偏心回転ノズルによる精錬反応装置の撹拌強化に関する研究

从浸没的旋转中向浴缸中注入气体。为了强化熔池搅拌，获得更好的气泡分散性能，提出了L喷嘴。进行了不同喷嘴转速和气体注入条件下的冷模实验，研究了不同喷嘴转速和气体注入条件对熔池混合的影响。实验结果表明：(1)喷嘴旋转产生的周向循环流动和气体注入产生的垂直循环流动强化了熔池的混合。通过混合时间与熔池深度的关系可以考察两种流动中哪一种对混合的影响较大。(2)在L/D=0.279(L：L喷嘴的弯头长度，D：熔池直径)的情况下，各参数对熔池混合时间t&lt；Mix&gt；可用公式t_&lt；Mix&gt；Q^&lt；-0.276&gt；R^&lt；-0.245&gt；H^&lt；0.119&gt；D^&lt；0.119式中，Q是气体流量，R是转速，H是熔池深度。(3)当熔池较浅时，机械搅拌比气体喷射搅拌提供更好的熔池混合。但提高浸入式喷嘴的转速对熔池混合的强化作用是有限的。(4)本工艺能较好地分散熔池中的气泡，熔池混合效果优于传统的注气搅拌。在转速较高、熔池较浅的情况下，喷吹气体会增加熔池的混合时间，从而对熔池的混合产生不利影响。

Gas injection into a bath from an immersed rotating. L-shaped nozzle has been proposed for intensifying the bath stirring and for obtaining better bubble dispersion behavior. Cold model experiments under various nozzle rotating rates and gas injection conditions were made to investigate their effects on the bath mixing. The experimental results of mixing time are compared with previous ones obtained gas injection stirring.The present results are summarized as follows.(1) The bath mixing is intensified by the circumferential circulating flow due to the nozzle rotation and by the vertical circulating flow due to the gas injection. Which of the two flows has a larger effect on the mixing can be examined by the dependence of mixing time on the bath depth. However, the contributions of the two powers to the bath mixing changes largely with the experimental conditions, so that quantitative estimation of the mixing time on the basis of mixing power density under widely ranged experimental conditions is quite difficult.(2) In the case of L/D=0.279 (L : elbow length of the L-shaped nozzle, and D : bath diameter), the effects of various parameters on the mixing time, t_<mix>, can be given by the following equation.t_<mix> Q^<-0.276>R^<-0.245>H^<0.119>D^<1.26>where Q is the gas flow rate, R is the rotating rate, and H is the bath depth.(3) When the bath is shallow, the mechanical stirring gives better bath mixing than the gas injection stirring. But there is a limitation to the intensification of bath mixing by increasing rotating rate of the immersed nozzle.(4) The present process can disperse bubbles widely in the bath, and the bath mixing is better than that by the conventional gas injection stirring. In the case of high rotating rate and shallow bath, the gas injection increases the mixing time, and hence gives a bad influence on the bath mixing.