JPH03221154A - Vertical grinder - Google Patents

Abstract

PURPOSE:To enhance grinding efficiency and to reduce operation cost by providing a freely rotatable auxiliary roller compressing the layer of the bitten raw material to a grinding roller by the peripheral surface thereof and providing the discharge port of a coarse powder conduit returning a coarse powder after classification to the grinding roller on the biting side of the auxiliary 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 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 and a classifier classifying the ground fine powder is provided to the top part of a grinder 1. 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 and the discharge ports of coarse powder conduits 100 returning the coarse powder after the classification in the classifier to the rollers are arranged on the biting sides of the auxiliary rollers 20. As a result, grinding efficiency is enhanced and running cost can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is based on the cooperation between a rotary table and a grinding roller.
This relates to a vertical crusher that crushes raw materials such as limestone, slag, and cement raw materials.

[Prior Art] As a type of pulverizer that grinds raw materials such as limestone, slag, and cement raw materials into fine powder, there is a vertical pulverizer equipped with a rotary table and pulverizing rollers, as shown in Fig. 4. l 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 lO of a hydraulic cylinder 9 via an arm 5 and an arm 7 which are pivotally supported in a swing phase by a shaft 6 in a casing 15, and is crushed by operating the hydraulic cylinder 9. The roller 4 is pressed onto the rotary table 3A to apply crushing pressure to the raw material.

3B is a tam ring provided on the outer periphery of the rotary table 3A to adjust the raw material layer pressure, 14 is an annular space passage for the waste blower 4 around the rotary table 3A, and I3 is a rotary separator for classifying the raw material crushed by the blade [13A] Reference numeral 16 indicates a discharge unit for taking out the product together with waste, and reference numeral 17 indicates a raw material input unit.

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 force in the rotational direction from the table 3A, is scraped with the rotary table 3A, and rotates somewhat slower than the rotation speed of the rotary table 3A.

1: The two forces, ie, 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, gas such as air or hot air is guided to the base of the casing 15 by a duct, and 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. As a result, the pulverized fine powder is entrained by gas and moves up inside the casing 15, and is subjected to a classification action by the blades 13A of the separator 13 located at the top, and products with a predetermined particle size are discharged together with the gas from the outlet 16 to the next product. It leads to the process.

By the way, the material to be crushed supplied to the crusher is rarely crushed to the fine powder particle size required by this crusher after being subjected to the crushing action by the crushing rollers once, and it is rare that the material to be crushed is crushed into the fine powder particle size required by this crusher, and the material may fall to the center of the rotary table. The crushed material is not bitten by the crushing rollers, so even if the powder particles that reach the outer peripheral edge of the rotary table rise up on the hot air current blowing up from the annular space, they will not be crushed. By the time the particles reach the separator installed at the top of the machine, depending on their particle size, they may fall or be classified and rejected by the separator and returned to the rotary table 7.

For this reason, efforts have been made to provide a coarse powder conduit 100 in the mill for actively returning the coarse powder after classification by the separator to the rotary table.

In this way, the material to be crushed, which is constantly fed into the crusher, rises from the rotary table to the separator or rotates until it reaches the desired fine particle size to become the final product and flows out of the crusher. The particles fall from the table to the separator over and over again and are gradually pulverized to the desired particle size.

[Invention or problem to be solved 8] In the conventional vertical crusher as described above, a coarse powder conduit as described in J- is connected to the biting side of the crushing roller and is crushed together with the raw material of Newfeet. Grinding with rollers increases the mill vibration value, which not only prevents smooth grinding action, but also causes serious damage to the equipment and makes it impossible to continue operation. .

This is because the coarse powder after classification in the coarse powder conduit is 1/10 to 1/1000 times finer than the raw material particle size of Newfeet, and has a small bulk specific gravity and a large specific surface area. This was caused by the increased content, and it was necessary to purge (exclude) the air present in the raw material by compacting the New Feed raw material and coarse powder together by some method.

The above phenomenon agrees with the experience in actual operation that when the product particle size is large (when obtaining a coarse product), the mill vibration is small, and as the product particle size becomes small, the frequency of occurrence of mill vibration and the value of mill vibration increase.

[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. A vertical crusher is equipped with a classifier at the top of the crusher that applies a predetermined crushing pressure to the crushing roller and crushes the raw material between the top surface of the rotary table and the circumferential surface of the crushing roller, and classifies the crushed fine powder. A rotatable auxiliary roller is disposed on the upper surface of the outer periphery of the rotary table between the crushing rollers and compresses the raw material bitten into the crushing roller with its circumferential surface, and the coarse powder after being classified by the classifier is The discharge port for the four coarse powder pipes to be returned to the crushing roller was arranged on the biting side of the auxiliary roller.

[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 between the auxiliary roller and the raw material particles, the auxiliary roller rotates and compresses the raw material particles with the required pressing force on its circumferential surface, and each compressed raw material particle is brought into a dense state, forming a so-called compacted layer. Ru. This compacted layer reaches the biting side of the crushing roller by the rotation of the rotary table, and even if the crushing roller is applied with a high pressing force as crushing force, it will be bitten with a higher probability and continuous crushing will be performed. In addition, the raw material particles, which are crushed by the crushing roller and flowed as a so-called coarse and dense layer, are discharged from the anti-biting side of the crushing roller and are subjected to a similar compaction effect by this auxiliary roller. It has a high probability of being bitten by the located crushing roller and being crushed efficiently. The pressing force of the auxiliary roller toward the top of the rotary table does not interfere with pulverization, but instead compresses the raw material particles into a layer with dense particles, the so-called consolidation layer (hereinafter, the action of forming such a layer is called consolidation). ), and the force is much smaller than the pressing force of the crushing roller.

If the above-mentioned auxiliary roller 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 directly flow into the raw material nipping side of the crushing roller, resulting in Since the ratio of the raw material flowing into the auxiliary roller's biting side increases, the compacted layer in which the raw material particles are compressed by the auxiliary roller and is densely packed together becomes less likely to be disturbed by the new raw material, and the biting into the crushing roller becomes more reliable. It will be held in Of course, the raw material crushed by the previous crushing roller and the new raw material (new feed) are consolidated by this auxiliary roller.

The coarse powder after being classified by the separator is also led to a coarse powder conduit whose discharge port is disposed just before the auxiliary roller bites, and is compacted by the auxiliary roller together with the New Feet raw material.

As a result, the auxiliary roller can be used to form a consolidated layer with a constant thickness, which helps to maintain the natural frequency of the raw material layer at a certain natural frequency that is far from the resonance region, making it difficult for vibrations to occur. This is the second main function of the roller.

In this way, the powder layer compacted by the auxiliary roller is efficiently pulverized by the pulverizing roller disposed after the auxiliary roller, and the natural frequency of the raw material layer is kept at a constant height to prevent vibrations. I have to.

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

1 to 3 provide a detailed explanation of the invention.

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 (however, the coarse powder conduit 100 is omitted), 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 designated 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, this 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 a 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, and a constant pressure of hydraulic pressure is applied to the rod end chamber 22b of the hydraulic cylinder 22, thereby applying a compressive force to the layer of raw material. The end of the hydraulic cylinder 22 on the side opposite to the piston rod is rotatably supported by the casing I5. Note that this compression force is achieved by adjusting the hydraulic pressure using a pressure regulating valve (not shown) attached to a hydraulic line connected to the front end chamber 22b of the hydraulic cylinder 22. Also, this hydraulic line has an accumulator! lc integrated, 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. At the bottom of the arm 21, there is a gap between the auxiliary roller 20, the rotary table 3AJ, and the surface for adjusting tJR and R! ! The gap adjuster 24 is fixed to the casing 15, and includes a base 24b having a screw hole screwed therein, and a screw screw supported by being screwed into the screw hole of the base 24b. It consists of a shaft 24a, and by bringing the tip of the a-child 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 in the hook position.

Further, a discharge port 100a of the coarse powder conduit 100 is provided on the upper wave side of the auxiliary roller 20, so that the coarse powder after being classified by the separator 13 is guided to the biting side of the auxiliary roller 2o. .

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, the raw materials that have already been crushed into fine powder by the crushing roller 4, and the fine powder raw materials introduced through the coarse powder conduit lOO are combined into coarse and dense materials. It flows into the gap between the auxiliary roller 20 and the top surface of the rotary table 3A as a layer 40, and the auxiliary roller 20 rotates while being slightly lifted by the raw material layer, and this coarse and dense layer flows between its peripheral surface and the top surface of the rotary table 3A. The layer 40 is compressed into a degassed compacted layer 30. This compacted layer 30 is the rotary table 3A
The rotation reaches the biting side 4A of the crushing roller 4, where the raw material particles are not separated but are formed into a dense compacted layer, so the crushing roller 4 applies a pressing force as a high crushing force. Even if there is a narrow gap between the particles and the upper surface of the rotary table 3A in order to obtain a predetermined product particle size, the particles will be caught in the crushing roller 4 more reliably, and the particles will be scraped through by the crushing roller 4 and crushed. The proportion (amount) of raw material that does not get caught in the roller 4 and flows past its side is reduced. This improves the pulverization efficiency. In addition,
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 shown only in the right half of the figure. ing.

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 so-called consolidation effect is imparted, and a low pressure that does not contribute to the crushing of the raw material is 1/20 to 1/10 compared to the reduction blade of the crushing roller. The pressing force of this auxiliary roller 20 is slightly higher than the height of the auxiliary roller 20 regulated by the screw shaft 24a when the raw material is inserted into the gap between the auxiliary roller 20 and the rotary table 3A. The force is said to be enough to lift 20. 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. For example, when 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 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. The compacted layer 30 coming out from the auxiliary roller 20 is closer to 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 shoe 17 onto the rotary table 3A is reduced, and the consolidated layer 30 is stabilized and the compacted state is difficult to disturb. 4 will be caught more reliably. In this embodiment, the diameter of the auxiliary roller 20 is smaller than the diameter of the crushing roller 4.
Generally (when the particle size of the raw material particles is small, the auxiliary roller 20
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 top 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 thicker when the raw material particle size is large, and when it is small. However, since the layer of raw material particles is compacted, this gap is too small to prevent the raw material particle layer from being disturbed and is relatively small so that it can be smoothly bitten by the auxiliary roller 20. For example, if the raw material particle size is 5 mm or less and the crushing roller 4 is placed in a large gap,
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.

[Effect of the invention] As is clear from the above explanation, the separator (classifier)
The coarse powder after classification is guided through a coarse powder conduit, and at the node, it is decompressed and compacted by an auxiliary roller together with the New Feed raw material to form a compacted layer, which is then crushed by a crushing roller, resulting in less vibration and stability. Since continuous operation can be carried out over a long period of time, grinding efficiency is improved and productivity is increased.

In addition, compared to a pulverizer that does not use a coarse powder conduit, the classified coarse powder can be turned into the required fine powder more quickly, which improves the pulverizing efficiency. It can also be expected to have the effect of limiting costs.

[Brief explanation of drawings]

1 to 3 show examples of the present invention, FIG. 1(A) is a plan view of the crushing roller and the auxiliary roller, and FIG. 1(B) is the same as that of FIG. 1(A). 2 is an overall perspective view of the crusher, FIG. 3 is a side view of an auxiliary roller attachment part, and FIG. 4 is a vertical sectional view of a conventional vertical crusher. 1... Vertical crusher, 3A... Rotary table 4... Grinding roller, 4A... Raw material biting side. 4B...Raw material discharge side, 17...Raw material input chute 20.50...Auxiliary roller 21...Arm, 22...Hydraulic sill 24... - Gap adjuster, 30... Consolidated layer, 40... Dense layer 100... Coarse powder conduit.

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 pulverizer equipped with a classifier at the top of the pulverizer for classifying the pulverized fine powder, the upper surface of the outer periphery of the rotary table between the pulverizing rollers is provided with a part that is bitten by the pulverizing rollers. A rotatable auxiliary roller that compresses a layer of raw material on its circumferential surface is provided, and an outlet of a coarse powder conduit that returns the coarse powder after classification in the classifier to the crushing roller is provided on the biting side of the auxiliary roller. Vertical crusher.