Device and method for single snorkel vacuum degassing refining of molten steel by employing bottom injection

Abstract

The invention belongs to the technical field of steel refining, and particularly relates to a device and a method for single snorkel vacuum degassing refining of molten steel by employing bottom injection. The device disclosed by the invention comprise an air supply system, a powder spray system, a single snorkel vacuum degassing refining furnace, wherein an airflow distributor on the air supply system is branched into three gas circuits which are connected with the powder spray system; a powder airflow delivery pipe in the powder spray system is connected with a bottom powder injection element; the bottom powder injection element is built at the bottom of a ladle furnace of the single snorkel vacuum degassing refining furnace; and an opening is formed in the lower end of a vacuum chamber of the single snorkel refining furnace and is inserted into a steel ladle molten pool. The method for single snorkel vacuum degassing refining of molten steel by employing bottom injection comprises the following steps: firstly, blowing a gas and stirring molten steel; blowing powder into the steel ladle through the bottom powder injection element under the transportation of a carrier gas flow; and after the blowing time is ended, entering the next work circle. The device and the method are easy to achieve, short in production cycle, and high in production capacity; equipment investment and operation costs on an overhead bunker and a wire feeding mechanism are reduced; the technological operation is simple; and energy conservation and emission reduction are facilitated.

Description

technical field [0001] The invention belongs to the technical field of iron and steel refining, and in particular relates to a device and method for vacuum degassing and refining molten steel by bottom spraying single nozzle. Background technique [0002] The vacuum degassing and refining molten steel method conventionally used in steel refining is a vacuum treatment method formed by combining ladle refining and vacuum degassing technology. The single-mouth refining furnace is a new type of refining device outside the furnace transformed from RH in the 1970s. While retaining the original metallurgical functions of the RH method, the two dipping tubes are changed into single-nozzles with a larger diameter. At the same time, the argon blowing in the ascending dipping pipe of RH is changed to the eccentric argon blowing at the bottom of the ladle. After argon is blown from the bottom of the ladle, the principle of the bubble pump is used to guide the molten steel to generate ri...

AI Technical Summary

Problems solved by technology

[0005] (3) The end face of the dipping tube is large, and the flow rate of the liquid steel ring is large;

[0010] At present, the single-nozzle furnace is mainly refined by injecting powder from the top spray gun, and when the single-nozzle refining furnace is combined with the powder spraying equipment for desulfurization and decontamination, argon is used as the carrier, and the powdery refining agent is sprayed into the steel through the immersion spray gun. Since the spray gun is a consumable spare part, the price is relatively high, and its service life is directly related to the cost of the refining process, and when the spray gun is inserted into the molten steel, it will inevitably come into contact with molten slag to cause slag leaching, and slag erosion is the key to shorten the service life of the spray gun One of the factors: the stroke of the spray gun is fixed, but the height of the liquid steel surface may change, resulting in the immersion of the spray gun is either too deep or too shallow, which affects the stability of the operation and is not conducive to smooth production; and once a power failure occurs during spraying , not only the spray gun is damaged, but the whole package of molten steel may be scrapped, and the submerged spray gun will also cause problems such as splashing or serious secondary pollution of molten steel.

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