JPH0753242B2 - Operation method in vertical crusher - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vertical crusher for crushing raw materials such as limestone, slag, and cement raw material by cooperation of a rotary table and a crushing roller.

[Conventional technology]

As a kind of pulverizer for pulverizing raw materials such as limestone, slag, and cement raw material into powder, as shown in FIG. 6, a vertical pulverizer 1 equipped with a rotary table and a pulverizing roller 1
Is widely used. This type of crusher has a disk-shaped rotary table 3A which is driven by a speed reducer 2 by a motor 2A at a lower portion of a cylindrical casing 15 and rotates at a low speed, and a hydraulic pressure is applied to a portion which equally divides an outer peripheral portion of an upper surface thereof in a circumferential direction. And a plurality of crushing rollers 4 that are driven to rotate by being pressed against each other.

The crushing roller 4 has a hydraulic cylinder 9 through an arm 5 and an arm 7 which are pivotally supported by a shaft 6 on a casing 15.
Is connected to the piston rod 10 of the hydraulic cylinder 9
The crushing roller 4 by rotating the rotary table.
Pressing on 3A gives crushing pressure to the raw material. 3B is a dam ring provided on the outer peripheral edge of the rotary table 3A for adjusting the raw material layer pressure, 14 is a gas blowing annular space passage around the rotary table 3A, 13 is a rotary separator for classifying the raw material crushed by blades 13A, 16 Is an outlet that takes out the product with the gas,
17 is a raw material charging chute.

In such a vertical crusher, the raw material supplied to the central portion of the rotary table by the raw material chute 17 is rotated when sliding on the rotary table 3A by the centrifugal force in the radial direction of the table due to the rotation of the rotary table 3A. The table 3A receives a force in the direction of rotation and slides with respect to the table 3A to perform rotation somewhat slower than the number of rotations of the table 3A. The above two forces, that is, the force in the radial direction and the force in the rotation direction are combined, and the raw material moves to the outer peripheral portion of the rotary table 3A in a spiral trajectory on the rotary table 3A. In this peripheral part,
Since the rollers are pressed against each other and rotate, the raw material in which the spiral is drawn enters between the crushing roller 4 and the rotary table 3A from a direction forming an angle with the roller axial direction, is bitten into the particles, and is 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 portion 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 in the gas and rises in the casing 15, and is subjected to the classification action by the blades 13A of the separator 13 located at the upper portion,
The product having a predetermined particle size is discharged together with the gas from the discharge port 16 and sent to the next step.

[Problems to be Solved by the Invention]

In the conventional vertical crusher as described above, on the table, a considerable amount of the crushed material reaching the biting side of the roller is pushed into the annular space portion without being bitten by the roller. Is normal. Then, of the objects to be crushed that are pushed into the annular space on the biting side of the roller, those with a large particle size become stones and fall into the annular space, increasing the amount of stones and increasing the amount of processing work. Let Also,
Of the objects to be crushed that have been swept into the annular space, those having a small particle size will be scattered again, so that the load applied to the separator will be large and the classification efficiency will tend to be reduced. Further, since a large amount of the object to be crushed is forced to flow into the annular space portion, a ventilation pressure loss in the annular space portion increases, which increases fan power.

As described above, in the crusher, an air blower having several times the required air volume for blowing up and circulating the overflow granules is required, and a large air volume and air pressure are required due to the increase in the circulation volume, resulting in equipment cost. In addition to a significant increase in power consumption, mill vibration often occurs when a raw material having relatively poor pulverizability is pulverized, and the vibration value (amplitude) Especially when the size is large, the equipment may be damaged or the vehicle may become inoperable, and the operation may be stopped without stopping.

Therefore, as a measure against large vibrations, the frequency of the raw material layer of the crushing part is changed to move away from the resonance range. (Dam ring height), crushing pressure, and table rotation speed may be manipulated to change, but of these, the variable drive device of the rotary table is too expensive to implement and the feasibility is low. Changing the (dam ring height) requires internal work after stopping the operation of the crusher, and changing the crushing pressure has the drawback that the product particle size changes to the desired one, so the mill throughput The actual situation is to reduce and respond to this, which would impair a stable production plan. Therefore, even if mill vibration occurs, the frequency of milling raw material layer is changed and the vibration amplitude is reduced without a significant reduction in the mill throughput, so that a normal stable, low-vibration operating state is quickly restored. The means were hungry. The generation of these vibrations tends to occur more frequently in the finely pulverized or ultrafinely pulverized regions than in the medium pulverized region.

[Means for Solving the Problems]

In order to achieve the above object, an operating method in a vertical crusher of the present invention is to arrange a plurality of rotatable crushing rollers on an upper surface of an outer peripheral portion of a rotary table, and feed the raw material supplied to the central portion of the rotary table to the crushing roller. A vertical crusher for applying a predetermined crushing pressure to crush between a rotary table upper surface and a crushing roller peripheral surface,
A rotatable auxiliary roller for compressing the layer of the raw material biting into the crushing roller on the peripheral surface is arranged on the upper surface of the outer periphery of the rotary table between the crushing rollers, and the auxiliary roller is provided on the upper surface of the rotary table. In a vertical crusher equipped with a pressing means for pressing with an arbitrary force, the pressing surface pressure of the auxiliary roller on the upper surface of the rotary table is 0.02 of the pressing surface pressure (ground surface pressure) of the crushing roller on the upper surface of the rotary table. The operating method in the vertical crusher was set to 0.3 times.

[Action]

The raw material supplied from the raw material feeding chute to the upper surface of the central part of the rotary table draws a spiral locus on the rotary table, moves to the outer peripheral side of the rotary table, reaches the biting side of the auxiliary roller, and is between the auxiliary roller and the rotary table. When the auxiliary roller rotates, the auxiliary roller rotates and compresses the raw material particles with a required pressing force on its peripheral surface, the gas between the particles is eliminated and deaeration occurs, and at the same time, the compressed raw material particles are dense. Being in a state,
So-called, It is said that The consolidation layer, which has been deaerated and consolidated, reaches the meshing side of the crushing roller by the rotation of the rotary table, is pressed by the rotary table with a high pressing force and is meshed with the crushing roller that is driven, and continuous crushing is performed. . Further, the raw material particles, which are crushed by the crushing roller and finely divided, and which are discharged from the non-meshing side of the crushing roller and flow as a so-called coarse layer, are subjected to the same deaeration and consolidation action again by this auxiliary roller and Efficiently crushed by being bitten by the crushing roller located at. Unlike the crushing roller, the pressing force of the auxiliary roller toward the upper surface of the rotary table does not contribute to the crushing and compresses the raw material particles to form a dense layer between particles, a so-called (Hereafter, the action of forming such a layer There is a thing. ) Is formed, which is significantly smaller than the pressing force of the crushing roller.

When the auxiliary roller is arranged close to the raw material catching side of the crushing roller, new raw material from the raw material charging chute guided to the outer peripheral portion of the rotary table is less likely to flow into the raw material catching side of the crushing roller, and the auxiliary roller is Since the ratio of the material flowing into the raw material entrapment side increases, the new raw material is less likely to disturb the consolidation layer in which the raw material particles are compressed and the raw material particles are densely packed, and the entrainment into the crushing roller is performed more reliably. .
Of course, the raw material crushed by the previous crushing roller and the new raw material are combined and compacted by this auxiliary roller.

At the same time, the auxiliary roller forms a consolidation layer with a certain thickness to keep the natural frequency of the raw material layer constant,
The second main function of the auxiliary roller is to prevent vibration from occurring.

In this way, the powder layer (consolidation layer) that has been compacted by the auxiliary roller is efficiently pulverized by the pulverizing roller arranged in the subsequent stage of the auxiliary roller, and the raw material layer is kept at a constant height to cause vibration. Although it is difficult, the layer thickness increased due to some reason and the mill vibration suddenly became violent for some reason.

In the method for operating the vertical crusher of the present invention, as a measure against the above-mentioned problem, in the vertical crusher in which auxiliary rollers are arranged between the crushing rollers and a pressing means for pressing the auxiliary roller to the rotary table is provided, the auxiliary rollers Since the operation is performed by selecting the ratio of the surface pressure of the crushing roller to the surface pressure of the crushing roller within the range of 0.02 to 0.3, which has a small vibration value, the compaction caused by the change in the grindability due to the change in the properties of the crushing raw material and the water content It is possible to suppress an increase in the layer thickness of the layer and an increase in the mill vibration value that occurs due to the increase, and to continue the quiet operation with a small mill vibration value.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

1 to 3 illustrate a first embodiment of the present invention, FIG. 4 illustrates another different embodiment, and FIG. 5 shows an auxiliary roller surface pressure and a crushing roller surface. It is a correlation diagram of a surface pressure ratio with pressure and a mill vibration value.

First, a first embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, FIG. 1 (A) is a plan view showing an arrangement state of a crushing roller and an auxiliary roller on a rotary table, FIG. 1 (B) is a front development view of FIG. 1 (A), and FIG. FIG. 3 is a perspective view showing the whole vertical crusher, and FIG. 3 is a side view of an auxiliary roller mounting portion. In the figure, the same parts as those in FIG. 6 are designated by the same reference numerals, and the description 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 portion of the rotary table 3A at positions symmetrical to the center of the rotary table 3A. 4 is located on the upper surface of the outer peripheral portion of the rotary table 3A while the auxiliary rollers 20 having a diameter smaller than that of the crushing roller 4 are disposed at positions close to the raw material biting side 4A of each crushing roller 4. As shown in FIG. 3, the auxiliary roller 20 is rotatably supported on a roller shaft 25 fixed to the tip of a substantially U-shaped arm 21 rotatably supported on a casing 15 by a shaft 23. Installed. A piston rod 22a of a hydraulic cylinder 22 is rotatably connected to the lower end of the arm 21. By applying a constant hydraulic pressure to the rod end chamber 22b of the hydraulic cylinder 22, a compression force is applied to the raw material layer. An end of the hydraulic cylinder 22 on the side opposite to the piston rod is rotatably supported by the casing 15. This compression force is performed by adjusting the hydraulic pressure by a pressure adjusting valve (not shown) attached to the hydraulic line connected to the rod end chamber 22b of the hydraulic cylinder 22, and an accumulator is provided in this hydraulic line. Connected, the rod end chamber 22b of the hydraulic cylinder 22 is kept 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. A gap adjuster 24 for adjusting and setting the gap between the auxiliary roller 20 and the upper surface of the rotary table 3A is provided below the arm 21, and the gap adjuster 24 is fixed to the casing 15 and has a screw hole. With the installed base 24b,
A screw shaft 2 screwed into and supported by the screw hole of the base 24b
4a, and the gap between the auxiliary roller 20 and the upper surface of the rotary table 3A can be set by bringing the tip of the screw shaft 24a into contact with the side end of the arm 21.

When the weight of the auxiliary roller 20 is sufficient as the compression force of the raw material layer, the hydraulic cylinder 22 is set free.

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

The raw material supplied from the raw material feeding chute 17 to the upper surface of the central portion of the rotary table 3A receives the centrifugal force of the rotary table 3A and draws a spiral locus on the rotary table 3A to move to the outer peripheral side of the rotary table. As shown in (B), most of the raw materials therein and the raw material which has already been pulverized by the pulverizing roller 4 into a fine powder are combined to form a coarse and dense layer 40 on the auxiliary roller 20 and the upper surface of the rotary table 3A. And the auxiliary roller 20 is rotated by being slightly lifted by the raw material layer, and the auxiliary roller 20 is compressed so that the coarse and dense layer 40 is compressed between the peripheral surface thereof and the upper surface of the rotary table 3A to form the consolidated layer 30. . This compaction layer 30 reaches the biting side 4A of the pulverization roller 4 by the rotation of the rotary table 3A, and here the raw material particles are not in a scattered state but in a compaction layer in a dense state, so that the pulverization roller 4 is Even if a pressing force as a high crushing force is applied and a narrow gap is formed between the rotary table 3A and the upper surface of the rotary table 3A in order to obtain a predetermined product grain size, the crushing roller 4 is more reliably bitten into the crushing roller 4, The proportion (amount) of the raw material that is scraped off by the crushing roller 4 and does not bite into the crushing roller 4 and flows through the side portions thereof is reduced. Therefore, the grinding efficiency is improved. In addition, in FIG. 1 (A), F is a moving locus of the raw material particles, C is a catching portion (crushing portion) between the roller and the rotary table 3A, and the moving locus of the raw material particles is shown in FIG.
Only the right half is shown.

At this time, the auxiliary roller 20 is provided with a so-called compacting effect of compressing the particles of the raw material to purge the interparticle gas to increase the density of the layer of the particles, so that the auxiliary roller 20 does not contribute to the pulverization of the raw material. Pressure is provided by adjusting the hydraulic pressure in hydraulic cylinder 22. The pressing force of the 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 put into the gap between the auxiliary roller 20 and the rotary table 3A and is in a biting state. It is supposed to be enough to lift 20. The pressing force of the 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, hydraulic pressure need not be applied. The pressing force of the auxiliary roller changes depending on the size of the raw material particles and the degree of adhered water. For example, when the diameter of the raw material particles is small, the pressing force may be small.

The raw material that has been bitten by the crushing roller 4 and crushed into a small size receives the rotating force of the rotary table 3A and the crushing roller 4 while receiving the compressive force in the narrow gap between the crushing roller 4 and the rotary table 3A. , The raw material discharge side 4B of the crushing roller 4 vigorously ejects the particles so that the particles are in a disjointed state, and is mixed with the new raw material supplied from the raw material feeding chute 17 to form a coarse and dense layer. 40, the coarse and dense layer 40 is subjected to the same consolidating action as described above by the auxiliary roller 20 located next, and is surely bitten by the crushing roller 4 located on the rotational direction side of the rotary table 3A. It is crushed and crushed, and it becomes closer to the product particle size. Then, since the auxiliary roller 20 is positioned close to the meshing side 4A of the crushing roller 4, the consolidation layer 30 that has come out of the auxiliary roller 20 is moved from the raw material charging chute 17 to the rotary table 3A.
Since the addition of new raw material supplied to the upper part is reduced, the consolidated state is less likely to be disturbed, the consolidated layer 30 is stable, and the crushing roller 4
Will be more reliably bitten into. Although the diameter of the auxiliary roller 20 is smaller than that of the crushing roller 4 in this embodiment, generally, when the particle diameter of the raw material particles is small, the diameter of the auxiliary roller 20 may be small. In addition, when the particle diameter of the raw material particles is large, the diameter is increased so that the compaction effect can be imparted according to the particle diameter of the raw material particles.

As a result of conducting an experiment in a vertical crusher equipped with an auxiliary roller, there is a significant correlation between the ratio of the auxiliary roller surface pressure to the crushing roller surface pressure (hereinafter referred to as surface pressure ratio) and the mill vibration value.
As shown in FIG. 5, it was observed that the vibration value sharply increased when the surface pressure ratio was 0.02 or less and 0.3 or more. Therefore, when the surface pressure ratio is set between 0.02 and 0.3, it is possible to obtain a good operating state with a low mill vibration value. The pressing force of the auxiliary roller, that is, the pressing surface pressure is adjusted by the hydraulic pressure supplied to the hydraulic cylinder 22. As shown in FIGS. 1 (A) and 1 (B), the pressing projected areas of the crushing roller and the auxiliary roller are S ₀ and S ₁ , respectively, and the pressing force is P ₀ ,
Assuming P ₁ , the surface pressure ratio K is K = (P ₁ / S ₁ ) / (P ₀ / S ₀ ) = (P ₁ S ₀ ) / (P ₀ S ₁ ).

The gap between the auxiliary roller 20 and the upper surface of the rotary table 3A is set by moving the screw shaft 24a of the gap adjuster 24 in and out. This gap is made large when the size of the raw material particles is large and made small when it is small, but since it is a compaction of the layer of raw material particles, this gap is too small and the raw material particle layer is conversely disturbed. In the relatively large gap so that the auxiliary roller 20 can be smoothly bitten, for example,
When 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 to 10 mm, an auxiliary roller
The gap between 20 and the turntable 3A is set to 40 to 60 mm.

Next, a second embodiment will be described with reference to FIGS. 4 (A) and 4 (B).

In this embodiment, an auxiliary roller 50 having a diameter smaller than that of the crushing roller is arranged on the upper surface of the outer peripheral portion of the rotary table 3A at the intermediate position between the crushing roller 4 and the crushing roller 4, as in the first embodiment. In this case, since the auxiliary roller 50 is brought closer to the raw material discharge side 4B of the crushing roller 4 as compared with the first embodiment described above, the dense and dense layer 40 crushed by the crushing roller 4 and discharged from the discharge side 4B is more compacted. It is performed with emphasis.
Of course, a part of the new raw material supplied from the raw material charging chute 17 is also charged into the auxiliary roller 50 and consolidated. In this embodiment, since the distance between the auxiliary roller 50 and the crushing roller 4 on the upper surface of the rotary table 3A becomes long, the consolidation layer 30 by the auxiliary roller 50 tends to be disturbed by the merging of the new feed material. The discharge side after being crushed by the crushing roller 4
Since the raw material particle layer discharged from 4B is more intensively processed, it is advantageous, for example, in the case of pulverizing a raw material having a good pulverizability and a property of being easily scattered.

Further, in this embodiment, since the crushing roller 4 and the auxiliary roller 50 are arranged at equal intervals, there is also an advantage that the manufacturing is easy.

If the auxiliary roller is arranged 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 compressed and bitten into the next crushing roller 4. it can.

〔The invention's effect〕

As is clear from the above description, in the operating method of the vertical crusher according to the present invention, the raw particles are compressed by the auxiliary roller to degas the gas existing between the particles, so that the particles are in a dense state. It is possible to form a consolidation layer, and since the operation method is appropriately selected by comparing the auxiliary roller surface pressure with the crushing roller surface pressure by the pressing means of the auxiliary roller to the upper surface of the rotary table, the mill vibration value is low. ,
Long-term continuous stable operation can be continued and productivity is improved. Also,
When you want to change the product grain size, even if you change the classification point and the grinding roller surface pressure to a value that is compatible with this, you can prevent the increase in mill vibration value by correspondingly changing the auxiliary roller surface pressure. .

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 (A) is a plan layout view of a crushing roller and an auxiliary roller, and FIG. 1 (B). ) Is a front development view of FIG. 1 (A), FIG. 2 is an overall perspective view of the crusher, FIG. 3 is a side view of an auxiliary roller mounting portion, and FIG. 4 is a second embodiment of the present invention. Yes, FIG. 4 (A) is a plan layout view of the crushing roller and the auxiliary roller, FIG. 4 (B) is a front development view of FIG. 4 (A), and FIG. 5 is a case where the auxiliary roller of the present invention is used. FIG. 6 is a vibration state diagram showing the mill vibration value, and is a correlation diagram between the surface pressure ratio between the auxiliary roller surface pressure and the crushing roller surface pressure and the mill vibration value. FIG. 6 is a vertical cross-sectional view of a conventional vertical crusher. 1 ... Vertical crusher, 3A ... Rotary table, 4 ... Grinding roller, 4A ... Raw material side, 4B ... Raw material discharge side, 17 ... Raw material chute, 20 ... Auxiliary roller, 21 ... … Arm, 22
...... Hydraulic cylinder, 24 …… Gap adjuster, 30 …… Consolidation layer,
40 ...... density layer, 50 ...... auxiliary rollers, P ₀ ...... pressing force of the grinding roller, the pressing force of P ₁ ...... auxiliary rollers.

Claims (1)

[Claims] 1. A plurality of rotatable crushing rollers are arranged on the upper surface of the outer peripheral portion of a rotary table, and a predetermined crushing pressure is applied to the raw material supplied to the central portion of the rotary table to apply a predetermined crushing pressure to the upper surface of the rotary table and the peripheral surface of the crushing roller. A vertical crusher for crushing between a surface and a surface of the rotary table between the crushing roller and the crushing roller. In a vertical crusher provided with rollers and pressing means for pressing the auxiliary roller against the upper surface of the rotary table with an arbitrary force, the pressing surface pressure of the auxiliary roller against the upper surface of the rotary table is controlled by the rotation of the crushing roller. 0.02 of pressing surface pressure (crushing surface pressure) against the table top
~ 0.3 times the operating method in the vertical crusher.