SU1082832A1 - Device for controlling parameters of converter process - Google Patents

Abstract

DEVICE FOR CONTROL OF PARAPERS OF THE CONVERTER PROCESS; containing a power source, two electrodes, a registering device, a signal | Her congestion, a computing unit, auxiliary resistance, a switch, a voltage-current converter, the first electrode being connected to the first input of the voltage-Current converter, the second input of which is grounded, the second electrode the type is connected to the first input of the switch, and the second input of the switch is connected through an added resistance to the first output of the power source, the second output of which is grounded, the output of the voltage-current converter is connected to the input of the computing unit, the first second and third outputs of which are connected respectively to the inputs of the registering device, the alarm device and the control input of the switch, the lance and converter housing being used as electrodes, in order to expand the operational capabilities of the device by predicting the temperature of the metal 5, a immersion thermocouple, a second voltage-current transducer, and a second recording device are inserted into it, and the immersion thermocouple output is in volts A voltage-current converter is connected to a computing unit, the fourth output of which is connected to the input D of the second recording instrument. N9 X IfS fO

Description

This invention relates to ferrous metallurgy, namely, to controlling parameters of a converter process. The closest to the present invention is a device for monitoring the wear of the lining of the oxygen converter, which is used mainly for controlling the parameters of the converter melting, which contains a power source, two electrodes, a recording device, a warning device, and a calculator. unit, additional resistance, switch, voltage converter, while the first electrode is connected to the first input of a voltage-current transducer, the second input of which is grounded, the second electrode is connected to the first input of the switch, and the second input of the switch is connected through an additional resistance the first output of the power source, another output of the last one is grounded, the output of the voltage-current converter is connected to the input of the computing unit, the first, second and third outputs of the computing unit are connected, responsibly to give WMOs recording device, a signal of congestion and a control input of the switch, wherein as the two electron genera used tuyere and converter housing. At the output of the computing unit, a signal is obtained that is proportional to the resistance of the converter lining, which is registered by the registering device. The magnitude of the resistance of the lining of the steelmaking unit functionally depends on the general condition and degree of wear of the lining. In the computational unit, the lining resistance is matched with the specified value of the critical lining resistance, when an emergency situation is possible. If the lining resistance is less than or equal to this critical lining resistance, a signal is output to the detector and, if necessary, the operator stops the process in the unit. In the known device, information containing a large amount of the electrical resistance of the converter lining is not fully used, which depends not only on the degree of wear of the lining, but also on the temperature change of the metal in the converter bath. The purpose of the invention is to expand the operational capabilities of the device by predicting the temperature of the metal. The goal is achieved by the fact that the device for controlling the parameters of the converter process. Containing a power source, two electrodes, a registering device, an alarm device, a computing unit, an additional resistance, a switch, a voltage-current converter, the first electrode being connected to the first input of the voltage-current converter, the second input of which is grounded, the second electrode being connected to the first the input of the switch and the second input of the switch through an additional resistance is connected to the first output of the power source, the second output of which is grounded, the output of the voltage-current converter is connected to i For a computational unit, the first, second and third outputs of which are connected respectively to the inputs of the registering device, the alarm device and the control input of the switch, the tuyere and the converter housing are used as electrodes, the immersion thermocouple is inserted, the second voltage-current converter and the second recording device, moreover, the output of the immersion thermocouple through the second voltage-current converter is connected to the computing unit, the fourth output of which is connected to the input of the second recording device. Figure 1 shows the block diagram of the proposed device / figure 2 is equivalent to the circuit of the lance-earth-housing-lining-melt-lance electrical circuit, in FIG. 3 - the structure of one of the variants of the computing unit; Fig. 4 is a characteristic diagram of the change in the temperature of the metal in the converter bath and the magnitude of the electrical resistance of the lining on smelting carried out in the oxygen converter shop. The device contains the first electrode 1, the second electrode 2, the switch 3, the additional resistance 4, the power source 5, the first voltage-current converter 6, the computing unit 7, the first registering one. the device 8, the detector 9, the thermocouple 10, the second converter 11 voltage-current, the second recording device 12. The first electrode 1 can be represented, for example, in the form of an oxygen-oxygen converter, the second electrode can be represented, for example, in the form of a housing oxygen converter Switch 3 can be represented in the complete control module contactless, for example, type A641-8, additional resistance 4 can be represented jieHO in the form of a resistor, for example type 180-60-20110% of ALS 466.036 TU, while the value of additional resistance at It is chosen equal to the value of the resistance of the electrical section of the body-to-ground circuit, since with Kdd5 k-3, the total resistance of the electrical section of the electrical circuit to the ground-body is halved, i.e. The maximum change in the total electrical resistance of the lance-ground-lining-melt: v-lance is achieved; the power supply 5 is a DC source, for example, a VSS type of 1 V and a current of up to 2 A. First converter 6 The voltage and the second voltage-current converter 11 are, for example, a NP-5-B1 normalizing measuring transducer. Computing unit 7 can be represented, for example, in the form of a computer CM-1. Computing unit 7 contains, for example, a normalization module 13, the output of which is connected to the ittw contactless switch 14 connected via an analog-to-digital converter. 15 with an input of the processor 16, the outputs of the last block are connected respectively with the inputs of the first contactless control module 17, the second contactless control module 18, the third contactless control module 19. and the fourth contactless control module 20, the output of the first contactless module is connected to the input of the first transducer 21 of the codec, and the output of the fourth contactless control module 20 is connected to the input of the second code-to-current converter 22. The recording devices 8 and 12 can be represented as a self-recording device, for example, type KSP-4 signaling device 9 can be represented as an acoustic signaling device, for example, type DEM-4. The immersion thermocouple 10 can be represented as a block, for example, of the TTCB-t0 type with a tungsten-rhenium thermocouple. The device works as follows. Before the next melting, the temperature of the metal in the converter bath t .- is entered into the computing unit 7. measured with InVr 1 using a thermocouple 10 of immersion at the pre-smelting melt and stored, in addition, the computing unit 7 stores information about the value of the electrical resistance of the lining measured before the end of the purge at the previous melt. In the course of melting in the mode of a submerged jet in the electrical circuit of the lance-body-lining-melt-lance the current flows. The signal about the magnitude of the potential difference across the electrical circuit of the lance-to-ground circuit is converted to a current signal in the range, for example, from 0 to 5 mA in the voltage-to-current converter 6. The output signal of the voltage-to-current converter 6 is fed to the input of the computing unit 7. In the computing unit 7, the value of the potential difference in the lance-to-ground electric circuit is stored for a given time. when the contacts of the switch 3 are open, then, by the control signal of the computing unit 7, the switch 3 closes the electrical circuit from the output of the power supply 5 through an additional resistance 4 with the second electrode 2 (aggregate housing). The magnitude of the current flowing in the electrical circuit of the truck-ground-housing-lining-melt welding machine changes, which leads to a change in the potential difference across the electrical section of the tuyere-ground circuit. In computing unit 7, it is remembered for a point in time (tt-dt) (4t; (. It is selected empirically and amounts to 0.5-1.5 s) the value of the potential difference in the electrical circuit of the tuyere ground when the contacts of switch 3 are closed. At the moment of time (t + + AtJ-Atj (t - is chosen experimentally and is 0.3-0.5 s) according to the control signal of the computing unit 7, the switch 3 opens the electrical circuit from the additional resistance 4 with the second electrode 2 (unit housing). In the computing unit 7, the value of the electrical lining resistance according to (1), as well as metal temperature in the converter bath according to (2) (), e, og) where R. is the electrical resistance of the lining. Ohms; The measured value of the potential difference in the electrical circuit part f ma-ground with open contacts K xnshutator measured value of the potential difference in the area of electrical circuitry ground with closed contacts K of switch 3, mV; d ,, t - constant coefficients1) (agents (,, J (, (2 "fcg-b temperature of the metal in the bath of the converter, C; temperature value of the metal in the converter's bath, measured by thermoelectric: 10 diving on the previous melt, C; the value of the electrical resistance of the lining measured before the end of the purge at the previous heat, Ohms electrical resistance of the fugers & OM, is a constant value characteristic of the converter non-refractory lining material. At the output of the computing unit 7, a signal proportional to the electrical resistance the converter lining for the moment of time (t + At-), which is recorded by the first recording device 8, as well as a signal proportional to the temperature of the metal in the converter bath for the time point (t + 4t), which is recorded by the second recording device 12. The electrical resistance of the steelmaking lining functionally depends on the general condition and degree of wear of the lining. In the computing unit 7 for the time (t + At J), the electrical resistance of the lining is compared with the specified the value of the critical electrical resistance of the lining when an emergency situation is possible. If the electrical resistance of the lining is less than or equal to the specified critical electrical resistance of the lining, a signal is given to the alarm device and, if necessary, the operator stops the process in the unit. At time (4t,) where At is chosen empirically and is 15-130 seconds, the signal unit U is stored in the computing unit, the switch circuit is closed again, the unit U signal in the computation unit 7 is calculated, the electrical resistance of the lining is calculated, and the metal temperature bath converter for time {t + 2At; ti L + At,), etc., up to the end of the heat at certain discrete points in time, the magnitude of the electrical resistance of the lining and the temperature of metazol in the bath of the converter are determined. The electrical circuit of the lance-earth body-lining-melt-lance can be represented as an equivalent electric one (FIG. 2). The source of electromotive force in this circuit is the potential difference that occurs during smelting at the metal slag boundary. The decarburization of the metal is accompanied by the release of electrons, in which case the metal receives an excess of negative charge. In the electrical circuit of the tuyere-earth -, case-lining-melt-tuyere, the resistance of a portion of the chain of case-liners of the ca-melt depends on the degree of wear of the lining. The resistance of the chain section of the lance-melt as well as the internal resistance of the EMF source is much less than the resistance of the lining, i.e. “Cf-yr when performing calculations for an electric circuit. Tg and R.p. Can be neglected. The resistance of the sections of the electric circuit of the lance-earth of Yaf-3 and also the case-element R ... j for this converter is a constant value. On the basis of the second Kirch law, goha with open switch contacts for the first circuit (Figure 2) follows the equation F-. where E is the source emf value, the amount of current flowing in the primary circuit when the switch contacts are open. BUT; resistance ohm j ohm resistance of a portion of the electrical circuit of the housing earth. Ohm; resistance of a lance-ground electric circuit, O The magnitude of the current flowing in the first circuit with open contact K of the switch follows from the equation for the amount of current flowing through the lance-ground electric circuit with open contacts of the switch. BUT; the measured value of the potential difference in the electrical circuit of the lance-ground circuit with open switch contacts, A. The following equation holds for the first circuit: E, J; (VcL-z. the amount of current flowing in the primary circuit at the circuit breaker contacts , A | the value of the current flowing in the second circuit with the switch contacts closed, A. For the second circuit we have the following equation: .v, K-BV); M, The value of the current flowing in the second circuit follows from equation (6) .. e.-ai t 2 and (7) follows From the equations „/ Е) RV 2 1 | с-Э / к-3 l (.yf V VSile, The value of the current flowing in the primary circuit when the switch contacts are closed is equal to the amount of current flowing through the electrical section of the lance-earth circuit with the switch contacts AJ being measured. commutator, V. The time interval between the measurement of the potential difference in the section of the electric circuit of the lance-ground with open contacts of the chute and the measurement of the potential difference in the section of the electric circuit of the lance When the contacts of the switch are closed, the ground is chosen to be minimal, so the change in the value of the potential difference at the metal-Vshak boundary will be minimal, i.e., the value of the change in the potential difference at the metal-slag boundary for such a minimum interval can be neglected. Proceeding from this and Eqs. (5) and (8), we obtain; (“F. y-k-e 3); (F-z-k-e. ()“ K-s ”Substituting equation (4) and (9) ) in equation (10) and deciding on the resistance of the lining Kf, we obtain, kz zGk-z F-E -VrV3- (R, .3 "AoffK; -3) In order to simplify the dependence, we introduce the following notation: KF.K K- 3V3. By half (12–16) in the equation (1 we get (““; ee) s -e. En) The resistance of the lining of the steelmaking 4 unit functions depending on the overall condition and degree of wear of the lining. The calculated value is compared to given by the value of the critical resistance RAs when an emergency situation is possible, according to dependencies - critical electrical resistance of the lining, when an emergency situation is possible. Ohm i 2. Then the calculator If R, the y unit gives a signal to the alarm device. The properties are based on the following. Most of the refractory materials at low temperatures are dielectrics. With increasing temperature and the appearance of the liquid phase of the internal refractory materials, their electrical conductivity begins to increase. There is a relationship between the electrical resistance of refractories and temperature, OE) where R is the electrical resistance of the refractory material, Ohm; T is the absolute temperature, Kj A is the coefficient, B is a constant value, characteristic of this refractory material. From equation (19) with respect to temperature we get m., (-. 210 Between the temperature of the metal in the converter bath and the temperature of the linings) there is a linear relationship, therefore, from equation (20) it is possible to get the relationship for determining the temperature of the metal in the converter bath. The value of the coefficient A in equation (20) can be calculated before the start of the next smelting using the information on the temperature value of the metal in the converter bath measured during the rolling, as well as the electrical resistance of the lining measured before the end of the purge ) (Where rf-e), (where the absolute temperature of the metal in the bath of the converter, K-, is the value of the electrical resistance of the lining, measured before the end of the purge at the previous melting. Ohm. Absolute temperature the tour is determined by the dependence, (22). where is the temperature of the metal in the converter bath, measured by the thermocouple immersion in the previous melt, page. Substituting (22) into (21) we get - ((. T-). W By substituting (23) in (20) we obtain) (I: "F. g-M,. (24j) Thus, by equation (17), it is possible to determine the value of the electrical resistance of the lining, which functionally depends on the general condition and degree of wear of the lining, and (24) determine the temperature of the metal in the bath of the converter. The device is simple to implement and allows you to control the temperature of the metal in the bath of the converter by purging. A graphic implementation of the change in parameters at one of the heats is shown in Fig. 4, which shows the change in the temperature of the metal in the converter bath and the change in the electrical resistance of the lining during the purge. The same shows the metal temperature temperature t and the actual value t f a calculated by the end of the first purge period during the redistribution of phosphoric iron, as well as the metal temperature tp and the actual value t calculated by the end of the second purge period. Tables 1–3 show comparisons of the calculated and actual values of the temperature of the metal in three heats. The constant coefficients a, B "c, d, e, b, have the following meanings: 66, 76 d-5.6, 1873

Melting № 224225

Table 1 The calculation of the electric resistance of the lining is carried out according to the formula (17), the calculation of the temperature of the metal in the converter bath is carried out according to the formula (24). The rms error of control for the results of the first period of 114 heats is 9 ,. The use of the proposed device makes it possible, by controlling the temperature of the metal in the bath of the converter, to optimally control the temperature mode of melting, which leads to a decrease in the number of heats with blown down temperatures. The economic effect consists of reducing the average duration of the heats by 1.0% due to an increase in the proportion of heats from the first turn within the specified limits on temperature. The annual economic effect is 140 950 rubles.

Smelting 224252

table 2

U1,2

24.5 24.9 143.2 25.2 26.1 150.3 27.2 156.3 160.2 28.0 166.1 29.0 17i, 0 28.9 175.8 31.9 181.6 32 , 6,185.4

Melting №224253

28.85

24.4

140.6

28.1 24.9

143

10 12

27.15 25.6

147.6

26.04 26.5

152.5

25.00 27.4

157.5

23.86 28.5

163.3 4 16 18

22.96 29.4

168.2

22.28 30.1

172.1

21.64

30.8

176.0.

20 22 24

20.74

31.9

181.7 20.12 32.6 185.8

1375.11

1385.15

1394.93

1419.02

1450.12

1470.21

1500., 03

1524.99 1530

-5.01

1550.05

1580.23

1600.29 1610

-9.71

Table 3

1520 -0.01

1610 + 2.19

fug. 2

Claims (1)

DEVICE FOR CONTROL OF CONVERTER PROCESS PARAMETERS, comprising a power source, two electrodes, a recording device, a signaling device, a computing unit, additional resistance, a switch, a voltage-current converter / wherein the first electrode is connected to the first input of the voltage-current converter, the second input of which is grounded, the second the electrode is connected to the first input of the switch, and the second input of the switch is connected through the additional resistance to the first output of the power source, the second output of which is earthed voltage converter output It is connected to the input of the computing unit, the first second and third outputs of which are connected respectively to the inputs of the recording device, the signal detector and the control input of the switch, with a lance being used as electrodes and a converter housing, characterized in that, in order to expand the operational capabilities of the device due to predicting the temperature of the metal, an immersion thermocouple, a second voltage-τ -κ converter and a second recording device are introduced into it, and the output of the immersion thermocouple through second voltage-current converter connected to a computing unit, fourth output of which is connected to the input of the second recording apparatus. ' 1 1082832 2