JPH03229652A - Vertical grinder - Google Patents

Abstract

PURPOSE:To keep long-term continuous and stable operation by providing a press means pressing each of a plurality of auxiliary rollers to the upper surface of a turntable by arbitrary force and gradually increasing the pressing forces of a plurality of the auxiliary rollers toward grinding rollers. 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 the raw material supplied to the central part of the turntable 3A is ground between the upper surface of the turntable 3A and the peripheral surfaces of the rollers 4 by applying predetermined grinding pressure to the rollers 4. A plurality of freely rotatable auxiliary rollers 20 compressing the layer of the bitten raw material to the rollers 4 by the peripheral surfaces thereof are provided to the upper surface of the outer peripheral part of the turntable 3A between the rollers 4. Press means each consisting of an arm 21, a hydraulic cylinder 22 and a gap controller 24 pressing a plurality of rollers 20 to the upper surface of the turntable 3A by arbitrary force are provided and the pressing forces of a plurality of the rollers 20 are gradually increased toward the rollers 4. As a result, long-term continuous and stable operation can be kept.

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 l equipped with a rotary table and pulverizing rollers is widely used, as shown in Figure 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 and rotates at a low speed in the lower part of a cylindrical casing 15;
It is provided with a plurality of crushing rollers 4 which are press-contacted with hydraulic pressure or the like and driven to rotate at locations that equally divide the outer peripheral portion of the upper surface in the circumferential direction.

The crushing roller 4 is connected to a piston rod 10 of a hydraulic cylinder 9 via an arm 5 and an arm 7 which are swingably supported by a shaft 6 on a casing 15, and by operating the hydraulic cylinder 9, The crushing roller 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 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.

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. 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 the rotary table and the circumferential surface of the crushing roller,
A plurality of rotatable auxiliary rollers are disposed on the upper surface of the outer periphery of the rotary table between the pulverizing rollers, and the auxiliary rollers are rotatable for compressing the layer of raw material caught in the pulverizing rollers on the circumferential surface, and the plurality of auxiliary rollers A pressing means for pressing each of the rollers onto the upper surface of the rotary table with an arbitrary force is provided, and the pressing force of the plurality of auxiliary rollers is increased as the auxiliary roller approaches the crushing roller.

[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 sequentially subjected to the same degassing and compaction action again by the plurality of auxiliary rollers, and then bitten into the next crushing roller and efficiently crushed. Unlike the crushing rollers, the pressing force of the multiple auxiliary rollers toward the top surface of the rotary table does not contribute to crushing, but rather compresses the raw material particles and creates a layer with dense particles, the so-called consolidation layer (hereinafter referred to as "consolidation layer"). The force that forms such a layer is sometimes referred to as consolidation.), and is much smaller than the pressing force of the crushing roller. The first function of the auxiliary roller is to perform the deaeration and compaction described above.

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 measure against the above-mentioned problems, a plurality of auxiliary rollers are provided, and in order to ensure that the powder bitten into the crushing roller by the auxiliary rollers becomes a compacted layer, the auxiliary rollers By providing a pressing means for pressing the material against the top surface of the rotary table with arbitrary force, and gradually increasing the pressing force of the plurality of auxiliary rollers as it approaches the crushing roller, the crushed raw material is consolidated in multiple stages and then crushed. I tried to crush it with a roller. Therefore, even if the vibration value increases due to changes in pulverizability due to changes in the properties of the pulverized raw material or its moisture content, the multi-stage densification process produces a stable densified layer and the thickness is adjusted to a constant level. Since the raw material layer is continuously supplied to the grinding roller, the vibration value can be reduced.

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 these factors, and when these change, it is possible to change the pressing force of the auxiliary roller accordingly to suppress an increase in the vibration value to some extent.

〔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 shows the mill vibration values, FIG. 4(A) shows the case when only one auxiliary roller is used, and FIG. 4(B) shows the case when two auxiliary rollers are used.

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 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.
On the upper surface of the outer periphery of the rotary table 3A between where the and the crushing rollers 4 are located, two auxiliary rollers 20 having a smaller diameter than the crushing rollers 4, namely 20a ( 1st stage auxiliary roller), 20b (2nd stage auxiliary roller)
A step auxiliary roller) is arranged. This auxiliary roller 20
As shown in FIG. 3, a and 20b are substantially U-shaped arms 2 rotatably supported by a shaft 23 on the casing 15.
The roller shaft 25 is rotatably supported and attached to a roller shaft 25 fixed to the tip of the roller.

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.

The pressing force of the second stage auxiliary roller 20b is set to be about 1.2 to 1.5 times higher than that of the first stage auxiliary roller 20a, and the gap is made smaller so that the first stage auxiliary roller 20a consolidates the pressure. The raw material layer is more strongly compacted by the second stage auxiliary roller 20b, so-called multi-stage compaction is performed.

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 the two auxiliary rollers 20a and 20b rotate while being slightly lifted by the raw material layer, and between their peripheral surface and the top surface of the rotary table 3A. Deko's coarse and dense layer 4
0 is compressed in stages to form a consolidated layer 30 with a constant layer thickness. 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 It is given a pressing force as a high crushing force,
In addition, even if a narrow gap is provided between the upper surface of the rotary table 3A and the top surface of the rotary table 3A in order to obtain a predetermined product particle size, the biting into the crushing roller 4 becomes more reliable, and the particles are scraped by the crushing roller 4 and transferred to the crushing roller 4. The proportion (amount) of material that does not get stuck and flows past its sides is reduced. This improves the pulverization efficiency. In Fig. 1 (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 the movement trajectory of the raw material particles is in the right half of the figure. Only shown.

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 needs to be much smaller than the crushing force of the crushing roller 4 (approximately 1/20), and if its own weight is sufficient, there is no need to apply hydraulic pressure. The first stage auxiliary roller 20a is the second stage auxiliary roller 20
The diameter shall be equal to or smaller than b. 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.

Experiments have shown that when using only one auxiliary roller,
Due to changes in operating conditions (changes in raw material properties, decrease in water content, decrease in separator classification point, increase in crushing roller tension, change in dam ring height, etc.), the pressing force of the auxiliary roller becomes too small. or if the amount was too low from the beginning,
As shown in FIG. 4(A), prominent vibrations with large vibration values appear intermittently at the normal average vibration level, impeding good operation. For this reason, if two auxiliary rollers are used as in the present invention and the pressing force of the latter auxiliary roller is increased compared to the preceding auxiliary roller to achieve an appropriate pressing force, protruding vibrations will occur as shown in FIG. 4(B). disappeared, and the vehicle was in good operating condition. This is consistent with the fact that sudden vibrations are more likely to occur when there is a large difference in the material layer thickness before and after compaction by the auxiliary roller.An extreme example of this is pulverization using only the pulverizing roller without the auxiliary roller; It is presumed that the generation of sudden vibrations is suppressed by making the difference in layer thickness between the front and rear layers smaller by having multiple layers. 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 5fi 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 crushed.
When the gap between the auxiliary roller 20 and the rotary table 3A is 5 to 10 fl, the gap between the auxiliary roller 20 and the rotary table 3A is set to 40 to 60 m.

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.

〔Effect of the invention〕

As is clear from the above explanation, in the present invention, the raw material particles are compressed in multiple stages using a plurality of auxiliary rollers to degas the gas existing between the particles, thereby achieving consolidation in which the particles are in a dense state. In addition to being equipped with means for pressing the auxiliary roller against the top surface of the rotary table, 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. can do. Therefore, long-term continuous stable operation can be continued and productivity can be improved.

[Brief explanation of drawings]

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. ), Figure 2 is an overall perspective view of the crusher, Figure 3 is a side view of the auxiliary roller attachment part, and Figure 4 is a vibration status diagram showing the mill vibration value when the auxiliary roller of the present invention is used. FIG. 4(A) shows the case where only one auxiliary roller is used, and FIG. 4(B) shows the case where two auxiliary rollers are used. FIG. 5 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, 20... Auxiliary roller, 20a... Auxiliary roller (first stage), 20b.
...Auxiliary roller (second stage), 21...Arm, 22.
...Hydraulic cylinder, 24...Gap adjuster, 30...
Consolidated layer, 40... coarsely compacted layer.

Claims (1)

[Claims] (1) A plurality of rotatable crushing rollers are arranged on the upper surface of the outer peripheral part 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 plurality of rotatable auxiliary rollers are provided on the upper surface of the outer periphery of the rotary table between the crushing rollers and the crushing rollers to compress the layer of raw material caught in the crushing rollers on the circumferential surface. and a pressing means for pressing each of the plurality of auxiliary rollers onto the upper surface of the rotary table with an arbitrary force, and the pressing force of the plurality of auxiliary rollers is increased as it approaches the crushing roller. A vertical crusher featuring: