JP2711774B2 - Operating method of vertical mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating 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 crusher for finely pulverizing raw materials such as limestone, slag, and cement raw material 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
A disk-shaped rotary table 3A, which is driven by the speed reducer 2 by the constant speed motor 2K and is rotated at a low speed at the lower portion of the cylindrical casing 15, is pressed against a portion equally dividing the outer peripheral portion of the upper surface in the circumferential direction by hydraulic pressure or the like. And a plurality of crushing rollers 4 that are driven and rotated.

The crushing roller 4 has a rotating shaft 6
The arm 5 is pivotally supported by an arm 5 and is connected to a piston rod 10 of a hydraulic cylinder 9 via an arm 7. By operating the hydraulic cylinder 9, the grinding roller 4 is pressed onto the rotary table 3 </ b> A. To give the grinding pressure to the raw material. 3B is a dam ring provided on the outer periphery of the rotary table 3A to adjust the thickness of the raw material layer, 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 guguto.
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, the amount of the raw material supplied into the crusher depends on the inlet pressure and the outlet pressure of the gas introduced into the vertical crusher. The differential pressure was controlled to be constant, and was independent of the thickness of the raw material layer on the rotating table during operation. However, in a vertical mill, there is a close relationship between the type of raw material to be ground and the amount of raw material supplied, the tension hydraulic pressure of the grinding roller, and the thickness of the raw material layer on the rotary table. In order to perform the operation with high grinding efficiency while maintaining the temperature at the same time and improving the processing capacity of the vertical grinding machine as much as It is essential to always use the rotating table drive motor, which is the main power unit of the crusher, with an allowable rated output. In addition, in order to maintain stable and continuous operation, it is important to continue grinding with a raw material layer thickness suitable for the type of raw material being ground. However, the operation method of changing and controlling each crushing condition of the vertical crusher so as to maintain the desired set range while monitoring the instantaneous measured values of the power value and the raw material layer thickness has been well established. I didn't.

[0007]

In order to solve the above problems, the present invention comprises a variable-speed constant feed ware for transporting raw materials, a variable-speed rotary table, and a raw material layer thickness. In a vertical pulverizer equipped with a laser displacement gauge and a programmable actuator for measuring the output, the output power value of the variable speed motor for driving the rotary table during operation and the measured value of the raw material layer thickness are compared with the preset setting range. ,
When the electric power value does not reach the set range, the raw material supply amount is increased in proportion to the shortage, and the rotation speed of the turntable is increased in proportion to the raw material supply increase ratio. The amount of raw material supplied is reduced in inverse proportion to the amount, and the number of revolutions of the rotary table is reduced in proportion to the raw material supply reduction ratio. When the power value is within the set range and the raw material layer thickness is lower than the set range, the grinding roller Reducing the tension hydraulic pressure and / or reducing the rotation speed of the rotary table, and increasing the tension hydraulic pressure of the grinding roller when the power value is within the set range and the raw material layer thickness is higher than the set range, and / or An operation method was adopted in which the number of revolutions of the turntable was increased, and when the electric power value and the thickness of the raw material layer were both within the set ranges, the operation state was maintained.

[0008]

In the operation method of the vertical crusher according to the present invention, the power value of the variable speed motor for driving the rotary table (for the mill) and the actually measured value of the raw material layer thickness which are measured every moment are supplied to the programmable actuator. The tension hydraulic pressure, the amount of raw material supplied, and the electric motor The number of revolutions (that is, the number of revolutions of the turntable) is controlled.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 5 relate to an embodiment of the present invention.
1 is a flow sheet of a vertical crusher, FIG. 2 is a control block diagram of the vertical crusher, FIG. 3 is a control system diagram of the vertical crusher, FIG. FIG. 5 is a principle diagram of the laser displacement meter.

In the drawing, 1 is a vertical mill, 2A is a variable speed motor for driving a rotary table, and 2B is a variable speed motor 2
Controller A, 9A is a hydraulic unit of the hydraulic cylinder 9 for tensioning the crushing roller 4, 60 is a raw material conveyor, 70
Is raw material hopper, 80 is constant feed wear,
80a is the same variable speed motor, 80b is a weighing machine of the constant feedware 80, 90 is a dust collector, 100 is a suction fan, 130 is a laser displacement meter, 150 is a programmable operation device, and 150 is a programmable operation device. As shown in FIG. 2, a comparator, a setting device, a controller (a controller and an operating device), and an amplifier are housed therein. Each device of the main body of the vertical crusher 1 is as described in the prior art, and the description thereof will be omitted.

Next, a description will be given of the laser displacement meter 130. As shown in FIGS. 4 and 5, a measuring plate 90 is fixed to a piston rod 9a of a hydraulic cylinder 9 connected to the crushing roller 4 via a support. A laser displacement gauge 130 is attached to the side surface of the hydraulic cylinder 90 so as to face the measuring plate 90, and a distance A corresponding to the raw material layer thickness B that changes every moment is measured. FIG. 5 shows the principle of the laser displacement meter 130. The laser light from the light source of the sensor section is obliquely incident on the measuring plate 90, is reflected on the surface of the measuring plate 90, and then passes through the condensing lens. An image is formed on the sensor. The image formed on the image sensor also moves in accordance with the position of the measurement plate moving in the measurement range W. This is caught by the image sensor driver and sent to the display unit in the form of an electric signal, and the digital or analog output signal is programmable. It is transmitted to the operation device 150.

Next, the operation of the programmable controller 150 will be described. As shown in FIG. 2, the measurement results of the variable speed motor wattmeter 2C for mill and the laser displacement meter 130, which are measured every time interval set by the timer, are converted into electric signals and input to the programmable controller 150. You. These two information (power value and raw material layer thickness) are compared with a set value input to the setter in advance by a comparator, and if the set value is out of the range, it is crushed via the controller. The power value and the raw material layer thickness are improved by changing the oil pressure applied to the rollers, and then the rotation speed of the variable speed motor 2A is controlled to increase or decrease the rotation speed of the turntable 3A. The reference power value and reference material layer thickness are set in the set values. The controller is composed of a controller and an operating device. The controller adjusts the tension and the speed of the variable speed motor for driving the constant feed wear according to the difference between the set value and the measured value of the electric power value or raw material layer thickness. It instructs the range of increase / decrease of the number of revolutions of the variable speed motor for driving the rotary table (for the mill). The control operation includes proportional operation (P operation), integration operation (I operation), differentiation operation (D operation), Proportional integration operation (PI operation), proportional differentiation operation (PD operation), etc.
It can be used properly according to the situation of the change of the raw material moisture. The raw material supply amount is obtained by integrating the measured values of the weighing machine 80b of the constant feed ware 80 in units of time. The above reference power value and reference material layer thickness are 1
It is not a point but a certain width. In the case of power value, it is up to 10% above and below the rating, and the thickness of the raw material layer is determined in consideration of the type, model number, and fineness of the raw material.

The operating device transmits an operation command to the hydraulic unit 9A or the variable speed motor 2A or the variable speed motor 80a based on an instruction from the controller. The line with the arrow in the figure indicates the signal flow.

The flow of the control system of the programmable controller 150 is as shown in FIG. That is,
The power value and raw material layer thickness of the variable speed electric motor for mill 2A are measured at the time intervals specified by the timer during operation, and when the power value is below the set range, the ratio input to the setter in advance in proportion to the shortage. Then, the rotation speed of the variable speed electric motor for mill 2A is increased to keep the raw material layer thickness at the original height so that the raw material supply amount is increased and the raw material layer thickness is not increased accordingly. On the other hand, when the power value exceeds the set range and the system is overloaded, stable operation is feared. Therefore, the amount of raw material supplied is reduced in inverse proportion to the excess amount according to a predetermined ratio, and the mill speed is reduced. The number of rotations of the electric motor 2A is reduced to maintain the thickness of the raw material layer. In this way, when the electric power value is within the set range and the raw material layer thickness is lower than the set range, the tension oil pressure is reduced according to a predetermined ratio, and after the time set by the timer, the actual measured value of the raw material layer thickness and the set range are again set. And if it is still low, reduce the number of revolutions of the turntable. Conversely, when the raw material layer thickness is higher than the set range, the tension oil pressure is increased, and after the timer set time, the measured value is similarly compared with the set range. When both the electric power value and the raw material layer thickness are within the set ranges, the operation is continued as it is.

In this way, after the operation is changed, after the elapse of a certain time by the timer, the electric power value and the laser displacement
The measured value of the raw material layer thickness according to 0 is compared with the set value, and when the set value is exceeded, the above operation is repeated. As described above, the set value of the electric power value is about ± 10% of the rated value, and the set value of the raw material layer thickness depends on the type of raw material, the model of the crusher, and the product particle size, and cannot be determined unconditionally. The set layer thickness increases as the size of the pulverizer or the size of the product increases. It is advisable to grasp the situation based on operation results and test runs and select an appropriate value.

By performing the automatic control having the above-described feedback mechanism, the power value increases suddenly, or the water content of the feed material suddenly decreases (or increases) during operation, and the grinding efficiency decreases. Even if the milling vibrations increase due to poor biting, the above operation improves the raw material supply amount and the raw material layer thickness, and the raw material bite is improved again to maintain the stable operation. You can return to the state.

[0017]

As is apparent from the above description, in the method of operating the vertical pulverizer of the present invention, the electric power value of the variable speed electric motor for the mill (for driving the rotary table) and the actually measured values of the raw material layer thickness are used. By constantly controlling the tension hydraulic pressure, the raw material supply amount, and the rotation table rotation speed so as to fall within the set ranges, stable continuous operation can be performed while obtaining a sufficient processing capacity. Therefore, driving operability and production efficiency are significantly 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 a vertical mill according to an embodiment of the present invention.

FIG. 3 is a control system diagram of a vertical mill according to an embodiment of the present invention.

FIG. 4 is a vertical sectional view of a main part of a vertical pulverizer according to an embodiment of the present invention.

FIG. 5 is a principle diagram of the laser displacement meter according to the embodiment of the present invention.

FIG. 6 is an overall vertical sectional view of a conventional vertical crusher.

[Description of Signs] 1 Vertical crusher 2 Reducer 2A Variable speed motor 2B Controller 2C Power meter 2K Constant speed motor 3A Rotary table 4 Crush roller 5 Arm 6 Rotary shaft 9 Hydraulic cylinder 9A Hydraulic unit 15 Casing 60 Raw material conveyor 70 Raw material Hopper 80 Constant feed wear 80a Variable speed motor 80b Weighing machine 90 Dust collector 100 Suction fan 130 Laser displacement meter 150 Programmable actuator

Claims (1)

(57) [Claims] 1. A variable speed constant feed ware for transporting raw materials, a plurality of rotatable crushing rollers arranged on an upper surface of an outer peripheral portion of a variable speed rotary table, and tensioning the crushing roller to the upper surface of the rotary table. A vertical cylinder having a hydraulic cylinder for grinding the raw material supplied to the rotary table between the upper surface of the rotary table and the peripheral surface of the grinding roller.
In a vertical grinding machine equipped with a laser displacement gauge for measuring the thickness of the raw material layer on the rotary table and a programmable controller, the output power value of the variable speed motor for driving the rotary table during operation and the measured value of the raw material layer thickness Is compared with a preset setting range, and when the power value does not reach the setting range, the amount of raw material supplied is increased in proportion to the shortage, and the number of rotations of the rotary table is increased in accordance with the raw material supply increasing ratio. Exceeds the set range, the feed rate is reduced in inverse proportion to the excess amount, and the rotation speed of the turntable is reduced in proportion to the feed rate reduction rate. If the thickness is lower than the set range, reduce the tension oil pressure of the grinding roller and / or reduce the number of revolutions of the rotary table so that the power value is within the set range and When the pressure is higher than the set range, the tension hydraulic pressure of the crushing roller is increased and / or the number of revolutions of the rotary table is increased. When both the electric power value and the raw material layer thickness are within the set range, the vertical operating state is maintained. Operating method of the mold crusher.