Method for judging dry dedusting gun flying condition

Abstract

The invention relates to a method for judging dry dedusting gun flying conditions, and belongs to the technical field of steelmaking methods. According to the technical scheme, the method comprises the steps that the oxygen content value of flue gas in a furnace mouth flue is monitored, monitoring and timing are started when a converter sends out a blowing starting signal, whether the converter meets the dry dust removal lance flying condition or not is judged, and after the dry dust removal lance flying condition is met, lance lifting and blowing stopping are conducted manually, and then treatment is conducted according to secondary lance lowering treatment measures. The method has the beneficial effects that the interlocking lance lifting condition can be quickly and accurately judged in advance by monitoring the oxygen content and the carbon monoxide content of the flue gas in the furnace mouth flue, lance flying accidents and repeated 69 automatic interlocking lance lifting can be effectively avoided, and the economic index and the production efficiency of the converter are improved.

Description

Technical Field

[0001] The invention relates to a method for judging the conditions of a dry dust removal flying gun, belonging to the technical field of steelmaking methods. Background Art

[0002] The existing method for judging the automatic interlocking gun raising condition of "69" (oxygen content ≥ 6% and carbon monoxide content ≥ 9%) of the dry dust removal of the converter is to use the oxygen content and carbon monoxide monitoring value of the flue gas at the outlet of the electrostatic precipitator of the dry dust removal system. The outlet of the electrostatic precipitator of the dry dust removal system is about 400-500m away from the furnace mouth, and the flue gas needs 90-120 seconds to reach the monitoring point, which is late. And when the dry dust removal judges that the automatic interlocking gun raising condition of "69" (oxygen content ≥ 6% and carbon monoxide content ≥ 9%) is met after 90-120 seconds, the silicon and manganese elements in the molten iron have basically been oxidized and entered the beginning stage of the carbon-oxygen reaction. At this time, the second gun is lowered and blown, and the molten pool reaction will directly enter the carbon-oxygen reaction, instantly producing a large amount of carbon monoxide. The oxygen content in the flue gas has not dropped in time, which will frequently cause multiple "69" automatic interlocking gun raising. At the same time, due to the 90-120 second automatic interlock gun lifting, the first and second batches of slag-making materials have been added to the molten pool at this time. Due to the short time, the slag-making materials have not yet been slag-melted, and the slag-making materials will form agglomerations in the furnace, causing the second gun to fail to ignite when blowing, and multiple "69" automatic interlock gun liftings. Multiple "69" automatic interlock gun liftings will cause the converter smelting cycle to be extended, and the molten steel cannot catch up with the continuous casting machine, causing production interruptions. At the same time, multiple "69" automatic interlock gun liftings will cause excessive oxidation of the molten steel in the furnace, causing multiple splashing accidents, and seriously deteriorating the technical and economic indicators of the converter. Summary of the invention

[0003] The purpose of the present invention is to provide a method for judging the flying gun conditions of dry dust removal. By monitoring the oxygen and carbon monoxide contents of the flue gas in the furnace flue, the "69" (oxygen content ≥6% and carbon monoxide content ≥9%) interlocking gun lifting conditions can be quickly, accurately and in advance judged. This can effectively avoid multiple flying gun accidents caused by the direct carbon-oxygen reaction after the secondary gun is lowered due to the automatic gun starting accident caused by the oxidation of silicon and manganese in the molten iron, which causes the carbon monoxide to rise too quickly. It can also effectively avoid the secondary gun being unable to ignite when the gun is opened due to the slag clumping, which can effectively improve the economic indicators and production efficiency of the converter, and effectively solve the above-mentioned problems existing in the background technology.

[0004] The technical solution of the present invention is: a method for judging the conditions of a dry dust removal flying gun, comprising the following steps: (1) Monitor the oxygen content of flue gas in the flue at the furnace mouth; (2) Start monitoring timing from the time the converter sends a blow-on signal; (3) Determine whether the furnace meets the dry dust removal flying gun conditions. The judgment criteria are as follows: if the flue gas oxygen content is ≥ 0.4% and the flue gas carbon monoxide content is ≥ 19.2%, the dry dust removal flying gun conditions are met; (4) After determining that the conditions for the dry dust removal flying gun are met, manually lift the gun to stop blowing, and then follow the secondary gun lowering disposal measures.

[0005] In the step (1), the frequency of monitoring the oxygen content of flue gas in the furnace flue is 1 second / time.

[0006] In the step (2), the time when the converter sends out a blowing start signal is the blowing start time.

[0007] In the step (3), the judgment criterion matches the variation pattern of the flue gas value at the furnace mouth to the outlet value of the electrostatic precipitator of the dry dust removal system.

[0008] The beneficial effects of the present invention are as follows: by monitoring the oxygen and carbon monoxide contents of the flue gas in the furnace mouth flue, the "69" (oxygen content ≥ 6% and carbon monoxide content ≥ 9%) interlock gun lifting conditions can be quickly, accurately and in advance judged, which can effectively avoid multiple flying gun accidents caused by the direct carbon-oxygen reaction after the secondary gun is lowered due to the completion of oxidation of silicon and manganese in the molten iron after the dry dust removal interlock automatic gun starting accident, resulting in excessive rise of carbon monoxide; it can also effectively avoid the secondary gun being unable to ignite when the gun is opened due to slag agglomeration, resulting in multiple "69" automatic interlock gun lifting accidents, which can effectively improve the economic indicators and production efficiency of the converter. DETAILED DESCRIPTION

[0009] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions of the present invention will be clearly and completely described in conjunction with the implementation cases below. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0010] A method for determining the condition of a dry dust removal flying gun comprises the following steps: (1) Monitor the oxygen content of flue gas in the flue at the furnace mouth; (2) Start monitoring timing from the time the converter sends a blow-on signal; (3) Determine whether the furnace meets the dry dust removal flying gun conditions. The judgment criteria are as follows: if the flue gas oxygen content is ≥ 0.4% and the flue gas carbon monoxide content is ≥ 19.2%, the dry dust removal flying gun conditions are met; (4) After determining that the conditions for the dry dust removal flying gun are met, manually lift the gun to stop blowing, and then follow the secondary gun lowering disposal measures.

[0011] In the step (1), the frequency of monitoring the oxygen content of flue gas in the furnace flue is 1 second / time.

[0012] In the step (2), the time when the converter sends out a blowing start signal is the blowing start time.

[0013] In the step (3), the judgment criterion matches the variation pattern of the flue gas value at the furnace mouth to the outlet value of the electrostatic precipitator of the dry dust removal system. Example 1

[0014] Before the converter starts blowing, ensure that the flue gas oxygen content and carbon monoxide monitoring equipment in the furnace flue are operating normally. After adding scrap steel and iron to the converter, the gun is lowered and blown, and monitoring begins when the converter sends a blow-on signal. This furnace ignites well. At 25 seconds, the flue gas monitoring values ​​are 0.51% oxygen content and 22.2% carbon monoxide content, meeting the requirements of oxygen content ≥ 0.4% and flue gas carbon monoxide content ≥ 19.2%. It is judged that this furnace meets the conditions for dry dust removal flying guns, and the blowing is stopped by manually lifting the gun, and then it is handled according to the secondary gun lowering disposal measures. Example 2

[0015] Before starting to blow the converter, ensure that the oxygen content and carbon monoxide monitoring equipment in the flue gas at the furnace mouth is operating normally. After adding scrap steel and iron to the converter, start lowering the gun and start blowing. Start monitoring from the converter sending a blowing signal. The ignition condition of this furnace is general. At 30 seconds, the flue gas monitoring values ​​are 2.61% oxygen content and 17.2% carbon monoxide content; at 35 seconds, the flue gas monitoring values ​​are 1.11% oxygen content and 21.2% carbon monoxide content, meeting the requirements of oxygen content ≥ 0.4% and flue gas carbon monoxide content ≥ 19.2%. It is judged that this furnace meets the conditions for dry dust removal flying guns, and the blowing is stopped by manually lifting the gun, and then it is handled according to the secondary gun lowering disposal measures. Example 3

[0016] Before the converter starts blowing, ensure that the flue gas oxygen content and carbon monoxide monitoring equipment in the furnace flue are operating normally. After adding scrap steel and iron to the converter, start lowering the gun and start blowing. Start monitoring from the converter sending a blowing signal. The ignition condition of this furnace is not good. At 30 seconds, the flue gas monitoring values ​​are 4.61% oxygen content and 12.2% carbon monoxide content; at 35 seconds, the flue gas monitoring values ​​are 2.74% oxygen content and 15.7% carbon monoxide content; at 40 seconds, the flue gas monitoring values ​​are 1.71% oxygen content and 20.7% carbon monoxide content. The requirements of oxygen content ≥0.4% and flue gas carbon monoxide content ≥19.2% are met. It is judged that this furnace meets the conditions for dry dust removal flying guns. The blowing is stopped by manually lifting the gun, and the subsequent treatment measures are handled according to the secondary gun lowering measures. Example 4

[0017] Before the converter starts blowing, ensure that the flue gas oxygen content and carbon monoxide monitoring equipment in the furnace flue are operating normally. After adding scrap steel and iron to the converter, start lowering the gun and start blowing. Start monitoring from the converter sending a blow start signal. The ignition of this furnace is normal. 20 seconds ago, the oxygen content is ≥0.4% and the flue gas carbon monoxide content is ≥19.2%. After 20 seconds, the oxygen content is <0.4%. It is judged that this furnace does not meet the dry dust removal flying gun conditions and is blowing normally. Example 5

[0018] Before the converter starts blowing, ensure that the flue gas oxygen content and carbon monoxide monitoring equipment in the furnace flue are operating normally. After adding scrap steel and iron to the converter, start lowering the gun and start blowing. Start monitoring from the converter sending a blow start signal. The ignition of this furnace is normal. 20 seconds ago, the oxygen-free content is ≥0.4% and the flue gas carbon monoxide content is ≥19.2%. After 20 seconds, the carbon monoxide content is <19.2%. It is judged that this furnace does not meet the dry dust removal flying gun conditions and is blowing normally.

[0019] Usage statistics: Before adopting this method, the three converters of the Long Products Division of Tangshan Branch of Hebei Iron and Steel Co., Ltd. had a "69" (oxygen content ≥6% and carbon monoxide content ≥9%) interlock gun lifting condition judgment time of 90 to 120 seconds in the early stage of smelting. After the "69" gun flying, the oxidation of silicon and manganese in the molten iron had been completed, resulting in a direct carbon-oxygen reaction after the second gun was lowered, causing carbon monoxide to rise too quickly, resulting in multiple gun flying accidents. And after the "69" gun flying, the slag-making material formed agglomerates in the furnace, resulting in multiple gun flying accidents caused by the failure of the second gun to blow, up to 5 times a month. The splashing rate caused by multiple gun lowering was 10.2%. After adopting this method, the "69" gun flying value monitoring time was advanced to within 40 seconds, 50 to 80 seconds earlier than before. The multiple interlock gun flying accidents caused by the second gun lowering were reduced to 0 times / month. The splashing rate caused by the early gun flying was reduced to 1.4%.

[0020] The present invention utilizes the variation law of the flue gas value at the furnace mouth to reach the outlet value of the electrostatic precipitator of the dry dust removal system, and monitors the oxygen and carbon monoxide content of the flue gas in the furnace mouth flue to quickly, accurately and in advance determine the "69" (oxygen content ≥ 6% and carbon monoxide content ≥ 9%) interlock gun lifting condition, which can effectively avoid multiple gun flying accidents caused by the direct carbon-oxygen reaction after the secondary gun is lowered due to the oxidation of silicon and manganese in the molten iron, which makes the carbon monoxide rise too fast. It can also effectively avoid the secondary gun lowering slag agglomeration, which causes the secondary gun to not ignite when it is opened, resulting in multiple "69" automatic interlock gun lifting. It can effectively improve the economic indicators and production efficiency of the converter.

Claims

1. A method for judging the conditions of a dry dust removal flying gun, characterized in that The following steps are involved: (1) Monitor the oxygen content of flue gas in the flue at the furnace mouth; (2) Start monitoring timing from the time the converter sends a blow-on signal; (3) Determine whether the furnace meets the dry dust removal flying gun conditions. The judgment criteria are as follows: if the flue gas oxygen content is ≥ 0.4% and the flue gas carbon monoxide content is ≥ 19.2%, the dry dust removal flying gun conditions are met; (4) After determining that the conditions for the dry dust removal flying gun are met, manually lift the gun to stop blowing, and then follow the secondary gun lowering disposal measures.

2. A method for judging the conditions of a dry dust removal flying gun according to claim 1, characterized in that: In the step (1), the frequency of monitoring the oxygen content of flue gas in the furnace flue is 1 second / time.

3. The method for judging the condition of a dry dust removal flying gun according to claim 1, characterized in that: In the step (2), the time when the converter sends out a blowing start signal is the blowing start time.

4. The method for judging the condition of a dry dust removal flying gun according to claim 1, characterized in that: In the step (3), the judgment criterion matches the variation pattern of the flue gas value at the furnace mouth to the outlet value of the electrostatic precipitator of the dry dust removal system.