Submersed nozzle with trumpet-shaped outlet and using method thereof

Abstract

The invention discloses a submersed nozzle with a trumpet-shaped outlet and a using method thereof. The submersed nozzle sequentially comprises a nozzle clamping head, a nozzle conical section, a nozzle vertical section and the trumpet-shaped outlet from top to bottom. The upper inner diameter of an inner cavity of the nozzle clamping head is 100-120 mm, the lower inner diameter of the inner cavity of the nozzle clamping head is 30-40 mm, and the length of the inner cavity of the nozzle clamping head is 60-80 mm. The length of the nozzle conical section is 360-500 mm, and the lower inner diameter of an inner cavity of the nozzle conical section is 20-30 mm. The length of the nozzle vertical section is 180-220 mm, and the outer diameter of the nozzle vertical section is 60-80 mm. The curvature radius of the trumpet-shaped outlet is 500-1500 mm, and the length of the trumpet-shaped outlet is 90-110 mm. When the pulling speed of a small square billet is 2.4-2.8 m / min, the depth of the nozzle inserted into molten steel is 110-120 mm, and when the erosion depth of the nozzle is larger than or equal to 10 mm, the nozzle is lifted upwards, and the insertion depth is changed into 90-100 mm. The utilization rate of the nozzle can be increased, the flow field in a crystallizer can also be stabilized, and direct significance is achieved for improving the quality of a casting blank and stably and smoothly conducting production.

Description

technical field [0001] The invention relates to the field of billet continuous casting, in particular to a submerged nozzle with a trumpet-shaped outlet and a use method thereof. Background technique [0002] The submerged nozzle for continuous casting mold is installed in the lower part of the tundish and inserted below the liquid surface of the mold to protect the casting refractory sleeve. It is the last refractory product used in the steelmaking-continuous casting process. It mainly has the following functions : ①Isolate the contact between molten steel and air to prevent secondary oxidation of molten steel; ②Improve the flow state of molten steel in the mold and promote the floating of inclusions; ③Slow down the impact of steel flow on the liquid surface of the mold to prevent slag entrainment, Improve the lubrication stability between the crystallizer and the surface of the slab, promote the uniform solidification of the slab shell, and improve the surface quality of t...

AI Technical Summary

Problems solved by technology

Due to the existence of negative pressure, the gap between the molten steel and the inner wall of the nozzle will suck air like an air pump, causing secondary oxidation of the molten steel and partial flow of the nozzle, affecting the quality of the continuous casting slab

[0005] During the production process, after the submerged nozzle is inserted into the molten steel, the slag line and the mold slag in the mold will have a long-term physical and chemical reaction, which will cause the nozzle to be severely eroded at the slag line. Replacing the nozzle will disrupt the production rhythm and affect Productivity

If the submerged nozzle breaks at the slag line, it may cause breakout of the slab shell, which will seriously affect the continuous casting production

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