CN-122007395-A - Immersed nozzle for improving flow stability of molten steel of crystallizer

Abstract

The application discloses a submerged nozzle for improving the flow stability of molten steel of a crystallizer, and relates to the technical field of ferrous metallurgy continuous casting. Compared with the scheme of cross sectional areas of other middle holes and side holes, the submerged nozzle for improving the flow stability of the molten steel of the crystallizer has obvious advantages. The structure not only avoids the severe fluctuation of the liquid level caused by the excessively high outflow speed of the molten steel due to the excessively large cross-sectional area ratio of the side holes and the middle holes, but also solves the problem that the molten steel cannot obtain sufficient kinetic energy when flowing out due to the excessively small cross-sectional area ratio of the side holes and the middle holes, so that the whole flow of the molten steel is unstable. The curve of the submerged nozzle is the most gentle, fluctuation consistency is strong, impact energy of molten steel can be effectively dispersed, fluctuation of liquid level is restrained, and risk of covering slag inclusion is reduced. In terms of flow field regulation, the structure has no abrupt peak value of flow velocity, and the problem of flow velocity distribution disorder is avoided.

Inventors

• LI YU
• BAI JINGANG
• WEI ZHICHAO
• WANG QI

Assignees

• 山西太钢不锈钢股份有限公司

Dates

Publication Date

20260512

Application Date

20260202

Claims (8)

1. 1. The utility model provides an improve immersed nozzle of crystallizer molten steel flow stability, includes mouth of a river body (1) and prevents nodulation inside lining, mouth of a river body (1) adopts three export reposition of redundant personnel structures mouth of a river body (1) left and right sides symmetry has been seted up side opening export (2) bottom center of mouth of a river body (1) has been seted up mesopore export (3), side opening export (2) downward sloping sets up, prevent nodulation inside lining setting is in on the inner wall of mouth of a river body (1).
2. 2. Submerged entry nozzle according to claim 1, characterised in that an inlet (4) is provided at the top of the nozzle body (1), the inlet (4) being in communication with the mid-bore outlet (3) and the side bore outlet (2).
3. 3. Submerged entry nozzle for improving the flow stability of molten steel in a mould according to claim 2 characterised in that the side hole outlet (2) has a declination angle of 25 °.
4. 4. A submerged entry nozzle according to claim 3, characterised in that the area ratio of the side hole outlets (2) to the mid hole outlets (3) is 1.5.
5. 5. The submerged entry nozzle of claim 4, characterized in that the side hole outlets (2) are 75 x 60mm 2 in size and the mid hole outlets (3) are 50 x 60mm 2 in size.
6. 6. The submerged entry nozzle of claim 5, characterized in that the size of the inlet (4) is 120 x 60mm 2 .
7. 7. The submerged entry nozzle of claim 1, wherein the anti-nodulation lining is comprised of zirconia-carbon composite.
8. 8. The submerged entry nozzle of claim 7, characterized in that the anti-nodulation lining is of uniform thickness and tightly bonded to the nozzle body (1).

Description

Immersed nozzle for improving flow stability of molten steel of crystallizer Technical Field The application belongs to the technical field of ferrous metallurgy continuous casting, and particularly relates to a submerged nozzle for improving flow stability of molten steel of a crystallizer. Background The submerged nozzle is a core functional component in slab continuous casting production, is arranged at the bottom of a tundish, and the lower end of the submerged nozzle is immersed in molten steel in a crystallizer. The method has the core effects that molten steel in the tundish is stably guided to the crystallizer, secondary oxidation caused by direct contact of the molten steel and air is avoided, and meanwhile, the form, flow velocity distribution and impact depth of a molten steel flow field are regulated and controlled through structural design, so that the flow stability, temperature uniformity and inclusion floating efficiency of the molten steel in the crystallizer are directly influenced, and the method is a key component for guaranteeing the surface quality, internal purity and production continuity of a casting blank. The core development direction of the continuous casting technology is to improve the pulling speed on the premise of ensuring the product quality so as to strengthen the production efficiency advantage. However, the high-pulling-speed working condition breaks the original dynamic balance in the crystallizer, and causes a series of technical problems that the heat flow density of the crystallizer is greatly increased, so that the solidified blank shell at the outlet is thinned, the friction between the blank shell and the wall of the crystallizer is obviously increased, and serious production accidents such as bulging, steel leakage and the like are easily caused. For continuous casting of sheet billet, the crystallizer has narrow internal molten pool space, compact copper plate spacing, larger molten steel flow resistance and higher requirement on the flow field regulating and controlling capability of the submerged nozzle. In order to alleviate the defect that high pull rate brought, generally adopt funnel formula crystallizer and ox nose immersion nozzle's combination scheme in the trade, the funnel formula crystallizer is through enlarging the melting of upper port surface area helping hand covering slag, suppresses the torrent, and ox nose mouth of a river is as the core part of molten steel guide, directly decides molten steel reposition of redundant personnel effect and flow field stability. However, the existing submerged nozzle still has a plurality of defects which are difficult to overcome, namely, firstly, the outlet area ratio is not accurately matched with the design, so that the flow rates of the side outlet and the bottom outlet are unbalanced, or the side flow rate is insufficient and cannot form stable backflow, or the bottom flow rate is too large to cause too deep impact, so that the stability of a flow field is further damaged. Secondly, the bottom structural design is improper, the convex bottom design can not buffer the turbulent energy of molten steel, the fluctuation of the liquid level can be aggravated, the concave bottom design leads to the overlong residence time of molten steel in the water gap, the inclusions are difficult to float out, and the water gap nodulation or casting blank inclusion is easy to cause. Thirdly, the inner wall of the water gap lacks an effective anti-nodulation design, and inclusions and alloy elements in molten steel are easy to adhere and deposit, so that a runner is narrowed, and the flow stability and the temperature field uniformity of the molten steel are further damaged. Disclosure of Invention In order to solve part or all of the technical problems in the prior art, the application provides a submerged nozzle for improving the flow stability of molten steel of a crystallizer. The application provides a submerged nozzle for improving the flow stability of molten steel of a crystallizer, which comprises a nozzle body and an anti-nodulation lining, wherein the nozzle body adopts a three-outlet flow distribution structure, side hole outlets are symmetrically formed in the left side and the right side of the nozzle body, a middle hole outlet is formed in the center of the bottom of the nozzle body, the side hole outlets are obliquely arranged downwards, and the anti-nodulation lining is arranged on the inner wall of the nozzle body. Preferably, an inlet is formed in the top of the nozzle body, and the inlet is communicated with the middle hole outlet and the side hole outlet. Preferably, the declination angle of the outlet of the side hole is 25 degrees. Preferably, the area ratio of the side hole outlet to the middle hole outlet is 1.5. Preferably, the side hole outlet has a size of 75×60mm 2, and the middle hole outlet has a size of 50×60mm 2. Preferably, the size of the inlet is 120 x 60mm 2. Preferably, the anti-nodulat