SU1463768A1 - Method of monitoring the flow of outgoing gases - Google Patents

Abstract

The invention relates to the field of automation of oxygen-converter steel production and is intended to control the flow of flue gases. The goal is the accuracy of control. The essence of the invention is that they correct the indications of the restriction device by the difference between the controlled and technologically determined values of the rate of oxygen supply to the slag at the time of its minimum value. 3 il.

Description

one

This invention relates to the automation of metallurgical processes and MO. Can be used in the oxygen-converter steel production.

The purpose of the invention is to improve the accuracy of control.

Figure 1 shows the structure of the technical means that implement the method; Fig. 2 is a diagram showing the change in the rate at which oxygen enters the slag; FIG. 3 shows data comparing the amount of oxygen accumulated in the slag.

Fig. 1 shows the device 1 for measuring the pressure drop, the device 2 for measuring the pressure, the device 3 for measuring the temperature of exhaust gases on the Venturi tube, the device 4 for measuring the chemical composition of the converter gases, the device 5 for measuring the flow rate of oxygen supplied through the lance, as well as

6-8 to determine the flow rate of the exhaust gases on the Venturi pipe, its corrected values, the oxygen flow rate into the slag, the device 9 to determine the moment of the minimum oxygen flow in the tank, the device 10 to determine the concentrations of nitrogen, oxygen, hydrogen, carbon oxide and carbon dioxide at the moment: the minimum oxygen supply to the slag, the device 11 for determining the flow of exhaust gases in this period, the device 12 for determining the consumption of oxygen in the same period. The structure also includes the devices 13-19 for measuring, before the start of blowing, the parameters of the charge materials - the mass of the loaded scrap, the mass of the cast iron, the number of scoops of scrap, the temperature of the cast iron, the chemical composition of the cast iron, the device

(S

WITH

to

and cx

to determine the technologically determined rate of entry of oxygen into the slag during the period of its minimum values, ia required for this rate, the value of the correction factor for measuring the flow of exhaust gases on the Venturi tube, the device 20 dp determining this factor for the next phase.

The essence of the method lies in the fact that during the blowing process, the rate at which oxygen enters the illac is determined by the instantaneous balance of oxygen entering the bath through the lance and leaving the converter with waste gases, for example,

1D6

-,

-V.V

 1H,

C +, + KV -

.-IM.U, (

V

04

about

og

- riJo-

n, “Ls”

Kp gsch

where UO is the rate at which sour is entering the slag, m / min;

oxygen consumption for purge, current waste gas flow through the venturi, m / min;

with

  concentration in the waste. oxide and dioxide gases

carbon, kzhshoroda, hydrogen and nitrogen, respectively, share; o

the correction factor for measuring the flow rate of waste gases in a given smelting, where n is the order of such a smelting number from the origin of the monitored pea is LIZ, and K 1. The determination of the correction factor is made by comparing the value of the rate of oxygen supply to the slag at the time of its minimum supply, determined from the measurement data, and the value of this value, determined by the characteristics of the charge materials, which is determined by a previously found relationship, for example,

,

 G, - T.

G.-ttsil4 Chmp1, Ch.,

Sosh

where v ...

0

five

0

25

thirty

35

- the value of the rate at which oxygen enters the slag at the time of its minimum values, m / min, due to the characteristics of the charge materials;

- mass of loaded scrap, kg;

- mass of cast iron, kg;

- amount of scrap scoops, pcs;

- temperature of cast iron. WITH;

-concentration of silicon, manganese, phosphorus, chu-guna, lobes;

- oxygen consumption for purging during the period of minimal supply of oxygen in the slag, m / min; Hell, A, A2 - empirical coefficients. you,

The value of the coefficient; corrections for this melting are made according to the previous melting according to a formula that takes into account the random nature of the change in the error rate of determining the flow of exhaust gases according to measurement data, for example, in the form of an exponential smoothing filter equation j

TO

Shopping center

Si C, SMP

LP.

v:

to „to

Uy, - (Iy-,)

to

P-1)

 Chz)

where K,

0

K „ff. five

0

TO

five

correction factor used in the previous melt; adjustment coefficient for a given heat; the weight coefficient of the smoothing filter, which is determined according to preliminary studies of the process of changing the measurement error of the exhaust gas flow during the operation of the gas exhaust pipe TpaKTaj, is the correction factor necessary for previous melting, determined on the basis of a comparison of the rate of oxygen entering the slag at the moment its minimum income

and its value due to the characteristics of pgahtovy materials, for example by

yl (w

 - - G to; tklmg-1vdg1g

V

yl

- the rate of oxygen in the slag at the time of minimum values, m / min;

og

- waste gas flow, measured. through the Venturi tube, at the time of minimum oxygen supply to the slag, m / min;

co, (OD, - concentrate in waste- OifL Sch vg, LEAN gases at the moment of NaV

minimum oxygen supply

slag, respectively, share.

The method of controlling the flow of waste gases is carried out as follows.

Before the start of the purge, the parameters of the charge materials are measured using the device 13-17; during purging with the help of the device 1-4, the necessary parameters of the waste, gases are measured and with the help of the device 6 and 7 the value of the flow of the exhaust gases through the Venturi pipe is determined and corrected using the correction factor found from previous heats using the device 5, the consumption of oxygen supplied through the lance is measured, the value of the rate of oxygen supply to the slag is determined by the formula (1) using the given consumption and chemical waste gas and the oxygen consumption in the device 8; at the same time. the device 9 searches for the moment of minimum oxygen supply to the slag according to the data on the rate of oxygen supply to the slag; using the device 10-12, it is possible to determine the concentrations of nitrogen, oxygen, hydrogen, carbon oxide and carbon dioxide, the consumption of exhaust gases and the consumption of oxygen at the time of the minimum oxygen supply to the slag; after purging with. devices 18 determine the value due to the parameters of the charge

five

0

with.

0 5 0 45 50 55

materials, the rate at which oxygen enters the slag at the time it is consumed. According to (2), then using the device 19, the value of the correction coefficient value required for this melting to measure the discharge of flue gases by this melting is given by formula (4) and the coefficient 2P is used to determine this coefficient for use on the next melt yo (3).

The dependence of the rate of entry, on the parameters of the charge materials is explained by the influence of the smelting of scrap and frozen south-iron, whose role in the development of smelting increases with increasing converter charge. When casting on scrap, the cast iron melts during blowing and the pig iron flowing into the bath displaces the distribution of 1 blow of hydrogen between the bath and the gas phase towards accumulation in the slag, the stronger the formed frost iron formed at the beginning of smelting, and also, the more impurities therein, the main ones of which are silicon, phosphorus and manganese.

The mathematical expression (2) reflects the dependence of the rate at which oxygen enters the slag at the moment of its minimum value on the parameters of the charge materials. Figure 2 shows a curve 21 of the process of changing the rate of oxygen supply to the slag, which has the character of a non-stationary random process, and curve 22, reflecting the low-frequency trend of the rate of oxygen supply, which can be distinguished by filtering, at the moment of blowing A on curve 22, you can select the minimum the value of the rate at which oxygen enters the slag. (point 23).

For blowdown conditions in 350-ton converters, which are tested using the method of correlation method 1463768

analysis and regression analysis, the following equation is obtained, which describes the rate of oxygen supply to the slag during its minimum I value:

  0.20610 + o, 000045 + 0.066105

"1ffs M ,, M / -M,

de g

BUT

the weight of the loaded scrap, the range of its fluctuations for a given workshop is 90-110 tons, kg; the mass of cast iron poured on the smelting, the range of variations is 240-270 tons, kg; number of scrap scrap 2-5 pieces

Temperature chu17una 1290-185 ° C, C

concentration in cast iron, fluctuation range 0.7–0.9%, DOLI — phosphorus concentration in chu PG not 0.7–1.3% „fraction of Mn - concentration, margensch in

  cast iron about, 6-0,8% 9 shares; v is the consumption of oxygen supplied through at the moment of minimal entry of oxygen into the slag, m / min. The moment of shiming: the story in Bshak is determined by the following

,

With a duration of 0.1 min, the rate of oxygen supply in the singular formula (1) is determined along the purge process, and these values, as well as oxygen consumption, waste gas consumption and sj3OTa concentrations, oxygen, and oxygen, and carbon dioxide in these gases, which are used to determine the rate at which oxygen enters; gplak.

Using the current average filter, in which the current average interval is 3 min., Determines the extent of the oxygen inlet velocity values to the slag, thereby reducing the effect of minimum distortion of oxygen into the slag of random distortions in the measurement of this parameter. The minimum rate of flow of oxygen into the slag is determined by the method of sequential comparison.

five

0

40

50

For the found minimum rate of oxygen intake in Nshak, the values of oxygen consumption, waste gas consumption, nitrogen, hydrogen, oxygen, carbon dioxide and carbon dioxide concentrations in the exhaust gases are determined using a similar filter. After the end of the purge-by-datum; The parameters of the charge materials are determined using formula (5), the value of the technologically determined rate of oxygen supply to the slag during its minimum values, and then according to the formulas. (3) and (4) determine the correction coefficient for the flow rate of waste OUT1SCh-1X gases dp next melt-and.

Fig. 3 presents data comparing the values of the amount of oxygen accumulated in the slag., Determined by its chemical composition and consumption of waste gases and oxygen, and

5 values of this parameter, found from the data on xp; the composition of the slag at the time of intermediate download. slag, represented by two, samples of heats, one of which consists

0 from the heats, on which the correction of the measurements of the flow of exhaust gases is not carried out, r g a and from the experimental: heats, on which use the proposed solution. The finished area refers to the results of pilot heats. The error in determining the amount of oxygen in the slag in the experimental heat is reduced by 62%.

Claims (1)

Thus, the use of the invention makes it possible to reduce the error in determining the flow of flue gases at the converting device, eliminating the need to control the content of argon in oxygen — using a mass spectrometer, and increase the reliability of the system for controlling and controlling the process of purging the bath of the converter. - Invention Formula 35 50 The method of controlling the flow of flue gases, which consists in determining the flow of flue gases according to C15 measurements of pressure, differential pressure and temperature, flue gases by a charging device, and measuring the chemical composition of flue gases, characterized in that In order to increase the accuracy of control, additionally during the blowing process, the rate of oxygen supply is determined at the moment of minimum speed, the value of the technologically determined speed of the postpump of oxygen into the slag is determined by the parameters of charge materials. the moment of its minimum value and corrects the measured value of the waste gas flow in the next smelting according to the difference between the controlled and technologically determined values of the rate of oxygen supply to the slag at the time of its smelting value on this smelting. 1 2 S S 6 7 S 3 to t 12 13 n IS fas.  J 5 IV (V) thous.