JP2613508B2 - Vertical crusher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical grinder for grinding raw materials such as limestone, slag, clinker, cement raw materials and chemicals by cooperation of a rotary table and a grinding roller.

[0002]

2. Description of the Related Art As one type of a crusher for finely pulverizing raw materials such as limestone, slag, and cement raw materials into powder, FIG.
As shown in FIG. 1, a vertical pulverizer 1 having a rotary table and a pulverizing roller is widely used. This kind of crusher is
The disk-shaped rotary table 3A, which is driven by the speed reducer 2 by the motor 2A at a lower portion of the cylindrical casing 15 and rotates at a low speed, is pressed by hydraulic pressure or the like to a portion equally dividing the outer peripheral portion of the upper surface in the circumferential direction, and is driven to rotate. And a plurality of crushing rollers 4.

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 pivotally supported on a casing 15 by a shaft 6 so that the crushing roller 4 is actuated. The crushing roller 4 is pressed on 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 layer pressure of the raw material, 14 is an annular space passage for gas blowing around the rotary table 3A, 14A is a gas supply path, and 13 is a raw material pulverized by the blade 13A. A rotary separator for classification, 16 is an outlet for taking out the product together with the gas, and 17 is a raw material input chute.

In such a vertical pulverizer, the raw material supplied to the center of the rotary table by the raw material charging chute 17 receives the centrifugal force in the table radial direction by the rotation of the rotary table 3A and slides on the rotary table 3A. When a force in the rotating direction is received by the rotating table 3A,
A slides with A and makes a rotation somewhat slower than the rotation speed of the turntable 3A. The above two forces, that is, the force in the radial direction and the force in the rotational direction are synthesized, and the raw material is
A moves to the outer periphery of the turntable 3A in a spiral locus on A. Since a roller is pressed against this outer peripheral portion and rotated, the raw material describing the spiral enters the crushing roller 4 and the rotary table 3A from a direction forming an angle with the roller axis direction and is caught. Rarely crushed.

On the other hand, a gas such as air or hot air is guided to the base of the casing 15 by a duct.
This gas blows up from the annular space 14 between the outer peripheral surface of the turntable 3A and the inner peripheral surface of the casing, so that the pulverized fine powder accompanies the gas and the casing 1
5, the blades 1 of the separator 13 located above.
The product having the predetermined particle size is subjected to the classification action by 3A, and is discharged together with the gas from the outlet 16 and sent to the next step.

[0006]

In the conventional vertical crusher as described above, a considerable amount of the material to be crushed on the table that has reached the crushing side of the crushing roller is caught by the crushing roller. It is normal to be washed away into the annular space without being swept away. Of the objects to be crushed, which have been flushed into the annular space at the biting side of the crushing roller, those having a large particle diameter become stones, fall down the annular space, increase the amount of stones removed, and reduce the amount of processing work. Increase. In addition, among the objects to be crushed that have been washed away into the annular space, those having a small particle size are scattered again, so that the load applied to the separator increases and the classification efficiency is likely to decrease. Further, a large amount of the material to be crushed is flushed into the annular space, so that the ventilation pressure loss in the annular space increases, thereby increasing the fan power.

[0007] In the conventional operation control, especially in the automatic operation of high-fine pulverization, the pulverizing amount, that is, the raw material supply amount, is controlled so that the mill differential pressure is constant, or the raw material is controlled so that the mill power is constant. The supply was controlled. In these methods, the particle size distribution of the input raw material changes suddenly,
If the amount of powder below 00μ becomes very large,
The raw material does not enter between the rotary table and the crushing roller well, so that it is difficult for the raw material to slip and bite properly, and the crushing work does not progress efficiently. As a result, the amount of raw material charged into the mill only increases, and the vibration gradually increases. As a result, operation becomes impossible and control becomes impossible. For this reason, it is unavoidable to switch to the manual operation of the operator (operator) to reduce the amount of pulverization. The inconvenience of adjusting has arisen. In particular, in the case of ultra-fine grinding of a raw material having a high powder ratio and poor physical properties such as sharks, mill vibration frequently occurs, and if the vibration value (amplitude) is particularly large, the equipment may be used. In some cases, the operation was stopped due to damage or inability to operate.

For this reason, as a countermeasure against large vibrations, the height of the table (weir) (dam ring height), It is conceivable to change the crushing pressure and the number of table rotations by manipulating them. Of these methods, changing the driving device of the rotary table makes the equipment cost too large, making it less feasible, and reduces the table weir height (dam ring height). In order to change the milling pressure, it is necessary to perform internal work after stopping the operation of the crusher, and if the crushing pressure is changed, the product particle size will change to the desired value. The reality is that the operation is switched to the operation operation to reduce the amount of mill processing, and the operation operation is troublesome. These vibrations tended to occur more frequently in the pulverization or ultrafine pulverization than in the medium pulverization region.

[0009]

In order to solve the above-mentioned problems, a vertical pulverizer according to the present invention comprises a plurality of rotatable pulverizing rollers arranged on an upper surface of an outer peripheral portion of a rotary table, and supplies the rotatable pulverizing roller to a central portion of the rotary table. In a vertical pulverizer that applies a predetermined pulverizing pressure to the pulverizing roller and pulverizes the pulverized raw material between the upper surface of the rotary table and the peripheral surface of the pulverizing roller, a constant feed ware for feeding the raw material from the raw material hopper to the pulverizer is used. And a particle size detector for measuring the powder rate of the raw material being transported is provided in the constant feedware, and when the measured powder rate of the particle size detector exceeds a preset value, the constant feedware is provided. And a control device for transmitting a command to change the rotation speed of the variable speed motor.

[0010]

In the vertical crusher of the present invention, the raw material powder ratio (fine powder contained in the raw material) obtained by the particle size detector, which is provided in the constant feed ware, and measures the particle size distribution of the raw material being transported. Ratio) is converted to an electrical signal and transmitted to the control unit. The comparator inside the control unit compares the information with a preset reference powder ratio. In order to prevent this from happening, a constant feed /
A command is sent to the wear-drive variable-speed motor to reduce its output rotation speed. In this way, the load in the mill is reduced quickly to reduce the load in the mill in response to the rapid increase in the powder rate of the feedstock, and the equipment supply is reduced due to the increase in mill vibration that occurs rapidly with the increase in the powder rate. Prevents mill stoppage due to damage or inability to operate.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 show a vertical pulverizer according to an embodiment of the present invention. FIG. 1 is a flow sheet, and FIG. 2 is a control block diagram of a control device. In the figure, 1 is a vertical crusher, 60 is a raw material conveyor, 70 is a raw material hopper, 80 is constant feed wear, 80a is a variable speed motor for driving constant feed wear, 90 is a dust collecting device, 100 is a suction fan. , 110 is a stone removal conveyor, 12
0 is a bucket elevator, 130 is a particle size detector, 140
Is a control device. The control device 140 contains therein a setter, a comparator, a controller (including a regulator and an operating device), an amplifier, and the like. The components of the main body of the vertical crusher 1 are as shown in FIG. 3 and are the same as those described in the related art, so that the description will be omitted.

Next, the operation of the control device 140 will be described. As shown in FIG. 2, the particle rate of the raw material loaded on the constant feedware 80 and being transported by the particle size detector 130 which is measured every time interval set by the timer is converted into an electric signal, and the control device 140 Is input to The control device 140, which has received this information, compares the set value, which is a reference powder ratio (percentage of fine powder in the raw material allowed in operation), which has been input to the setter in advance, with a comparator. When it exceeds, the command is issued to the variable speed motor 80a via the controller according to the process of the excess, the output rotation speed is reduced, and the load in the mill is reduced.

The controller is composed of a controller and an operating device.
The controller adjusts the constant feed ware 8 according to the degree of excess of the measured value (raw material particle ratio) to the set value (reference powder ratio).
The control operation includes proportional operation (P operation), integration operation (construction operation), differentiation operation (D operation), proportional integration operation (PI operation), and proportional differentiation operation (P operation). PD operation) and the like can be properly used after grasping the correlation between the raw material powder ratio and the raw material supply amount and the load in the mill and the state of vibration generation. The operation device transmits an operation command to the variable speed motor 80a based on the command from the controller. The line with the arrow in the figure indicates the signal flow.

In this way, after a certain period of time (for example, every 5 seconds) elapses after the operation is changed, the measured value obtained by the particle size detector 130 and the set value are compared again.
When the set value is exceeded, the raw material transport amount is reduced again. However, when the measured value falls below the set value, the raw material supply amount is increased according to the degree, and of course, the original operating state is restored. is there. As a reference powder ratio, when the amount of fine powder having a particle size of 300 μ or less exceeds about 5%, it is tentatively used. However, since it slightly differs depending on the type of raw material, it is preferable to determine the reference based on past operation results.

The particle size detector 130 is an application of a measuring device for constant feed wear (hereinafter referred to as CFW) 80. The CFW 80 includes a load detecting unit and a belt traveling distance detecting unit in one part of the conveyor, While the raw material is being sent, the load on the belt and the travel distance of the belt are converted into electric signals and transmitted to the arithmetic and control unit. In the arithmetic controller, the passage volume is calculated by integrating the passage cross-sectional area with the belt traveling distance, and the instantaneous bulk specific gravity is calculated from the accumulated weight and the accumulated passage volume. When the passage volume is maintained at a constant value, the bulk specific gravity becomes small and the bulk specific gravity becomes small when there are many bulk materials having a small amount of powder. On the other hand, when the amount of fine particles is small and the amount of fine powder is large, the porosity decreases, and the bulk specific gravity increases accordingly. Accordingly, there is a correlation between the bulk specific gravity and the fraction of the fine powder contained in the raw material, that is, the raw material powder ratio. By knowing the bulk specific gravity, the value of the raw material powder ratio can be generally but known. The particle size detector 130 applies the above principle. Note that a load cell is used for a load detection unit that performs weight detection.

By executing the automatic control having the above-mentioned feedback mechanism, the raw material powder ratio is suddenly increased, the load in the mill becomes excessive, the vibration value is sharply increased, and the operation becomes inoperable. Also, it is possible to monitor the powder ratio of the raw material to be charged into the mill in advance, and to take measures to appropriately reduce the amount of the raw material charged.

[0017]

As is clear from the above description, in the vertical pulverizer of the present invention, the operation for maintaining the raw material powder ratio of the feed material at a predetermined appropriate value is continued, and the operation becomes higher than the set value. In this case, by automatically reducing the amount of raw material supplied, it is possible to maintain stable operation with less vibration in order to keep the raw material biting into the crushing roller well and prevent overload in the mill before it occurs. Driving operability is improved.

[Brief description of the drawings]

FIG. 1 is a flow sheet of a vertical crusher showing an embodiment of the present invention.

FIG. 2 is a control block diagram of the control device according to the embodiment of the present invention.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical grinder 3A Rotary table 4 Grinding roller 17 Raw material input chute 22 Hydraulic cylinder 60 Raw material conveyor 70 Raw material hopper 80 Constant feedware 80a Variable speed motor 90 Dust collector 100 Suction fan 110 Stone discharging conveyor 120 Bucket elevator 130 Particle size detection Vessel 140 controller

Claims (1)

(57) [Claims] A plurality of rotatable crushing rollers are disposed on the upper surface of an outer peripheral portion of a rotary table, and a raw material supplied to a center portion of the rotary table is supplied with a predetermined crushing pressure to the crushing roller to apply a predetermined crushing pressure to the upper surface of the rotary table. A vertical crusher for crushing between a surface and a surface is provided with a constant feed ware for transporting the raw material from the raw material hopper to the crusher, and a particle size detector for measuring the powder ratio of the raw material being transported is provided on the constant feed crusher. A vertical control device, which is provided in a ware, and has a control device for issuing a command to change the rotation speed of the variable speed motor of the constant feed ware when a measured powder fraction of the particle size detector exceeds a preset value. Crusher.