SU742466A1 - Device for forecasting metal and slag discharge from convertor - Google Patents

Description

The invention relates to metallurgy, in particular, to the control of the oxygen-converter process.

A device for control of slag and offsets emissions s metal from the converter during blowing time photosensitive ^comprising: Tel'nykh element svizirovanny on the torch which is formed by blow molding, as well as the useful signal allocation scheme in the presence of noise [1].

The use of the known device allows to obtain quantitative information about emissions and removals, but with its help it is not possible to predict their occurrence.

The closest to the invention in technical essence and the achieved result is a device containing a flue gas pressure sensor under the dome of the fireplace, a unit for the ratio of gas pressure to blast flow rate, the output of which through an integrator is connected to the first input of the comparison unit, the second input of which is connected to the minimum acceptable unit the integral of the above ratio, and the output is with the block for selecting the control parameter and the magnitude of its change (2J.

In fact, in the known device, an analogue of the decarburization rate V _{c of the} converter bath is measured, and then the ratio of the amount of oxygen spent on the oxidation of carbon of iron to the spent oxygen of the blast is calculated. The calculation of this value allows us to estimate the amount of oxygen accumulated at a given point in time in the slag, which can potentially react with carbon and, under certain conditions, contribute to the formation of emissions. A disadvantage of the known device is that the integral characteristic of the process due to insufficient resolution does not the ability to predict emissions resulting from the rapid redistribution of oxygen from slag to the carbon oxidation reaction.

The purpose of the invention is to increase the reliability of forecasting.

The goal is achieved by the fact that in the device for predicting metal and slag emissions from the converter, containing a sensor for measuring a parameter characterizing V _c , a decarburization rate differentiation unit, series-connected memory blocks, threshold elements, a logic block and a multi-channel display unit are additionally introduced, and the outputs of the first and the last memory blocks are connected, respectively, with three and one threshold elements, the outputs of the remaining blocks are connected with two threshold elements, and the outputs of the threshold elements through; a logic unit is connected to a multi-channel display unit.

In FIG. 1 shows a block diagram of a device; in FIG. 2 - “smooth” melting; in FIG. 3 - “arrhythmic” melting; in FIG. 4 - graphs of the most likely changes in V _c during the period of penetration and formation of emissions; in FIG. 5 is a graph of outlier situations.

The device comprises a carpet 1, a lance 2, a converter duct 3, one of the possible sensors 4, 5, 6, which indirectly characterize V _c (gas pressure sensor or gas analyzers and flow meter), V _c determination unit 7, moving average determination unit 8, differentiator 9 , memory blocks 10 .... 14, threshold elements 15 ... 24, circuits AND 25 ... 30, comprising <logic block, control unit 31.

According to studies conducted on 300-ton converters, all swimming trunks according to the nature of the change in V _c can be conditionally divided into “even” and ^: “arrhythmic” - ““ Arrhythmic ”melts are characterized by significant, rapid changes in V _c in time, which are one from the reasons for the formation of metal and slag emissions from the converter, during which metal losses of up to 5% of the converter cage are possible. In addition, during emissions, emergencies are possible associated with the ingress of metal and slag on the access roads, as well as with the instability of the exhaust pipe. Studies of the nature of the change in the rate of carbon oxidation before emission in the purge interval from the moment of the end of the oxidation of Si and Mn (about 1-5 min for Car.MK conditions) to the moment V _c at the end of the melting during the melting period decreases the carbon content in the metal, showed that emissions occur with a rapid change (increase) V _c due to the transition of oxygen from the slag to the reaction. oxidation of carbon, and V _c before emissions has in most cases a decrease in absolute value. The presence of this phenomenon allows us to predict the possibility of

thirty.

742466 4 emission changes before their formation, which in turn makes it possible to prevent them by changing the position of the tuyere, oxygen consumption or additive bulk materials. In FIG. Figure 4 presents the most probable changes in V _c during the period of formation and occurrence of emissions. According to implementation a) up to the moment of a sharp increase in V _c, it has a rather rapid decline within 35-40 s, according to implementation, b) the decrease in V _c is longer.

The operation of the device is as follows.

At t = t _H (t _H ”the end of oxidation S1), the control unit 31 turns on the system, in the unit 7 for determining V _{c, the} current value of the rate of carbon oxidation is calculated (for example, according to the formula V _c = kQ ^ CO + CO ₂ , where k is the proportionality coefficient , Οθ _Γ is the gas flow rate in the gas duct, СО, СО ₂ content of carbon monoxide and carbon dioxide in the exhaust gases). In block 8, the value V _c is determined for the average over several samples (meaning discrete reading of information), for example, when averaging over three samples, the following operation is performed: ~, and it should be specially noted that both the presence of block 8 and the averaging interval depend from the characteristics of the converter process (oscillation) and the equipment used for monitoring (inertia of the devices). In block 9 differentiation is made (with discrete reading) the determination of the increment V _c between the samples (Δ Vg). Further, these increments enter the sequentially connected memory blocks 10 ... 14, and in block 14 there is (i-4) count Δ V _c , in block 13 - (i-З) in block 12 - (i-2), in block 11 - (i-1), in block 10 - (i), where i is the reference number from the time t = t _H. As blocks of memory 'can be used registers, and the rewriting of numbers from one register to another is carried out by commands from block 32 of the control. Analysis of the change in V _c according to the current samples located in the memory block is performed using a set of threshold elements 15 ... 24 and circuits 25 .... 30 I. The specified combination of threshold elements and circuits AND allows you to identify the following situations (Fig. 5) leading to outliers: the rate of decline of the characteristic V _{c is} less than the rate of increase V _c (Fig. 4), but greater than some critical δι obtained statistically (threshold element 15, triggered when κ · Δ Vc> (Fig. 5a); the decay rate V _{c is} greater than (equal to) - δ ₃ , and with an increase in the duration of the decline the probability emissions increases (threshold elements 16 ... 20, circuits 25 ... 27 And, and the signal at the output of circuit 25 And appears under the condition κ · Δ ν £ <-δ ₃ and κ · Δ Vg <-δ ₃ and κ-Δ <- δ _{3> the} signal at the output of circuit 26 And appears when the previous condition is fulfilled and κ · Δ ν £ <-δ ₃ , _{5 the} signal at the output of circuit 27 And appears when the previous condition is fulfilled and κ · Δ Vc <- δ ₃ (Fig. 56); the decay rate V _{c is} greater than (equal to) - δ ₂ and a sign change is possible Δ ν _€ (1-δ ₂ /> / - δ ₃ /), threshold elements 21 ... 24, w 28..30 And, moreover, the signal at the output of the circuit, 28 And appears at κ? Δ V ^ <-δ ₂ and κ · Δ V _c <- δ ² ₂ , at the output of the circuit 29 And appears when the previous condition is satisfied and κ «Δ v £ <-δ ₂ , at the output of the circuit 30 And is appears when the previous condition is fulfilled and κ · Δ Vq> 0 (Fig. 5c). The signals from circuit 25-30 And are recorded on a multi-channel (with separate registration) display unit, which allows us to predict the probability of 20 emissions.

It should also be noted that the number of memory blocks is chosen to be five from the condition that it is necessary to analyze the change in V _c during π »40 s, at a sampling step of time equal to 8 s, which follows from the most probable implementations presented in FIG. 4. At another sampling step, the number of memory blocks must change.

The device allows to increase the reliability of h ₀ forecasting emissions and have a certain time interval from the moment the forecast is received to their occurrence, which makes it possible to take measures to combat them. So for the situations presented in FIG. 5, the indicated interval is: for FIG. 5a 10 + 15 s, for FIG. 56 “60 s, for FIG. 5c == 35 s.

Claims (2)

(54) APPROACH FOR PREDICTING METAL AND SLAG EMISSIONS FROM A CONVERTER The invention relates to metallurgy, in particular, to the control of the oxygen-converter process. A device for controlling the outflows and slag emissions — and the metal from the converter during purging — contains a photosensitive element, swiched to a flare that is formed by T1 during purging, as well as a scheme for isolating the useful signal in the presence of interference 1. Using a known device provides quantitative information about larvae and supers, but with its help it is not possible to predict their occurrence. The device closest to the invention with the technical essence and the achieved result is a device comprising a pressure sensor for exhaust gases under the fireplace dome, a pressure ratio of gases to flow rate system, the output of which is connected to the first input of the comparison unit through the integrator, the second input to which is connected to the unit determining the minimum permissible value of the integral of the above ratio, and the output with the control parameter selection block and the value of its change 2. In fact, in a known device, the analogue V. bath decarburization spine converter, and then calculates a ratio of the amount of oxygen spent in okislenye carbon iron to oxygen blowing expended. The calculation of this value allows one to estimate the amount of oxygen accumulated at a given point in time in the slag, which can potentially react with carbon and, under certain conditions, contribute to the formation of emissions. A disadvantage of the known device is that the integral characteristic of the process is due to insufficient resolution. the ability to predict emissions resulting from the rapid redistribution of oxygen from slag to the carbon oxidation reaction. The purpose of the invention is to increase the reliability of prediction. The goal is achieved in that the device for predicting the emissions of metal and slag from the 1-invertor, which contains a sensor for measuring the parameter characterizing V., was additionally equipped with a differential block of the decarburization rate, serially connected memory blocks, threshold elements, a logic block and a multi-channel display unit, moreover, the outputs of the first and last memory blocks are connected respectively with three and one threshold elements, the outputs of the remaining blocks with two threshold elements, and the outputs of the threshold element They are connected to a multichannel display unit through a logic unit. FIG. 1 is a block diagram of the device; in fig. 2 - smooth melting; in fig. 3 - arrhythmic fusion; in fig. 4 shows graphs of the most likely changes in V, during the period of inoculation and the formation of outliers; in fig. 5 are plots of situations leading to outliers. The device contains a covertor 1, a lance 2, a converter flue 3, one of the possible sensors 4, 5, 6 indirectly characterizing Vg (gas pressure sensor or gas analyzers and a flow meter), V determination unit 7, moving average determination unit 8, differentiator 9, blocks 10 .... 14 memory, threshold elements 15 ... 24, schemes AND 25..30, components (logic block, control block 31. According to studies conducted on ZOO-tsynykh converters, all melts by nature V changes (. can be conditionally divided into even and arrhythmic - Arrhythmic melts are characterized by major, rapid changes in V over time, which is one of the reasons for the emission of metal and scrap from the converter, during which metal losses of up to 5% from the metal charge of the converter are possible. study of the nature of the change in the rate of carbon oxidation before the emission for the interval of purge from the moment of the end of the oxidation S i and Mn (approx. about 1–5 min for Kar.MK conditions until V declines at the end of smelting during the period of smelting, the decrease in carbon content in the metal, showed that emissions occur with a rapid change (increase) in Vg due to the transition of oxygen from the donkey to the reaction, oxidation carbon, with pre-emission CS, in most cases, a decrease in the absolute value. The presence of this phenomenon makes it possible to predict the possibility of 7 4 new emissions before their formation, which in turn makes it possible to prevent them by changing the position of the tuyere, oxygen consumption or the addition of bulk materials. FIG. Figure 4 shows the most likely changes in V at the time of formation and emission. According to the implementation of a) until a sharp increase in V, it has a rather rapid decline over 35-40 s, according to the implementation, b) the decline of the US is longer. The operation of the device is as follows. At t tjj (t end of oxidation SI), control unit 31 turns on the system, in block 7 of determining a DC, the current value of the oxidation rate of carbon is calculated (for example, according to the formula CD kQ CO + CO2, where k is the proportionality coefficient. C ,,, is the gas flow in the flue , CO, CO2 the content of oxide and carbon dioxide in the exhaust gases). In block 8, the mean value of the mean value over several counts is determined (meaning discrete reading of information), for example, averaging over three readings results in the following operation: Y — fci ± Ja, —three it should be noted that the very presence of block 8, and the averaging interval depends on the characteristics of the converter process (oscillation) and the control equipment used (inertia of the instruments). In block 9 of differentiation, a discrete increment determination is performed (in discrete readout) between readings (D V). Further, the specified increments enter the serially connected memory blocks 10 ... 14, and in block 14 there is (i-4) count D U., in block 13 - (i-3) in block 12 - (i-2), in block 11 - (ii), in block 10 - (|), where i is the reference number from the point in time. Registers can be used as memory blocks, and the rewriting of numbers from one register to another is carried out according to commands from the 32T1 equalizer block. The analysis of the change in the ESS on the current readings in the memory block is carried out using a set of threshold elements 15 ... 24 and schemes 25 .... 30 I. The specified combination of threshold elements and schemes And allows to reveal the following situations ( Fig. 5), leading to outliers: the decay rate of the characteristic of the CONS is less than the rate of increase of Y (. (Fig. 4), but more than a certain critical Sj obtained by statistical means (threshold element 15, triggered by K-D) DC ( Fig. 5a); the decay rate of the EOS is greater than (equal to) - bz, and with an increase in the duration of the decay, the emission increases (threshold elements 16 ... 20, circuits 25 ... 27 And, and the signal at the output of the circuit 25 And appears under the condition K-D V bz and k. D US -6z and KA Vc -83, the signal at the output of circuit 26 And appears when the previous condition is met and K-D US -8z sigal at the output of circuit 27 And appears when the previous condition is met and CD US -§3 (Fig. 56); (is equal to) - Sj and the sign change is possible А А У (1-52 / / -5з /), threshold elements 21 ... 24, shells 28..JO И, and the signal at the output of the circuit, 28 AND appears when : D US -Sj and CD US - n output of circuit 29 And it appears when performing pr preceding one condition and CD -b2 output of AND circuit 30 is in the previous conditions, and k D FF G (FIG. 5c). The signals from the circuit 25 ... 30 And are recorded on a multi-channel (with separate registration) indication block, which allows the forecast of the emission probability. It should also be noted that the number of memory blocks is chosen equal to five from the condition that it is necessary to analyze the change in Y within 40 seconds, with a time discretization step equal to 8 seconds, which follows from the most likely implementations presented in the fng. 4. With another sampling stage, the number of memory blocks must change. The device makes it possible to increase the reliability of the prediction of emissions and to have a certain666 time interval from the moment the forecast is received to their occurrence, which makes it possible to take measures to control them. So for the constructions shown in FIG. 5, the indicated interval is: for FIG. 5a IQtlS, for FIG. 56 60 s, for figs. 5c 35 s. Claims An apparatus for predicting metal and slag emissions from a converter, comprising a sensor for indirect measurement of metal decarburization rate, characterized in that, in order to increase the prediction reliability, it further comprises a differentiation unit; decarburization rates, serially connected memory blocks, threshold elements, logic block and multi-channel display unit, the outputs of the first and last memory blocks are connected to three and one threshold emitters, respectively, and the outputs of the threshold elements are connected to the multi-channel display unit. Sources of information taken into account in the examination 1. USSR author's certificate number 358850, cl. C 21 C 5/30, 1968. 2. Author's certificate of the USSR N 303888, cl. C 21 C 5/30, 1% 7.  , / WITH but h. with. yl { Fel.g, Swt i Ours 0s t 60 L thirty - "" IM e . ifO Sh "" (R Fig .. 5 t.SuT r V. Ul NIN %ten 690 v ../ v. / Ve Ve of I ff / L C & t / 3.4 / /