阅读说明：本技术 一种连铸中间包烘烤操作方法 (Continuous casting tundish baking operation method ) 是由 程传良 伏兆勇 钱志友 王雄文 雷永佳 冯国辉 于 2020-09-11 设计创作，主要内容包括：本发明公开了一种连铸中间包烘烤操作方法,涉及钢铁生产技术领域,以中间包烘烤为核心,通过烘烤前的中间包检查、烘烤器检查及中间包和浸入式水口烘烤过程跟踪等环节,有效降低了开浇头炉事故发生率,提高了连铸机作业率和经济效益。(The invention discloses a continuous casting tundish baking operation method, which relates to the technical field of steel production, and is characterized in that tundish baking is taken as a core, and the accident rate of a topping furnace is effectively reduced and the operation rate and the economic benefit of a continuous casting machine are improved through links such as tundish inspection, roaster inspection, tundish and immersion nozzle baking process tracking and the like before baking.)

1. A continuous casting tundish baking operation method is characterized in that: the method comprises the following steps:

step one, inspection of tundish

a1, cleaning and drying the inner part of the middle bag, and keeping the inner lining and the bag cover intact;

a2, the installation of the stopper meets the requirements;

a3, confirming that the argon pipeline is well connected by an argon blowing middle package without leakage;

a4, correct installation of the submerged nozzle;

step two, roaster inspection

b1, good roaster;

b2, the pressure of baking gas is normal;

b3, ensuring normal suction by a submerged nozzle roaster;

step three, baking the tundish and the submerged nozzle

c1, when baking, the user can fall down the baking device after confirming that no one is on the tundish;

c2, when the tundish is baked, baking with a small fire, adjusting to a medium fire, and then, observing the conditions in the tundish at any time to prevent the caking materials from collapsing;

c3, opening the nozzle roaster to bake the submerged nozzle when the tundish temperature is more than or equal to 900 ℃.

2. The baking operation method for the continuous casting tundish according to claim 1, wherein: in the step one, the stopper rod is all installed straight stick, and stopper rod installation stroke sets up to: the argon blowing tundish is 50-65mm, and the argon non-blowing tundish is more than or equal to 70 mm.

3. The baking operation method for the continuous casting tundish according to claim 1, wherein: in the first step, the purity of argon in the argon blowing tundish is set to be more than or equal to 99.5%, the pressure of sealed argon is set to be more than or equal to 0.2MPa, and the flow is set to be 30-100L/min.

4. The baking operation method for the continuous casting tundish according to claim 1, wherein: in the second step, the pressure of the baking gas is set to be more than or equal to 6 kPa.

5. The baking operation method for the continuous casting tundish according to claim 1, wherein: in the third step, the baking method of the tundish is as follows:

baking under normal conditions: the baking end point temperature of the tundish is more than or equal to 1100 ℃, the baking time is more than or equal to 180min, and the temperature of the submerged nozzle is more than or equal to 900 ℃; if the tundish is baked for more than 10 hours due to planning or other reasons, the tundish must be scrapped, and the submerged nozzle must be replaced when the submerged nozzle is baked for more than 6 hours; the tundish baking process needs to be continuously heated, and the tundish is not baked intermittently in the midway;

baking under abnormal conditions: the baking end point temperature of the tundish is more than or equal to 1100 ℃, the baking time is more than or equal to 120min, and the temperature of the submerged nozzle is more than or equal to 900 ℃; the baking process of the tundish needs to be continuously heated, and the tundish is not baked intermittently in midway.

6. The baking operation method for the continuous casting tundish according to claim 5, wherein: in the third step, the submerged nozzle baking method comprises the following steps:

the immersion nozzle is wrapped with refractory fiber cotton for heat preservation;

the baking time of the submerged nozzle is more than or equal to 90 min;

when the tundish temperature is more than or equal to 900 ℃, the submerged nozzle can be baked by opening the nozzle baking device;

when the tundish is baked, the baking condition of the submerged nozzle should be checked after the submerged nozzle is baked, if abnormal, the tundish and the submerged nozzle baking device are checked and correspondingly processed.

7. The baking operation method for the continuous casting tundish according to claim 5, wherein: in the third step, the baking device of the middle ladle is lifted until the large ladle is cast for less than 10 min; if the time is more than 10min, the tundish car is required to be driven back to the baking position, and the tundish and the submerged nozzle are baked for more than 30min again to be poured again; the asbestos of the submerged nozzle must be removed after the tundish car is driven to the pouring position.

8. The baking operation method for the continuous casting tundish according to claim 1, wherein: in the third step, the tundish baking gas is converter gas with the heat value more than 1600 kcal/kg.

Technical Field

The invention relates to the technical field of steel production, in particular to a continuous casting tundish baking operation method.

Background

The continuous casting tundish is a transition container between a steel ladle and the crystallizer and plays roles in storing molten steel, distributing steel flow, stabilizing pouring speed and reducing impact momentum of the steel flow in the crystallizer. The baking of the tundish not only influences the service performance of the refractory material of the tundish, but also relates to the stability of continuous casting pouring and normal production and also influences the product quality. In addition, the stopper rod can be preheated by baking the tundish, so that the phenomenon that the stopper rod is broken due to sudden and sharp temperature rise when high-temperature molten steel is injected into the tundish can be reduced.

Therefore, the baking effect of the tundish directly determines the casting or butt joint (heat exchange) success rate of the continuous casting machine, and has important effects on improving the number of continuous casting furnaces of the tundish of the casting machine, the operation rate and the steel yield and reducing the production cost. In current production, the pouring basket toasts the temperature lowly, and it is many to open pouring basket inside lining and immersion nozzle absorption molten steel's heat behind the watering, and when the absorption heat was too big, the partial solidification can take place for pouring basket bottom molten steel, at the inside nodulation of pouring basket mouth of a river and immersion nozzle, causes the flux of steel to diminish, causes the stopper rod to become and lasts the grow crystallizer liquid level and can't satisfy the production needs, finally leads to shutting down the emergence.

Disclosure of Invention

In order to solve the technical problems, the invention provides a continuous casting tundish baking operation method, which comprises the following steps: step one, inspection of tundish

a1, cleaning and drying the inner part of the middle bag, and keeping the inner lining and the bag cover intact;

a2, the installation of the stopper meets the requirements;

a3, confirming that the argon pipeline is well connected by an argon blowing middle package without leakage;

a4, correct installation of the submerged nozzle;

step two, roaster inspection

b1, good roaster;

b2, the pressure of baking gas is normal;

b3, ensuring normal suction by a submerged nozzle roaster;

step three, baking the tundish and the submerged nozzle

c1, when baking, the user can fall down the baking device after confirming that no one is on the tundish;

c2, when the tundish is baked, baking with a small fire, adjusting to a medium fire, and then, observing the conditions in the tundish at any time to prevent the caking materials from collapsing;

c3, opening the nozzle roaster to bake the submerged nozzle when the tundish temperature is more than or equal to 900 ℃.

The technical effects are as follows: the invention takes the tundish baking as a core, and effectively reduces the accident rate of the topping furnace and improves the operation rate and the economic benefit of the continuous casting machine through the links of tundish inspection before baking, roaster inspection, tundish and immersion nozzle baking, and baking process inspection tracking process tracking and the like.

The technical scheme of the invention is further defined as follows:

in the foregoing continuous casting tundish baking operation method, in the first step, the stopper rods are all provided with straight rods, and the installation stroke of the stopper rods is set as follows: the argon blowing tundish is 50-65mm, and the argon non-blowing tundish is more than or equal to 70 mm.

In the continuous casting tundish baking operation method, in the first step, the purity of argon of the argon blowing tundish is set to be more than or equal to 99.5%, the pressure of sealed argon is set to be more than or equal to 0.2MPa, and the flow is set to be 30-100L/min.

In the above continuous casting tundish baking operation method, in the second step, the pressure of the baking gas is set to be not less than 6 kPa.

In the third step, the baking method of the tundish is as follows:

baking under normal conditions: the baking end point temperature of the tundish is more than or equal to 1100 ℃, the baking time is more than or equal to 180min, and the temperature of the submerged nozzle is more than or equal to 900 ℃; if the tundish is baked for more than 10 hours due to planning or other reasons, the tundish must be scrapped, and the submerged nozzle must be replaced when the submerged nozzle is baked for more than 6 hours; the tundish baking process needs to be continuously heated, and the tundish is not baked intermittently in the midway;

baking under abnormal conditions: the baking end point temperature of the tundish is more than or equal to 1100 ℃, the baking time is more than or equal to 120min, and the temperature of the submerged nozzle is more than or equal to 900 ℃; the baking process of the tundish needs to be continuously heated, and the tundish is not baked intermittently in midway.

In the foregoing continuous casting tundish baking operation method, in step three, the submerged nozzle baking method is as follows:

the immersion nozzle is wrapped with refractory fiber cotton for heat preservation;

the baking time of the submerged nozzle is more than or equal to 90 min;

when the tundish temperature is more than or equal to 900 ℃, the submerged nozzle can be baked by opening the nozzle baking device;

when the tundish is baked, the baking condition of the submerged nozzle should be checked after the submerged nozzle is baked, if abnormal, the tundish and the submerged nozzle baking device are checked and correspondingly processed.

In the third step, the tundish roaster is lifted until the ladle is opened for casting must be less than 10 min; if the time is more than 10min, the tundish car is required to be driven back to the baking position, and the tundish and the submerged nozzle are baked for more than 30min again so as to be re-poured; the asbestos of the submerged nozzle must be removed after the tundish car is driven to the pouring position.

In the third step, the tundish baking gas is converter gas with the heat value of more than 1600 kcal/kg.

The invention has the beneficial effects that:

(1) in the invention, because the preliminary preparation work such as tundish inspection, roaster inspection and the like before the tundish is baked is sufficient, the tundish baking can reach the ideal temperature and atmosphere in the shortest time, and the failure of the topping furnace caused by the tundish baking can be greatly reduced, thereby improving the topping furnace topping success rate, further improving the operation rate of the casting machine and reducing the abnormal consumption of refractory materials;

(2) in the invention, the submerged nozzle is baked after the tundish temperature is higher than 900 ℃ so as to reduce the oxidation of the inner wall protective layer of the submerged nozzle in the temperature rise stage;

(3) according to the invention, the refractory fiber cotton is wrapped by the submerged nozzle, so that the temperature drop of the submerged nozzle from a baking position to waiting before casting can be reduced.

Drawings

FIG. 1 is a schematic view of the baking curve in the present invention.

Detailed Description

The baking operation method for the continuous casting tundish provided by the embodiment comprises the following steps:

step one, inspection of tundish

a1, cleaning and drying the inner part of the middle bag, and keeping the inner lining and the bag cover intact;

a2, the installation of the stopper meets the requirements;

a3, confirming that the argon pipeline connection of the argon blowing tundish is good and has no leakage, setting the purity of the argon blowing tundish to be more than or equal to 99.5 percent, setting the pressure of the sealed argon to be more than or equal to 0.2MPa, and setting the flow to be 30-100L/min;

a4, correct installation of the submerged nozzle;

step two, roaster inspection

b1, good roaster;

b2, the pressure of baking gas is normal;

b3, ensuring normal suction by a submerged nozzle roaster;

step three, baking the tundish and the submerged nozzle

c1, igniting and then feeding gas during baking, and then feeding air to support combustion, wherein the gas is converter gas with the heat value larger than 1600kcal/kg, the gas pressure is set to be larger than or equal to 6kPa, and the roaster can be dropped after the tundish is determined to be unmanned;

c2, when the tundish is baked, baking with a small fire, adjusting to a medium fire, and then, observing the conditions in the tundish at any time to prevent the caking materials from collapsing;

c3, opening the nozzle roaster to bake the submerged nozzle when the tundish temperature is more than or equal to 900 ℃.

The method specifically comprises the following steps:

s1, ensuring that the tundish on line is clean and free of impurities, and covering the pouring steel hole, the temperature measurement sampling hole and the stopper mounting hole with the tundish and capable of being mounted without residual steel slag;

s2, ensuring that the tundish stopper mechanism has no looseness and blockage, and ensuring that the test action of the mechanism after installation is abnormal;

s3, selecting air-permeable or air-impermeable stopper rods according to the steel grade, and confirming the correct stopper rod type before installation; installing the air-permeable stopper rod after testing argon gas and confirming normal; before the stopper rod is installed, the condition of the stopper rod is checked, and no crack or defect phenomenon is determined; the stopper rod should be carefully and lightly placed in the installation and debugging processes, and no collision occurs; when the stopper rod is installed, the stroke of the stopper rod is not less than 70mm, and the stroke of the argon blowing steel is 50-65 mm;

s4, the stopper rod is firmly installed, and vertical centering is guaranteed during installation; after the installation, testing the full travel switch stopper rod for more than 3 times, and finishing after confirming that no abnormity exists;

s5, before the tundish is installed, whether the submerged nozzle roaster and the tundish roaster are normal is checked; the baking conditions of the tundish, the stopper rod and the submerged nozzle are checked every 20min or so in the tundish baking process, whether the tundish has fallen residual steel slag, whether the stopper rod is broken or not and whether the nozzle is baked normally are checked, if impurities block the upper nozzle hole or the submerged nozzle hole of the tundish, the upper nozzle hole or the submerged nozzle hole needs to be cleaned in time or is treated well before casting, if the stopper rod is broken, the pouring is not required to be cast, and the baking temperature of the nozzle does not meet the requirement and the pouring is not required to be cast.

The tundish baking method comprises the following steps:

baking under normal conditions: the baking end point temperature of the tundish is more than or equal to 1100 ℃, the baking time is more than or equal to 180min, and the temperature of the submerged nozzle is more than or equal to 900 ℃; if the tundish is baked for more than 10 hours due to planning or other reasons, the tundish must be scrapped, and the submerged nozzle must be replaced when the submerged nozzle is baked for more than 6 hours; the baking process of the tundish needs to be continuously heated, and the tundish is not baked intermittently in midway. The baking time was controlled as follows:

temperature rising section (. degree. C.) at baking	Baking flame	Baking time (min)
			0-800	Small fire	20
800-1100	Middle fire	80
			1100-start pouring temperature	Big fire	80

The refractory materials, the stopper rod and the water gap are all easily oxidized at the temperature of 700-800 ℃, and the baking at the temperature section is reduced as much as possible; the baking condition should be checked every 20min during the baking process and adjusted.

Baking under abnormal conditions: the baking end point temperature of the tundish is more than or equal to 1100 ℃, the baking time is more than or equal to 120min, and the temperature of the submerged nozzle is more than or equal to 900 ℃; the baking process of the tundish needs to be continuously heated, and the tundish is not baked intermittently in midway. Control of baking time, e.g.The following:

temperature rising section (. degree. C.) at baking	Baking flame	Baking time (min)
			0-800	Small fire	20
800-1100	Middle fire	50
			1100-start pouring temperature	Big fire	50

The baking condition should be checked every 20min during the baking process and adjusted.

The baking of the nozzle is carried out according to the baking curve that the temperature is stably increased to the highest temperature shown in a graph within 30min, and then the temperature is kept for at least 20-30min to uniformly heat the nozzle body, so that cracks caused by uneven temperature in the steel casting process are avoided.

The submerged nozzle baking method comprises the following steps:

the submerged nozzle is wrapped with refractory fiber cotton for heat preservation so as to reduce the heat dissipation of the nozzle from the rise of the roaster to the casting time period;

the baking time of the submerged nozzle is more than or equal to 90 min;

opening a water gap roaster to bake the submerged water gap when the tundish temperature is more than or equal to 900 ℃, wherein the baking time between 350 and 800 ℃ is as short as possible, and is preferably controlled within 20 min;

when the tundish is baked, the baking condition should be checked every 20min after the immersion nozzle is baked, if abnormal, the tundish and the immersion nozzle baking device are checked and processed correspondingly.

The middle ladle roaster is lifted until the ladle is opened for casting for less than 10 min; if the time is more than 10min, the tundish car is required to be driven back to the baking position, and the tundish and the submerged nozzle are baked for more than 30min again to be poured again; the asbestos of the submerged nozzle must be removed after the tundish car is driven to the pouring position.

The method successfully solves the problems of abnormal shutdown caused by low molten steel temperature and the like due to excessive heat absorption of the inner lining of the tundish of the casting head furnace because the tundish is not baked sufficiently and the temperature does not reach the standard in the continuous casting and butt joint (heat exchange) head furnace. In the process of continuous casting head-opening furnace, the problem that the temperature does not reach the standard due to insufficient baking of the tundish easily occurs, so that the inner lining of the tundish of the head-opening furnace absorbs too much heat to cause low molten steel temperature, the steel passing amount of the inner wall nodulation of the water gap is small even if the head-opening furnace is not stopped, the casting blank quality, the consumption of sector equipment and steel materials are influenced by maintaining production only by reducing the pulling speed and requiring the previous process to put the molten steel in advance for ladle replacement, and the long-time low-pulling-speed production causes particularly serious damage to the sector equipment. By implementing the operation method, the failure of opening the topping furnace caused by insufficient baking of the tundish can be effectively reduced, the production stability and continuity of the continuous casting machine are improved, and the labor intensity of workers is reduced. Can be popularized to each continuous casting machine, improves the baking temperature and atmosphere of the tundish and reduces the occurrence of abnormal shutdown caused by baking the tundish.

In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention.