JPH0456673B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an operation control device for a pulverization system, and particularly to one improved so that the operation efficiency thereof is always optimized.

[Background of the invention and its problems]

Generally, the operation control device for a grinding system such as a ball mill uses a CFW constant flow rate control method using a so-called constant feedway (hereinafter referred to as CFW) to control the amount of material to be ground fed into the grinding system. Ta. However, since this method does not take into account changes in the operating conditions of the grinding system, it is not always possible to obtain satisfactory control results.

For this reason, recent efforts have been made to detect physical quantities that change according to the operating conditions of the crushing system and to keep them constant.
A CFW flow rate variable control system that variably controls the CFW flow rate is adopted.

In other words, this CFW flow rate variable control method is the fourth
As shown in the figure, the operating efficiency of the grinding system can be improved by determining the physical quantity when the grinding amount of the grinding system reaches its maximum, such as the so-called bucket elevator load value or mill sound pressure value, and setting this as the target value. This is a method of controlling to achieve the optimum.

However, even with this method, due to changes in the properties of the material to be crushed, changes in the balls in the mill over time, and various other disturbances, the optimum values of the above physical quantities, that is, the target values to be set, may change as shown in Figure 5. As a result, it has been difficult to control the operating efficiency of the grinding system so that it is always optimal.

[Purpose of the invention]

Therefore, this invention was made in view of the above points, and it is possible to accurately and quickly search for the optimum point of the target value corresponding to the physical quantity to be set by following its fluctuation, thereby improving the operation. The object of the present invention is to provide an extremely good operation control device for a grinding system that has been improved so that efficiency can always be controlled to the optimum level.

[Summary of the invention]

That is, in order to achieve the above object, the present invention includes a detection means for detecting a physical quantity that changes depending on the operating conditions of a crushing system as a controlled signal, and a detection means for detecting a physical quantity that changes depending on the operating conditions of a grinding system, and a detection means for detecting a physical quantity that changes depending on the operating conditions of a crushing system, and a detection means for detecting a physical quantity that changes depending on the operating conditions of a grinding system. and a control system for sending a control signal for a constant value control mode to the grinding system to variably control the amount of material to be crushed to be supplied to the grinding system based on the target value, the target value Setting value data for each three points A ₁ , A ₂ , A ₃ that takes a predetermined step as
a setting means for sequentially setting the above-mentioned setting value data A ₁ ,
Pulverization amount actual data for the above-mentioned crushing system based on A ₂ and A ₃
A calculation means for calculating X ₁ , X ₂ , X ₃ , and actual crushing amount data X ₁ , X ₂ ,
After comparing X ₃ and determining that the X ₂ data is not the maximum, perform the above 3 so that the X ₂ data is the maximum.
a first comparison command means for instructing the setting means to change the setting value data A ₁ , A ₂ , A ₃ for each point; and crushing amount actual data calculated by the calculation means.
Compare X _{1 , X 2 ,} and ₁ ,
The present invention is characterized by comprising second comparison command means for commanding the setting means to change the settings of A ₂ and A ₃ .

[Embodiments of the invention]

An embodiment of the present invention will be described in detail below with reference to the drawings.

That is, in FIG. 1, 10 is a crushing system, a ball mill 11, and a bucket elevator 1.
2. Separator 13, belt scale 14, and sound pressure detectors 15a and 15b such as microphones.
It is composed of etc. Then, the crushed clinker, which is obtained by crushing the clinker which is the material to be crushed discharged from the ball mill 11, is transported to the bucket elevator 1.
2 to the separator 13. The crushed clinker transferred to this separator 12 is classified here, so that a part of it is transferred to the discharge port 13.
1 is discharged as a pulverized product, and the remainder is fed into the ball mill 11 again via a return path 132.

Further, clinker, which is a material to be crushed, is fed into the ball mill 11 in an amount according to a command by a control signal outputted from a control unit 30 as a control system, which will be described later, using a belt scale 14. .

The bucket elevator 12 is provided with a detector 16 for detecting a driving load (for example, bucket elevator current or electric power) of a motor (not shown) that is a driving source of the bucket elevator 12.

Each detection output from each of the detectors 15a, 15b, and 16 is sent to an analog-to-digital converter (hereinafter referred to as
ADC) 31 is supplied as a controlled signal component that provides a physical quantity that changes according to the operating conditions of the grinding system 10.

On the other hand, the control unit 30 as the control system includes, in addition to the ADC 31, a digital input unit (hereinafter referred to as DI) 32, a central processing unit (hereinafter referred to as CPU) 33, a read
Only memory (hereinafter referred to as ROM) 34a, random access memory (hereinafter referred to as RAM)
34b, interface 35 and digital
Analog converter (hereinafter referred to as DAC) 36
It is composed of etc.

Each of the detection outputs, that is, the controlled signal components inputted to the ADC 31 is digitized and then supplied to the CPU 33 via the DI 32.

Here, the CPU 33 uses the controlled signal component as the above-mentioned input signal according to the program contents stored in the ROM 34a and three-point target settings for the automatic control follow-up fixed value control mode registered in advance in the RAM 34b. A CFW that performs so-called PID calculations and other necessary calculations based on each value data and has a three-point comparison tracking function as described below.
A control signal based on the variable flow rate control system is converted into an analog signal via an interface 35 and a DAC, and is supplied to the belt scale 14 in the grinding system 10.

Note that the RAM 34b has the above-mentioned 3
It is assumed that an area is provided in addition to the area for storing the point set value data, in correspondence with each of these points, for storing the operating efficiency of the grinding system 10 at each set value. For example, if the initial setting value is A ₀ and the step width is given as △a, then A ₁ = A ₀ - △
a, A ₂ = A ₀ , A ₂ = A ₀ + △a, taking a value that is centered around A ₀ and deviates by a slight amount △a at its height.
Three set values A ₁ , A ₂ , and A ₃ are set in the RAM 34b.

Next, the operation of the pulverization system operation control device configured as described above will be explained with reference to the flowchart shown in FIG.

That is, first, set value data A ₁ ,
Steps S1 to A2 to set _A2 and _A3 in order and sample the performance of each operation efficiency.
S4 is performed. The results of this sampling are expressed as values X ₁ , X ₂ , and X ₃ that are the sum of the amount of pulverization for a certain period of time after the operation for each of the above-mentioned set values has become sufficiently stable in steps S5 and S6, for example.

Next, the actual values obtained in this way X ₁ , X ₂ ,
For the _X3 data, by steps S7 to S8,
When they are all present, S ₁ = (X ₂ −X ₁ ) and
3 above, which calculates the sign of S ₂ = (X ₃ − X ₂ )
A comparison is made of each actual value against the point set value.

Then, in step S9, the above comparison formulas _S1 and
Find each combination of codes in S ₂ and perform a different post-processing procedure for each combination.

First, both S ₁ and S ₂ are positive (S ₁ , S ₂
), the optimum point is further in the positive direction than each set value A ₁ , A ₂ , A ₃ , so step S1
0, A ₂ → A ₁ , A ₃ → A ₂ , that is, the actual value becomes X ₂ → X ₁ , X ₃ → X ₂ , and _{A 3 +} △a is changed to a new A to clear set as ₃ ,
A command is issued to perform sampling accordingly.

Also, if S ₁ is positive and S ₂ is negative (S ₁
, S ₂ ) has an optimal point between A ₁ and A ₂ , so
The maximum point is determined in step S11. That is, in step S11, a quadratic curve passing through the three points (A ₁ , X ₁ ), (A ₂ , X ₂ ), and (A ₃ , X ₃ ) in the (A, The A coordinate that gives the maximum value is set as a new A ₂ , and A ₂ + △a
=A ₃ , A ₂ +△a=A ₁ and these new A ₁ ,
By sampling A ₂ and A ₃ in this order, a command is issued that can clear the above-mentioned X ₁ , X ₂ , and X ₃ . Note that the limit (Amax) in step S12 is Amax=X ₂ A ₁ ² −X ₁ A ₁ ² +X ₁ A ₃ ² −X ₂ A ₃ ² /2 (X ₂ A ₁ −X ₃ A,
+X ₃ A ₂ −X ₁ A ₂ +X ₁ A ₃ −X ₂ A ₃ ).

Then if S ₁ is negative S ₂ is positive (S ₁ ,
Since there is a minimum point between A ₁ and A ₂ in S ₂ ), which does not match the actual process, the data is retaken in step S12, that is, X ₁ , X ₂ ,
A command is issued to clear X ₃ and perform sampling again in the order of A ₁ , A ₂ , and A ₃ .

Then, both S ₁ and S ₂ are negative (S ₁ ,
In the case of _S2 ), it is determined that the optimal point is further in the negative direction than _A1 , so step S13
Therefore, A ₂ →A ₃ , A ₁ →A ₂ or X ₂ →X ₃ , X ₁ →X ₂
A new A ₃ + △a to clear X ₁ as
Set it as A ₁ and issue a command to perform sampling accordingly.

The commands from steps S11 to S13 are used to perform the same processing as steps S1 to S9 through changing the set values in step S14.

In other words, according to the control form of the three-point comparison follow-up method as described above, when the operating efficiency improves in the order of the three set values A ₁ , A ₂ , and A ₃ set in a predetermined step, the higher The three set values A ₁ , A ₂ , A ₃ are changed so that the efficiency at A 2 is maximized, and the efficiency at A ₂ is reached at the maximum _.
When the state where the efficiency is maximum is reached, approximation is performed using a quadratic curve, and its extreme value is A ₂ (or X ₂ )
Since sampling control is performed so that the following is achieved, the operating efficiency can always be optimized.

Thus, according to this embodiment, the optimal point of the setting values of the mill 11 can be searched for accurately and quickly.
The mill 11 can be operated stably with high efficiency. This effect will be specifically explained with reference to FIG. 3 as follows.

That is, suppose that the mill had been operating at the sound pressure optimum point x ₁ until a certain point t ₀ , but this optimum point changed significantly due to changes in the concretion and became x ₂ . At this time, by controlling the three-point comparison follow-up method as described above, a new optimal point _x2 can be quickly found as shown by the solid line Q in FIG. It has also been confirmed that the optimum point search speed of this embodiment is faster even for random disturbances with a frequency comparable to the sampling period.

Note that the present invention is not limited to the embodiments described above. For example, the crusher is not limited to a ball mill, and various types of mills may be used. In addition, the physical quantities defined as set values are not limited to BE current, sound pressure, etc.
Any value that changes depending on the operating conditions of the mill may be used. Moreover, as a value for evaluation, it is possible to use the power source unit E instead of the amount of pulverization.

〔Effect of the invention〕

Therefore, as detailed above, according to the present invention, it is possible to accurately and quickly search for the optimal point of the target value corresponding to the physical quantity to be set by following its fluctuation, thereby improving operational efficiency. It is possible to provide an extremely good operation control device for a grinding system that has been improved so that it can always be controlled optimally.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram showing an embodiment of the operation control device for a grinding system according to the present invention, FIG. 2 is a flowchart for explaining the operation of FIG. 1, and FIG. 3 is an effect of FIG. 1. FIGS. 4 and 5 are schematic diagrams for explaining changes in the optimum point of set values due to various disturbances. 10... Grinding system, 11... Ball mill, 12...
...bucket elevator, 13...separator,
14... Belt scale, 15a, 15b...
Sound pressure detector (microphone), 131...exhaust port,
132...Return path, 16...Detector, 3
0...Control unit (control system), 31
...ADC, 32...DI, 33...CPU, 34a
...ROM, 34b...RAM, 35...Interface, 36...DAC.

Claims (1)

[Claims] 1. A detection means for detecting a physical quantity that changes depending on the operating conditions of the grinding system as a controlled signal, and a detection means for detecting the amount of material to be ground to be supplied to the grinding system so that the controlled signal from this detection means is constant. In an operation control device for a grinding system that includes a control system that sends a control signal for a fixed value control mode to the grinding system that performs variable control based on a target value, set values for every three points that take a predetermined step as the target value are set. Data A ₁ , A ₂ , A ₃
a setting means for sequentially setting , and setting value data A ₁ , for each of the three points sequentially set by this setting means;
Actual crushing amount data for the above-mentioned crushing system based on A ₂ and A ₃
A calculation means for calculating X ₁ , X ₂ , X ₃ , and actual crushing amount data X ₁ , X ₂ ,
After comparing X ₃ and determining that the X ₂ data is not the maximum, perform the above 3 so that the X ₂ data is the maximum.
a first comparison command means for instructing the setting means to change the setting value data A ₁ , A ₂ , A ₃ for each point; and crushing amount actual data calculated by the calculation means.
Compare X _{1 , X 2 ,} and ₁ ,
An operation control device for a crushing system, comprising: second comparison command means for commanding the setting means to change the settings of A 2 _{and A 3 .}