JPS62286558A - Vertical type crusher - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention provides a vertical pulverizer that pulverizes cement raw materials, coal, chemicals, etc. through cooperation between a rotating table and a pulverizing roller. It is related to.

[Prior Art] Vertical pulverizers equipped with a rotary table and rollers are widely used as a type of pulverizer for finely pulverizing powders such as cement raw materials, coal, and chemicals. This type of crusher consists of a disk-shaped rotary table that is driven by a motor with a reducer to rotate at low speed in the lower part of a cylindrical casing, and a part that divides the outer circumference of the upper surface into equal parts in the circumferential direction, which is pressed by hydraulic pressure or the like. It is equipped with a plurality of rollers that are driven to rotate.

In this vertical crusher, powder as a raw material is supplied to the center of the rotary table through a supply pipe, and when the table rotates, the powder is subjected to centrifugal force in the radial direction of the table, and as it slides on the table, it is rotated by the table in the direction of rotation. It receives the force, slides between it and the table, and rotates somewhat slower than the table rotation speed.

The above two forces, that is, the forces in the radial direction and the force in the rotational direction are combined, and the powder moves in a spiral trajectory on the table toward the outer periphery of the rotary table. A roller is pressed into contact with this outer periphery and rotates, so the particles with spiral lines enter between the roller and the rotary table from a direction that forms a certain angle with the roller axis, and are crushed. do.

On the other hand, hot air is guided to the base of the casing by a duct, and this hot air blows up from the annular space between the outer circumferential surface of the rotary table and the inner circumferential surface of the casing, preventing the fine powder from being dried. It rises inside the casing and is discharged from the outlet as a mixture with hot air and sent to the next 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 if it is subjected to the crushing action by the crushing rollers only once. Not all of the objects to be crushed that fall onto the top are 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, By the time the particles reach the separator installed at the top of the crusher, depending on their particle size, they may fall down or be classified and rejected by the separator before being returned 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 passes through the rotary table until it reaches the desired fine powder particle size to become the final product and flows out of the crusher. The powder is gradually crushed by falling from the middle of the separator many times until it reaches the desired particle size.

[Problems to be Solved by the Invention] In such a vertical crusher, the ratio K (K
=ω/ω0) is the second coefficient for the vibration amplification coefficient M of the crusher.
There is a relationship as shown in the figure, and this ratio = ω/ω0 is 1.0
When the value is close to , the amplification coefficient M theoretically becomes infinite due to resonance. Of course, since there is actually attenuation, the value will not reach infinity, but it will become extremely large, causing large vibrations and making it impossible to operate.

Under normal operating conditions, when K<1.0 or K>1.0, the amplification coefficient M is A' in Fig. 2 (when K is 1.0),
Although it was in the stable region of B' (when K>1.0), due to factors such as changes in raw material properties, ω0 changed to state A or B, and the vibration became large.

Conventionally, such large vibrations have been dealt with by reducing the amount of raw material supplied, but since it is a manual operation method, it is difficult to respond quickly and accurately. Furthermore, there are cases in which vibrations do not subside even if the same measures are taken.

[Means for Solving the Problems] The present invention includes a rotary table in a casing, a plurality of crushing rollers disposed on the rotary table, and an electric motor that drives the rotary table via a speed reducer. In the vertical crusher, a sensor for detecting vibration frequency is attached to the crusher, and based on the output value of the sensor, the rotation rate of the table is determined based on the output value of the sensor. This control device includes a rotation speed changing means for changing the rotation speed of the electric motor by a predetermined number of rotations, a means for comparing the frequency detected by the sensor with a reference imaging frequency, and a means for changing the motor rotation speed. Equipped with means for determining increase or decrease in the frequency detected by the front and rear sensors,
The vertical crusher is characterized in that the rotational speed changing means increases or decreases the motor rotational speed in accordance with the determination results of the comparison means.

[Operation] In the present invention, the rotational speed of the rotary table is increased or decreased in accordance with the vibration state of the crusher, and the vibration of the crusher is controlled so as to fall within an allowable range. That is, in the present invention,
In FIG. 2, the rotation speed of the rotary table is controlled so that the amplification coefficient M is below a predetermined value, and the K value is always maintained in a stable range below 1.0.

[Example code] FIG. 1 shows an embodiment of a vertical crusher according to the present invention.

The crusher 1 includes a casing 20 that houses the entire crushing section such as a rotary table 3, which will be described later. Internal cone 2 with circular cross section
It is provided with a middle casing 20b whose 0c is an inner thigh, and an upper casing 20d joined to the upper end of the middle casing 20b.

A reducer 2 with a motor is disposed in the center of the lower casing 20a, and a rotary table 3 formed in a circular shape is attached to the output shaft facing upward. It is driven and rotates clockwise when viewed from above in FIG. A plurality of roller boss arms 5 are arranged at the upper outer peripheral end of the rotary table 3, and each of the roller boss arms 5 has a conical head-mounted crushing roller 4 pivotally attached to its lower end, which is pivoted in a substantially horizontal state. ing.

A pressure frame 6 having an annular shape (an annular shape in this embodiment) is fixed to the upper surface of the upper inner peripheral end of the roller boss arm 5 by means such as bolt tightening, and a plurality of crushing rollers 4 and a roller The boss arm 5 and the pressure frame 6 are integrally formed and mounted on the upper surface of the rotary table 3. On the other hand, the upper outer peripheral end of each roller boss 5 is rotatably connected to a connecting rod 8 and a turnbuckle 9 by a pin 7 and a fork end 7a.
and the hydraulic cylinder 1 via the cylinder rod 10a.
0, and the lower end of the hydraulic cylinder 10 is connected to the rotating pin 11.
and is connected to a base plate 13 by a rotating seat 12.

Each crushing roller 4 is connected to a roller boss 5 via a roller glaze 4a.
The rotary table 3 is rotatably supported by a shaft, and its circumferential surface is in contact with the outer peripheral surface of the upper end of the rotary table 3, so that it can be rotated in accordance with the rotation of the rotary table.

On the other hand, above the center of the rotary table 3 is a raw material supply pipe 1.
6 to the upper casing 2 via the final refined powder discharge pipe 22.
The separator 15, which is formed of an inverted conical cylinder, is supported by the middle casing 20b by a stay (not shown) around the raw material supply pipe 16. A plurality of movable vanes 15a are arranged evenly in the circumferential direction on the upper surface of the upper end of the separator 15 to apply swirling force to the inflowing powder seat gas, and a shaft 15b whose one end is supported by a bearing 15c and handle 15
d, it can be rotated and adjusted from the outside.

Furthermore, a duct 18 is provided below the outer periphery of the rotary table 3.
An annular hot air passage 21 is provided which is connected to the hot air generator by a hot air generator.
An annular space 14 is defined by the outer wall 14a and the outer peripheral wall 14b. In this annular space 14, a plurality of plate-shaped blades 14 are provided.
c are arranged and fixed at equal intervals around the circumference while maintaining a required inclination angle with respect to the horizontal plane.

In addition, at the bottom of the hot air passage, there is a discharge chute 1 that temporarily discharges foreign objects during crushing and excess crushed materials in the event of overload.
9 is installed, and can be taken out from a discharge door 19b which is rotatable around a rotary bin 19a.

Thus, the crusher 1 (in this embodiment, the middle casing 20b)
) is attached to a sensor 30 for detecting vibration frequency, and its detection signal is input to a control device 31. This control device 31 outputs a control signal to a control section of a motor attached to the reduction gear 2.

This control device 31 is constructed using a known microcomputer, and the microcomputer itself includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output device, a central processing unit, and a central processing unit for connecting these. Equipped with data bus etc.

The signal from the sensor 30 is converted into a digital signal by an A/D converter, then inputted into the microcomputer from the input/output device, processed, and a control signal based on the processing result is sent to the motor control unit. Output.

In the present invention, as described above, the rotation speed of the rotary table 3 is controlled so that the vibration of the crusher 1 is within the permissible range.
This will be explained with reference to FIG.

FIG. 3 is a flowchart showing an example of a control program. In FIG. 3, in step 41, a vibration permissible limit value Hc is calculated from the specified rotational speed Nc of the rotary table.

Next, in step 42, the crusher vibration frequency H+ is read from the sensor 30, and in step 43, this Hl and Hc are compared. If Hl is equal to Hc or smaller than Hc, the vibration state of the crusher is within the permissible range, so this state is maintained for a predetermined time in step 44, and then the process returns to step 41 and the above-mentioned process is performed. Repeat the process.

If the determination result in step 43 is that Hl is larger than Hc, the process moves to step 45, and first the rotation speed of the motor is increased by X1%. and step 46
Maintain this state for a predetermined period of time and wait for the response of the crusher.
After that, in step 47, the number H of detected images from the sensor 30 is
Load 2. Then, proceeding to step 48, Hl and Hc
Make a comparison with If Hl is equal to or smaller than Hc, it means that the vibration of the crusher has fallen within the permissible range by increasing the motor rotation speed, so the process moves to step 49 and maintains this state for a predetermined period of time. , and then returns to step 41 to repeat the same process as above.

On the other hand, if the determination result of Hl and Hc in step 48 is that Hl is larger than Hc, that is, the vibration state of the crusher still exceeds the permissible limit, the process moves to step 50, and the difference between Hl and Hc is determined. Make a comparison. This step 5
0 is for determining whether the vibration of the crusher has increased or decreased as a result of increasing the speed of the motor. As a result of the determination between Hl and Hl in step 50, if Hl is smaller than Hl, the vibration will tend to decrease as the motor speed increases, so the process moves to step 51 and further increases the motor rotation speed by %, thereby further reducing the vibration frequency of the crusher (note that even when Hl and H4 are equal, in this example, the vibration is treated as decreasing.
. Then, in step 52, after waiting for a predetermined time and waiting for the response of the crusher, in step 53, the vibration frequency H3 of the crusher is changed.
Load. Next, in step 51.7, H3 and Hc are compared, and if H3 is equal to or smaller than the permissible vibration limit value Hc, the vibration state of the crusher is within the permissible range. Therefore, step 4
Return to step 1 and repeat the same procedure as above.

If the determination result in step 54 is that H3 is still greater than Hc, the process returns to step 51 and the motor speed is further increased. Thereafter, after waiting for a predetermined time using the timer 52, the crusher vibration frequency H3 is read (step 53).
In step 54, a comparison with Hc is made. If the frequency H3 of the crusher becomes equal to or less than Hc, the process returns to step 41, and if it still exceeds Hc, the process returns to step 51 again, and this process is repeated until the frequency H3 becomes less than or equal to Hc. .

On the other hand, the determination result in step 50 indicates that Hl is Hl
If it exceeds , this indicates that the vibration of the crusher tends to increase due to motor speed increase, so the process moves to step 55, where the motor rotation speed is reduced by X1%.
After waiting for a predetermined time (step 56), the crusher vibration frequency H4 is read in step 57, and this H4 and Hc are compared in step 58. If H4 is equal to or smaller than Hc, it means that the vibration of the crusher is within the permissible range, so the process returns to step 41 and the above process is repeated. On the other hand, if the determination result in step 58 exceeds H4h)Hc, the process returns to step 55 again and the motor is decelerated. Then, the loop between steps 55 and 658 is repeated until H4 becomes equal to or smaller than Hc.

In this way, the speed of the motor is increased or decreased until the frequency of the crusher becomes equal to or lower than Hc.

FIG. 4 is a flowchart showing the configuration of different control programs employed in the present invention.

The flowchart in Figure 4 is intended to deal with transient vibrations caused by temporary changes in raw material properties, etc., and the table rotation speed (motor rotation speed) will change once the transient vibrations have passed. It is programmed to return to its original speed.

In FIG. 4, in step 61, the crusher is driven at a specified rotation speed Nc. In step 62, a vibration permissible limit value Hc is calculated based on this Nc, and the process moves to step 63, where the vibration frequency ZI of the crusher at that time is read. Then, this Zl is compared with the aforementioned Hc (step 64).
, Zl are less than or equal to Hc, it means that the crusher is in a vibrating state within the permissible range, so in step 65 this state is maintained for a predetermined time, and then the process returns to step 63 and the same procedure is repeated.

On the other hand, if the determination result in step 64 is that Zl is greater than Hc, the process moves to step 66 and the number of rotations of the motor is
Increase speed by I%. After maintaining this state for a predetermined time in step 67, the vibration frequency 22 of the crusher is read (step 68), and Zl and Z2 are compared (step 6).
9). If the crusher vibration frequency 22 after increasing the motor speed is equal to or lower than the initial vibration value 21 of the crusher, step 70 is performed, and after maintaining this state for a predetermined time, the motor rotation speed is decreased by x1% (step 71). ), and after further holding for a predetermined time (
Step 72), reads the rotation speed 23 of the crusher (Step 73), and compares Hc with 23 (Step 7).
4).

As a result of the determination in step 74, if Z3 is larger than Ha, the process returns to step 66 and processes from step 66 onwards are performed. The determination result in step 74 is 22.
If it is less than Hc, in step 75, the rotational speed is returned to Nc, and after returning to steady operation, the process returns to step 63 and the control according to the same procedure as above is repeated.

On the other hand, the determination result in step 69 is that Z2 is
If it is larger than l, the rotational speed of the motor is reduced by Make a comparison (step 69)
). This deceleration causes the vibration frequency Z2 of the crusher to decrease to the initial vibration value Z
If the value is equal to or smaller than 1, the process proceeds to step 70. On the other hand, if 22 still exceeds the initial vibration value Z1, the motor is repeatedly decelerated until Z2 becomes 21 or less. After 22 becomes equal to or less than ZI, the process moves to step 70, and control is performed according to the same procedure as above.

In this manner, in the control shown in FIG. 4, after the temporary vibration has passed, the table rotation speed is returned to the rotation speed of the steady operating state in step 75.

In both of the controls according to the flowcharts of FIGS. 3 and 4, the crusher is maintained within a range below the permissible vibration limit.

In the flowchart of FIG. 4, the rotational speed of the motor is increased by x1% in step 66, and the motor is decelerated by x1% and x2% in steps 71 and 76, respectively. %, and in steps 71 and 76 the motors are accelerated by x1% and x
The speed may be increased by 2%.

[Effects of the Invention] As described above, according to the vertical crusher of the present invention, the vibration of the crusher is always kept within the permissible vibration limit value, and accurate vibration control of the vertical crusher becomes possible. Long-term continuous stable operation can be achieved regardless of the disturbance.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view showing the configuration of the vertical crusher, Figure 2 is a response curve of the vibration amplification coefficient of the vertical crusher, Figures 3 and 4.
The figure is a flowchart illustrating a control program employed in the present invention. 1... Vertical crusher, 3... Rotary table,
4... Grinding roller, 6... Pressure frame, 14...
...Annular space part, 15g...Separator chute, 30...Sensor, 31...Control device.

Claims (1)

[Claims] (1) A vertical crusher that includes a rotary table in a casing, a plurality of crushing rollers arranged on the rotary table, and an electric motor that drives the rotary table via a speed reducer. It is equipped with an attached sensor for detecting vibration frequency, and a control device that adjusts the rotation speed of the electric motor for rotating the table based on the output value of the sensor. comprising means for changing the rotational speed, means for comparing the frequency detected by the sensor with a reference frequency, and means for determining an increase or decrease in the frequency detected by the sensor before and after changing the motor rotational speed,
A vertical crusher characterized in that the rotation speed changing means increases or decreases the motor rotation speed in accordance with the determination results of the comparison means.