with arbitrary force, and air is applied to the upper surface of the rotary table between the auxiliary roller and the crushing roller. The structure is equipped with an injection nozzle.

[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 and vibrated. However, in spite of this, the layer thickness has increased due to some reason, and as a result, the mill vibration has occasionally become violent.

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 auxiliary roller can be optionally installed. The device is equipped with a pressing means that uses force to press against the top surface of the rotary table, and can cope with increases in vibration values and increases in the thickness of the consolidated layer caused by changes in pulverizability due to changes in the properties and moisture content of the pulverized raw materials. The vibration value can be reduced by increasing the pressing force to suppress an increase in the consolidated layer thickness and keeping the thickness constant.

Furthermore, on the compacted layer between the auxiliary roller and the crushing roller formed by the auxiliary roller, an air jet is used to prevent the fine powder blown up in the annular space from freely falling and getting caught in the crushing roller while remaining stacked. A nozzle blows air to dislodge these fine particles. Therefore, only the compacted layer that has been sufficiently deaerated is bitten by the crushing roller, so that vibrations are small.

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. There is also a relationship between Become one.

〔Example〕

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

1 to 3 are detailed explanations of the present invention,
FIG. 4 is an overall vertical cross-section of a conventional vertical crusher.

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. FIG. 2 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. 4 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.
0 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 21 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 a rod end chamber 22b of the hydraulic cylinder 22, thereby applying 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 hydraulic 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, and an accumulator is connected to this hydraulic line. 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.

On the other hand, between the auxiliary roller 20 and the crushing roller 4 on the upper surface of the rotary table 3A, as shown in FIGS. 100 is attached to the inner surface of the casing 15 of the vertical crusher via a bracket (not shown). From the tip of this air injection nozzle 100, compressed air at a low pressure of 0.5 to 5 kg/cd is ejected to expel fine powder falling onto the compacted layer to the outside. Note that the supply amount and discharge pressure of this compressed air are regulated by a control valve installed outside the vertical machine.

Next, the operation of the 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 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 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 comes out of the auxiliary roller 20 has an intervening air layer in order to purge the fine powder that falls while being bitten by the crushing roller 4 with compressed air using the air injection nozzle 100 to an extent that does not destroy the compacted layer. The compacted state is less likely to be disturbed, the compacted layer 30 is stabilized, and the compacted layer 30 is more reliably bitten by the crushing roller 4, resulting in less vibration. In addition, in this embodiment, the case where the diameter of the auxiliary roller 20 is smaller than the diameter of the crushing roller 4 has been described, but - 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 contrary, when the particle size of the raw material particles is large, the diameter is increased to a size that can provide a compaction effect according to the particle size of the raw material particles.

According to experiments, the pressing force of the auxiliary roller increases with changes in operating conditions (changes in raw material properties, decrease in moisture content, decrease in separator classification point, increase in tension of the crushing roller, change in dam ring height, etc.). If it becomes too small or is too small from the beginning, prominent vibrations with large vibration values will appear intermittently at the normal average vibration level, impeding good operation. Therefore, when the pressing force of the auxiliary roller was increased to an appropriate pressing force, the protruding vibration disappeared and a good operating condition was achieved.

Note that the pressing force of the auxiliary roller is adjusted by the hydraulic pressure supplied to the hydraulic cylinder 22.

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 size of the raw material particles is large, and is made smaller when the size of the raw material particles is small, but since the purpose is to consolidate the layer of 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 gap between the crushing roller 4 and the rotary table 3A is 5 mm to 5 mm, so that the particle size of the raw material is 5 mm or less, and the particle size of the raw material is 5 mm or less. When the distance is 101 m, the gap between the auxiliary roller 20 and the rotary table 3A is set to 40 to 60 m.

In this embodiment, since the crushing roller 4 and the auxiliary roller 50 are arranged at equal intervals, there is an advantage that manufacturing is facilitated, but the intervals do not necessarily have to be equal.

In addition, 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 will be consolidated more intensively, and the amount of falling fine powder will also be reduced, resulting in a stable consolidated layer and the next step. It is possible to ensure that the powder is bitten into the crushing roller 4.

〔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, the gas existing between the particles is degassed, and a compacted layer can be formed in which the particles are in a dense state. At the same time, it eliminates fine powder that falls into the compacted layer, making it difficult for vibrations to occur.

In addition, since it is equipped with means for pressing the auxiliary roller against the top surface of the rotary table, even if the vibration value becomes large due to some change in the crushing conditions, the vibration value can be reduced by changing the pressing force of the auxiliary roller, and the crushing Your abilities will also improve. Therefore, long-term continuous stable operation can be continued and productivity can be improved.

[Brief explanation of drawings]

FIGS. 1 to 3 show examples of the present invention, and FIG. 1 (A) is a plan view of the crushing roller and auxiliary roller, and FIG. A front development view, FIG. 2 is an overall perspective view of the crusher, FIG. 3 is a side view of the auxiliary roller attachment part, and FIG. 4 is a vertical sectional view of a conventional vertical crusher. 1...Vertical crusher Machine, 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,
24... Gap adjuster, 30... Consolidation layer, 40...
Dense layer, 100...Air injection nozzle.

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. and a pressing means for pressing the auxiliary roller onto the top surface of the rotary table with an arbitrary force, and an air injection nozzle is provided on the top surface of the rotary table between the auxiliary roller and the crushing roller. mold crusher.