CN107299183B - System and method for intelligently reducing converter final slag oxidability - Google Patents

System and method for intelligently reducing converter final slag oxidability Download PDF

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CN107299183B
CN107299183B CN201710509793.3A CN201710509793A CN107299183B CN 107299183 B CN107299183 B CN 107299183B CN 201710509793 A CN201710509793 A CN 201710509793A CN 107299183 B CN107299183 B CN 107299183B
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carbon powder
plc
converter
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blowing
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CN107299183A (en
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韩健
范佳
高福彬
何顺生
唐文明
王玉生
丁剑
靖振权
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HBIS Co Ltd Handan Branch
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/36—Processes yielding slags of special composition
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

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Abstract

The invention relates to a system and a method for intelligently reducing the oxidability of converter final slag, belonging to the technical field of converter steelmaking control. The technical scheme is as follows: the system for intelligently reducing the oxidability of the final slag of the converter consists of a carbon powder weighing device, a carbon powder adding device and a process control device, and is used for automatically adding a slag deoxidizer into the converter, wherein the adopted slag deoxidizer is carbon powder, the carbon powder is formed by grinding coke, and the granularity of the carbon powder is 2-5 mm. The invention has the beneficial effects that: the intelligent control of the actual adding amount and adding mode of the carbon powder for converter final slag deoxidation is realized, the unit oxygen content of the converter slag is effectively removed, the viscosity and melting point of the converter slag are improved, the slag splashing furnace protection effect is improved, the erosion amount of the refractory material of the converter lining is reduced, the service life of the converter is prolonged, and the efficient and stable production of the converter is ensured. Meanwhile, the method also reduces the labor intensity of field operators, ensures the life safety and has great popularization and use values in the industry.

Description

System and method for intelligently reducing converter final slag oxidability
Technical Field
The invention relates to a system and a method for intelligently reducing the oxidability of converter final slag, belonging to the technical field of converter steelmaking control.
Background
The slag splashing furnace protection process is usually adopted after the blowing of the converter is finished, so that the service life of the converter lining of the converter can be greatly prolonged, and the production cost is reduced. The specific process is that after tapping steel of the converter is finished, partial final slag is left in the converter, then nitrogen with certain pressure and flow is blown in by an oxygen lance, the final slag in the converter is splashed and adhered to a furnace wall to form a slag splashing layer, the slag splashing layer is used for protecting a furnace lining in the smelting process of the next furnace, and the service life of the furnace lining is prolonged. Under some special conditions, such as smelting of low-carbon steel and ultra-low-carbon steel, the oxidability of converter final slag is higher, the highly oxidable slag has the characteristics of low melting temperature (1250-1300 ℃) and low viscosity, the physical slag is not easy to adhere to a converter lining after being splashed, and a splashed slag layer is thinner; the other point is that the slag splashes and melts off too early when the next furnace is smelted due to low melting temperature, so that the slag splashing furnace protection function cannot be realized. Therefore, before slag splashing protection, the oxidability in the slag is effectively reduced, the melting point and the viscosity of the slag are improved, and the slag splashing protection method has important significance for improving the slag splashing protection effect and prolonging the service life of a furnace lining.
The prior art methods for improving the viscosity and melting point of the slag mainly comprise the following steps: firstly, after tapping of the converter is finished, firstly, the converter is shaken to a position which is about 45 degrees with the horizontal ground, then an operator manually throws a large amount of carbon powder bags into the converter, and the carbon element and the oxygen element in the slag are utilized to carry out chemical reaction, so that the oxidability in the final slag of the converter is reduced. The method can play a certain role in reducing the oxidability of the converter final slag and improving the melting point and the viscosity of the slag; however, the method is mainly completed manually, so that the labor intensity of field operators is high, and meanwhile, the method has certain danger and is easy to cause injury to human bodies; in addition, the carbon powder container is easy to be thrown to a certain position in the converter in a centralized way, so that the oxygen element in the slag is not uniformly distributed, and the effect of slag splashing and furnace protection is finally influenced. Secondly, after tapping of the converter is finished, firstly, the converter is shaken to a position which is about 90 degrees to the horizontal ground, and then an operator adds a large amount of light-burned dolomite into the converter by using field feeding equipment; the main component of the substance is MgO, which has certain alkalinity, so the substance can be used for adjusting the viscosity and the melting point of the slag to a certain extent; however, this method has the disadvantage that the amount of light-burned dolomite to be added to the furnace is very large, which increases the production cost; meanwhile, the amount of slag in the furnace can be increased, thereby causing great influence on ecological environment protection. Thirdly, on the basis of the second method, an operator adds a certain amount of composite materials into the furnace, namely: the mixture of aluminum alloy and light-burned dolomite, thereby improving the viscosity and melting point of the converter final slag. Although the method can reduce the final slag amount and better improve the properties of the slag, the method has the defects that the production cost is greatly increased and the effective popularization cannot be realized on site. Therefore, an intelligent method which can effectively reduce the oxidability of the converter final slag, improve the viscosity and the melting point of the slag, effectively control the production cost and is easy to popularize on site is developed, and the method has very important significance for the stable production of the converter on site.
If the method for intelligently reducing the oxidability of the converter final slag is to be realized, firstly, the oxygen content in the converter final slag needs to be accurately detected, and then, the dosage of the deoxidizer can be calculated according to the oxygen content, and the subsequent adding operation is completed. At present, the method for detecting the oxygen content in the slag is mainly realized by a method of a detection instrument, namely: an operator firstly obtains a slag sample of the slag from the converter and then detects the oxygen content of the slag through a detection instrument. Although the method can obtain the corresponding calculation result more accurately, the method can only be used as a means for process research due to long process time, and cannot actually guide field production. Based on this, a method for intelligently reducing the oxidability of the converter final slag cannot be effectively developed.
Disclosure of Invention
The invention aims to provide a system and a method for intelligently reducing the oxidability of converter final slag, which can reduce the oxidability of the converter final slag, improve the thickness of a slag splashing layer during the slag splashing protection of a converter, ensure the slag splashing effect, reduce the corrosion of a furnace lining and solve the technical problems in the prior art.
The technical scheme of the invention is as follows:
A system for intelligently reducing the oxidability of converter final slag comprises a carbon powder weighing device, a carbon powder adding device and a process control device; the carbon powder weighing device consists of a carbon powder bin, an upper gate valve, an electric vibration system and a weighing system. The carbon powder bin is mainly used for storing carbon powder required by slag deoxidation; the upper gate valve is used for controlling carbon powder to enter the electric vibration system; the electric vibration system is mainly used for vibrating the carbon powder in the carbon powder bin into the weighing system; the weighing system mainly weighs the weight of the vibrated carbon powder, so that the used carbon powder can meet the requirement of slag deoxidation. In addition, the concrete connection of each part of the whole carbon powder weighing device is as follows: the carbon powder bin is connected with the upper gate valve; then, the upper gate valve is connected with an electric vibration system; a weighing system is connected behind the electric vibration system;
the carbon powder adding device consists of a carbon powder tank, a lower gate valve, a sealing butterfly valve, a check valve, an injection gas inlet pipe, a mixing hose, an injection pipe, an injection trolley, a track and an injection electromagnetic valve; the lower gate valve is respectively connected with a weighing system and a sealing butterfly valve in the carbon powder weighing device; the sealing butterfly valve is connected with the carbon powder tank; the carbon powder tank is connected with a check valve; the check valve is connected with the injection pipe through a mixing hose; the blowing pipe is erected on the blowing trolley and can be driven by the blowing trolley to be inserted into a hearth of the converter; the blowing trolley is arranged on the track; in addition, two branch pipes branched from the injection gas inlet pipe are respectively connected with the carbon powder tank and the mixing hose, and one end of the pipeline is provided with an injection electromagnetic valve; the carbon powder tank stores carbon powder which is planned to be used; the lower gate valve is used for controlling carbon powder to enter the carbon powder tank; the sealing butterfly valve is used for ensuring that carbon powder cannot reenter various devices of the carbon powder weighing device under the action of external gas pressure after entering the carbon powder tank; the check valve is used for ensuring that the carbon powder can completely enter the converter under the action of external gas pressure and cannot be blown into the carbon powder tank again; the injection gas inlet pipe is used for introducing high-pressure nitrogen required by carrying carbon powder; the mixing hose is used for conveying a mixture of carbon powder and high-pressure nitrogen; the injection pipe is used for blowing a mixture of carbon powder and high-pressure nitrogen into the converter; the blowing trolley is used for controlling the insertion depth of the blowing pipe in the converter, so that the carbon powder deoxidation effect is ensured; the rail is used for transporting the blowing trolley; the injection electromagnetic valve is mainly used for the entrance of high-pressure nitrogen.
The process control device comprises a computer, a waiting limit switch, a blowing limit switch, an electric vibration system PLC, an upper gate valve PLC, a lower gate valve PLC, a sealing butterfly valve PLC, a blowing electromagnetic valve PLC, a blowing trolley control PLC and a signal feedback PLC. The waiting limit switch and the injection limit switch are used for detecting the positions of the injection trolley on the track, are respectively arranged on the track in the carbon powder adding device, are respectively arranged on two sides of the injection trolley and are used for indicating the waiting position and the injection position to the injection trolley; PLC (programmable logic controller) and upper gate valve of electric vibration systemThe PLC, the lower gate valve PLC, the sealing butterfly valve PLC, the blowing electromagnetic valve PLC and the blowing trolley control PLC are respectively connected with the electric vibration system, the upper gate valve, the lower gate valve, the sealing butterfly valve, the blowing electromagnetic valve and the blowing trolley and are used for assisting a computer to realize the control of the electric vibration system, the upper gate valve, the lower gate valve, the sealing butterfly valve, the blowing electromagnetic valve and the blowing trolley; the signal feedback PLC is respectively connected with the waiting limit switch, the blowing limit switch and the weighing system and is used for receiving the real-time feedback signals of the related devices and sending the real-time feedback signals to the computer; in addition, the signal feedback PLC also receives a converter tilting angle signal, oxygen flow and flue gas flow in an oxygen lance and detected by a direct insertion type flue gas analyzer which are sent by a converter production control system in real time 2、O2And sending this information to the computer; the computer is respectively connected with the electric vibration system PLC, the upper gate valve PLC, the lower gate valve PLC, the sealing butterfly valve PLC and the blowing electromagnetic valve PLC, the blowing trolley control PLC and the signal feedback PLC, and a built-in control model is utilized to analyze the change of different data in real time and send out a targeted control signal at the same time, so that the intelligent control of the converter final slag deoxidation is realized;
a method capable of intelligently reducing the oxidability of converter final slag is characterized in that a slag deoxidizer is automatically added into a converter by adopting the system capable of intelligently reducing the oxidability of converter final slag, the slag deoxidizer is carbon powder, the carbon powder is formed by grinding coke, and the granularity of the carbon powder is 2-5 mm; comprises the following steps:
step 1: the site operator observes the production state of the converter in real time, and when the converter starts smelting production, the working mode of the computer is adjusted to a smelting starting mode, and the computer performs the following operation steps:
firstly, the computer respectively sends control signals to the upper gate valve PLC, the electric vibration system PLC, the sealing butterfly valve PLC, the lower gate valve PLC and the injection solenoid valve PLC to close the upper gate valve, the electric vibration system, the sealing butterfly valve, the lower gate valve and the injection solenoid valve. In addition, the computer also sends a signal to the blowing trolley control PLC to control the blowing trolley to move to the waiting position. When the blowing trolley contacts the waiting limit switch, the switch can send a signal to the computer through the signal feedback PLC. After receiving the signal, the computer sends a signal to the blowing trolley control PLC to stop the operation of the blowing trolley;
Secondly, the computer feeds back the real-time received signals to the flue gas flow of the converter at the current moment fed back by the PLC and the CO and CO in the flue gas detected by the direct insertion type flue gas analyzer2、O2The oxygen blown into the converter by the oxygen lance and the CO and CO in the flue gas are calculated by utilizing a built-in model2、O2The cumulative volume of (a) is, in particular:
Figure GDA0003628859780000041
Figure GDA0003628859780000042
Figure GDA0003628859780000043
Figure GDA0003628859780000044
in the formula: voxgIs the total oxygen volume, m, blown into the converter 10 during the smelting process of the converter3；
VCOIs the total volume m of CO in the flue gas in the smelting process of the converter3；
VCO2Is CO in the flue gas in the smelting process of the converter2Total volume, m3；
VO2Is residual O in the flue gas in the smelting process of the converter2Total volume, m3；
Figure GDA0003628859780000045
The current oxygen flow, m, blown into the converter 10 during the smelting process of the converter3/s；
Figure GDA0003628859780000046
The current smoke flow m in the converter smelting process3/s；
Figure GDA0003628859780000047
Is the volume percentage content percent of CO in the flue gas at the current moment in the smelting process of the converter;
Figure GDA0003628859780000048
is CO in the flue gas at the current moment in the converter smelting process2Volume percent,%;
Figure GDA0003628859780000049
is residual O in the flue gas at the current moment in the converter smelting process2Volume percent,%;
t is the detection period of the related parameters, and is usually 1-2 s.
Step 2: when the current smelting is finished, the working mode of the computer is adjusted to a smelting finishing mode by field operators, and the computer obtains the mass of free total oxygen contained in the converter final slag by using a built-in model according to the detection result in the smelting process, and further obtains the mass of carbon powder required to be added, namely:
mO＝1.429·(Voxg-0.5·VCO-VCO2-VO2)
In the formula: m is a unit ofOThe mass of free total oxygen contained in the converter final slag obtained was calculated as kg.
mC＝0.75·mO·a
In the formula: m isCThe mass of the set carbon powder added into the converter final slag is kg;
a is a weight, usually 1.1 to 1.3.
And step 3: after the computer calculates the carbon powder required by the converter final slag deoxidation, the operation of weighing the carbon powder is started, and the specific operation steps are as follows:
firstly, the computer sends an instruction to the upper gate valve PLC to control the upper gate valve to open. At the moment, the carbon powder flows out of the carbon powder bin and falls to the electric vibration system;
and secondly, the computer sends an instruction to the electric vibration system PLC to start the electric vibration system. At the moment, the carbon powder falls into the weighing system under the action of the electric vibration system;
and thirdly, the weighing system continuously weighs the falling carbon powder and transmits the falling carbon powder to the computer in real time through the signal feedback PLC. When the computer detects the weight of the carbon powder in the current weighing system and the calculated set mass m of the carbon powderCWhen the difference value is-0.1 kg- + 0.1kg, the command is sent to the upper gate valve PLC and the electric vibration system PLC at the same time, and the upper gate valve and the electric vibration system are closed;
and fourthly, the computer simultaneously sends instructions to the lower gate valve PLC and the sealing butterfly valve PLC, the lower gate valve and the sealing butterfly valve are simultaneously opened, and time recording is started. At this point, the weighed toner will fall from the weighing system into the toner tank. When the computer analyzes that the lower gate valve and the sealing butterfly valve are opened for 10s, the computer sends an instruction to the lower gate valve PLC and the sealing butterfly valve PLC again to close the lower gate valve and the sealing butterfly valve simultaneously;
And 4, step 4: after the carbon powder weighing operation is finished, adding carbon powder, wherein the specific operation steps are as follows:
the computer 25 receives the converter tilting angle signal fed back by the signal feedback PLC in real time. When the computer receives that the tilting angle of the converter is in the range of minus 5 degrees to plus 5 degrees, the furnace mouth of the converter is basically horizontal, and at the moment, the computer sends a signal to the blowing trolley control PLC to control the blowing trolley to move to a blowing position along the track;
and secondly, when the injection trolley is in contact with an injection limit switch arranged on the track, the injection limit switch sends a feedback signal to the computer through a signal feedback PLC. After receiving the signal, the computer sends an instruction to the blowing trolley control PLC to stop the movement of the blowing trolley;
and thirdly, the computer sends an instruction to the blowing trolley control PLC, and when the blowing trolley stops moving, the computer sends an instruction to the blowing electromagnetic valve PLC simultaneously, so that the blowing electromagnetic valve is opened. At the moment, high-pressure nitrogen with the pressure of 6-8 bar enters the carbon powder tank and the mixing hose along the injection gas inlet pipe, and when the high-pressure nitrogen is fully mixed with carbon powder, the carbon powder is brought into the converter along the mixing hose and the injection pipe and is injected to the surface of the final slag of the converter;
And 5: and the computer sends an instruction to the injection solenoid valve PLC, opens the injection solenoid valve, and starts to record time while injecting carbon powder into the furnace. And when the computer analyzes that the blowing is carried out for 300s in the furnace, the computer sends an instruction to the blowing electromagnetic valve PLC and the blowing trolley control PLC at the same time, closes the blowing electromagnetic valve and controls the blowing trolley to move towards the waiting position. When the blowing trolley is in contact with the waiting limit switch, the waiting limit switch sends a feedback signal to the computer through the signal feedback PLC; after receiving the signal, the computer sends an instruction to the blowing trolley control PLC to stop the movement of the blowing trolley;
through the steps, the operation of blowing the carbon powder into the converter is completed.
The invention has the beneficial effects that: by developing a system for automatically adding a slag deoxidizer into a converter and a use method aiming at the intelligent system, the intelligent control of the actual adding amount and adding mode of carbon powder for converter final slag deoxidation is realized, the unit oxygen content of the converter slag is effectively removed, the viscosity and melting point of the slag are improved, the effect of slag splashing protection is improved, the erosion amount of refractory materials of the converter lining is reduced, the service life of the converter is prolonged, and the efficient and stable production of the converter is ensured. Meanwhile, the method also reduces the labor intensity of field operators, ensures the safety of people and has great popularization and use values in the industry.
Drawings
FIG. 1 is a system block diagram of an embodiment of the present invention;
fig. 2 is a schematic diagram of a process control process according to an embodiment of the present invention.
Labeled as: a toner hopper 1; an electric vibration system 2; a weighing system 3; a sealing butterfly valve 4; a carbon powder tank 5; an injection gas introduction pipe 6; a mixing hose 7; a blowing trolley 8; an injection pipe 9; a converter 10; waiting for the limit switch 11; a rail 12; a blowing limit switch 13; an upper gate valve 14; a lower gate valve 15; a check valve 16; the device comprises a blowing electromagnetic valve 17, an electric vibration system PLC 18, an upper gate valve PLC 19, a lower gate valve PLC 20, a sealing butterfly valve PLC 21, a blowing electromagnetic valve PLC 22, a blowing trolley control PLC 23, a signal feedback PLC 24 and a computer 25.
Detailed Description
A system for intelligently reducing the oxidability of converter final slag comprises a carbon powder weighing device, a carbon powder adding device and a process control device; the carbon powder weighing device consists of a carbon powder bin 1, an upper gate valve 14, an electric vibration system 2 and a weighing system 3, wherein the carbon powder bin 1 is connected with the upper gate valve 14; then, the upper gate valve 14 is connected with the electric vibration system 2; the electric vibration system 2 is connected with the weighing system 3; the carbon powder bin 1 is used for storing carbon powder required by slag deoxidation; the upper gate valve 14 is used for controlling carbon powder to enter the electric vibration system 2; the electric vibration system 2 is used for vibrating the carbon powder in the carbon powder bin 1 into the weighing system 3; the weighing system 3 weighs the weight of the vibrated carbon powder to ensure that the used carbon powder can meet the requirement of slag deoxidation;
The carbon powder adding device comprises a carbon powder tank 5, a lower gate valve 15, a sealing butterfly valve 4, a check valve 16, an injection gas inlet pipe 6, a mixing hose 7, an injection trolley 8, an injection pipe 9, a track 12 and an injection electromagnetic valve 17, wherein the lower gate valve 15 is respectively connected with a weighing system 3 and the sealing butterfly valve 4; the sealing butterfly valve 4 is connected with the carbon powder tank 5; the carbon powder tank 5 is connected with a check valve 16; the check valve 16 is connected with the injection pipe 9 through the mixing hose 7; the blowing pipe 9 is erected on the blowing trolley 8 and is driven by the blowing trolley to be inserted into a hearth of the converter 10; the blowing trolley 8 is arranged on the track 12; two branch pipes branched from the injection gas inlet pipe 6 are respectively connected with the carbon powder tank 5 and the mixing hose 7, and an injection electromagnetic valve 17 is arranged on the injection gas inlet pipe; the toner tank 5 stores toner scheduled for use; the lower gate valve 15 is used for controlling carbon powder to enter the carbon powder tank 5; the sealing butterfly valve 4 is used for ensuring that carbon powder cannot reenter various devices of the carbon powder weighing device under the action of external gas pressure after entering the carbon powder tank 5; the non-return valve 16 is used for ensuring that the carbon powder can completely enter the converter 10 under the action of external gas pressure and cannot be blown into the carbon powder tank 5 again; the injection gas inlet pipe 6 is used for introducing high-pressure nitrogen required by carrying carbon powder; the mixing hose 7 is used for conveying a mixture of carbon powder and high-pressure nitrogen; the injection pipe 9 is used for blowing a mixture of carbon powder and high-pressure nitrogen into the converter 10; the blowing trolley 8 is used for controlling the insertion depth of the blowing pipe 9 in the converter 10, so that the carbon powder deoxidation effect is ensured; the track 12 is used for transporting the blowing trolley 8; the blowing solenoid valve 17 is mainly used for the entry of high-pressure nitrogen.
The process control device comprises a computer 25, a waiting limit switch 11, a blowing limit switch 13, an electric vibration system PLC 18, an upper gate valve PLC 19, a lower gate valve PLC 20, a sealing butterfly valve PLC 21, a blowing electromagnetic valve PLC 22, a blowing trolley control PLC 23 and a signal feedback PLC 24, wherein the waiting limit switch 11 and the blowing limit switch 13 are used for detecting the position of a blowing trolley 8 on a track 12, are respectively arranged on the track 12 and are respectively arranged on two sides of the blowing trolley 8 and used for indicating the waiting position and the blowing position to the blowing trolley 8; the electric vibration system PLC 18, the upper gate valve PLC 19, the lower gate valve PLC 20, the sealing butterfly valve PLC 21, the injection solenoid valve PLC 22 and the injection trolley control PLC 23 are respectively connected with the electric vibration system 2, the upper gate valve 14, the lower gate valve 15, the sealing butterfly valve 4, the injection solenoid valve 17 and the injection trolley 8 and used for assisting the computer 25 to realize the control of the electric vibration system 2, the upper gate valve 14, the lower gate valve 15, the sealing butterfly valve 4, the injection solenoid valve 17 and the injection trolley 8; the signal feedback PLC 24 is respectively connected with the waiting limit switch 11, the blowing limit switch 13 and the weighing system 3, and is used for receiving real-time feedback signals of related devices and sending the real-time feedback signals to the computer; the signal feedback PLC 24 receives the converter tilting angle signal, the oxygen flow and the flue gas flow in the oxygen lance and the CO and CO in the flue gas detected by the direct insertion type flue gas analyzer which are sent by the site converter production control system in real time 2、O2And sending this information to the calculationA machine 25; the computer 25 is respectively connected with the electric vibration system PLC 18, the upper gate valve PLC 19, the lower gate valve PLC 20, the sealing butterfly valve PLC 21, the injection solenoid valve PLC 22, the injection trolley control PLC 23 and the signal feedback PLC 24, and by utilizing a built-in control model, through analyzing the change of different data in real time, targeted control signals are sent out at the same time, so that the intelligent control of the converter final slag deoxidation is realized.
A method capable of intelligently reducing the oxidability of converter final slag is characterized in that a slag deoxidizer is automatically added into a converter by adopting the system capable of intelligently reducing the oxidability of converter final slag, the slag deoxidizer is carbon powder, the carbon powder is formed by grinding coke, and the granularity of the carbon powder is 2-5 mm; comprises the following steps:
step 1: the site operator observes the production state of the converter 10 in real time, and when the converter 10 starts smelting production, the working mode of the computer 25 is adjusted to a smelting start mode, and the computer 25 performs the following operation steps:
firstly, the computer 25 respectively sends control signals to the upper gate valve PLC 19, the electric vibration system PLC 18, the sealing butterfly valve PLC 20, the lower gate valve PLC 20 and the injection solenoid valve PLC 22 to close the upper gate valve 14, the electric vibration system 2, the sealing butterfly valve 4, the lower gate valve 15 and the injection solenoid valve 17. In addition, the computer 25 will send a signal to the blowing trolley control PLC 23 to control the blowing trolley 8 to move to the waiting position. When the blowing trolley 8 contacts the waiting limit switch 11, the switch sends a signal to the computer 25 through the signal feedback PLC 24. After receiving the signal, the computer 25 sends a signal to the blowing trolley control PLC 23 to stop the operation of the blowing trolley 8;
Secondly, the computer 25 feeds the real-time received signal back to the flue gas flow of the converter 10 at the current moment fed back by the PLC 24 and the CO and CO in the flue gas detected by the direct insertion type flue gas analyzer2、O2The oxygen blown into the converter by the oxygen lance and the CO and CO in the flue gas are calculated by utilizing a built-in model2、O2The cumulative volume of (a) is, in particular:
Figure GDA0003628859780000091
Figure GDA0003628859780000092
Figure GDA0003628859780000093
Figure GDA0003628859780000094
in the formula: voxgThe total oxygen volume, m, blown into the converter 10 during the smelting process of the converter 103；
VCOIs the total volume m of CO in the flue gas in the smelting process of the converter 103；
VCO2Is CO in the flue gas in the smelting process of the converter 102Total volume, m3；
VO2Is residual O in the flue gas in the smelting process of the converter 102Total volume, m3；
Figure GDA0003628859780000095
The oxygen flow m blown into the converter 10 at the current moment in the smelting process of the converter 103/s；
Figure GDA0003628859780000096
Is the flue gas flow m at the current moment in the smelting process of the converter 103/s；
Figure GDA0003628859780000097
Is the volume percentage content of CO in the flue gas at the current moment in the smelting process of the converter 10,%;
Figure GDA0003628859780000098
is CO in the flue gas at the current moment in the smelting process of the converter 102Volume percent,%;
Figure GDA0003628859780000099
is the residual O in the flue gas at the current moment in the smelting process of the converter 102Volume percent,%;
t is the detection period of the related parameters, and is usually 1-2 s.
Step 2: when the current smelting is finished, the working mode of the computer 25 is adjusted to the 'smelting finishing' mode by field operators, and the computer 25 obtains the mass of free total oxygen contained in the converter final slag by using a built-in model according to the detection result in the smelting process, and further obtains the mass of carbon powder required to be added, namely:
mO＝1.429·(Voxg-0.5·VCO-VCO2-VO2)
In the formula: m isOThe mass of free total oxygen contained in the converter final slag obtained was calculated as kg.
mC＝0.75·mO·a
In the formula: m isCThe mass of the set carbon powder added into the converter final slag is kg;
a is a weight, usually 1.1 to 1.3.
And step 3: after the computer 25 calculates the carbon powder required for converter final slag deoxidation, the operation of weighing the carbon powder is started, and the specific operation steps are as follows:
the computer 25 sends an instruction to the upper gate valve PLC19 to control the upper gate valve 14 to open. At the moment, the carbon powder flows out of the carbon powder bin 1 and falls to the electric vibration system 2;
secondly, the computer 25 sends an instruction to the electric vibration system PLC 18 to start the electric vibration system 2. At the moment, the carbon powder falls into the weighing system 3 under the action of the electric vibration system 2;
thirdly, the weighing system 3 continuously weighs the fallen carbon powder and realizesIt is communicated to the computer 25 by the signal feedback PLC 24. When the computer 25 detects the weight of the carbon powder in the current weighing system 3 and the calculated set mass m of the carbon powderCWhen the difference value is-0.1 kg- + 0.1kg, the command is sent to the upper gate valve PLC19 and the electric vibration system PLC 18 at the same time, and the upper gate valve 14 and the electric vibration system 2 are closed;
and fourthly, the computer 25 simultaneously sends instructions to the lower gate valve PLC 20 and the sealing butterfly valve PLC 21, simultaneously opens the lower gate valve 15 and the sealing butterfly valve 4 and starts to record time. At this time, the weighed toner will fall from the weighing system 3 into the toner tank 5. When the computer 25 analyzes that the lower gate valve 15 and the sealing butterfly valve 4 are opened for 10s, the computer sends an instruction to the lower gate valve PLC 20 and the sealing butterfly valve PLC 21 again to close the lower gate valve 15 and the sealing butterfly valve 4 simultaneously;
And 4, step 4: after the carbon powder weighing operation is finished, adding carbon powder, wherein the specific operation steps are as follows:
firstly, the computer 25 receives the tilting angle signal of the converter fed back by the signal feedback PLC 24 in real time. When the computer 25 receives that the tilting angle of the converter is in the range of minus 5 degrees to plus 5 degrees, the furnace mouth of the converter 10 at the moment is indicated to be basically horizontal, and at the moment, the computer 25 sends a signal to the blowing trolley control PLC 23 to control the blowing trolley 8 to move to a blowing position along the track 12;
secondly, when the blowing trolley 8 is contacted with a blowing limit switch 13 arranged on the track 12, the blowing limit switch 13 sends a feedback signal to a computer 25 through a signal feedback PLC 24. After receiving the signal, the computer 25 sends an instruction to the blowing trolley control PLC 23 to stop the movement of the blowing trolley 8;
and thirdly, the computer 25 sends an instruction to the blowing trolley control PLC 23 to stop the movement of the blowing trolley 8 and simultaneously sends an instruction to the blowing electromagnetic valve PLC 22 so as to open the blowing electromagnetic valve 17. At the moment, high-pressure nitrogen with the pressure of 6-8 bar enters the carbon powder tank 5 and the mixing hose 7 along the injection gas inlet pipe 6, and when the high-pressure nitrogen is fully mixed with carbon powder, the carbon powder is brought into the converter 10 along the mixing hose 7 and the injection pipe 9 and is injected to the surface of the converter final slag;
And 5: the computer 25 sends an instruction to the injection solenoid valve PLC 22 to open the injection solenoid valve 17 and start recording the time while injecting the carbon powder into the furnace. When the computer 25 analyzes that the blowing is carried out for 300s in the furnace, the computer sends an instruction to the blowing electromagnetic valve PLC 22 and the blowing trolley control PLC 23 at the same time, closes the blowing electromagnetic valve 17 and controls the blowing trolley 8 to move towards the direction of the waiting position. When the blowing trolley 8 is in contact with the waiting limit switch 11, the waiting limit switch 11 sends a feedback signal to the computer 25 through the signal feedback PLC 24; after receiving the signal, the computer 25 sends an instruction to the blowing trolley control PLC 23 to stop the movement of the blowing trolley 8;
through the steps, the operation of blowing the carbon powder into the converter is completed.
The invention detects the CO and CO in the obtained smoke2、O2The content of the carbon dioxide can be related to the content of manganese, phosphorus and sulfur in slag in the invention patent of China (patent publication number: 103160640B) in a method for dynamically detecting the content of manganese, phosphorus and sulfur in the slag in the steelmaking process of a converter to obtain CO and CO in the flue gas2、O2In percent by volume.

Claims (1)

1. A method for intelligently reducing the oxidability of converter final slag is characterized in that a system for intelligently reducing the oxidability of converter final slag is adopted to automatically add a slag deoxidizer into a converter, and the system for intelligently reducing the oxidability of converter final slag consists of a carbon powder weighing device, a carbon powder adding device and a process control device; the carbon powder weighing device consists of a carbon powder bin (1), an upper gate valve (14), an electric vibration system (2) and a weighing system (3), wherein the carbon powder bin (1) is connected with the upper gate valve (14); then, the upper gate valve (14) is connected with the electric vibration system (2); the electric vibration system (2) is connected with the weighing system (3) at the back; the carbon powder bin (1) is used for storing carbon powder required by slag deoxidation; the upper gate valve (14) is used for controlling carbon powder to enter the electric vibration system (2); the electric vibration system (2) is used for vibrating the carbon powder in the carbon powder bin (1) into the weighing system (3); the weighing system (3) weighs the weight of the carbon powder under vibration;
The carbon powder adding device comprises a carbon powder tank (5), a lower gate valve (15), a sealing butterfly valve (4), a check valve (16), an injection gas introducing pipe (6), a mixing hose (7), an injection trolley (8), an injection pipe (9), a track (12) and an injection electromagnetic valve (17), wherein the lower gate valve (15) is respectively connected with a weighing system (3) and the sealing butterfly valve (4); the sealing butterfly valve (4) is connected with the carbon powder tank (5); the carbon powder tank (5) is connected with a check valve (16); the check valve (16) is connected with the injection pipe (9) through a mixing hose (7); the blowing pipe (9) is erected on the blowing trolley (8) and is driven by the blowing pipe to be inserted into a hearth of the converter (10); the blowing trolley (8) is arranged on the track (12); two branch pipes divided from the injection gas inlet pipe (6) are respectively connected with the carbon powder tank (5) and the mixing hose (7), and an injection electromagnetic valve (17) is arranged on the injection gas inlet pipe; the carbon powder tank (5) stores carbon powder which is planned to be used; the lower gate valve (15) is used for controlling carbon powder to enter the carbon powder tank (5); the sealing butterfly valve (4) is used for ensuring that carbon powder cannot reenter various devices of the carbon powder weighing device under the action of external gas pressure after entering the carbon powder tank (5); the non-return valve (16) is used for ensuring that the carbon powder can completely enter the converter (10) under the action of external gas pressure and cannot be blown into the carbon powder tank (5) again; the injection gas inlet pipe (6) is used for introducing high-pressure nitrogen required by carrying carbon powder; the mixing hose (7) is used for conveying a mixture of carbon powder and high-pressure nitrogen; the injection pipe (9) is used for blowing the mixture of carbon powder and high-pressure nitrogen into the converter (10); the blowing trolley (8) is used for controlling the insertion depth of the blowing pipe (9) in the converter (10), so that the carbon powder deoxidation effect is ensured; the track (12) is used for transporting the blowing trolley (8); the injection electromagnetic valve (17) is used for the entrance of high-pressure nitrogen;
The process control device comprises a computer (25), a waiting limit switch (11), an injection limit switch (13), an electric vibration system PLC (18), an upper gate valve PLC (19), a lower gate valve PLC (20), a sealing butterfly valve PLC (21), an injection solenoid valve PLC (22), an injection trolley control PLC (23) and a signal feedback PLC (24), wherein the waiting limit switch (11) and the injection limit switch (13) are used for detecting the position of an injection trolley (8) on a track (12), are respectively installed on the track (12), are respectively arranged on two sides of the injection trolley (8) and are used for indicating a waiting position and an injection position to the injection trolley (8); electric vibration system PLC (18), upper gate valve PLC (19), lower gate valve PLC (20) and sealing butterfly valveThe PLC (21), the injection solenoid valve PLC (22) and the injection trolley control PLC (23) are respectively connected with the electric vibration system (2), the upper gate valve (14), the lower gate valve (15), the sealing butterfly valve (4), the injection solenoid valve (17) and the injection trolley (8) and used for assisting the computer (25) to control the electric vibration system (2), the upper gate valve (14), the lower gate valve (15), the sealing butterfly valve (4), the injection solenoid valve (17) and the injection trolley (8); the signal feedback PLC (24) is respectively connected with the waiting limit switch (11), the blowing limit switch (13) and the weighing system (3) and is used for receiving real-time feedback signals of related devices and sending the real-time feedback signals to the computer; the signal feedback PLC (24) receives the converter tilting angle signal, the oxygen flow and the flue gas flow in the oxygen lance sent by the on-site converter production control system and the CO and CO in the flue gas detected by the direct insertion type flue gas analyzer in real time 2、O2And sending this information to a computer (25); the computer is respectively connected with the electric vibration system PLC (18), the upper gate valve PLC (19), the lower gate valve PLC (20), the sealing butterfly valve PLC (21), the injection solenoid valve PLC (22), the injection trolley control PLC (23) and the signal feedback PLC (24), and a built-in control model is utilized to analyze the change of different data in real time and simultaneously send out a targeted control signal, thereby realizing the intelligent control of the converter final slag deoxidation;
the adopted slag deoxidizer is carbon powder, the carbon powder is prepared by grinding coke, and the granularity of the carbon powder is 2-5 mm; comprises the following steps:
step 1: the site operator observes the production state of the converter (10) in real time, and when the converter (10) starts smelting production, the working mode of the computer (25) is adjusted to a smelting starting mode, and the computer performs the following operation steps:
firstly, a computer (25) respectively sends control signals to an upper gate valve PLC (19), an electric vibration system PLC (18), a sealing butterfly valve PLC 20, a lower gate valve PLC (20) and a blowing electromagnetic valve PLC (22) to close an upper gate valve (14), an electric vibration system (2), a sealing butterfly valve (4), a lower gate valve (15) and a blowing electromagnetic valve (17); in addition, the computer also sends a signal to the blowing trolley control PLC (23) to control the blowing trolley (8) to move to a waiting position; when the blowing trolley (8) is contacted with the waiting limit switch (11), the switch can send a signal to the computer (25) through the signal feedback PLC (24); after receiving the signal, the computer sends a signal to the blowing trolley control PLC (23) to stop the operation of the blowing trolley (8);
Secondly, the computer (25) feeds back the real-time receiving signal to the flue gas flow of the converter (10) at the current moment fed back by the PLC (24) and CO in the flue gas detected by the direct insertion type flue gas analyzer2、O2The oxygen blown into the converter by the oxygen lance and the CO and CO in the flue gas are calculated by utilizing a built-in model2、O2The cumulative volume of (a) is specifically:
Figure FDA0003628859770000031
Figure FDA0003628859770000032
Figure FDA0003628859770000033
Figure FDA0003628859770000034
in the formula: voxgThe total oxygen volume, m, blown into the converter (10) in the converter smelting process3；
VCOIs the total volume m of CO in the flue gas in the smelting process of the converter3；
VCO2Is CO in flue gas in the smelting process of a converter2Total volume, m3；
VO2Is residual O in the flue gas in the smelting process of the converter2Total volume, m3；
Figure FDA0003628859770000035
The oxygen flow m blown into the converter (10) at the current moment in the converter smelting process3/s；
Figure FDA0003628859770000036
The current smoke flow m in the converter smelting process3/s；
Figure FDA0003628859770000037
Is the volume percentage content percent of CO in the flue gas at the current moment in the smelting process of the converter;
Figure FDA0003628859770000038
is CO in the flue gas at the current moment in the converter smelting process2Volume percent,%;
Figure FDA0003628859770000039
is residual O in the flue gas at the current moment in the converter smelting process2Volume percent,%;
t is the detection period of the related parameters and is 1-2 s;
step 2: when the current smelting is finished, the working mode of the computer (25) is adjusted to a 'smelting finished' mode by field operators, and the computer (25) firstly obtains the free total oxygen mass contained in the converter final slag by using a built-in model according to the detection result in the smelting process, and further obtains the mass of the carbon powder required to be added, namely:
mO＝1.429·(Voxg-0.5·VCO-VCO2-VO2)
In the formula: m is a unit ofOKg of free total oxygen contained in the converter final slag obtained by calculation;
mC＝0.75·mO·a
in the formula: m is a unit ofCThe mass of the set carbon powder added into the converter final slag is kg;
a is a weight value of 1.1-1.3;
and step 3: after the computer (25) calculates the carbon powder required by the converter final slag deoxidation, the operation of weighing the carbon powder is started, and the specific operation steps are as follows:
firstly, a computer (25) sends an instruction to an upper gate valve PLC (19) to control the upper gate valve (14) to be opened; at the moment, the carbon powder flows out of the carbon powder bin (1) and falls to the electric vibration system (2);
secondly, the computer (25) sends an instruction to the electric vibration system PLC (18) to start the electric vibration system (2); at the moment, the carbon powder falls into the weighing system (3) under the action of the electric vibration system (2);
the weighing system (3) continuously weighs the falling carbon powder and transmits the weight to the computer (25) through the signal feedback PLC (24) in real time; when the computer (25) detects the weight of the carbon powder in the current weighing system (3) and the calculated set carbon powder mass mCWhen the difference value is-0.1 kg- + 0.1kg, the command is sent to the upper gate valve PLC (19) and the electric vibration system PLC (18) at the same time, and the upper gate valve (14) and the electric vibration system (2) are closed;
the computer (25) simultaneously sends instructions to the lower gate valve PLC (20) and the sealing butterfly valve PLC (21), the lower gate valve (15) and the sealing butterfly valve (4) are simultaneously opened, and time is recorded; at the moment, the weighed carbon powder falls into the carbon powder tank (5) from the weighing system (3); when the computer (25) analyzes that the lower gate valve (15) and the sealing butterfly valve (4) are opened for 10s, the computer sends an instruction to the lower gate valve PLC (20) and the sealing butterfly valve PLC (21) again to close the lower gate valve (15) and the sealing butterfly valve (4) simultaneously;
And 4, step 4: after the carbon powder weighing operation is finished, adding carbon powder, wherein the specific operation steps are as follows:
firstly, a computer (25) receives a converter tilting angle signal fed back by a signal feedback PLC (24) in real time; when the computer (25) receives that the tilting angle of the converter is in the range of minus 5 degrees to plus 5 degrees, the furnace mouth of the converter (10) at the moment is basically horizontal, and at the moment, the computer (25) sends a signal to the blowing trolley control PLC (23) to control the blowing trolley (8) to move to a blowing position along the track (12);
when the injection trolley (8) is in contact with an injection limit switch (13) arranged on a track (12), the injection limit switch (13) sends a feedback signal to a computer (25) through a signal feedback PLC (24); after receiving the signal, the computer (25) sends an instruction to the blowing trolley control PLC (23) to stop the movement of the blowing trolley (8);
the computer (25) sends an instruction to the blowing trolley control PLC (23), stops the movement of the blowing trolley (8), and simultaneously sends an instruction to the blowing electromagnetic valve PLC (22), so that the blowing electromagnetic valve (17) is opened; at the moment, high-pressure nitrogen with the pressure of 6-8 bar enters the carbon powder tank (5) and the mixing hose (7) along the injection gas introducing pipe (6), and when the high-pressure nitrogen is fully mixed with carbon powder, the carbon powder is brought into the converter (10) along the mixing hose (7) and the injection pipe (9) and injected to the surface of the converter final slag;
And 5: the computer (25) sends an instruction to the injection solenoid valve PLC (22), opens the injection solenoid valve (17), and starts to record time while injecting carbon powder into the furnace; when the computer (25) analyzes that the blast furnace is blown for 300s, the computer sends an instruction to the blowing electromagnetic valve PLC (22) and the blowing trolley control PLC (23) at the same time, closes the blowing electromagnetic valve (17) and controls the blowing trolley (8) to move towards the waiting position; when the blowing trolley (8) is in contact with the waiting limit switch (11), the waiting limit switch (11) sends a feedback signal to the computer (25) through the signal feedback PLC (24); after receiving the signal, the computer (25) sends an instruction to the blowing trolley control PLC (23) to stop the movement of the blowing trolley (8);
through the steps, the operation of blowing the carbon powder into the converter is completed.
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