JPH0584448A - Vertical grinder - Google Patents

Abstract

PURPOSE:To provide a vertical grinder capable of quietening abnormal vibration and of returning to an original stable operation state by automatically changing the rpm of a turntable before vibration value is suddenly increased by some cause during operation and also this state is continued and operation is made impossible. CONSTITUTION:A vibrometer 140 is fitted to a casing 15 and also a variable speed motor 2A is used for a motor for driving a turntable. A controlling device 150 is equipped which lowers the rpm of the variable speed motor 2A when a vibration mode recorded by the vibrometer 140 is compared with the previously set vibration mode and both coincide.

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 limestone, slag, clinker, cement raw materials and chemicals in cooperation with a rotary table and a pulverizing roller.

[0002]

2. Description of the Related Art FIG. 5 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
At the lower part of the cylindrical casing 15, a disk-shaped rotary table 3A is driven by the speed reducer 2K by the constant speed motor 2K and rotates at a low speed, and 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 a plurality of crushing rollers 4 which are driven to rotate.

The crushing roller 4 has a casing 15 and a rotating shaft 6
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, and by operating the hydraulic cylinder 9, the crushing roller 4 is pressed onto the rotary table 3A. To give crushing pressure to the raw materials. 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 an outlet 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 feeding 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 rotation direction, and the rotary table 3A
It slides with A and performs 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 periphery and is rotating, the raw material in which the spiral is drawn enters the crushing roller 4 and the rotary table 3A from a direction forming an angle with the roller axial direction and is bitten. It is crushed and crushed.

On the other hand, at the base of the casing 15, gas such as air or hot air is introduced by a duct,
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, so that the pulverized fine powder is entrained in the gas and the casing 1
5, the blade 1 of the separator 13 that is located in the upper part
The product having a predetermined particle size is subjected to the classification action by 3A and is discharged together with the gas from the discharge port 16 and sent to the next step.

[0006]

In the conventional vertical crusher as described above, in order for the raw material dropped on the rotary table 3A of the pulverizer to be successfully brought into contact with the pulverizing roller 4 and to be bitten, the raw material is In the case of a raw material having a smooth surface with a smooth surface and a small friction coefficient, even if the crushing roller 4 is strongly pressed toward the rotary table 3A, the raw material interposed between the two is It is not possible to escape to the side and give effective crushing power to the raw material. Raw materials with a small coefficient of friction generally contain less water, so
The coefficient of friction must be increased by adjusting the water content of the raw material to an appropriate value in advance. Of these raw materials with low water content and low friction coefficient, especially those with relatively poor pulverizability,
Mill vibration often occurs, and when the vibration value (amplitude) is particularly large, the equipment may be damaged or operation may stop, and the machine may be forced to suspend operation.

As described above, when the vibration value of the mill during operation becomes much larger than the normal value of 50 μm of one-sided amplitude, and when this state continues, some measure is taken to reduce the vibration value of the mill immediately. There must be. As a means for that, for example, the raw material supplied to the crusher is temporarily reduced, the air flow of the mill is increased, water is added to the raw material, or the mill operation is stopped. .. However, a decrease in the supply of raw materials and suspension of mill operation lead to a decrease in processing capacity. An increase in air flow through the mill results in coarser product grain size, resulting in lower product quality. Improving the friction coefficient by adding moisture increases product moisture. Then, the quality of the product is deteriorated, which in turn has a secondary adverse effect.

The vibrations of the vertical crusher are roughly classified into transient vibrations and self-excited vibrations. The transient vibrations are shown in FIG.
As shown in, the amplitude is small and the amplitude is small and converges in a short time.
On the other hand, the self-excited vibration is also called “chatter vibration”, and as shown in FIG. 7, once the vibration starts, it lasts for a considerable time and the amplitude is large, which causes damage to the equipment and lowers the grinding efficiency. ， In extreme cases, it becomes impossible to operate.

[0009]

In order to solve the above problems, in the vertical crusher of the present invention, a plurality of rotatable crushing rollers are arranged on the upper surface of the outer peripheral portion of the rotary table. A vertical pulverizer equipped with hydraulic means for varying the oil pressure for pressing the crushing roller against the rotary table and crushing the raw material supplied to the central part of the rotary table between the upper surface of the rotary table and the peripheral surface of the crushing roller is A vibrometer was attached and the motor for driving the rotary table was a variable speed motor, and the vibration waveform recorded by the vibrometer (vibration mode) was compared with several preset vibration waveforms (vibration mode) and designated. When the vibration waveform (vibration mode) substantially matches, the control device is provided to reduce the rotation speed of the variable speed motor.

[0010]

In the vertical crusher of the present invention, the vibration waveform (vibration mode) measured momentarily by the vibrometer attached to the casing of the vertical crusher is compared with the preset vibration mode,
The vibration value is reduced by issuing a command to the controller of the variable-speed motor to reduce the rotation speed only when the specified vibration mode is approximately met. The designated mode that requires vibration countermeasures is so-called self-excited vibration (chatter vibration), and other transient vibrations with small amplitude will be calmed down without action, so there is no problem. ..

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 4 show a vertical crusher according to an embodiment of the present invention, FIG. 1 is a flow sheet of the vertical crusher, FIG. 2 is a control block diagram of a control device, and FIG. 3 shows one embodiment. Control system diagram, FIG. 4 is a control system diagram showing another embodiment. In the figure, 1 is a vertical crusher, 2A is a variable speed electric motor for driving a rotary table, 2B is a controller for the variable speed electric motor 2A, 9A is a hydraulic unit of a hydraulic cylinder 9 which is a hydraulic means for tensioning the crushing roller 4, 9B is a pressure gauge, 60
Is a raw material conveyor, 70 is a raw material hopper, 80 is a constant feed ware, 80a is a variable speed electric motor for the same, 80
b is a constant feed ware 80 weighing machine, 90
Is a dust collector, 100 is a suction fan, 140 is a vibrometer, 1
Reference numeral 50 denotes a control device, and the control device 150 includes a setting device, a control device (regulator and operation device), as shown in FIG.
The amplifier is stored. Each device of the main body of the vertical crusher 1 is as described in the related art, and its description is omitted.

Next, the operation of the controller 150 will be described. As shown in FIG. 2, the measurement result of the vibrometer 140, which is measured at every time interval set by the timer, the rotation speed of the variable speed motor 2A, the crushing roller 4, and the tensioning hydraulic cylinder 9
Information of the tension pressure of the pressure gauge 9B is converted into an electric signal and input to the control device 150. Vibration waveform (vibration mode) of these three information (vibration value, rotation speed, tension pressure)
And a specified vibration mode input to the setting device in advance are compared by a comparator, and when the measured vibration mode matches the specified vibration mode, the rotational speed of the variable speed electric motor 2A is controlled via the controller. To increase or decrease the rotation speed of the turntable 3A. The specified vibration mode, standard rotation speed, and standard tension hydraulic pressure are put in the setter. The controller is composed of an adjuster and an operating device, and the adjuster is a range of increase / decrease of the rotation speed of the variable speed electric motor 2A for driving the rotary table according to the difference between the vibration mode and the vibration value (maximum amplitude) and the set value. Vibrations such as proportional action (P action), integral action (I action), derivative action (D action), proportional integral action (PI action), proportional derivative action (PD action), etc. It can be used properly according to the change situation of the value. In addition to the above, the controller also has a role of instructing the width of decreasing the rotational speed and the width of decreasing the tension hydraulic pressure according to how the measured value exceeds the set value of vibration. The operation unit transmits an operation command to the controller 2B of the variable speed electric motor 2A and the hydraulic unit 9A based on the instruction from the controller. The lines with arrows in the figure show the flow of signals.

FIG. 3 shows a flow of a control system showing one embodiment of the present invention. Vibration measurement is performed at a time interval designated by a running timer, and a vibration value and a vibration mode are compared with a set value. When they match or almost match, the rotation speed of the variable speed electric motor 2A is decreased. When the measured vibration mode does not match the specified vibration mode and the vibration value is low and the rotation speed is lower than the standard value, the rotation speed is increased, and if the standard rotation speed is reached, the operation is continued as it is. As described above, when the vibration is severe, the rotation speed is reduced to reduce the vibration, and when the vibration is stopped, the rotation speed is returned to the original standard value, which is the control method shown in FIG.

On the other hand, FIG. 4 shows another embodiment, and is a control system diagram showing a control for controlling not only the rotational speed but also the tension hydraulic pressure as the vibration occurs. That is, the measured vibration waveform and the measured vibration value are compared with the designated vibration mode. Decrease the rotation speed and reduce the hydraulic pressure unless the tension hydraulic pressure is lower than the specified range. On the other hand, when the vibration value is low and the vibration mode is different from the specified one, the hydraulic pressure is increased if the tension hydraulic pressure is below the specified range, and if the tension hydraulic pressure is within the specified range, the decrease in rotational speed is covered and increased. .. The control in the case of FIG. 4 is to perform two operations of oil pressure and rotation speed when vibration occurs, and to selectively use oil pressure changing operation and rotation speed changing operation according to the degree of vibration.
Depending on the type of crushed raw material, the one that is effective in suppressing vibration is mainly controlled. The specified vibration mode is the self-excited vibration mode as shown in FIG. 7, but in addition to this, even if a moderate vibration mode is specified and an operation for this is performed, good.

The increase and decrease of the feed material in the above two control operations both adjust the supply amount according to the pressure loss in the mill. This is to increase or decrease the rotation speed of the variable speed electric motor 80a of the constant feed wear 80 so that the differential pressure in the mill is achieved.

By performing the automatic control having the feedback mechanism as described above, when the vibration value sharply increases and this state is continued, the oil pressure is reduced in order to promptly improve this state. By lowering the rotation speed or lowering the rotation speed, the biting and crushing action of the raw material is improved, and the original stable operating state can be restored.

[0017]

As is apparent from the above description, in the vertical crusher of the present invention, the rotary table is automatically rotated before the vibration value becomes large during operation and the vibration value continues and eventually becomes inoperable. Change the number to suppress the continuation of abnormal vibration,
Return to the original stable operating condition. In addition, after abnormal vibration is stopped, it automatically returns to the standard operating state to prevent a reduction in the crushing amount, ensuring long-term stable continuous operation, and improving maintenance, operability, and production efficiency.

[Brief description of 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 a control system diagram showing one embodiment of a vertical crusher of the present invention.

FIG. 4 is a control system diagram showing another embodiment of the vertical crusher of the present invention.

FIG. 5 is an overall vertical sectional view of a conventional vertical crusher.

FIG. 6 is a vibration state (transient vibration) diagram of a conventional vertical crusher.

FIG. 7 is a vibration state (self-excited vibration) diagram of a conventional vertical crusher.

[Explanation of symbols]

 1 Vertical Grinder 2 Reducer 2A Variable Speed Motor 2K Constant Speed Motor 3A Rotary Table 4 Grinding Roller 5 Arm 9 Hydraulic Cylinder 9A Hydraulic Unit 9B Pressure Gauge 15 Casing 60 Raw Material Conveyor 70 Raw Material Hopper 80 Constant Feed Wear 80a Variable Speed Electric Motor 80b Weighing machine 90 Dust collector 100 Suction fan 140 Vibrometer 150 Controller

Claims (1)

[Claims] 1. A rotary table is provided with a plurality of rotatable crushing rollers on an upper surface of an outer peripheral portion thereof, and a hydraulic means having a variable oil pressure for pressing the crushing rollers against the rotary table is provided, and is supplied to a central portion of the rotary table. In a vertical crusher that crushes the raw material between the upper surface of the rotary table and the peripheral surface of the crushing roller, a vibrometer was installed in the casing, and the motor for driving the rotary table was a variable speed electric motor. A vibration waveform (vibration mode) is compared with several preset vibration waveforms (vibration mode), and when the vibration waveform (vibration mode) substantially matches the specified vibration waveform, a control device that reduces the rotation speed of the variable speed motor is provided. A vertical crusher equipped.