RU2037347C1 - Device for control of fusion level in blast furnace horn - Google Patents

Abstract

FIELD: melting. SUBSTANCE: control system has detector of voltage drop in furnace shell, transformer, quantization unit, block fixing the starting and the final point of melted products release, unit calculating sliding weighted average value, correcting unit, first scaling block, block introducing starting conditions, resisting appliance, control block, second scaling block. Usage of all these members permits to measure voltage drop component in a shell, caused by blast furnace heat alteration. EFFECT: improved design. 1 dwg

Description

 The invention relates to ferrous metallurgy, in particular to devices for controlling parameters of a blast furnace, and can be used to control the thermal state of a blast furnace.

 As a prototype, a well-known system for controlling the melt level around the hearth of a blast furnace was selected [1]. The system contains a voltage drop sensor on the furnace shell, a block for fixing the beginning and end of the release of melting products, a correction device, an input unit for initial conditions, a control unit and a recording device with a unit scaling.

 The specified system does not provide for the correction of the resulting signal from the monotonous component, which depends on the current heating of the furnace both during the accumulation period and the period of release of the melting products.

 Closest to the proposed invention in technical essence and the achieved result is a system for monitoring the level of the melt in the furnace of a blast furnace (application N 4937041/02 (042311) from 05.20.91 1st option).

 However, the use of this system only for fixing changes in the number of liquid phases in the furnace of a blast furnace leads to a loss of information about the thermal work of the blast furnace, which reduces the efficiency of blast furnace smelting.

 The aim of the invention is to reduce the consumption of coke and increase the productivity of the furnace due to operational control of the thermal state of the blast furnace.

 This is achieved by the fact that the control system of the melt level in the furnace of a blast furnace contains a voltage drop sensor on the furnace cover, a converter, a device for calculating a moving average weighted value, a recording device with a first scaling unit, an input unit for inputting initial conditions, a block for fixing the beginning and end of the release of melting products, the first output of which is connected to the first input of the control unit, and the second and third outputs with the first and second input of the correction device, as well as a signal quantization device, the first input to which is connected to the output of the converter, the input of which is connected to the voltage drop sensor, the output of the converter is connected to the third input of the correction device, the fourth input of which is connected to the output of the device for calculating the moving average value, and the first output with the first input of the first scaling unit, the second and third inputs of which connected to the first and second outputs of the input unit input conditions, the fourth input of the first scaling unit is connected to the first output of the control unit, and the fifth and sixth the inputs, respectively, with the fourth and first outputs of the block for fixing the beginning and end of the release of melting products, the fifth output of which is connected to the second input of the signal quantization device, the first and second outputs of which are connected respectively with the first and second inputs of the block for fixing the beginning and end of the release of melting products, the third input which is connected to the third output of the input unit input conditions, the fourth output of which is connected to the second input of the control unit, the first output of which is connected to the third input of the device is quantized signal and the first input of the device for calculating the moving average value, the second input of which is connected to the second output of the control unit, the third input of which is connected to the second output of the block fixing the beginning and end of the release of melting products, the third input of the device for calculating the moving average value is connected to the third output of the quantization device signal. The system is additionally equipped with a second scaling unit connected to a recording device, while the first input of the second scaling unit is connected to the second output of the correction device, and the second, third, and sixth inputs are connected to the sixth, fifth, and seventh outputs of the initial condition input unit and the fourth input the first output of the control unit.

 The drawing shows a block diagram of a system for monitoring the level of the melt in the furnace of a blast furnace.

 The control system includes a voltage drop sensor 1 on the casing of the blast furnace, connected to the input of the converter 2, the output of which is connected to the first input of the signal quantization device 3 and to the third input of the correction device 6. The first, second and third outputs of the signal quantization device 3 are connected respectively to the first, second inputs of the block for fixing the start and end of the melting products release and to the third input of the moving average value calculation device 5, the output of which is connected to the fourth input of the correction device 6. The first and second outputs of the correction device 6 are connected respectively to the first inputs of the first 7 and second 11 scaling units, the outputs of which are connected to the inputs of the recording device 9. The first, second, third and fourth outputs of the initial condition input unit 8 are connected respectively to the second, third inputs of the first block 7 scaling, to the third input of block 4 fixing the beginning and end of the release of melting products and to the second input of block 10 of the control, and the fifth, sixth and seventh outputs of block 8 to the third, second and sixth inputs torogo scaling unit 11. The first, second, third, fourth and fifth outputs of the block 4 for fixing the beginning and end of the release of melting products are connected respectively to the first input of the control unit 10 and the sixth input of the first scaling unit 7, with the first input of the correction device 6 and the third input of the control unit 10, with the second the input of the correction device 6, with the fifth input of the first scaling unit 7 and with the second input of the signal quantization device 3. The first output of the control unit 10 is connected to the third input of the signal quantization device 3, to the first input of the moving average value calculation device 5 and to the fourth inputs of the first 7 and second 11 scaling units, and the second output of the 10 unit to the second input of the moving average weighted value calculation device 5 .

 Block 8 input the initial conditions in the control system of the melt level in the furnace of a blast furnace additionally contains for entering information about the content of the sample on a silicon master based on, for example, a digital type master PP-10-Me, the output of which is connected to the sixth output of block 8; for fixing the moment of entering the content of the sample on silicon and the moment of taking the sample on the silicon content in the melting products, two control buttons, for example, the type of switch P-2K-00000 with the control signal connected to the fifth and seventh outputs of block 8, respectively.

 As a recording device 9 can be used, for example, an analog device, showing and recording (two-point) type A542, which is designed to display the controlled parameters of the proposed system on graph paper and scales of the device 9.

 The control system (Fig. 1) works as follows.

 By the "Start" command, carried out from the corresponding control button of the initial conditions input unit 8 and fed through the fourth output of the unit 8 to the second input of the control unit 10, clock pulses are generated at its first output. These pulses correspond to the actuation of the loading device at the moment of the next feeding of a portion of the charge into the furnace, for example, at the moment of lowering the large cone of the charging apparatus, and are generated in block 10 as a result of the signal arriving at its input from the control circuit of the charging apparatus of the blast furnace.

 The clock pulses generated at the first output of the control unit 10 synchronize the operation of the monitoring system as a whole, including the operation of the signal quantization device 3, the moving average value calculation device 5, the first 7 and second 11 scaling units.

So, with each arrival of clock pulses at the third input of the signal quantization device 3, the latter reads a new value N _v in the code coming from the output of the converter 2 to the first input of the device 3.

N

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

,B (2)
Таким образом, с приходом на третий вход устройства 3 очередных тактов, образующихся на первом выходе блока 10 управления, устройство 3 вычисляет в период накопления продуктов плавки величину ΔN_v по формуле (I) и в период выпуска величину |ΔN_v| по формуле (2).In the device 3, the number in the code N _v is divided into the current N _v ^k value and the previous N _v ^k-1 value of the informative signal, which, respectively, from the first and second outputs of the device 3 are supplied to the first and second inputs of the block 4 for fixing the beginning and end of the release of melting products , and also the value of their difference is calculated
ΔN _v = N _v ^k -N _v ^k-1 , B (1)
In block 4, under the condition N _v ^k > N _v ^k-1 , a control signal is generated at its fifth output, which acts on the device 3 through the second input, providing in the last calculation the absolute value | N _v | the difference of the current N _v ^k and the previous N _v ^k-1 values of the informative signal

N

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

, B (2)
Thus, with the arrival at the third input of the device 3 of the next cycles generated at the first output of the control unit 10, the device 3 calculates the value ΔN _v by the formula (I) and during the production period the value | ΔN _v | by the formula (2).

 With each arrival of a clock pulse from the first output of the control unit 10 to the third input of the device 3 and to the first input of the device for calculating the moving average weighted value, at the third output of the device 3, pieces of information are formed, calculated by formulas (1) and (2), which are received through the third the input to the shift registers of the device 5 and stored there until at the second input of the device 5 there is new information about the set by the unit 10 value of the number of cycles of operation of the loading apparatus of the furnace.

 By the command “Closing the notch”, block 4 on the second output gives a short pulse, which transfers block 10 through its third input to the initial position, and by the command “Opening the notch” block 4 on the first output generates a short pulse, which arrives at the first input of block 10 , providing the appearance of information on its second output about a given value n of the number of cycles of operation of the loading apparatus of the blast furnace.

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

,B (3)
Таким образом, при каждом срабатывании загрузочного аппарата печи на выходе устройства 5 в соответствии с формулой (3) формируется информация ΔN_v ^cp как конечный результат процесса выделения составляющей информативного сигнала, обусловленной технологическим фактором нагрева доменной печи.Subsequently, with the appearance of information about a given value n of the number of cycles of operation of the furnace loading apparatus at the second input of the device 5, its multiplexer is launched. Portions of information calculated by formulas (1) and (2) in device 3 and stored in the shift registers of device 5 are fed through its multiplexer to the calculation circuit in the device 5 for calculating the arithmetic mean value
ΔN $\genfrac{}{}{0ex}{}{\text{c}}{\text{v}}$ ^p 1 / n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

, B (3)
Thus, with each operation of the loading apparatus of the furnace at the output of the device 5, in accordance with formula (3), information ΔN _v ^cp is generated as the final result of the process of extracting the component of the informative signal due to the technological factor of heating the blast furnace.

In order to eliminate the accumulation of errors when measuring an informative signal, it is necessary to correct the resulting signal present at the output of the control system device 5. To do this, when closing the notch of the furnace, block 4 acts by its second exit through the first entrance to the correction device 6. At the same time, on the third output, block 4 provides information on the value of N _v ^{min of the} amplitude of the minimum inflection of the informative signal change curve, the number in the code of which goes to the second input of device 6. From the output of device 5, the quantity ΔN _v ^cp calculated arithmetic mean value according to the formula (3).

N

=

1/_n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

,B (4) и осуществляет процесс коррекции по формуле
N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ ^II= N $\genfrac{}{}{0ex}{}{\text{m}}{\text{v}}$ ⁱⁿ+1/n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

-

1/n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

,B (5)
В последующие периоды накопления и выпуска продуктов плавки при неизменных величинах N_v ^min и (ΔN_v ^cp)³ число в коде N_v ^kII поступает с второго выхода устройства 6 на первый вход второго блока 11 масштабирования до обновления величин N_v ^min и(ΔN_v ^cp)³ при последующем закрытии летки доменной печи. С учетом обновления этих величин устройство 6 в дальнейшем будет осуществлять коррекцию выходного сигнала устройства 5 уже в новых условиях работы доменной печи и системы контроля.With the arrival of a short pulse from the second output of block 4 to the first input of device 6, the latter captures in its memory cell information about the value of (ΔN _v ^cp ) ³ at the time of closing the notch

N

=

1 / _n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

, B (4) and carries out the correction process according to the formula
N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ ^II = N $\genfrac{}{}{0ex}{}{\text{m}}{\text{v}}$ ⁱⁿ + 1 / n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

-

1 / n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

, B (5)
In subsequent periods of accumulation and release of smelting products at constant values of N _v ^min and (ΔN _v ^cp ) ^{3, the} number in the code N _v ^kII comes from the second output of device 6 to the first input of the second scaling unit 11 until the values of N _v ^min and (ΔN _v ^cp ) ³ upon subsequent closure of the tap hole of the blast furnace. Taking into account the updating of these values, the device 6 will continue to correct the output signal of the device 5 already in the new operating conditions of the blast furnace and the control system.

In the second block 11, the process of scaling the current adjusted value ^N _v ^kII in the code is carried out (formula 5).

On the front panel of the initial conditions input unit 8, using the control button, the moment of sampling for the silicon content in cast iron during the release of smelting products from the furnace of the blast furnace is established, and using the knob and the corresponding control button, the N _Si value is set in the code for the silicon content in cast iron, obtained as a result of his chemical analysis, and the moment of entering this content on the master.

 Information in accordance with this comes from the seventh, sixth and fifth outputs of block 8 to the sixth, second and third inputs of the second scaling block 11.

N^min+1/n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

-

1/n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

,B (6)
По команде "Ввод содержания пробы на кремний в чугуне" через третий вход блока 11 запускается его схема вычисления коэффициента масштабирования
N $\genfrac{}{}{0ex}{}{\text{m}}{\text{K}}$ ^II=

/ B (7)
Величина N_k ^mII, вычисленная по формуле (7), постоянно хранится во внутреннем регистре блока 11 до последующего ввода содержания кремния в чугуне и поступления соответствующей команды на третий вход блока 11.At the time of the appearance of the control signal characterizing the sampling for the silicon content in cast iron, at the sixth input of the second scaling unit 11, the value N _m ^{II will be} recorded in the last according to the information received at the first input of block 11
N $\genfrac{}{}{0ex}{}{\text{I}}{\text{m}}$ ^I

N ^min + 1 / n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

-

1 / n

N $\genfrac{}{}{0ex}{}{\text{K}}{\text{v}}$ -N

, B (6)
By the command "Enter the content of the sample for silicon in cast iron" through the third input of block 11, its scaling factor calculation circuit is started
N $\genfrac{}{}{0ex}{}{\text{m}}{\text{K}}$ ^II =

/ B (7)
The value of N _k ^mII calculated by the formula (7) is constantly stored in the internal register of block 11 until the subsequent input of the silicon content in cast iron and the corresponding command arrives at the third input of block 11.

With the next occurrence of a synchronizing pulse from the first output of the control unit 10 at the fourth input of the block 11, the operation according to the formula
S _i = N _k ^mII ˙N _v ^kII , (8)
Thus, in the second scaling unit 11, a physical quantity is formed that characterizes the current thermal state of the blast furnace, namely, the predicted silicon content in cast iron that is currently accumulated in the metal detector of the furnace hearth.

 After converting the result obtained by formula (8) from a digital code into an analog signal, the latter is fed to the input of a two-point recording device 9, where the trend of the predicted silicon content in cast iron is fixed on one of the channels on a scale and on chart paper. At the same time, a change in the number of melting products currently located in the metal detector of the furnace of the blast furnace is displayed on another measuring channel. The latest information was formed as a result of processing an informative signal from the output of the transducer 2 to the third input of the correction device 6. In this case, the corrected signal comes from the first output of the device 6 to the first input of the first scaling unit 7. After the scaling process in block 7, information about the change in the number of smelting products is received from the output of block 7 to the input of the recording device 9.

 The proposed control system allows you to predict the silicon content in cast iron, which contributes to the rapid assessment of the tendency of the furnace to change heating.

 The implementation of the proposed control system contributes to the maintenance of a blast furnace with less heat reserve due to the stabilization of the chemical composition of the melting products and the reduction of fluctuations in furnace heating, which allows to reduce the coke consumption by 1.5.2.0 kg / t of pig iron and increase the furnace productivity by 0.4.0.6 %

Claims (1)

 MELT CONTROL SYSTEM IN THE DOMAIN OVEN MINE, including a voltage drop sensor on the furnace cover, a recording device with a first scaling unit, an initial input unit, a block for fixing the start and end of the melting products, the first output of which is connected to the first input of the control unit, and the second and third outputs with first and second inputs of the correction device, characterized in that it is equipped with a converter, a device for calculating a moving average value, a second scaling unit, by quantizing the signal, the first input of which is connected to the output of the converter, the input of the latter is connected to a voltage drop sensor on the furnace cover, the output of the converter is connected to the third input of the correction device, the fourth input of which is connected to the output of the moving average calculation device, and the first output to the first the input of the first scaling unit, the second and third inputs of which are connected to the first and second outputs of the input unit input conditions, the fourth input of the first scaling unit connected to the first output of the control unit, and the fifth and sixth inputs, respectively, with the fourth and first outputs of the unit for fixing the beginning and end of the release of smelting products, the fifth output of which is connected to the second input of the signal quantization device, the first and second outputs of which are connected respectively to the first and second inputs block fixing the beginning and end of the release of melting products, the third input of which is connected to the third output of the input block input conditions, the fourth output of which is connected to the second input of the control unit, the first you the course of which is connected to the third input of the signal quantization device and the first input of the moving average calculation device, the second input of which is connected to the second output of the control unit, the third input of which is connected to the second output of the block for fixing the beginning and end of the output of the melting products, the third input of the moving average calculation device the values are connected to the third output of the signal quantization device, the second scaling unit is connected to the recording device, the first input of the second block scaling is connected to the second output of the correction device, and the second, third, and sixth inputs, respectively, with the sixth, fifth, and seventh outputs of the initial condition input unit and the fourth input with the first output of the control unit.

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