RU2026360C1 - Device for determining the instant of metal discharge from converter - Google Patents

Abstract

FIELD: converter process control. SUBSTANCE: technical solution is based on measurement of slag temperature used for determining the value of slag overheat above the liquidus temperature, which makes it possible to determine the time of metal holding in the converter before the discharge up to the complete deposition of metal shots from slag. The object of the invention is attained by additional introduction of a probe with a slag temperature meter connected to a maximum signal separation unit and slag liquidus temperature measurement unit connected to adders, comparison units, two memory units and timer. EFFECT: enhanced converter capacity. 1 dwg

Description

 The invention relates to metallurgy, and in particular to the management of the converter process, and can be used in the management of steelmaking workshops.

 A device for stopping purging of an oxygen converter is known, comprising units for measuring the flow rate of oxygen supplied through the lance and the intensity of gas evolution from the converter, as well as a block for adjusting the amount of oxygen per purge depending on the average change in gas evolution from the converter. The specified device provides when felling obtain a given carbon content, while the temperature of the metal can be obtained with a deviation from the set values. The moment of metal discharge is the moment the carbon content and the bath temperature reach the set values after corrective operations.

 The disadvantage of this device is the low productivity caused by the time spent on corrective actions.

 A device for stopping purging of an oxygen converter at a given carbon content, comprising control units for the carbon content and its predetermined amount, connected to a comparison unit, the output of which is connected to the input of the purge unit, a flame emission spectrum control unit, a characteristic spectral line presence unit connected to a predetermined unit amount of carbon computing units. The device allows you to quickly carry out corrective operations to obtain a given carbon content. The moment of metal discharge is the moment when the adjustment reaches the set values of carbon content and bath temperature.

 The disadvantage of this method is the low productivity caused by increased time spent on corrective measures for temperature.

 The closest in technical essence to the claimed invention is a device containing blocks for calculating the carbon content and its predetermined value, connected through a unit for comparison with meters of carbon content and bath temperature, a unit for a given temperature value, blocks for calculating the control actions to obtain when the specified carbon content is reached preset bath temperature.

 The disadvantage of this device is the low productivity of the converter, associated with large losses of metal in the slag in the form of kings.

 The aim of the invention is to increase the performance of the Converter.

 This goal is achieved in that the device for determining the moment of discharge of metal from the converter, containing blocks for calculating the carbon content and a predetermined content of its value, connected through a comparison unit with meters of carbon content and bath temperature, made in the form of a measuring probe, a block of a set value of the bath temperature, blocks calculation of control actions to obtain at the moment of reaching a given carbon content a given bath temperature, made in the form of the first and second functional blocks, the inputs of which are respectively connected to the set carbon content block and the carbon content meter, and the outputs to the first and second adders, the third and fourth adders connected to the bath temperature meter and the set temperature block, further comprises a probe with a slag temperature meter, output which is connected to the block for extracting the maximum signal and the block for determining the liquidus temperature of the slag connected to the input of the fifth adder, the output of which is through the third functional the second block is connected to the second comparison block, the second input of which is connected via a timer to the second output of the first comparison block, which, in addition, is connected to the second probe and the first circuit And, the second input of which is connected to the drive of the first probe, and the output is connected to the reset circuits -records of the first and second memory blocks, the inputs of which are connected respectively to the second and third adders, and the output to the first and fourth adders, and the output of the first adder is connected to the input of the fourth adder, a block of a given carbon content connected to the third comparison unit to which is also connected to meter carbon block temperature setpoint is connected to the fourth comparison unit to which is also connected measuring the bath temperature, and outputs the second, third and fourth comparators are connected to a second scheme I.

 Using a measurement of the temperature of the slag allows you to find the value of the overheating of the slag over its liquidus temperature, which makes it possible to determine the initial concentration of the kings of all fractions in the slag and the length of time of deposition of the kings of the metal from the slag. This allows the metal to be aged in the converter before draining until the metal kings are completely precipitated from the slag.

 The drawing shows a diagram of the proposed device.

 The carbon content calculation unit 1 is connected to the first comparison unit 2, to which the predetermined carbon content unit 3 is also connected. The output of block 3 is connected to the first functional block 4. The output of the first comparison block 2 is connected to the probe drive 5, connected to the carbon content and bath temperature meters 6 and 7. The output of the meter 6 is connected to the second functional unit 8, which is connected to the first 9 and second 10 adders, which are also connected to the first functional unit 4. The output of the meter 7 is connected to the third 11 and fourth 12 adders. The second output of the first comparison unit 2 is connected to the reset-start circuit of the timer 13, the first 5 and second probe drive 14 and the I 15 circuit, the second input of which is connected to the drive of the first probe 5. The second probe 14 is connected to the slag temperature meter 16. The outputs of the meter 16 are connected to the block 17 allocation of the maximum signal and block 18 determining the liquidus temperature of the slag. The outputs of blocks 17 and 18 are connected to the fifth adder 19, the output of which through the third functional block 20 is connected to the second comparison block 21. The outputs of blocks 3 and meter 6 are connected to the third comparison unit 22. The output of circuit And 15 is connected to the reset-write circuits of memory blocks 23 and 24, with the input of the first memory block 23 connected to the second adder 10, and the output to the first adder 9, the input of the second memory block 24 connected to the third adder 11, and the output the fourth adder 12. Block 25 of the set temperature value is connected to the third 11 and fourth 12 adders and to the fourth block 26 comparison. Blocks 21, 22 and 26 of the comparison are connected to the second circuit And 27, and the input of the second block 21 of the comparison is connected to the input of the timer 13.

 Block 1 for calculating the carbon content can be made in the form of a device (ed. St. N 1097684), blocks 3 and 25 - on the basis of the regulators RZD AKECD system, blocks 2, 22 and 26 of the comparison - on the basis of the BKR blocks of the AKESR system, and functional blocks 4, 8 and 20 - based on mechanical elements built into secondary devices. As a probe 5, meters 6 and 7, standard devices installed on converters can be used, as adders 9, 10, 11, 12 and 19 - ACWD system BWO units, as a timer 13 - ACECD system BJP unit, as a probe 14 and meter 16 — a standard probe mounted on a converter, immersed in slag, as circuits I 15 and 27 — standard blocks of computer engineering, as a block 17 for extracting the maximum signal — a BSL block of the ACECD system, and as block 18 — series-connected blocks BKR in differential mode tion and block BSL AKESR system, and as the blocks 23 and memory 24 - block BDP AKESR system.

During purging in an oxygen converter with exhaust gases from the interaction zone, metal volumes of various sizes — kings — are thrown into the slag. When the purge is stopped, the kings settle in the slag, as a result of which in the latter their content decreases with time. The content of kings in the slag in time after stopping the purge process is
K = K _o - κτ (1) where K and K _o are the current and initial concentration of kings in the slag, respectively,%;
κ is the sedimentation rate of kings,% / min;
τ is the time, min

The quantities K _o and κ are functions of the overheating of slag over the liquidus line. An increase in the degree of overheating of the slag, on the one hand, contributes to the formation of a slag-metal emulsion at the final stages of purging, thereby increasing the concentration of kings of all fractions in the slag. On the other hand, it speeds up the process of making kings, which increases κ. With sufficient accuracy for practical purposes, the total equation can be represented as
K = α ₁ + α ₂ Δt- (α ₃ + α ₄ Δt) τ, (2) where α, α ₂ , α ₃ and α ₄ are the coefficients, respectively, equal to 9%, 0.137% / deg, 0.9% / min, 0.0234% / deg ˙ min;
Δ t is the amount of overheating of the slag in relation to the liquidus temperature, K.

(3)
Если время выдержки металла в конвертере меньше времени полного оседания корольков, то часть металла теряется с шлаком.Thus, from expression (2), the total settling time of the metal kings τ _W , min, can be found in the form
τ _* =

(3)
If the exposure time of the metal in the converter is less than the time of complete settling of the kings, then part of the metal is lost with slag.

In the purge process, the carbon content is determined by the following formula:
C = α ₅ C ₁ + α ₆ C ₂ , (4) where C is the carbon content in the liquid metal bath,%;
С ₁ and С ₂ - carbon content, determined by the material balance and, accordingly, by the decarburization rate,%;
α ₅ and α ₆ are the degree to which the carbon content is taken into account, which is determined respectively by the material balance and decarburization rate.

-

v_cdτ (5) где С_л и С_ч - содержание углерода соответственно в ломе и чугуне, %;
G_л, G_ч, G_р и G_и - масса на плавку соответственно лома, чугуна, руды и известняка, т;
а₁ - коэффициент, характеризующий содержание двуокиси углерода в известняке и степень разложения последнего, %;
а₂ - коэффициент, характеризующий степень усвоения руды и содержание в ней кислорода;
а₃ - коэффициент, характеризующий среднюю скорость угара компонентов садки, т/мин;
V_с - скорость обезуглероживания металла, %/мин.Here
C ₁ =

-

v _c dτ (5) where C _l and C _h are the carbon content in scrap and cast iron, respectively,%;
G _l , G _h , G _p and G _and - the mass for melting, respectively, of scrap, cast iron, ore and limestone, t;
and ₁ is a coefficient characterizing the content of carbon dioxide in limestone and the degree of decomposition of the latter,%;
and ₂ is a coefficient characterizing the degree of assimilation of ore and its oxygen content;
and ₃ is a coefficient characterizing the average rate of burning components of the charge, t / min;
V _s - decarburization rate of metal,% / min.

(6) где β₁ и β₂ - коэффициенты.Carbon content determined by decarburization rate:
C ₂ =

(6) where β ₁ and β ₂ are coefficients.

(β₄·p + β₅t_ф+ β₆v)dτ+ β₇Δt_к (7) где t - температура ванны, ^оС;
Р - давление газов под куполом камина, Па;
t_ф - температура факела на срезе горловина-кессон, ^оС;
V - интенсивность подачи кислорода, при нормальных условиях, м³/мин;
Δ t_k - температурный перепад воды, охлаждающей кессон, ^оС;
β₃-β₇ - коэффициенты.The temperature of the bath is determined by the formula
t = β ₃ +

(β ₄ · p + β ₅ t _f + β ₆ v) dτ + β ₇ Δt _k (7) where t is the bath temperature, ^о С;
P is the gas pressure under the dome of the fireplace, Pa;
t _f - the temperature of the torch at the slit neck-caisson, ^о С;
V is the oxygen supply rate, under normal conditions, m ³ / min;
Δ t _k - temperature difference of the water cooling the caisson, ^о С;
β ₃ -β ₇ - coefficients.

(9) где с_x и с_з - содержание углерода в металле соответственно в момент измерения при помощи зонда и заданное, %;
Δ V_g(i-1) - погрешность в определении объема кислорода при нормальных условиях на предыдущей плавке, м³;
G_c - садка конвертера, т, и температуру металла после продувки этого объема кислорода:
t_i = t_ж + 0,0005 V_giC_r - 0,5 Δ t_(i-1), (10) где t_ж - температура металла в момент ее измерения при помощи зонда, ^оС;
Δ t_(i-1) - погрешность в определении конечной температуры на предыдущей плавке, ^оС.Upon reaching a carbon content value exceeding a predetermined value by 0.3%, the carbon content and bath temperature are measured using a probe. Then determine the amount of oxygen that must be supplied to the bath to achieve a given value of carbon content
V _gi = f (c _* ) -f (c _s ) - 0.5 Δ V _{g (i-1)} , (8) where f (c _x ) and (c _s ) are functions with the corresponding arguments, equal
f (c) =

(9) where _cx and _cc are the carbon content in the metal, respectively, at the time of measurement with the probe and the specified,%;
Δ V _{g (i-1)} is the error in determining the volume of oxygen under normal conditions on the previous heat, m ³ ;
G _c is the charge of the converter, t, and the temperature of the metal after purging this volume of oxygen:
t _i = t _W + 0.0005 V _gi C _r - 0.5 Δ t _(i-1) , (10) where t _W is the metal temperature at the time of its measurement with the probe, ^о С;
Δ t _(i-1) is the error in determining the final temperature on the previous heat, ^about C.

+ 0,81

- 0,5δG_u(i-1) (11)
Δ H_i= - 0,066 Δ G_иi, (12) где Δ G_иi - корректирующая масса известняка на охлаждение плавки, т;
t_з - заданная температура металла, ^оС;
Δ G_и(i-1) - погрешность определения корректирующей массы известняка на охлаждение предыдущей плавки, т;
Δ Н_i - изменение расстояния от торца фурмы до уровня спокойного металла при окончании продувки, эквивалентное по охлаждающему воздействию корректирующей добавки известняка, м.If it is necessary to cool the melts, the calculation of cooling materials
ΔG and _i = -

+ 0.81

- 0.5δG _{u (i-1)} (11)
Δ H _i = - 0.066 Δ G and _i , (12) where Δ G and _i is the correcting mass of limestone for cooling the smelting, t;
t _s - a given temperature of the metal, ^about C;
Δ G _{and (i-1)} is the error in determining the correcting mass of limestone to cool the previous heat, t;
Δ N _i - change in the distance from the end of the lance to the level of a quiet metal at the end of the purge, equivalent to the cooling effect of the correcting limestone additives,

 The device operates as follows.

, причем коэффициент - _

устанавливается как масштабный коэффициент сумматора. Напряжение, пропорциональное заданному значению температуры ванн, поступает в четвертый сумматор 12, в который одновременно поступает напряжение, пропорциональное значению температуры с измерителя 7. Туда же поступает напряжение, пропорциональное величине V_gi с первого сумматора 9. Выходное напряжение четвертого сумматора 12 пропорционально значению Δ G_иi по выражению (11), причем напряжение, пропорциональное величине Δ C_ти(i-1) поступает с второго блока 24 памяти. По окончании продувки с второго входа первого блока 2 сравнения поступает сигнал на привод зонда 5 на измерение содержания углерода и температуры ванны. Напряжение, пропорциональное значению содержания углерода в ванне конвертера, поступает во второй функциональный блок 8 и далее во второй сумматор 10. Туда же одновременно поступает выходное напряжение первого функционального блока 4. Таким образом, выходное напряжение сумматора 10 будет пропорциональным величине Δ V_g. В момент окончания измерения зондом 5 сигнал на подъем зонда поступает на первую схему И 15, на которую ранее поступает сигнал с блока 2 сравнения о равенстве расчетного содержания углерода заданному. Схема И срабатывает и значение Δ V_g записывается в первый блок 23 памяти. Аналогично по каналу третий сумматор 11, второй блок 24 памяти записывается значение δ G_и. Сигнал с блока 2 сравнения о равенстве расчетного содержания углерода заданному поступает также на запуск таймера 13 и на привод второго зонда 14, производящего измерение температуры шлака измерителем 16. Измеритель 16 передает в блок 17 сигнал, пропорциональный температуре шлака. В блоке 17 выделяется максимальный сигнал. Сигнал измерителя 16 также передается в блок 18 определения температуры ликвидуса шлака. В блоке 18 производится последовательное дифференцирование сигнала падения температуры и определение минимального значения сигнала. Выходные напряжения с измерителей 17 и 18 поступают в пятый сумматор 19, выходное напряжение которого, пропорциональное величине Δ t, поступает в третий функциональный блок 20. Выходное напряжение функционального блока 20, пропорциональное величине τ_*, поступает во второй блок 21 сравнения. При равенстве напряжений с выхода таймера 13 и функционального блока 20 на выходе блока 21 сравнения устанавливается "единичный" сигнал. Аналогично на выходе третьего блока 22 сравнения устанавливается "единичный" сигнал при выполнении условия С ≅ С₃, а на выходе блока 26 срав- нения при выполнения условия t ≥ t₃. Вторая схема И 27 срабатывает, подавая сигнал к приводу конвертера на слив металла. В случае необходимости предварительно выполняются рекомендации сумматоров 9 и 12 на выполнение корректирующих операций.In the process of purging the converter, the carbon content in the converter bath is calculated according to formulas (5), (6) in block 1 for calculating the carbon content. The output signal, proportional to the carbon content, enters the block 2 comparison, which simultaneously receives a voltage proportional to the specified carbon content in the metal from block 3. Upon reaching a carbon content exceeding the set value by 0.3%, the signal from block 2 comparison to actuate the 5 probe drive. The probe is lowered into the converter and measures the carbon content in the metal and its temperature, the values of which are recorded in meters 6 and 7, respectively. A voltage proportional to the set value of the carbon content comes from block 3 to the first functional block 4, the output signal of which is proportional to f (s _h ) according to the formula (9). A voltage proportional to the carbon content of the bath measured by the probe is supplied from the meter 6 to the second functional unit 8, the output voltage of which is proportional to the value of f (s _x ). The output of the adder 9 forms a voltage proportional to V _gi according to the formula 8. Moreover, the voltage proportional to the value Δ V _{g (i-1)} is supplied from the memory unit 23. A voltage proportional to the set temperature value enters the third adder 11, which simultaneously receives a voltage proportional to the temperature value from the meter 7. A voltage proportional to the value - is removed from the output of the adder 11 -

, and the coefficient is _

set as the scale factor of the adder. The voltage proportional to the set value of the temperature of the baths enters the fourth adder 12, which simultaneously receives a voltage proportional to the temperature value from the meter 7. The voltage proportional to the value of V _gi from the first adder 9 is also received. The output voltage of the fourth adder 12 is proportional to the value Δ G _{and i} according to expression (11), moreover, a voltage proportional to Δ C _{ti (i-1) is} supplied from the second memory unit 24. At the end of the purge, from the second input of the first comparison unit 2, a signal is supplied to the drive of the probe 5 to measure the carbon content and bath temperature. A voltage proportional to the carbon content in the converter bath is supplied to the second functional unit 8 and then to the second adder 10. The output voltage of the first functional unit 4 is simultaneously received there. Thus, the output voltage of the adder 10 will be proportional to Δ V _g . At the time of completion of the measurement by probe 5, the signal for raising the probe enters the first circuit And 15, which previously receives a signal from unit 2 of comparison about the equality of the calculated carbon content to the given one. The circuit AND is triggered and the value Δ V _{g is} recorded in the first memory block 23. Similarly, through the channel, the third adder 11, the second memory block 24, the value δ G _{and is} recorded. The signal from the comparison unit 2 about the equality of the calculated carbon content to the given one also arrives at the start of the timer 13 and at the drive of the second probe 14, which measures the temperature of the slag by the meter 16. The meter 16 transmits to the block 17 a signal proportional to the temperature of the slag. In block 17, the maximum signal is allocated. The signal of the meter 16 is also transmitted to the block 18 for determining the liquidus temperature of the slag. In block 18, sequentially differentiates the temperature drop signal and determines the minimum signal value. The output voltages from the meters 17 and 18 are supplied to the fifth adder 19, the output voltage of which, proportional to Δ t, is supplied to the third function block 20. The output voltage of the function block 20, proportional to τ _* , is supplied to the second comparison unit 21. If the voltages from the output of the timer 13 and the function block 20 are equal, the “single” signal is set at the output of the comparison unit 21. Similarly, at the output of the third comparison unit 22, a “single” signal is set when condition C ≅ C _{3 is} fulfilled, and at the output of comparison unit 26 when condition t ≥ t _{3 is} fulfilled. The second circuit And 27 is triggered by applying a signal to the drive of the converter to drain the metal. If necessary, the recommendations of adders 9 and 12 on the implementation of corrective operations are preliminarily carried out.

+ 0,81

- 0,5ΔG_ик(i-1)= 4,81т,(ΔG_ик(i-1)=2т). Производим реализацию управляющих воздействий. По окончании процесса измеряют содержание углерода и температуру ванны: соответственно 0,26% и 1575^оС, температуру шлака 1570^оС и температуру ликвидуса шлака 1550^оС. Определяем время выдержки металла по формуле (3): τ=

= 8,6 мин. По истечении 8,6 мин производят слив металла из конвертера.PRI me R. The 130-ton converter is necessary to melt the metal for the production of steel construction 35 having a carbon content of 0.28% to povalke, temperature 1570 ^C. Determine the carbon content at which the bath must be measured parameter 0.28 + 0.3 = 0, 58% Control the carbon content by the formulas (4-6) and on reaching a value of 0.58%, produce measurement bath parameters: C = 0,60%, t = 1590 ^C. Determine the amount of oxygen which must be submitted to the bath, for achieve a given amount of carbon according to formulas (7) and (8). V _gi = (3.4 + 16 ˙ 0.60) ˙ 130- (3, 4 + 16x x0.28) ˙ 130-0.5 ˙ 20 = 796 m ³ under normal conditions. Δ V _{g (i-1)} = 20 m ³ under normal conditions. We calculate the cooling materials ΔG _uк = -

+ 0.81

- 0.5ΔG _{ik (i-1)} = 4.81 t, (ΔG _{ik (i-1)} = 2t). We produce control actions. Upon completion of the process is measured carbon and bath temperature: 0.26%, respectively, and ^about 1575 C, the slag temperature ^of 1570 C and the slag liquidus temperature ^of 1550 C. Determine the dwell time of the metal by the formula (3): τ =

= 8.6 minutes After 8.6 minutes, the metal is drained from the converter.

 Tests of the device’s model at the Azovstal Mariupol Combine showed that using the proposed device can increase the converter’s productivity by 0.3%, respectively, reducing metal charge consumption by 1 ton of steel due to increased yield.

Claims (1)

 DEVICE FOR DETERMINING THE MOMENT DRAINING METAL FROM THE CONVERTER, containing blocks for calculating carbon content and its predetermined value, connected via a comparison unit with carbon and bath temperature meters placed in the measuring probe with a drive, a set temperature block, control action calculation blocks to obtain at the moment achieving a given carbon content of a given bath temperature, made in the form of the first and second functional blocks, the inputs of which are respectively connected to the unit of the set value of the carbon content and the meter of carbon content, and the outputs of each of them to the first and second adders, the third and fourth adders connected to the bath temperature meter and the unit of the set temperature, characterized in that, in order to increase the performance of the Converter, the device further comprises a probe with a drive and a slag temperature meter, the output of which is connected to a maximum signal extraction unit and a slag liquidus temperature determination unit, are connected m to the input of the fifth adder, the output of which through the third function block is connected to the second comparison unit, the second input of which is connected via a timer to the second input of the first comparison unit, which, in addition, is connected to the drive of the second probe and the first circuit And, the second input of which is connected to the drive of the first probe, the output of which is connected to the reset-write circuits of the first and second memory blocks, the inputs of which are connected respectively to the second and third adders, and the outputs to the first and fourth adders, the first adder is connected to the input of the fourth adder, the carbon content setpoint unit is connected to the third comparison unit, to which the carbon content meter is also connected, the temperature setpoint unit is connected to the fourth comparison unit, to which the bath temperature meter is also connected, the outputs of the second, the third and fourth comparison units are connected to the second circuit AND, the output of the maximum signal extraction unit is connected to the second input of the fifth adder.

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