JPH0724342A - Vertical grinder - Google Patents

Abstract

PURPOSE:To provide a vertical grinder suppressed in the abnormal vibration produced at the time of grinding in a finely grinding region and capable of keeping a relatively high grinding capacity. CONSTITUTION:A vertical grinder 1 is constituted by alternately arranging two or more kinds of grinding rollers 4L, 4s having different diameters and has the pressing means of the grinding rollers making the pressing force of the grinding rollers 4s having a small average diameter to a turntable 3A larger than that of the grinding rollers 4L having a large average diameter to the turntable 3A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical crusher for crushing raw materials such as cement raw materials, limestone, slag, clinker, ceramics and chemicals by cooperation of a rotary table and a pulverizing roller, and particularly fine pulverization. The present invention relates to a vertical crusher intended to suppress abnormal vibration generated during crushing of a region and to improve crushing ability.

[0002]

2. Description of the Related Art FIG. 3 is a kind of crusher for pulverizing raw materials such as limestone, slag and cement raw material into fine powder.
As shown in (1), a vertical crusher 1 having a rotary table and a crushing roller is widely used. This kind of crusher
In the lower part of the cylindrical casing 15, a disk-shaped rotary table 3A is driven by a speed reducer 2 by a motor 2A and rotates at a low speed, and hydraulically pressure-contacted with a portion equally dividing the outer peripheral portion of the upper surface in the circumferential direction to rotate the driven table 3A. Multiple grinding rollers 4
It has and.

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 15 on a casing 15, and by operating the hydraulic cylinder 9. The crushing roller 4 is pressed against the rotary table 3A to apply 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 thickness, 14 is a gas blowing annular space passage around the rotary table 3A, 14A is a gas supply passage, and 13 is a raw material crushed by blades 13A. A rotary separator for classification, 16 is a discharge port for taking out a product together with gas, and 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 charging chute 17 receives the centrifugal force in the radial direction of the rotary table 3A and slides on the rotary table 3A. At times, the rotary table 3A receives a force in the rotational direction, and the rotary table 3
It slides with A and makes a rotation somewhat slower than the rotation speed of the rotary table 3A. The above two forces, that is, the radial direction force and the rotational direction force are combined, and the raw material is the rotary table 3.
A spiral locus is drawn on A to move to the outer peripheral portion of the rotary table 3A. Since the roller is pressed against the outer peripheral portion and is rotating, 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 and is bitten therein. It is crushed and crushed.

On the other hand, a gas such as air or hot air is introduced to the base of the casing 15 by a hot air duct 20, and this gas is an annular space between the outer peripheral surface of the rotary table 3A and the inner peripheral surface of the casing. By being blown up from 14, 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 part, and the product of a predetermined particle size is discharged together with the gas through the discharge port 16 And sent to the next process.

In the conventional vertical crusher as described above, particularly in the case where medium crushing is intended, such as when crushing cement raw materials or coal, the size of the crushing roller is varied to maximize the crushing ability. The original size (roller average diameter and roller width) is designed, and the maximum size that can be arranged on the rotary table is determined as a target. ~
0.85) D and three rollers d = (0.55 to
0.70) D and 4 rollers d = (0.40 to
0.55) d was selected. That is, in the numerical range of the above-mentioned roller average diameter d, the upper limit value is set by the geometrical limit on the table arrangement, and the lower limit value is compared with the crushing capacity required by the customer. When the standard capacity of the vertical crusher of the model number is large, it shows a limit to reduce the cost of the equipment by reducing the roller average diameter.

[0007]

However, when the conventional vertical pulverizer is used to pulverize the fine pulverization region having a finer product grain size than the medium pulverization region, the raw material is caught in the pulverization roller. Not only can stable operation not be continued due to reduced efficiency and abnormal vibration of the mill,
The crushing ability was also reduced.

[0008]

In order to solve the above-mentioned problems and to provide a vertical crusher having a high crushing capacity with less abnormal vibration even in the fine crushing area, in the present invention, the outer peripheral portion of the rotary table is provided. A plurality of rotatable crushing rollers are arranged on the upper surface, and the raw material supplied through the raw material feeding chute hanging above the center of the rotary table is given a predetermined crushing pressure to the crushing roller to give the rotary table upper surface and the crushing roller peripheral surface. In the vertical crusher for crushing between the crushing roller and the crushing roller, a plurality of crushing rollers having different average diameters are alternately arranged, and the pressing force of the crushing roller having a small average diameter to the rotary table is averaged. The pressing means for the crushing roller, which is larger than the pressing force of the crushing roller having a large size on the rotary table, is provided.

[0009]

In the vertical crusher of the present invention, the small-diameter rollers and the large-diameter rollers having different average diameters are alternately arranged, and the small-diameter rollers are pressed against the rotary table with a pressing force larger than that of the large-diameter rollers. Since it is configured, the raw material is primarily pulverized by the large diameter roller and finely pulverized by the small diameter roller having a large pressing force.
Therefore, the large-diameter roller having a large difference in sliding speed between the large-diameter portion and the small-diameter portion of the crushing roller has a small pressing force, so that the abnormal vibration is small, and the large pressing force is likely to cause the abnormal vibration. Since the difference in sliding speed between the large diameter portion and the small diameter portion of the small diameter roller is smaller than that of the large diameter roller, the occurrence of abnormal vibration is suppressed accordingly.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a plan view of a main part of a vertical crusher of the present invention, and FIG. 2 is a side view of a main part of the vertical crusher of the present invention. The vertical crusher 1 equipped with the standard roller of the conventional example is suitable for crushing cement raw materials, limestone, etc. to 88 μR 10-15%, for example, to be used in the so-called medium crushing area, and to increase the crushing capacity as much as possible. Is intended.

That is, the upper limit of the numerical range of the roller average diameter d of the standard roller of the conventional machine is determined on the basis of the geometric maximum value that can be arranged on the rotary table 3A (the roller average diameter is made larger than this. Then, adjacent crushing rollers cannot contact each other, and the lower limit is the average diameter of the crushing rollers within the range that satisfies the customer's required capacity when the crushing capacity of the specified model is larger than the customer's required capacity. It shows the limit to reduce the cost of equipment by reducing the average diameter of the pulverizing roller, and the initial cost of the pulverizing roller, roller bearing, swing arm, arm bearing and other related equipment can be significantly reduced.

On the other hand, the vertical crusher 1 of the present invention is intended for a fine crushing region having an average particle size of 10 μm or less for obtaining a finer product particle size than the medium crushing region. For example, blast furnace slag or clinker. Abnormal vibration of the mill frequently occurs in the vertical crusher with the standard roller of the above-mentioned conventional machine when crushing the powder with a specific surface area of 2500 cm ² / g or more, or when producing calcium carbonate to obtain the specific surface area of 7000 cm ² / g or more. It is intended to solve the problems that it is difficult to continue the continuous stable operation and that the raw material biting efficiency is reduced and the crushing ability is reduced. For example, as shown in FIG. The crushing rollers include a large-diameter roller 4L and a small-diameter roller 4 having different average diameters.
It was divided into s and arranged alternately. In this case, the average diameter dL of the large diameter roller 4L is the same as the average diameter d of the conventional standard roller, and the average diameter ds of the small diameter roller 4s is a value of 0.5 to 0.8 of the average diameter dL of the large diameter roller 4L. And
During operation, the crushing roller 4 (4
The pressing force for pressing L, 4s) is larger in the small diameter roller 4s than in the large diameter roller 4L. That is, the crushing surface pressure P of the large diameter roller 4L is 150 kg used in the medium crushing region.
/ cm, whereas the ² mm, and 200～240Kg / cm ^{2 or} so of the grinding surface pressure to be used in the milling area in the small diameter roller 4s. The above-mentioned crushing surface pressure is a value obtained by dividing the tension of the crushing roller by the occupied area where the raw material immediately below the crushing roller exists, and the occupied area is the product of the roller width and the chord length corresponding to the central angle θ (experience value) of the crushing roller. It is calculated by.

When pulverization in a fine pulverization region (obtaining a product having an average particle size of 10 μm or less) is performed in a conventional machine having a standard roller, abnormal vibration frequently occurs and operation is hindered.
As a result, the crushing ability is lowered, but the following two points can be considered as the causes. One is that, as shown in FIG. 2, the center axis of the crushing roller does not intersect the center axis of the rotary table and extends far beyond the center axis of the rotary table, and it has a large diameter part (diameter d ₁ ) and a large diameter part of the crushing roller. The diameter portion (diameter d ₂ ) is a point that cannot roll together and slides in the width direction of the crushing roller, and the difference between the diameter of the small diameter portion and the diameter of the large diameter portion is large as the diameter of the large diameter roller 4L is large. This is the point where there is a large amount of sliding. Conversely speaking, the difference in sliding speed between the rotary table and the crushing roller based on this sliding contributes to the crushing. The other is that the larger the pressing force of the crushing roller against the rotary table, the more likely abnormal vibrations will occur. From the above consideration, in the present invention, the large-diameter roller 4L having a large sliding degree with the rotary table 3A is limited to the pressing force corresponding to the crushing surface pressure at the time of medium pulverization, and the small-diameter roller 4s having a small sliding degree is necessary for the fine pulverization. The large-diameter roller 4L is mainly responsible for the primary crushing (medium crushing), and the small-diameter roller 4s is finely crushed to suppress the occurrence of abnormal vibration. While attempting to carry out the desired grinding. The average diameter ds of the small-diameter roller 4s is set to 0.5 to 0.8 times the average diameter dL of the large-diameter roller 4L, but the lower limit value indicates the limit that the crushing ability decreases when the small-diameter roller 4s is further reduced. , The upper limit indicates the limit of occurrence of abnormal vibration.

As described above, in the vertical crusher of the present invention, with the intention of preventing the occurrence of abnormal vibration as much as possible, a relatively low pressing force is applied to the large diameter roller to share the primary crushing. By applying a strong pressing force to the small diameter roller, fine pulverization for finish pulverization is performed. As a result, the occurrence of abnormal vibration is suppressed, and continuous stable operation can be continued to maintain a stable crushing capacity.

[0015]

As described above, the vertical crusher of the present invention has less abnormal vibration of the mill and can maintain a stable and high crushing ability.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a vertical crusher according to an embodiment of the present invention.

FIG. 2 is a side view of a main part of a vertical crusher according to an embodiment of the present invention.

FIG. 3 is an overall vertical sectional view of a conventional vertical crusher.

[Explanation of symbols]

1 Vertical grinding machine 3A Rotating table 4 Grinding roller 4L Large diameter roller 4s Small diameter roller 5 Arm 6 Shaft 7 Arm 9 Hydraulic cylinder d Grinding roller average diameter d ₁ Grinding roller small diameter part d ₂ Grinding roller large diameter part dm Grinding roller average diameter dL Large diameter roller average diameter ds Small diameter roller average diameter

Claims (1)

[Claims] 1. A plurality of rotatable crushing rollers are arranged on the upper surface of the outer periphery of a rotary table, and a raw material supplied through a raw material chute hanging above the center of the rotary table is applied to the pulverizing roller at a predetermined crushing pressure. In a vertical crusher for giving and crushing between the upper surface of the rotary table and the peripheral surface of the crushing roller,
The crushing roller has a plurality of types of crushing rollers having different average diameters alternately arranged, and the crushing roller having a small average diameter exerts a pressing force on a rotary table of a crushing roller having a large average diameter. A vertical crusher equipped with a pressing means for a crushing roller that becomes larger.