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研究了侧顶复吹条件下AOD精炼过程中熔池内的传质特性.实验在120 t侧顶复吹AOD转炉1/4的水模型装置上进行,采用分析纯氯化钠作粉剂,在AOD过程的条件下,测定了液体内溶质(NaCl)的传质系数.考察了侧吹和顶吹气量、侧枪枪位及支数、粉剂(气泡)尺寸等对传质速率的影响.结果表明,本工作条件下,熔池液体内溶质的传质系数在7.31×10-5~3.84×10-4m/s范围内;对给定侧枪支数和侧吹气量的纯侧吹过程,传质系数随相邻两侧枪间夹角的增大而非线性增大;侧吹主枪气体对熔池内的传质特性有决定性的作用,而顶吹气体射流使传质速率减小,相应的传质系数比纯侧吹下要小,顶吹气量越大越明显;增大颗粒(气泡)尺寸使传质系数增大;对应于实际工艺所规定的顶吹气量,7枪、22.5°和6枪、27°以及5枪、22.5°的侧枪配置均能提供较大的传质速率.分别考虑颗粒与液流的相对速度,紊流中脉动速度引起的能量耗散和将颗粒与钢液间的传质视为刚性的气泡与钢液间的传质,得到了有关的无量纲关系式.
The mass transfer characteristics of molten pool in AOD refining process with side-top and bottom-blowing were studied.The experiment was carried out on a water model device of 1/4-side AOD converter with 120 t top side, using analytical sodium chloride as powder, The mass transfer coefficient of solute (NaCl) in the liquid was measured, and the effects of side blowing and top blowing volume, gun position and count, powder (bubble) size on the mass transfer rate were investigated. Under this working condition, the mass transfer coefficient of the solute in the molten pool is in the range of 7.31 × 10-5 ~ 3.84 × 10-4m / s. For the pure side-blown process with a given number of side guns and the side air volume, the mass transfer The coefficient increases nonlinearly with the angle between adjacent guns. The side-blown main gun gas plays a decisive role in the mass transfer in the molten pool, while the top-blown gas jet reduces the mass transfer rate. Correspondingly, The mass transfer coefficient is smaller than the pure side blowing, the larger the top blowing air volume is, the more obvious the larger the particle (bubble) size is, the larger the mass transfer coefficient increases. Corresponding to the actual top blowing gas amount, 7 guns, 22.5 ° and 6 Gun, 27 ° and 5 guns, 22.5 ° side guns configuration can provide greater mass transfer rate, respectively, considering the relative velocity of particles and the flow of turbulent Moving speed caused by the energy dissipation and the mass transfer between the particles and the molten steel is regarded as a rigid mass transfer between gas bubbles and molten steel to give the relevant dimensionless relationship.