CN116622929A - A Method of Automatically Controlling the Opening of Converter Erwen Throat - Google Patents

Abstract

The invention relates to a method for automatically controlling the opening degree of a converter secondary throat, which is characterized in that in the converter blowing process, when the converter is in a charging state, when the converter blows to a slag point, after the converter blows to the slag point, before the converter sublance process is tested, when the temperature of molten steel is close to a smelting end point, a flue gas analyzer, a flame machine vision device and an audio signal acquisition device are used for acquiring the gas content of top gas, the change of the light intensity of the converter mouth or the light intensity of the lower edge of the converter mouth and the data information of a converter blowing sonar slag measurement value, and the acquired data information is transmitted to a PLC/DCS system, so that the opening degree of the converter secondary throat is automatically controlled in the converter blowing process when the converter is in the charging state. The invention has the advantages that: no manual intervention is needed, the smoke overflow is reduced, the gas recovery rate is improved, and the production safety is maintained.

Description

A Method of Automatically Controlling the Opening Degree of the Erwen Throat of Converter

technical field

The invention relates to the technical field of converter gas recovery, in particular to a method for automatically controlling the opening of the second throat of the converter.

Background technique

In converter steelmaking, the control of the flue throat is very important. If the control is not good, the following situations will occur: the gas recovery rate will be affected, and the carbon emission of negative energy steelmaking will be affected; it will easily cause smoke and dust to overflow and affect environmental protection; it will easily cause The flames burned the frame and platform equipment of the factory building, endangering production safety.

Existing methods for controlling the Erwen throat include the following:

1. Manually control the fire and watch the fire, and manually adjust the opening of the Erwen throat when the fireworks are too large.

2. The differential pressure at the furnace mouth is automatically adjusted. This method cannot be used normally because the pressure taking port is inside the fume hood, the environment is harsh, and it is often blocked by hot smoke, steel slag, and splashes.

3. Static mode adjustment method, according to big data, set a fixed opening at a fixed time; the publication number is CN107630120B, which discloses "A Method for Adjusting the Erwen Throat of a Converter", and the disclosure content is as follows:

1) During the period of adding iron and scrap steel, the opening of Erwen throat is controlled at 40% to 50%;

2) During the silicon-manganese oxidation period before the oxygen blowing volume is 20%, the RD valve opening is controlled at 50%-60%;

3) In the intense oxidation period of carbon and oxygen with oxygen blowing volume of 20% to 75%, the opening of RD valve should be controlled above 90%;

4) After the oxygen blowing volume is 75%, the RD valve opening is controlled at 65% to 75%;

5) When the secondary gun process test starts, the opening of the RD valve is controlled at 50% to 60%;

6) After the oxygen blowing ends, the opening of the RD valve is controlled at 40% to 50%;

The disadvantage is that the adjustment method is to statically control the Erwen throat.

4. Automatic mode adjustment method, the publication number is: CN105154615B, which discloses "an automatic adjustment device and adjustment method for the two-way throat of a converter", which breaks through the traditional differential pressure control method of the furnace mouth pressure sensor and adds gas analysis. The instrument sensor, oxygen analyzer sensor, oxygen lance position sensor, and oxygen regulating valve position sensor are respectively installed on the side of the flue gas pipe of the fan and the three-way valve. Control the hydraulic station at the throat. When the detection signals all meet the requirements, the weight moves downward to the specified position. When any of the detection signals does not meet the conditions, the weight moves upward and returns to the initial position, thereby realizing the second phase of the converter. The automatic control and adjustment of the Wen throat; the gas content is used to dynamically control the Wen throat, but the shortcoming is that the variable is single.

Contents of the invention

The purpose of the present invention is to provide a method for automatically controlling the opening of the second throat of the converter, through the feeding state, the change of the gas content of the top gas of the converter, the light intensity of the converter mouth or the light intensity of the lower edge of the furnace mouth when the converter starts to blow. Change the multiple variables of the slag value measured by the blowing sonar, and automatically control the opening of the second throat of the converter, which reduces the smoke and dust overflow during steelmaking, improves the gas recovery rate, and maintains production safety.

To achieve the above object, the present invention is achieved through the following technical solutions:

A method for automatically controlling the opening of the second throat of the converter, realized based on the PLC/DCS system, using the experience value before the start of blowing as the initial value of the opening of the second throat of the converter. When the converter starts blowing, it specifically includes The following content:

1) When the converter is in the state of charging, the opening of the second throat of the converter is set as follows: increase the opening by one on the basis of the initial value, and return to the initial value after maintaining the set time for one;

2) When the converter blowing reaches the slag point, the sum of the carbon monoxide concentration and carbon dioxide concentration of the furnace top gas is greater than the set value 1, or the carbon dioxide concentration of the furnace top gas is greater than the set value 2, and the opening of the second throat of the converter is set It is: increase the opening degree 2 on the basis of the initial value, and return to the initial value after maintaining the set time 2;

3) When the converter blowing reaches the slag point, the following steps are included:

Step S1, when the light intensity value of the converter mouth is less than the set threshold value 1, the opening of the second mouth of the converter is set as follows: increase the opening degree 3 on the basis of the initial value, and maintain it until the light intensity value of the converter mouth returns to Return to the initial value as soon as the threshold is set;

Step S2, when the light intensity value at the lower edge of the converter mouth is greater than the set threshold value 2, the opening of the second mouth of the converter is set as follows: increase the opening degree 4 on the basis of the initial value, and maintain it to the lower edge of the converter mouth. When the light intensity value returns to the set threshold two, it will return to the initial value;

4) When the converter blowing reaches the slag point and the slag value measured by sonar falls in the dry back area, the opening of the second mouth of the converter is set as follows: reduce the opening by five on the basis of the initial value, and maintain it until the slag is measured by sonar Return to the initial value when the value leaves the re-drying area;

5) Before the process test of the converter sub-lance, if it is detected that the sum of the carbon monoxide concentration and the carbon dioxide concentration of the top gas suddenly drops, and the slag value measured by sonar falls in the splash area, the opening of the converter secondary throat is set as follows: Increase the opening six on the basis of the initial value, and maintain it until the slag measured by sonar leaves the splash area, or when the slope of the sum of the carbon monoxide concentration and carbon dioxide concentration in the top gas is greater than zero, then return to the initial value;

6) When the temperature of the molten steel is close to the end of smelting, the light intensity value of the furnace mouth becomes stronger, and the opening of the second throat of the converter is restored to the initial value.

The slag value measured by converter sonar is the sound intensity value of fixed frequency sound.

The carbon monoxide concentration of the top gas and the carbon dioxide concentration of the top gas are detected by the flue gas analyzer, which is installed at the end of the rising section of the converter waste heat boiler vaporization cooling flue; the light intensity value of the converter mouth or the converter mouth The strong light value of the lower edge is detected by the flame machine vision device, which is set directly opposite the converter fire door; the sonar slag measurement value is detected by the flame machine vision device, which is set on the side wall of the converter trunnion Facing the furnace mouth.

The flame machine vision device includes a camera, the flame machine vision device includes a sound sensor, the flue gas analyzer, the flame machine vision device, and the flame machine vision device are all connected to the PLC/DCS system.

Compared with prior art, the beneficial effect of the present invention is:

The gas content of the furnace top gas, the light intensity of the converter mouth or the change of the light intensity at the lower edge of the converter mouth, and the slag value measured by converter blowing sonar are collected by flue gas analyzers, flame machine vision devices, and audio signal acquisition devices Information, and the collected data information is transmitted to the PLC/DCS system. When the converter is in the feeding state, the opening of the second throat of the converter and the gas recovery rate are automatically controlled during the converter blowing process to maintain production safety.

Description of drawings

Fig. 1 is a structural schematic diagram of the method for automatically controlling the opening of the Erwen throat of the converter.

Figure 2 is the test curve of converter steelmaking blowing process.

Figure 3 is a schematic diagram of Erwen throat control principle.

In the figure: 1-flame machine vision device 2-audio signal acquisition device 3-flue gas analyzer 4-converter waste heat boiler vaporization cooling flue.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings, but it should be pointed out that the implementation of the present invention is not limited to the following embodiments.

The following examples are carried out on the premise of the technical solutions of the present invention, and detailed implementation methods and specific operation processes are provided, but the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

【Example 1】

The main reasons for flue gas overflow during converter steelmaking blowing are as follows:

1. When the converter is in the feeding state, there will be dust overflow;

2. The smoke will overflow when the molten steel is splashed;

3. When the carbon monoxide produced during blowing or the carbon dioxide of the furnace top gas changes suddenly, the flue gas will overflow;

For the above three reasons, the change of the gas content of the furnace top gas, the light intensity of the converter mouth or the change of the light intensity of the lower edge of the converter mouth, the converter The data information of sonar slag value (converter sonar slag value is the sound intensity value of fixed frequency sound), and the collected data information is transmitted to the PLC/DCS system. When the converter is in the state of feeding, the converter blowing process is realized. In the automatic control of the opening of the second throat of the converter, see Figure 1, a method for automatically controlling the opening of the second throat of the converter, the carbon monoxide concentration of the top gas and the carbon dioxide concentration of the top gas are measured by the flue gas analyzer 3 For detection, the flue gas analyzer 3 is installed before the end of the ascending section of the converter waste heat boiler vaporization cooling flue 4; The glare value of the lower edge is detected by the flame machine vision device, which is installed 20 meters directly opposite the fire door of the converter, and the camera can observe the flame at the furnace mouth of the converter during steelmaking; the slag value measured by sonar is passed The audio signal acquisition device is used for detection, and the audio signal acquisition device is installed on the side wall of the converter trunnion facing the gap between the furnace mouth and the fume hood; the flame machine vision device includes a camera, which is used to detect the area of the furnace mouth and the area along the lower edge of the furnace mouth. The light intensity of the furnace mouth changes and whether there is steel slag overflowing from the lower edge of the furnace mouth. The audio signal acquisition device includes a sound sensor and an audio transmitter. The sound sensor converts the collected signal into a 4-20mA signal through the audio transmitter. The audio signal acquisition device The sound sensor is used to detect the slag value measured by sonar, and the flue gas analyzer, flame machine vision device, and audio signal acquisition device are all connected to the PLC/DCS system.

See Figure 2, see Figure 3, a represents the light intensity detection curve at the furnace mouth, b represents the sonar curve, c represents the curve of the sum of carbon monoxide and carbon dioxide, d represents the carbon dioxide curve, and e represents the carbon monoxide curve; Throat opening is set to 65% according to manual experience. When blowing begins, specifically include the following:

1) When the converter is in the state of charging, the opening of the second throat of the converter is set as follows: increase the opening by 5% on the basis of the initial value to 70%, and return to the initial value after maintaining it for 20 seconds;

2) When the converter blowing reaches the slag point, the carbon monoxide concentration of the furnace top gas is 20% to 27% higher than the set value, or the carbon dioxide concentration of the furnace top gas changes from rising to falling, the smoke and dust will become larger and there will be spray Splash trend, the opening of the converter Erwen throat is set as: increase the opening by 10% on the basis of the initial value of 65%, and return to the initial value after maintaining for 1 minute;

3) When the converter blowing reaches the slag point, the following steps are included:

Step S1, when the light intensity value of the converter mouth is less than the set threshold value 27, the flue gas is too large to block the light, and the opening of the converter throat is set to: increase the opening by 10% on the basis of the initial value of 65%. , and maintain until the light intensity value of the converter mouth recovers to the set threshold 32 and returns to the initial value;

Step S2, when the light intensity value at the lower edge of the furnace mouth of the converter is greater than the set threshold of 50, steel slag overflows to the lower edge of the furnace mouth, and the opening of the second throat of the converter is set to be increased by 10% on the basis of the initial value of 65%. The opening degree, and maintain until the light intensity value at the lower edge of the converter mouth returns to the set threshold of 45, then return to the initial value;

4) When the converter blowing reaches the slag point and the slag value measured by sonar falls in the back-drying area, the flue gas generated at this time decreases, and the opening of the converter's second throat is set to: decrease on the basis of the initial value of 65%. 10% opening, and maintain it until the sonar slag value is out of the back-drying area, then return to the initial value, which is used to increase the gas recovery rate;

5) Before the process test of the converter sub-lance, if the sum of the detected carbon monoxide concentration and carbon dioxide concentration drops suddenly and the slag value measured by sonar falls in the splash area, it means that the molten steel splash is about to occur. The degree setting is: increase the opening degree by 10% on the basis of the initial value of 65%, and maintain it until the slope of the sum of the carbon monoxide concentration and carbon dioxide concentration is greater than zero or the slag value measured by sonar leaves the splash area and returns to the initial value;

6) When the temperature of molten steel is very high and near the end of smelting, when the light intensity at the furnace mouth becomes stronger to the set threshold of 72, restore the opening of the second throat of the converter to 65% of the initial value.

The invention collects the gas content of the top gas, the light intensity of the converter mouth or the change of the light intensity of the lower edge of the converter mouth, and the slag value of the converter blowing sonar through the flue gas analyzer, the flame machine vision device, and the audio signal acquisition device. The data information collected will be sent to the PLC/DCS system. When the converter is in the feeding state, the opening of the second throat of the converter can be automatically controlled during the converter blowing process, without manual intervention, and the smoke and dust overflow can be reduced. The gas recovery rate is improved, and production safety is maintained.

Claims (4)

1. The method for automatically controlling the opening of the second venturi throat of the converter is realized based on a PLC/DCS system, and is characterized in that an empirical value before starting converting is taken as an initial value of the opening of the second venturi throat of the converter, and the method specifically comprises the following steps when the converter starts converting:

1) When the interior of the converter is in a charging state, the opening of the converter II throat is set as follows: increasing the opening degree I on the basis of the initial value, and returning to the initial value after maintaining the set time I;

2) When the converter blows to a slag point, the sum of the carbon monoxide concentration and the carbon dioxide concentration of the top gas is larger than a first set value, or the carbon dioxide concentration of the top gas is larger than a second set value, and the opening of a throat of the converter II is set as follows: increasing the opening II on the basis of the initial value, maintaining the setting time II, and returning to the initial value;

3) When the converter blows to a slag point, the method comprises the following steps:

s1, setting the opening of a converter II throat as: increasing the opening III on the basis of the initial value, and returning to the initial value after the light intensity value reaching the converter mouth is restored to the set threshold value;

s2, when the light intensity value of the lower edge of the converter mouth is larger than a second set threshold value, setting the opening of the converter II throat to be: increasing the opening fourth on the basis of the initial value, and returning the initial value after the light intensity value reaching the lower edge of the converter mouth is maintained to be restored to the set threshold value II;

4) When the converter blows to a slag point and the sonar slag measurement value falls in the dry return area, the opening of the second venturi throat of the converter is set as follows: reducing the opening five on the basis of the initial value, and returning to the initial value after the sonar residue detection value is separated from the dry return region;

5) Before the converter sublance process test, if the sum of the carbon monoxide concentration and the carbon dioxide concentration of the top gas is detected to suddenly drop, and the sonar slag detection value falls in a splash zone, setting the opening of the converter II throat to be: increasing the opening by six on the basis of the initial value, and returning to the initial value when the sonar slag measurement value is separated from the splashing region or when the slope of the sum of the carbon monoxide concentration and the carbon dioxide concentration of the top gas is greater than zero;

6) When the temperature of the molten steel approaches to the smelting end point, the light intensity value of the furnace mouth becomes strong, and the opening of the second venturi throat of the converter is restored to the initial value.

2. The method for automatically controlling the opening of the two-venturi throat of the converter according to claim 1, wherein the converter sonar slag measurement value is a sound intensity value of fixed-frequency sound.

3. The method for automatically controlling the opening degree of a two-venturi throat of a converter according to claim 1, wherein the carbon monoxide concentration of the top gas and the carbon dioxide concentration of the top gas are detected by a flue gas analyzer, and the flue gas analyzer is arranged at the tail end of the rising section of the vaporization cooling flue of the waste heat boiler of the converter; the light intensity value of the converter mouth or the strong light value of the lower edge of the converter mouth is detected by a flame machine vision device which is arranged right opposite to the converter fire door; the sonar slag measurement value is detected through a flame machine vision device, and the flame machine vision device is arranged on the side wall of the trunnion of the converter and is opposite to the furnace mouth.

4. The method for automatically controlling the opening of the two-venturi throat of the converter according to claim 3, wherein the flame machine vision device comprises a camera, the flame machine vision device comprises a sound sensor, and the smoke analyzer, the flame machine vision device and the flame machine vision device are all connected with the PLC/DCS system.