JPH03254842A - Vertical crusher - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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.

[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 rotary 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.

3A is a dam ring provided on the outer peripheral edge of the rotary table 3A to adjust the raw material layer pressure; 14 is an annular space passage for blowing up gas around the rotary table 3A; 13 is a wing $11'l; 13
A rotary separator for classifying the raw material pulverized by A, 1
6 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 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.

[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 In addition, among the materials 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 reduce 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. 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, in order to change the vibration frequency of the raw material layer in the crushing section and move it away from the resonance area, the table weir height (dam ring height), crushing pressure , it is conceivable to change the rotation speed of the table by manipulating it, but of these, making the drive device of the rotary table variable would require too much equipment cost and is not very practical, and it is difficult to change the height of the dam ring. In order to change the grinding pressure, it is necessary to stop the operation of the crusher and carry out internal work.Also, changing the crushing pressure has the disadvantage that the product particle size changes from the desired one.In the end, the mill throughput has to be reduced to cope with this problem. In reality, this was causing a loss of stable production plans. 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.

[Means for Solving the Problems] In order to achieve the above object, the vertical crusher of the present invention has the following features: A plurality of rotatable crushing rollers are arranged 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, the raw material is crushed between the top surface of the rotary table and the circumferential surface of the crushing roller by applying a predetermined crushing pressure to the crushing roller. The structure is such that a sweeping body that sweeps and smoothes the layer of raw material bitten into the raw material with its lower end surface is swingably disposed in the raw material flow direction.

[Operation] The raw material supplied from the raw material input chute to the upper surface of the central part of the rotary table draws a spiral trajectory on the rotary table, moves toward the outer circumference of the rotary table, reaches the scavenging body, and rotates with the lower end surface of the scavenging body. When the material flows between the table and the table, the sweeping body swings in the raw material flow direction and presses the raw material particles with its lower end surface, sweeping and smoothing the raw material surface, and removes the gas interposed between the particles. is removed from the raw material and deaeration occurs, and at the same time the pressed raw material particles are brought into a dense state, forming 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 that are crushed by the crushing roller and flowed as so-called 5 coarse and dense layers, which are discharged from the anti-biting side of the crushing roller, are subjected to similar degassing and compaction effects again by this sweeping body. It is bitten by the next crushing roller and is efficiently crushed. Unlike the crushing roller, the pressing force of the scavenging body toward the upper surface of the rotary table does not contribute to crushing, but rather compresses the raw material particles to form a dense layer between the particles, which is sometimes referred to as consolidation. ), which is much smaller than the pressing force of the crushing roller.

If the above-mentioned scrubbing body is arranged close to the raw material nipping 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 nipping side of the crushing roller, resulting in sweeping. Since the proportion flowing into the lower end surface of the body increases, the raw material particles are compressed by the scavenging body, and the raw material particles are packed together, and the compacted layer with a smooth surface is disturbed by the new raw material, resulting in pulverization. Biting into the roller is performed more reliably. Of course, the raw material crushed by the previous crushing roller and the new raw material are consolidated and leveled by this sweeping body.

At the same time, the second main function of the scavenger is to maintain the inherent vibration frequency of the raw material layer at a constant level by forming a consolidated layer with a constant thickness, making it difficult for vibrations to occur. It is.

In this way, the powder layer (consolidated layer) is consolidated by the scavenging body.
The material is efficiently pulverized by a pulverizing roller disposed after the sweeping body, and the raw material layer is kept at a constant height to prevent vibration.

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

1 and 2 show one embodiment of the present invention, and FIG. 1 (A
) is a plan view showing the arrangement of the crushing rollers and sweeping bodies on the rotary table, Figure 1 (B) is a front development view of Figure 1 (A), and Figure 2 (A) is a diagram of the vertical crusher. A perspective view showing the whole
Fig. 2(B) is a partially enlarged perspective view, Fig. 3 shows another embodiment of the present invention, Fig. 3(A) shows a case where the scavenging body is a mesh; The case where the rubbing body is a looper is shown.

Figure 4 is an explanatory diagram of the vibration level indicated by a vibration meter attached to the casing of a vertical crusher. A case in which a scrubbing body according to the present invention is provided is shown. FIG. 5 is an overall vertical sectional view of a conventional vertical crusher. 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.
On the upper surface of the outer circumference of the rotary table 3A between the grinding rollers 4 and 4, a sweeping member 20 is arranged at a position close to the raw material biting side 4A of each grinding roller 4. The scrubbing body 20 includes a rotating shaft 20a fixedly installed in the crusher and this rotating shaft 20a.
A weight 20c is removably attached to the lower end of the main body 20b, which is composed of a steel plate-shaped main body 20b that is suspended from the main body 20b and can swing in the flow direction of the raw material.

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

The raw material supplied from the raw material input shoe 17 to the upper surface of the central part of the rotary table 3A is subjected to centrifugal force by the rotary table 3A, and draws a spiral trajectory G on the rotary table 3A as shown in FIG. 1(A). and move it to the outer circumference of the rotary table.
As shown in FIG. 1(B), most of the raw materials and the raw materials that have already been crushed into fine powder by the crushing roller 4 and discharged from the raw material discharge side 4B of the crushing roller are at -g. This flows into the space between the sweeping body 20 and the rotary table 3A as a coarse and dense layer 40, and the sweeping body 20 is slightly lifted by the raw material and swung in the flow direction of the raw material. The main body 20b of 20 and the weight attached to the lower end of the main body 20b press the surface of the coarse and dense layer 40 of the raw material to purge the gas interposed between the raw material particles and sweep the surface, A consolidated layer 30 is formed that has a substantially constant layer thickness and is made of a material that has been consolidated to some extent. Then, this compacted layer 30 reaches the biting side 4A of the crushing roller 4 due to the rotation of the rotary table 3A and is bitten therein, but here, the raw material particles are not scattered but form a compacted layer that is in a somewhat dense state. Because of this, it enters the crushing roller smoothly and is applied with a pressing force as a high crushing force of the crushing roller 4. In Fig. 1 (A), C is the biting part (pulverizing part) of the crushing roller, F is the movement trajectory of the compacted layer after passing through the sweeping body, and G is the movement of raw material particles between the crushing roller and the sweeping body. The trajectory is shown, and only the right half of the figure shows the movement trajectory.

The pressing force of the scrubbing body 20 can be varied by adjusting the mounting height of the rotating shaft 20a and changing the weight of the weight 20c attached to the main body 20b, but the latter is usually used.

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, forming a state in which the particles are closely spaced 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 sweeping member 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. , and the consolidated layer 3 coming out from the sweeping body 20
0, since the scavenging body 20 is located close to the biting side 4A of the crushing roller 4, the amount of new raw material supplied from the raw material input chute 17 onto the rotary table 3A is reduced, so that consolidation is achieved. When the state is disturbed, the compacted layer 30 is stable and difficult to move outward, and is more reliably bitten by the crushing roller 4.

According to experiments, in a crusher without a scavenging body or in a crusher with a small scavenging body weight of 20C even if there is a scavenging body, changes in operating conditions ( Changes in raw material properties, decrease in moisture content, decrease in separator classification point, and increase in crushing roller tension.

Due to changes in the dam ring height, etc.), the stable operating condition may be disrupted and protruding vibrations may appear. On the other hand, when the sweeping member 20 of the present invention was used and a pressing force above a certain level was applied to the raw material layer, the protruding vibrations disappeared and a stable operating condition was achieved as shown in FIG. 4(B). In this case, the pressing force is approximately 1/20 of the pressing force of the crushing roller.

Next, other embodiments of the scrubbing body will be described.

The scavenging body 22 in FIG. 3(A) has a mesh 22c such as a wire mesh built into the frame of a main body 22b, and the pressing force against the raw material layer is applied to a bracket 22e stretched from a rotating shaft 22a and a main body 22b. Bracket provided at the bottom end) 22f
The biasing force of a compression coil spring interposed between the Since the air interposed between the particles of the dense layer 40 passes through the mesh 22c when the scrubbing body 22 is pressed, it can be easily discharged. The mesh size of the mesh 22c is approximately 3 mm to 10 mm.

In the other embodiment of the sweeping body 24 shown in FIG. 3(B), a main body 24b forming a frame is provided with a louver 24c having a plurality of horizontal or vertical slits at equal intervals, and the pressing force is An oil damper 24d (or hydraulic cylinder) installed between the upper and lower brackets 24e and 24f is used, and in this case as well, air existing between raw material particles can be easily purged.

[Effects of the Invention] As is clear from the above explanation, in the present invention, the coarse and dense layer of the raw material before being bitten by the crushing roller is pressed by the scavenging body to air purge (deaeration), and the Since it can be bitten into the crushing roller as a thick compacted layer,
Not only can efficient crushing be performed, but abnormal vibrations such as protruding vibrations can be eliminated, allowing long-term stable continuous operation.

[Brief explanation of drawings]

1 to 3 show embodiments of the present invention, and FIG. 1(A)
1(B) is a front development view of FIG. 1(A), FIG. 2(A) is an overall perspective view,
FIG. 2(B) is a partially enlarged perspective view, FIG. 3 shows another embodiment of the scavenging body, and FIG. 3(A) shows one with a mesh attached.
Figure 3 (B) shows the one with the louver attached, Figure 4 is an explanatory diagram showing the vibration state of the crusher casing, and Figure 4 (A)
shows the case of a conventional vertical crusher, and FIG. 4(B) shows the case of the vertical crusher of the present invention. FIG. 5 is an overall vertical 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, 20.22.24...Scavenging bodies 20a, 22a, 24a-rotating shaft, 20b, 22b, 24b...Main body, 30...
... Consolidated layer, 40... Consolidated 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 a vertical crusher that crushes between the crushing rollers, a sweeping body is installed on the upper surface of the outer peripheral part of the rotary table between the crushing rollers and the lower end surface of the rotary table to level the layer of raw material bitten by the crushing rollers. A vertical crusher characterized by being arranged so that it can swing freely in any direction.