Refining device and method for removing liquid steel inclusions in continuous casting tundish

Abstract

The invention relates to a refining device and method for removing liquid steel inclusions in a continuous casting tundish. The refining device comprises a turbulence controller, a refining cover and air curtain ventilation bricks. The two side ends of the refining cover are fixed to a permanent lining on the wall of the tundish, the lower end of the refining cover is immersed into liquid steel below a steel slag layer inside the tundish, the refining cover is located over the air curtain ventilation bricks and is opposite to the air curtain ventilation bricks, a gas channel is formed in the body of the refining cover, the two ends of the gas channel are communicated with a gap between a tundish cover and the steel slag layer inside the tundish, gas exhaust holes communicated with the gas channel are formed in the body of the refining cover and are opposite to the air curtain ventilation bricks, large-flow argon is blown in through the air curtain ventilation bricks, an air curtain barrier with the large continuous intensity is formed between the air curtain ventilation bricks and the refining cover, the inclusions are captured and are adsorbed and removed by the steel slag layer, the argon flows through the gas channel and forms argon seal between the steel slag layer inside the tundish and the tundish cover, the steel slag face is protected, secondary oxidation of liquid steel is avoided, the cleanliness of the liquid steel is greatly improved, and the 0.5 level of the four kinds of inclusions in LHG2 steel reaches more than 90%.

Description

technical field [0001] The invention relates to a refining device and a refining method for removing liquid steel inclusions in a continuous casting tundish, belonging to the technical field of iron and steel metallurgy continuous casting tundish. Background technique [0002] The continuous casting tundish air curtain retaining wall technology is a new technology developed at the end of the 20th century to remove non-metallic inclusions in the molten steel in the continuous casting tundish. Bricks are placed at a certain position at the bottom of the tundish, and argon gas is blown in, and the argon gas floats through the breathable brick to form a micro-bubble air curtain barrier. The purpose of removing inclusions and purifying molten steel. [0003] For example, Chinese patent document CN101121199 (application number: 200710121680.2) discloses a method for removing non-metallic inclusions in the continuous casting tundish air curtain retaining wall, placing breathable b...

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Problems solved by technology

[0005] Although the permeable brick air curtain retaining wall of the above two patent documents can remove the inclusions in the molten steel to a certain extent and purify the molten steel, there are still the following technical defects: the air blowing volume of the permeable brick is limited, and it cannot be blown On the slag opening surface, the blowing volume is large, and the steel slag surface is easily blown away to cause secondary oxidation of molten steel slag and molten steel. Therefore, the argon bubbles formed by the air curtain wall have limited ability to capture and remove inclusions. Compared with the same period, the traditional flow control device is used to improve There is no superiority in the flow characteristics of molten steel and the removal of inclusions, and it cannot meet the control requirements of high-purity clean steel for inclusions

But this invention has the following deficiencies: 1) The cover body of the immersion hood is provided with an exhaust hole, and the argon gas blown from the air-permeable brick air chamber permeates the molten steel gas and is discharged from the exhaust hole on the immersion hood. Directly wash the refractory lining of the tundish cover above the dipping cover (not shown in the figure), and the airflow will wash the same position of the refractory lining of the tundish cover for a long time, resulting in delamination of the lining at this position and contamination of the molten steel. , it will crack and deform the tundish cover, which will seriously affect the service life of the tundish cover and increase the cost; The argon gas is not circulated and utilized outside the tundish, resulting in waste of argon gas

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