RH vacuum refining bottom blowing powder injection device

Abstract

The invention relates to an RH vacuum refining bottom blowing powder injection device. The device comprises a driving gas system, a vacuum chamber, a steel ladle and a bottom blowing powder injection member, wherein the vacuum chamber is formed above the steel ladle; the driving gas system comprises a driving gas channel and an air compressor connected with the driving gas channel; an ascending pipe and a descending pipe are arranged at the bottom of the vacuum chamber and stretch into molten steel; the driving gas channel is communicated with the ascending pipe; the bottom blowing powder injection member comprises a powder injection element and a gas storage chamber; a steel sleeve is sleeved outside the powder injection element; the gas storage chamber is fixed below the powder injection element; a powder gas flow conveying pipe at the port of the gas storage chamber is connected with a powder injection system; a gap is formed on the powder injection element; one or two bottom blowing powder injection members are arranged at the bottom of the steel ladle; the distance between the bottom blowing powder injection member and the center of the bottom of the steel ladle is 0 to 0.9 time the radius of the bottom of the steel ladle; and the powder injection element penetrates through the bottom of the steel ladle. The device enhances a stirring effect and improves the quality of steel by combining vacuum refining, molten steel circular flow and bottom blowing powder injection refining.

Description

technical field [0001] The invention belongs to the technical field of iron and steel refining, in particular to a bottom blowing powder injection device for RH vacuum refining. Background technique [0002] The RH cycle vacuum degassing method is commonly used in iron and steel refining. This method combines vacuum refining with molten steel circulation. Oxygen cycle vacuum degassing (RH-OB) method; the second is to combine powder spraying metallurgy with additional powder spraying function, such as Nippon Steel’s cycle degassing powder spraying (RH-PB) method. The use of circulating degassing and powder spraying can realize vacuum degassing, reduce impurities, uniform composition and temperature, and can realize functions such as powder spraying desulfurization and dephosphorization, and the hydrogen content in steel after treatment w [H]<0.0002%, dehydrogenation rate 50%~80%, nitrogen content w [N]<0.004%, nitrogen removal rate 15%~25%, oxygen content w [o]=0.002...

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Problems solved by technology

like figure 1 The structure diagram of the RH-Injection method device is shown. The spray gun A is directly inserted into the molten steel to contact with the molten steel. The spray gun A as a consumable is expensive, but its service life is not long, which leads to an increase in the cost of the refining process; spray gun A When in use, the drop may touch the convex hull, causing huge vibration and seriously affecting the molten steel treatment plan and production scheduling; the stroke of the spray gun is constant, but the height of the molten steel level changes greatly, making the immersion of the spray gun A too deep or too shallow, affecting the operation The stability of the spray gun A is not conducive to production; the peeling or breaking of the spray gun A into the molten steel will seriously affect the quality of the molten steel; in case of power failure and other accidents, not only the spray gun A may be damaged, but the entire package of molten steel may also be scrapped

like figure 2 The structure diagram of the RH-PB method device is shown. The device is equipped with a powder injection component B on the side of the vacuum chamber. Although the shortcoming of the spray gun directly inserted into the molten steel is overcome, the nozzle is close to the liquid surface, which is easy to cause splashing, and the spraying Low efficiency of powder metallurgy

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