SU1225860A1 - Device for monitoring temperature conditions of converter melting - Google Patents

Description

To the input of the hydrogen flow meter, which is formed as a result of water dissociation in the converter, the output of the flow meter of waste converter gases is connected to the third input of the nitrogen and hydrogen flow meter in the waste converter gases, the first, second and third outputs of which are connected to the first, second and The third inputs of the consumption invention relates to ferrous metallurgy, namely to the control and regulation of the process of oxygen-converter melting, and can be used in the oxygen-converter production and.

The purpose of the invention is to improve the accuracy of temperature control of the converter melting.

FIG. 1 shows a block diagram of the proposed device; 2 shows the internal structure of the control unit.

The proposed device (Fig. 1) contains a block 1 for calculating an integral oxygen flow blowing, an oxygen flow meter 2 blowing, a control unit 3, an analyzer 4 a composition of waste converter gases, a flow meter 5 a waste of converter gases, a calculation unit 6 for calculating the current temperature increase of the metal in the bath converter, flowmeter 7 of nitrogen and hydrogen in the off-gas converter gases, flowmeter 8 of hydrogen produced as a result of water dissociation in the converter, unit 9 for calculating the change in metal temperature due to heat consumption for heating, evaporation and the dissociation of water in the converter, the bioc 10 to calculate the current temperature of the metal and the recording device 11.

 The unit 1 for calculating the integral flow rate of oxygen blowing is presented in the form of a static control system of converter melting, which, before the start of blowing through the static algorithm, calculates the integral flow rate of oxygen to blow the heat, for 228,660

the measure of hydrogen formed as a result of water dissociation in the converter, the output of the latter is connected to the first input of the unit for calculating the temperature change of the metal due to heat consumption for heating, evaporation and dissociation of water in the converter, the output of which is connected to the third input of the unit for calculating the current metal temperature .

the initial temperature of the metal and the calculated temperature of the metal at the end of melting. The oxygen flow meter 2 is represented as a narrowing device with typical pressure sensors and a differential pressure of oxygen and its temperature.

The control unit 3 (see FIG. 2) is represented, for example, in the form of a timer, which generates two alternating commands that are shifted in time, for example, within 0.2-2.5 s, determined experimentally. Control unit 3 (see Fig. 2)

consists of a serially connected one-shot 12, an inverter 13 and the circuit And 14, and the input of the one-shot 12 is connected to the second input of the circuit And 14.

Analyzer 4 of the composition of the waste converter gases is presented, for example, in the form of an MX-1215 mass spectrometer.

The flow meter 5 of waste converter gases is presented, for example, in the form of a Venturi tube with typical pressure and differential pressure sensors of the waste converter gases and its temperature.

Unit 6 for calculating the current temperature increase of the metal in the bath of the converter is presented, for example, in the form of analog integrated circuits that implement the dependence

rap nach vr

and

Jvojltl s

 02О

And consists of series-connected first inverter I5, first 3

the adder 16, the first divider .17.and the first multiplier 18, as well as the first integrator 19, the first, second and third outputs of the unit 1 for calculating the integral oxygen flow blowing are connected respectively to the input of the first inverter 15, to the second input of the first the adder 16 and the second input of the first divider 17, and the first and second inputs of the first integrator 19 are connected respectively to the outputs of the control unit 3 and the oxygen flow meter 2 to blow, the output of the first integrator 19 is connected to the second input of the first multiplier 18.

Flowmeter 7 of nitrogen and hydrogen in the off-gas converter gases is presented, for example, in the form of analogue integrated circuits that realize the dependence

°: v

or

uor

Poor

, V., v

N,

100

 N,

or

100

And it consists of a second multiplier 20 and a third multiplier 21, the first and second outputs of the analyzer 4 of converter gas composition are connected to the first inputs of the second multiplier 20 and third multiplier 21, respectively, and the output of the flow meter 5 of converter gases is connected to the second inputs of the second multiplier 20 and the third multiplier 21.

Compr: odometer 8 of hydrogen formed as a result of water dissociation in the converter, is presented, for example, in the form of analog integrated circuits that implement the dependence

by

AND

of

or

n °; + co ° HI

and consists of the fourth multiplier 22, the second adder 23, the third adder 24 and the second divider 25, with the output of the third multiplier 21 connected to the first input of the fourth rt multiplier 22, the first output of the analyzer 4 of the composition of the exhaust converter gases to the second inputs of the fourth the multiplier 22 and the second adder 23, the third output of the analyzer 4 of the composition of the exhaust converter gases is connected to the first input

25860.4

The second adder 23, the output of which is connected to the second input of the second divider 25, the output 5 of the fourth multiplier 22 is connected to the first input of the second divider 25, and the outputs of the second multiplier 20 and the second divider 25 are connected to the first and second inputs of the third adder.

10 Block 9 for calculating the change in metal temperature due to the heat consumption for heating, evaporation and dissociation of water in the converter is presented, for example, in the form of analog integrated circuits realizing the dependence

,. |, .c.h.4 (

about

AND CONSTITUTE of the series-connected logarithm block 26, the initial level formation unit 27, the exponent formation unit 28 and the second integrator 29, and

the second output of the control unit 3 is connected to the second input of the second integrator 29, the output of the third adder 24 is connected to the second input of the logarithm block 26.

Unit 10 for calculating the current temperature of the metal is presented, for example, in the form of an adder based on analog integrated circuits that implement the dependence

ats

pc (cn nach

ZV

02

ivo, W "-.,

and consists of a second inverter 30

and the fourth adder 31, and the output of the second integrator 29 is connected to the input of the second inverter 30, the output of which is connected to the third input of the fourth adder 31, and

the first and second inputs of the latter are connected, respectively, the output of the first multiplier 18 and the first. output of the unit 1 for calculating the integral oxygen flow to blow, the output of the fourth adder 31 is connected to the input of the recording device 11.

The recording device 11 is presented, for example, in the form of a secondary device KSP-4.

The device works as follows.

Before the start of the next melting in block 1, the calculation of the integral flow rate

Yes, oxygen is blown according to the static algorithm, the integrated oxygen consumption is blown for melting, the initial temperature of the metal and the calculated temperature of the metal at the end of melting. Upon the opening of the oxygen shut-off valve to blow the first signal from control unit 3, the integrators of blocks 6 and 9 are zeroed, and the second signal starts the oxygen flow meter 2 to blow, the analyzer 4 of the composition of the exhaust converter gases and the flow meter 5 of the exhaust converter gases. With the start of the purge, the signal from the contacts of the oxygen shut-off valve relay blows to the input of the vibrator 12 and the first input of the circuit 14. The one-vibrator is triggered by a signal differential from

zero state in a single and produces a pulse duration,

for example, in the range of 0.2-2.5 s, determined experimentally. The front edge corresponds to the time when the signal from the contacts of the relay of the oxygen cut-off valve blows. The signal from the output of the one-shot 12 enters the integrators 19 and 29 as a reset signal. The same signal is fed to the input of the inverter 13. From the output of the inverter 13, a zero signal is fed to the second input of the circuit AND 14 of the signal from the contacts of the relay of the oxygen-flow shut-off valve to blow. At the end of the pulse, the output of the one-shot 12 is set to a zero signal, which is inverted by the inverter 13, and a single signal from its output goes to the second input of circuit 14. At the output of circuit 14, a single signal appears that goes to blocks 1, 2, 4 and 5.

When entering from the output of the block for calculating the integral oxygen flow rate, blow an analog signal proportional to T f. , the INPUT of the first inverter 15 from the output of the inverter 15 is a signal proportional to T., is fed to the input of the first adder 16. The second input of the first adder J6 receives an analog signal, proXt

ration. T., from the second output of unit 1 of the calculation of the integral flow of oxygen to blow. From the output of the first adder 16, the proportional signal (Trasr - TCdts) is fed to the first input of the first divider 17.

ten

2258606

The second input of the first divider 17 receives an analog signal proportional to SVg from the third output of the calculating block 1 of the integral 5 oxygen consumption to blow. From the output of the first divider 17 signal, proportionalV -L pc cn -L night

national - rm- comes

, Vo, j

the first input of the first multiplier 18. An analog signal, proportional to the output of the oxygen flow meter 2, is blown to the first input of the first integrator 19. The first integrator 19 is also made according to the standard scheme. The second input of the first integrator 19 receives a signal from the output of the control unit 3, which first integrator 19 embraces the signal from the output of the first integrator 19.

Ny Vo (i

0

five

five

J V (tl (3t, post about

It goes to the third input of the first multiplier 18. From the calculation of the first multiplier 18, the signal is proportional

T t rasp

ZV

0

. Vg (t) dt, post-0

five

0

pata on the first input of the fourth adder 31, performed according to the standard scheme.

From the first output of the analyzer 4 of the composition of the waste converter gases, an analog signal proportional to

gdog

H, is fed to the first input of the second multiplier 20, made according to the standard scheme, as well as to the first input of the second adder 23, installed also according to the standard scheme, and the second input of the fourth multiplier 22. To the second input of the second multiplier 20, an analog signal proportional to V, from the outlet of the flow meter 5 waste converter gases. From the output of the second multiplier 20, the signal proportional to V, 5 is fed to the first input of the third

From the second output of the analyzer 4 of the composition of the waste converter gases, an analog signal proportional to N is fed to the first input of the third multiplier 21, the second input of which receives a signal from the output of the flow meter 5 of the waste converter gases proportional to VOP.

From the output of the third multiplier 21, the signal proportional to Vj is fed to the first input of the fourth multiplier 22, the signal from the first output of the analyzer 4 is received

0

waste converter boxes, proportional to H. From the output of the fourth multiplier 22, a signal proportional to h H2 is fed to the first input of the second divider 25, which is executed on the basis of the multiplier circuit by adding an inverting amplifier after one of the logarithmic amplifiers. The analog signal is proportional to the „, of the wide range of H2, from the first output of the analysis

The congestion 4 of the waste converter gases enters the first input of the second adder 23, the second input of which receives a signal, proportional to CO, from the third output of the analyzer 4 of the composition of the exhaust converter gases. From the output of the second adder 23, the signal proportional to (H +) is fed to the second input of the second divider 25. From the output of the second divider 25, the signal is proportional to 0 ОГ

„Ъ-On VN ,, najnyi, -ot-iJI QQB r arrives on

the second input of the third adder 24.

From the output of the third adder 24 signal proportional to V +

 V J + N ° + with ° - is fed to the input

a logarithm block 26, made on the basis of a logarithmic amplifier according to the standard scheme.

From the output of block 26 logarithm, the signal is proportional

4K

C h) is fed to the input of the initial level formation unit 27, made on the basis of an adder circuit, to one of whose outputs

constant voltage is applied. From the output of the initial level formation unit 27, the signal proportional to (b-, (-1:)) is fed to the input of the exhibitor formation unit 28, performed according to the standard scheme. From the output of the exponential generator 28, the proportional signal e L is fed to the first input of the second integrator 29. To the second input of the second integrator 29

The signal comes from the second output of the control unit 3, which zeroes the second. Integrator 29.

From the output of the second integrator 29 signal proportional to

 njb dt arrives on

d

0

The input of the second inverter 30, made on the basis of the inverting amplifier. From the output of the second inverter

30 signal proportional to

aje-t - H, (t l dt, arrives on

about

the third input of the fourth adder 31 At the first input of the fourth adder

31 a signal is received, proportional to Tco, c, from the first outputs of block 1 for calculating the integral flow rate of oxygen to blow.

With the release of the fourth adder 31 sig nal, proportional

on h

+

nach

Z

- with, .

02

. ml t) dt- J 2

s 0

five

about

enters the input of the recording device 11.

The control of the temperature of the metal in the bath of the converter using the proposed device is based on the following theoretical assumptions.

The formula for calculating the hydrogen consumption in the converter gas is obtained from the oxygen balance equation in the gas path of the converter and the ratio between the amounts of hydrogen and carbon monoxide burned in the gas path and the concentrations of these gases in the gas path. The oxygen balance equation in the gas path is

 :; Oogf -v; ) .2. v -, (2)

where Vj.Q is the carbon monoxide consumption of

Og

converter, nm / min;

V is the carbon monoxide consumption in the exhaust gas, nm / min;

with

V mA

V (, is the oxygen consumption in the air drawn into the gas path, which is related to the stoichiometric ratio with the nitrogen flow in the gas path, nm / min.

The indicated ratio between the amount of the gases being burned and their concentrations in the gas path is

H

og

v -v

Hj hi

V ..- Vr, CO

.

 CO 4o

Solving equation (2) and locally obtaining the equation for lazy consumption of hydrogen in nom gas

n Ng j n ° + С

 and nitrogen flow in waste

2E,

9

where V is the consumption of hydrogen, forming a state in the dissociation of moisture entering the bath of the converter, nm / min;

v, 0r

 t (

gas, H, concentrations of hydrogen and carbon monoxide in the exhaust gas,%;

jj is a stoichiometric coefficient of 0.532. The integral amount of converter hydrogen for smelting fluctuates at different melts in the range of 300–1300 nm. The method allows to take into account the variations in the temperature of the metal, which correspond to the specified range of change in the integral value of hydrogen, equal to

Heat consumption for heating, evaporation and dissociation of moisture entering the converter with charge materials and when the oxygen form is burned up is determined by the formula

Where

So NgO So

O is the heat effect of heating,

V hjo

evaporation and dissociation of water, kJ / t;

 о stoichiometric conversion factor, nm of hydrogen in 1 ton of water. Determine the temperature change of the metal in the converter by taking into account

heat consumption for heating, evaporation

 isp and dissociation of moisture Q c ,, for

oxygen converter shop and accepted production figures of 300 tons of converter: metal weight 320 tons slag weight 50 tons, metal heat capacity 250 kJ / t- ° C, heat capacity of slag 400 kJ tons, Thus, the denominator of formula (2) is 100,000.

From tab. 2, it follows that the cooling effect of steam compared to the choking effect of scrap is 10 times greater. Thus, 1% of steam, constituting for 300 tons of a converter of 3 tons, gives a cooling effect of 9 ° C, and 1 ton of steam, respectively, 30 ° C.

The stoichiometric coefficient of conversion of nm hydrogen to 1 kg of water is 0.803

Substituting dependence (4) into equation (1), after transformation, we obtain the dependence for determining the change in the temperature of the metal in van22586010

no converter due to heat consumption for heating, evaporation and dissociation of water in the converter

yt

 1n, o n20 n

 .Wa

0

five

Considering; THAT 1000 kg of steam gives a cooling effect of 30 ° C, we get

4nV 9l§93 5 aj)

100,000 from here

q 3731 kJ / mm.

with e

Thus, for 300 nm hydrogen a change in the temperature of the metal in the converter will be 2 ° C, and for 1300 nm hydrogen aT., 48.5 ° C.

The equation for calculating the change in temperature, metal due to heat consumption for heating, evaporation and dissociation of water in the converter, depending on the consumption of hydrogen in the converter gas, is as follows:

MT (t.o, 5BJe-f - ° "jt., (5)

about

Rewriting this equation with the introduction of the coefficients a, b, c, we get:

35

aT (t), o a. | e-tb -M. (e)

where uT (i) is the change in the temperature of the metal due to the heat consumption for heating, evaporation and dissociation of water in the converter, C;

.n (current consumption of hydrogen in converter gas,

i is the purge time in min; and 0.583 1 empirical coefficients b 2.7456V, determined 0.9995j empirically.

The growth rate of the metal chemistry in the bath of the converter during the purge is determined by the following relationship:

dt (g) - - 1 a 1 t

 Oh

nach

) dt ,, (7)

111225860

de u T (t) is the current temperature increase of the metal in the bath of the converter, ° C;

  the design temperature of the metal in the bath of the converter at the end of melting, determined by dependence (1),

races of the floor of pos 5 in to and

g-j

night the initial temperature of the metal, ° C;

5iVo is the integral oxygen consumption to blow for melting, determined by the static algorithm, nm;

VQ (il - current oxygen consumption

blow nm / min; t is the purge time, min

Thus, taking into account the obtained dependences (5), (6), we obtain the formula for determining the current temperature of the metal in the converter bath:

ntl T,

I rasp nach

„T - k + c-b.v Wl 4 --- jVoltldt-QJe dt

S i i (8

Experimental studies have shown that taking into account the change in metal temperature due to heat consumption for heating, evaporation and dissociation of moisture in the converter improves the accuracy of controlling the temperature regime of converter melting.

In tab. Figures 1 and 2 show the changes in the measured and calculated parameters on the characteristic melting of R 342701, on which the main source of hydrogen in the converter bath is only moisture entering the converter bath with charge materials, and on smelting no. 342948, on which the discharge source The hydrogen in the bath of the converter is moisture that enters with charge materials, as well as the water that enters during the combustion of the oxygen tuyere.

In characteristic melt No. 342701 (Table 1), on which the main source of hydrogen evolution in the converter bath is only moisture entering the converter bath with charge materials, the deviations of the actual metal temperature from

5860

12

calculated on the intermediate smelting, obtained by means of the proposed method are +3.558 C, and by means of the known - 14.49 ° C, and 5 at the end of the melting, respectively 3.087 and 10.3b c.

In characteristic melting N 342948 (Table 2), where the source of hydrogen evolution in the converter bath is moisture entering the converter bath with charge materials, as well as water entering during the combustion of the oxygen tuyere, the deviations of the actual temperature of the metal from the calculated one melting, obtained by means of the device proposed, is 0.565 C, and by

known - 35.58 ° C, and at the end of melting, respectively, 8.932 and 21.69 s. Consequently, in swimming trunks, in which the oxygen lance burns out, the known device for determining the temperature of the metal has the greatest error, and the proposed one has a higher accuracy of control — the sperypyry of the metal in the bath of the converter as in the trunks in which the oxygen lance burns out, and without burning out the oxygen tuyere.

Thus, the proposed device allows to determine the temperature of the metal closest to its true value. Received

the temperature of the metal by means of a known device is significantly different from the true one. The mean square error of the control of the metal temperature according to the results of the comparison of the calculated temperature with the actual one at 115 heats is 9.48 ° C.

The technical efficiency of the device is that due to the higher accuracy of controlling the temperature conditions of the converter melting, the number of heats with post-blowing corrections decreases,

which leads to a decrease in the average duration of the heat, i.e. Converters productivity increases.

i

Compiled by A. Abrasimov. Editor. Gunko Tehred V. Kadar KoppeKTop A.JjicKO

Order 2103/19 Circulation 552Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch of the PU; P Patent, Uzhgorod, Proektna St., 4

vl /

FIG. 2

Claims (1)

DEVICE FOR CONTROL OF TEMPERATURE MODE OF THE CONVERTER Smelting, comprising a unit for calculating the integral oxygen flow rate of the blast, a oxygen flow meter of the blast, a control unit, an analyzer for the composition of the exhaust converter gases, a flow meter, an exhaust converter gas, a current temperature calculation unit and a recording device, while the first output of the control unit is connected respectively, to the inputs of the unit for calculating the integral oxygen flow of the blast, the oxygen flow meter of the blast, the analyzer of the composition of the exhaust converter gases and converter exhaust gas flowmeter, the first output of the unit for calculating the integral oxygen flow rate of the blast is connected to the first input of the unit for calculating the current metal temperature, and the output of the latter is connected to the input of the recording device, characterized in that, in order to improve the accuracy of monitoring the temperature regime of converter melting, unit for calculating the current increase in metal temperature in the converter bath, a nitrogen and hydrogen flow meter in the exhaust gases, a hydrogen flow meter resulting from dissociation during s in the converter, and a unit for calculating changes in metal temperature due to the heat consumption for heating, evaporation and dissociation of water in the converter, the first, second and third outputs of the unit for calculating the integral oxygen consumption of the blast connected to the first, second and third inputs of the unit for calculating the current gain metal temperature in the converter bath, the output of which is connected to the second input of the unit for calculating the current metal temperature, the output of the oxygen flow meter for blasting is under-1 s SS ω It is Din to the fourth input of the unit for calculating the current increase in metal temperature in the converter bath, the second output of the control unit is connected respectively to the fifth input of the unit for calculating the current increase in metal temperature in the bath of the converter and to the second input of the unit for calculating the change in metal temperature due to heat consumption for heating, evaporation and dissociation of water in the converter, the first, second and third outputs of the analyzer of the composition of the exhaust converter gases are connected respectively to the first, second inputs of the nitrogen flow meter and hydrogen an ode in the exhaust converter gases and a quart1225860 And to that input of the hydrogen flowmeter resulting from the dissociation of water in the converter, the outlet of the exhaust gas converter flowmeter is connected to the third input of the nitrogen and hydrogen flowmeter in the exhaust converter gases, the first, second and third outputs of which are connected respectively to the first, second and third inputs of the flowmeter of hydrogen generated as a result of dissociation of water in the converter, the output of the latter is connected to the first input of the unit for calculating the change in the rate metal temperature due to the heat consumption for heating, evaporation and dissociation of water in the converter, the output of which is connected to the third input of the unit for calculating the current metal temperature.