JPS59123904A - Raw material blending control system - Google Patents

Abstract

PURPOSE:To obtain a product of high quality by analyzing composition of mixed raw materials, operating the result of analysis, sending a controlling signal from the result to gate mechanisms of hoppers and correcting the quantity of supply of the raw materials. CONSTITUTION:Raw materials passed through gate mechanisms 11a, 11b... of a group of hoppers that supply raw materials are mixed 13 and the composition is analyzed 14 and sent to a controlling device 20. In the device 20, the result of analysis is stored in a memory 23 as an analysis table X. Then, a processing unit 22 performs estimated calculation of composition and calculation of quantity of supply of the raw materials from the contents of the table X, and stores the quantity of supply of each ras material in a table S as function of time. For the quantity of supply thus obtained, a processing unit 22 calculates the amount of control for gate mechanisms 11a, 11b..., and sends out controlling signals to the gate mechanism 11a etc. through an I/O interface circuit 24, and the corrected quantity of raw materials are supplied from the group of hoppers 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a raw material blending control system, and particularly to a raw material blending control system for cement.

The outline is that a memory is provided that has a storage table for the component composition ratio of each cement raw material and a storage table for the amount of raw material cut out, and the component ratio of the mixed raw materials is analyzed by an analyzer. The calculation processing unit calculates the component composition ratio of a predetermined raw material from the analyzed component composition ratio and the raw material cutting amount, and calculates the component composition ratio of the predetermined raw material in the storage table. A raw material blending control method that calculates and controls the amount of correction for the amount of raw material cut out using the data in the updated memory table By doing this, even if there is a change in the component composition ratio of the raw material, it can be adjusted accordingly. It is possible to produce high-quality cement with a predetermined hydraulic hardness rate, silicate rate, and iron weight through precise control.

By the way, in raw material mixing control for cement,
Generally, multiple types of raw materials are cut out, crushed, and mixed, and during the mixing process, it is necessary to adjust the component composition ratio to a certain standard range.

Here, the raw material usually contains various components, including a predetermined component as the main component. The composition of materials used as raw materials for cement includes, in addition to the main component, other components that make up the cement. Therefore, in general, the average value of the composition ratio for each raw material is stored in a table, and this is used as basic data for control calculations to determine the amount of cement raw material to be cut out, and to achieve a predetermined hydraulic ratio. , to obtain silicic acid rate and mixed raw materials for iron cars.

First, the structure and problems of such a conventional raw material mixing control system for cement will be explained.

FIG. 1 is a block diagram showing the processing of a conventional raw material mixing control system for cement.

In the figure, ■ is a process to be controlled,
Specifically, it consists of a mixing device that mixes and adjusts the components of cement, an analyzer that analyzes the blend composition ratio, and the like. Normally, each raw material for cement is once supplied to each hopper, and a gate mechanism provided at the outlet of each hopper is controlled to supply a predetermined amount (Wj) of each raw material stored in each hopper.
) is cut out and supplied to a mixing device as this process 1.

In process 1, the composition ratio of the mixed cement raw materials is analyzed by an analyzer, and the analysis results are sent to the arithmetic processing unit 3 of the control device 2.

Here, the control device 2 is a so-called computer comprising an arithmetic processing section 3 mainly composed of a microprocessor and a memory 4, and the control device 2 calculates the hydraulic hardness, silicic acid content, etc. based on the analyzed composition ratio. Calculate the rate and train in processing step 3a,
The hydraulic ratio is calculated by reading out the previously set hydraulic ratio, silicic acid ratio, and iron rolling stock from the memory 4 from the area 4a.

Find the difference value between the silicate rate and the iron car. Then, in processing step 3b, each of these raw material composition ratios is read out from the area 4b that stores the memory table stored in the memory 4, and the raw material cutting amount is calculated from this and the calculated difference value. A control signal is sent to a gate mechanism provided in the hopper that adjusts the amount of raw material cut out, to correct the target hydraulic ratio, silicate ratio, and iron car. This controls the mixed raw materials to the set values (target hydraulic ratio, silicic acid ratio, and iron wheel).

Here is the target hydraulic rate stored in memory.

The silicate rate and iron wheel are generally set using an input/output device such as a keyboard input device.

However, with this control method, satisfactory control cannot be achieved depending on the nature of the composition variation rate of the raw material.

That is, if the fluctuation period of the composition ratio of the raw material is short compared to the target time (for example, in batch processing, the time required to mix the raw material to 60% to 70% of the silo capacity), even with this method, Since the fluctuations are integrated, it is not a big problem from a total perspective, but if the fluctuation period is long compared to the target time, for example, if there is a trend where the composition fluctuation within the target time changes at an angle. is not effective if the average value of the raw material composition ratio is used as the basic data for control calculations.

Hereinafter, to explain this in detail, as shown in FIG.
．． ..., n), the component analysis is generally not performed for each raw material, but for the prepared product. Then, based on the analysis result of the composition ratio of this mixed raw material and the composition ratio data of each raw material (stored in the memory table), the raw material cut-out amount Wj (j=1.2. . . ) in the next step is determined. , n),
A control signal for the amount of each raw material cut out is sent to the gate mechanism, and the composition ratio is controlled to the desired mixing amount.

Therefore, in relatively short cycles, errors cancel out, but in cases such as trends, errors accumulate. In other words, each value of the composition ratio stored in the table is an average value and is constant, but on the other hand, the composition ratio of the raw material that is actually cut out gradually changes.
This deviation becomes larger. Therefore, the errors are accumulated without being canceled, and as a result, the blended raw materials deviate from the target ratio, leading to a decrease in product quality, which is a problem.

In order to overcome this problem, as shown in Figure 2, the raw materials collected from the mountain 5 are not directly put into the omper,
There is the so-called minx hesod method, in which the raw materials are once piled up in a layer at another location (the state is 6), and then the raw materials are cut out from a certain direction again and transported to the hopper, but the transportation work is twice. This is a problem because it is time consuming and requires space to pile up.

This invention has been made in view of the problems of the prior art, and provides a raw material blending control system that eliminates the problems of the prior art and can produce high-quality products, such as cement l-. The purpose is to provide

In order to achieve such an object, the present invention performs calculations to estimate the raw material composition ratio at each time based on the analysis results of the analyzer, and uses the contents of the raw material composition ratios stored in the memory table as the calculation results. Based on this information, it will be updated sequentially. Then, based on this updated data, the raw material cutting amount corrected to the target value is obtained and controlled.

Therefore, the present invention has a composition ratio storage table that stores component composition ratios for predetermined components of a plurality of raw materials,
and a memory for storing a target component composition ratio or a component ratio between the components when the plurality of raw materials are mixed; a hopper, a mixing device that mixes the raw materials supplied from the hoppers, and a gate mechanism that supplies a predetermined amount of each raw material in the hopper to the mixing device in accordance with a control signal from the arithmetic processing unit. and an analyzer for analyzing the component composition ratio of the mixed raw materials mixed by the mixing device, and obtains a difference value between the target component composition ratio and the analyzed component composition ratio, or obtains the difference value between the target component composition ratio and the analyzed component composition ratio, or obtains the difference value between the target component composition ratio and the analyzed component composition ratio. Obtain the difference value between the component ratio and the component ratio obtained from the analyzed component composition ratio, refer to the composition ratio storage table, and adjust the mixed raw materials to achieve the target component composition ratio or the target component ratio. In the raw material formulation control method,
A raw material supply amount storage table is provided in the memory, and the raw material supply amount to be supplied is calculated based on the control signal, and this is used as actual raw material supply amount data to be sequentially stored in the raw material supply amount storage according to each control point. The component composition ratio of a predetermined raw material is estimated and calculated from the actual data of the raw material supply amount stored in the raw material supply amount storage table and the component composition ratio obtained from the analysis device, and the composition ratio is stored in the raw material supply amount storage table. The raw material blending control method having such a configuration updates the component composition ratio of a predetermined raw material stored in the raw material composition ratio.

With this configuration, the amount of raw material to be cut out can be determined in response to a change in the composition ratio of the raw material, and the control accuracy can be improved and the mixture can be prepared close to the target value.

Taking cement as an example, there are three types of target values set as important values for quality control: hydraulic ratio, silicate ratio, and iron wheel. It is expressed by the formula of component ratio.

However, each symbol C, S, A, and F in the above formula indicates each component of cement, and symbol C is Ca.
O, S is 5i02. A is AI, 0. , F is Fθ□03. Furthermore, HM indicates the hydraulic rate, SM indicates the silicic acid rate, and IM indicates the iron car.

Hereinafter, an embodiment of a raw material mixing control system for cement will be described with reference to the drawings, in which raw materials for cement are mixed using the hydraulic ratio HM, silicate ratio SM, and iron car IM as control targets.

FIG. 3 is a block diagram of a raw material blending control system for cement production using the raw material blending control method of the present invention.

In the figure, 10 is a group of hoppers that supply each raw material,
It consists of hoppers 10a, lOb, ++, and lOn. This hopper group 10 is provided with a gate mechanism group 11. The gate mechanism group 11 includes each hopper 10a.
, 10b, . . . , 10n gate mechanisms 11a, llb, .
It is equipped with This gate mechanism 11a, llb, ・
. Each cut raw material is
Once it is dropped onto a belt conveyor 12, it is conveyed to a mixing device 13 via this belt conveyor 12.

The blended raw materials mixed in the mixer 13 pass through the analyzer 14 and are dropped onto the belt conveyor 15, and the blended raw materials are conveyed to the blending silo 16 by the belt conveyor 15, and then proceed to the next process. and move on.

Here, the analyzer 14 analyzes the composition ratio of the prepared mixed raw material and sends it to the controller 20.

In the control device 20, this analysis result Xi (i=l.

2,..., m), the input/output interface circuit 21
The arithmetic processing section 22 receives and accepts the interrupt signal via the arithmetic processing section 22, and temporarily stores these in the memory 23 as an analysis result table X. Note that the raw material composition ratio table A1 is already stored in the memory 23.

Here, the component composition ratio of the analyzed mixed raw material obtained from the analyzer 14 can be sampled at regular intervals and taken into the arithmetic processing section 22.

Next, based on the contents of this analysis result table It is stored in the raw material cutting amount performance table S as a function of the control time. In addition, in the case of a process in which the component composition ratio of the analyzed mixed raw material is sampled at regular intervals and taken into the arithmetic processing unit 22, it becomes a function of this sampling time.

Here, the calculation process for estimating the composition ratio and the calculation process for the raw material cut-out amount are performed with reference to the raw material composition ratio table A and the raw material cut-out amount performance table S. Further, when calculating the amount of raw material cut out, the raw material composition ratio table A is updated with the raw material composition ratio calculated in the composition ratio estimation calculation process, and then calculation is performed using the updated data.

Corresponding to each new raw material cutting amount calculated in this way,
The arithmetic processing unit 22 processes each gate mechanism 11 of the gate mechanism group 11.
A control signal for 'a, llb, -, lln is calculated and generated, and is passed through the input/output interface circuit 24.
It is sent to these gate mechanism group 11 as a control signal 25. As a result, a modified amount of raw material is cut out from the hopper group 10.

Next, the processing of the arithmetic processing section 22 of this control device 20 will be explained in detail.

FIG. 4 is a block diagram illustrating how the arithmetic processing section 22 of the control device 20 performs processing.

Here, the process 1 is a plant consisting of a mixing device 13, an analyzing device 14, etc., as in FIG. 1.

In addition, the calculation processing unit 22 is a so-called computer, and calculates the hydraulic ratio, silicic acid ratio, and iron car in a processing step 22a based on the analyzed composition ratio, and calculates the water hardness that is set as a target. rate.

These are read from the area 23a of the memory 23 in which the silicic acid rate and the iron car are stored, and the difference value between the calculated hydraulic ratio 5, the silicic acid rate and the iron car is determined. Then, in processing step 22c, each raw material composition ratio is read out from the area 23b of the memory 23 that stores the raw material composition ratio table A, and the target hydraulic ratio, silicate ratio and iron A correction value for the amount of raw material cut out for the vehicle is calculated, a corresponding control signal is sent to a gate mechanism provided in the hopper that adjusts the amount of raw material cut out, the amount of raw material cut out is corrected, and the set value ( Control to achieve the target hydraulic ratio, silicate ratio, and iron car).

Here, the composition ratio of each raw material stored in the raw material composition ratio table A in the area 23b is different from the conventional one, and for a predetermined raw material, an estimation calculation of the raw material composition ratio is performed, and the updated data is It is something that will be remembered. The predetermined raw material in this case does not only mean one or several specific raw materials, but may also refer to all raw materials.

This calculation for estimating the raw material composition ratio is performed in step 22b of the processing unit 22 for estimating the raw material composition ratio. This estimation calculation is performed in advance before calculating the amount of raw material cut out. Here, the composition ratio of each raw material in the raw material composition ratio table A or the composition ratio of the specific raw material is calculated. Then, the values on the raw material composition ratio table A are updated according to the calculation results corresponding to the determined composition ratio of a certain raw material.

Note that the update process takes the difference value between the corresponding data already stored in the raw material composition ratio table A and the result of the estimated calculation, and updates only when this difference value changes by more than a predetermined value. Alternatively, it may be updated at all times regardless of whether there is a difference value.

Next, processing step 22b for estimating the raw material composition ratio
will be explained in detail.

First, the raw material composition ratio table A is expressed as Aij,
It is given as a matrix like this: Note that i corresponds to each component, and its number is herein defined as m, and j corresponds to each raw material, and its number is defined as n.

5 Further, the raw material cutting amount performance table S is expressed as Stj and is given as the following matrix. Note that t corresponds to each control time point, and here the number is expressed as l
and j corresponds to each raw material, and the number is n.

Here, the relationship between the amount w3 of each raw material cut out and the composition ratio Xi (i=1. 2. . . +, m) at a certain point in time is generally expressed as follows. However, H is the total amount of raw material cut out.

Moreover, for the extracted actual value, the component ratio Xis to be found is: X1s-ΣS j x A ij / H
-----(2))-1. Therefore, here, sj was calculated from the raw material cutting amount record table S, and calculated from this and the current Aij)
(By comparing is and the actual analysis value Xi stored in the analysis result table X, it is possible to grasp the component that is on the increase.

In addition, as the actual result st3 of the raw material cut-out amount, an average value from the past to the present may be taken and used, or a matrix calculation may be performed using the raw material cut-out amount from the present to a specific period in the past. . Furthermore, sampling calculations suitable for actual plants can be performed.

Here, it can be seen that the increase in the composition ratio of a specific component is caused by a change in the composition ratio of a certain raw material.

Regarding the components that are on the increase, assume that the corresponding component of a certain raw material has increased, and for this increased amount, the increased component composition ratio for each raw material is an unknown quantity, and the actual raw material cutout amount Stj Assuming that there is no increase in other components, an equation for obtaining the analyzed composition ratio Xi will be solved for each raw material. Then, the closest value Aij for obtaining the analyzed composition ratio Xi is calculated by estimation calculation. At this time, the estimation is performed by excluding raw materials for which an increase is not expected in reality based on experience.

With respect to the new Aij obtained in this way, the corresponding component composition ratio Aij of the corresponding raw material, which is increasing, is updated.

Note that if there are multiple components that tend to increase above a predetermined reference value, either set a temporary value to one of them, or perform arithmetic processing assuming that it will not increase, and then perform similar processing on the other components. Then, mutual adjustments are made and estimation calculations are performed.

Based on the composition ratio Aij of a certain raw material updated in this way, a new raw material composition ratio table A is created, and based on this, the hydraulic ratio, silicic acid ratio, and Find the iron car, take the target hydraulic hardness rate, silicate rate, and the difference value from the iron car, calculate the necessary correction amount for each raw material cutting amount from this difference value and the updated raw material composition ratio table A, and The arithmetic processing unit 22 calculates a target hydraulic ratio, a silicate ratio, and a control signal for controlling the iron train corresponding to the correction amount. And convert this to input/output interface times I
i! & 24 to the gate mechanism section 11 to produce a cement raw material having a mixed hydraulic ratio, silicic acid ratio, and composition ratio for iron wheels.

Here, the composition ratio of each raw material in the raw material composition ratio table A in the initial state when this control is started is to start from the average value of the composition ratio, but in this case, for each raw material, the composition ratio actually measured and the composition ratio If the composition ratio of high lifespan is known, that data may be used.

Figures 5(a) to 5(a) illustrate the differences between the case where the raw material composition ratio table is processed in this way and the control is performed using the updated raw material composition ratio table A, and the conventional control.
d).

9 Here, FIG. 5(a) shows a graph when CaO in a certain raw material decreases, and the vertical axis represents the increase in CaO,
Time is plotted on the horizontal axis. In addition, FIG. 5(b) shows the fifth
It shows a graph of hydraulic modulus HM corresponding to figure (a),
The vertical axis represents the amount of increase in HM, and the horizontal axis represents time.

On the other hand, FIG. 5(C) shows a graph of the raw material cut-out amount with respect to FIG. 5(a), in which the vertical axis represents the increase in the raw material cut-out amount W, and the horizontal axis represents time.

Figure 5(d) shows the state of HM in the silo after blending for the control results in Figure 5(C), with the vertical axis representing the amount of increase in HM and the horizontal axis representing time. There is. In these figures, the state in which the present invention is applicable is shown by thick dotted lines, and the conventional state is shown by thin dotted lines.

Now, as shown in FIG. 5(a), if we assume that the CaO component of a certain representative raw material is trending in a decreasing direction from a certain time Tz, there is a time delay TL.

Later, the composition ratio of CaO obtained from the analyzer 14 decreases,
As shown in FIG. 5(b), the hydraulic ratio HM obtained as a result of the calculation decreases, and a difference value δHM occurs between it and the target hydraulic ratio HM. As a control value for correcting this variation, a control signal corresponding to δHM1 is generated at time T. As a result, as shown in FIG. 5(C), the amount of each raw material cut out was δW.

(The value of δW is different for each raw material, and some of them do not change), and therefore, as shown in Fig. 5(d).
As can be seen, at time T4, on the thick dotted line,
The hydraulic ratio can be controlled to a value close to the set hydraulic ratio I(M).

In addition, C,, C,, C3゜... shown in Fig. 5(a) represent the composition ratio of the actual raw materials, and C-CS+C'1
．． . . . indicates values of the raw material composition ratio table A updated by estimation calculation processing.

In this way, Ca of a certain raw material shown in FIG. 5(a),
Depending on the change in the composition ratio of O, C,, C2, C,..., δHM, δHM, δHM,.

... is obtained, and the amount of raw material cut out is δW4. δW Yu, δW
3. ...and in a nearly linear state with a value close to the set hydraulic ratio HM, K, , K□.

3. ...and can be controlled.

On the other hand, in conventional control, the composition ratio is the average value c.

As shown in Figure 5(a), Ca
O becomes linear regardless of the actual decrease. Therefore, as shown in FIG. 5(b), a difference value ΔHM,, ΔHM,, 66M3. ... occurs, and the amount of each raw material cut out is ΔW.

, ΔWJ, ΔWR, . . . , and as shown by the thin dotted line, the hydraulic modulus is controlled to a value far from the set hydraulic modulus HM.

As described above in detail, the present invention is applicable not only to such a raw material mixing control method for cement, but also to, for example, a raw material mixing control method for chemicals, materials, and the like. When applied to such things, instead of calculating and controlling the hydraulic ratio, silicate ratio, and iron fist, take the component ratio that is the corresponding control value and compare it with the target value,
Alternatively, the target component composition ratio after blending is directly compared with the analyzed composition ratio, and control is performed based on the difference value.

Here, the memory in the above embodiment stores the target component composition ratio, and includes a storage table that stores the component composition ratio of the raw materials, and further includes a memory table that stores the target component composition ratio, and further includes a memory table that stores the component composition ratio of the raw materials, and is Although the amount of raw material cut out is sequentially stored, it is not necessarily necessary to store these in one memory, and each may be stored in a corresponding memory (including the case of a register). Therefore, the term "memory" in this specification is defined to include memories arranged separately in this manner.

As can be understood from the above description, the present invention has a composition ratio storage table that stores component composition ratios for predetermined components of a plurality of raw materials, and when the plurality of raw materials are mixed. A memory for storing a target component composition ratio or a component ratio between the components of the mixed raw material, a calculation processing unit, a plurality of hoppers provided corresponding to each of the raw materials, and each of the above-mentioned components supplied from these hoppers. a mixing device for mixing raw materials; a gate mechanism for supplying a predetermined amount of the banya 3 material in the hopper to the mixing device in response to a control signal from the arithmetic processing unit; and an analyzer for analyzing the component composition ratio of the target component ratio and the analyzed component composition ratio, or obtain the difference value between the target component ratio and the analyzed component composition ratio, or the component obtained from the target component ratio and the analyzed component composition ratio. In a raw material blending control method that obtains a difference value from the ratio and refers to the composition ratio storage table to control the mixed raw materials to achieve a target component composition ratio or a target component ratio, the raw materials are stored in the memory. A supply amount storage table is provided, and the raw material supply amount to be supplied based on the manufacturing control signal is calculated, and this is stored as actual raw material supply amount data in the raw material supply amount storage table in accordance with each control and time point. Estimating the component composition ratio of a predetermined raw material from the actual data of the raw material supply amount stored in the raw material supply amount storage table and the component composition ratio obtained from the analyzer, and storing it in the composition ratio storage table. Since the system is configured to update the component composition ratio of a predetermined raw material, the amount of raw material to be cut out can be determined in response to changes in the composition ratio of the raw material, and the control accuracy is good and the composition is close to the target value. be able to. As a result, a product of good quality can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the processing of the conventional raw material blending control system for cement, Fig. 2 is an explanatory diagram of the raw material supplying system using the conventional minxbesod method, and Fig. 3 is a block diagram showing the processing of the raw material blending control system of the present invention. A block diagram of the raw material blending control system in cement production to which the invention is applied, FIG. 4 is a block diagram explaining the processing method of the arithmetic processing section of the control device, and FIGS. 5(a) to (d) are FIG. 5(a) is an explanatory diagram illustrating the difference in control from conventional control when the composition rate estimation process is performed; FIG. (b) is a graph of the hydraulic modulus HM corresponding to Fig. 5(a), and Fig. 5(
C) is a graph showing the amount of raw material cut out for FIG. 5(a), and FIG. 5(d) is a graph showing the state of HM in the silo after blending for the control results in FIG. 5(C). It is. 10 is a group of hoppers, and 11 is a group of gate mechanisms. 12.15 is a belt conveyor, 13 is a mixing device. 14 is an analysis device, and 16 is a blending silo. 20 is a control device, 21 and 24 are input/output interface circuits, 22 is an arithmetic processing unit, 23 is a memory, and 22a is an arithmetic processing step for hydraulic ratio, silicate ratio, and iron fist. 22b is a processing step for estimating the raw material composition ratio. 22c is a step of calculating a correction value for the amount of raw material cut out. 23a is a storage area that stores target hydraulic ratio, silicate ratio, and iron fist. 23b is a storage area in which the raw material composition ratio table A is stored. Patent Applicant Fuji Electric Manufacturing Co., Ltd. Fuji Facom Control Co., Ltd. Agent Patent Attorney Tetsuya Mori Patent Attorney Takashi Naito Patent Attorney Shimizu Regular Patent Attorney Submitted Double Chief'tt 36- ~

Claims (2)

[Claims] (1) It has a composition ratio storage table that stores the component composition ratios for predetermined components of a plurality of raw materials, and the target component composition ratio or mutual component ratio of the mixed raw material when the plurality of raw materials are mixed. a memory for storing component ratios in the calculation processing section; a plurality of hoppers provided corresponding to the respective raw materials; a mixing device for mixing the respective raw materials supplied from these hoppers; a gate mechanism for supplying a predetermined amount of each of the raw materials in the hopper to the mixing device according to a control signal of the mixing device; and an analysis device that analyzes the component composition ratio of the mixed raw materials mixed by the mixing device, Obtain the difference value between the target component composition ratio and the analyzed component composition ratio, or obtain the difference value between the target component ratio and the component ratio obtained from the analyzed component composition ratio, and store the composition ratio storage table. In the raw material preparation 11J control method of controlling the mixed raw materials to achieve a target component composition ratio or a target component ratio with reference to Calculate the amount of raw material supplied to The component composition ratio of a predetermined raw material is estimated and calculated from the performance data of and the component composition ratio obtained from the analysis device, and the component composition ratio of the predetermined raw material stored in the composition ratio storage table is updated. A raw material blending control method. (2) A raw material mixing control method for cement production according to claim 1, wherein each raw material is a raw material for manufacturing cement, and the component ratios are hydraulic ratio, silicate ratio, and iron ratio. .