Long nozzle argon blowing refining device and method capable of effectively removing tundish inclusions

Abstract

The invention discloses a long nozzle argon blowing refining device capable of effectively removing tundish inclusions. The device is composed of a long nozzle, a swirling chamber and a swirling chamber outlet. An annular groove is reserved in the position, close to the top, of the inner wall of the long nozzle. An annular dispersion gas inlet chamber is arranged in the annular groove and connected with an argon conveying system through gas inlet holes formed in the wall of the long nozzle. The lower portion of the long nozzle is connected with the swirling chamber in the tangential direction.According to an argon blowing refining method adopting the device, the inclusions are removed by means of the adhering effect of dispersed phase argon bubbles, and the problems that a traditional argon blowing device is large in bubble size, the time of standing in molten steel is too short, the casting powder surface is prone to being broken, and consequentially, secondary oxidation and heat loss of the molten steel are caused are solved; and in addition, long nozzle argon blowing prevents scaffolding blockage of the long nozzle to a certain extent, meanwhile, gravitational potential energyof the molten steel in the swirling chamber is converted into rotational kinetic energy, the inclusions are promoted to collide, grow up and float upwards before being removed, and accordingly, the cleanliness of the molten steel is improved.

Description

technical field [0001] The invention belongs to the technical field of continuous casting and pouring in the metallurgical industry, and in particular relates to a long nozzle argon blowing refining device and method for effectively removing impurities in a tundish. Background technique [0002] With the development of economy and society, the requirements for steel quality are higher. In order to continuously improve the quality of their own products, major steel mills continue to improve their processes, forcing steel to develop along the direction of high cleanliness, high component control precision and high performance. The steel continuous casting process is an extremely important link in determining the quality of steel. Due to its unique position in continuous casting, the tundish has unique advantages in removing inclusions. The continuous casting tundish is the last refractory container that molten steel contacts before solidification. In the early days, the tundis...

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Problems solved by technology

[0003] A large number of experimental studies by metallurgists have shown that optimizing the flow field through the flow control device is effective in removing large-particle inclusions, but small particles are included in molten steel, and the inclusions follow the fluid very well, and the floating speed is slow, only relying on their own buoyancy It is difficult to remove and cannot meet the requirements of high-clean steel, so relying on the adhesion of argon bubbles in the dispersed phase to promote the removal of inclusions in the tundish is an effective method for removing inclusions

[0004] Chinese patent (patent number: CN201058374, publication date: May 14, 2008) discloses an airtight ladle shroud, which belongs to the field of continuous pouring of the tundish, and is used to reduce the flow of molten steel from the ladle into the tundish secondary oxidation, the argon blowing device used in this patent only plays the role of argon gas sealing, and cannot effectively remove non-metallic inclusions in molten steel; ) discloses a tundish shroud device capable of removing inclusions. In this patent, argon gas is introduced from the upper part of the shroud to close the lower end of the shroud. The outlet of the shroud body is set as a swirling side hole to make the molten steel rotate However, due to the relatively large volume of the tundish, the rotation of the molten steel produced by the swirl side holes is not obvious, and the argon bubbles entering the tundish stay in the molten steel for a short time, and the removal effect on inclusions is limited

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