| All physical and chemical reactions are completed during the flow of molten steel in bottom-blown argon ladle.Improving the flow field plays an important role in improving the purity of molten steel,removing inclusions,homogenizing chemical composition and temperature in ladle.Based on the geometric parameters of 130 t ladle in the actual steelmaking process,the water model with 1:5 ratio is modeled by using similarity principle.The flow field and mixing time in the water model are analyzed by using STAR-CCM+simulation software.Scholars did not pay attention to the effect of tracer on mixing flow field when they studied the influence of blowing gas flow rate,nozzle diameter and other factors using water model.In view of this situation,VOF model and Euler-Euler model are used to study the effects of passive scalar?virtual tracer without physical properties?,KCl solution tracer and pure water tracer?with the same properties as liquid phase in water model?on flow field and mixing time in water model,and the effects of tracer density and quantity on flow field are analyzed.The mechanism of the"butterfly effect"of tracer in water model is further discussed.The results are summarized as follows:1)In VOF model,the KCl solution tracer flow downward to the bottom of water model along the off-side wall with a higher speed than that of water tracer.In addition,due to the existence of"dead zone"at the bottom of off-side of water model,the KCl solution tracer transport to the another side of the bottom and further flow upward to the top surface with a lower speed than that of water tracer.Finally,the previous rising KCl solution tracer on the top of water model flow downward to the bottom with a higher speed than that of water tracer.2)In Euler-Euler multiphase flow model,the main circulation of tracer in water model is as follows:the tracer moves far away from the eccentric side after it is added,then moves downward along the far away eccentric side wall to the bottom,and from the bottom moves to the gas column and eccentric side respectively.When tne tracer moves to the gas column,the tracer moves up to the upper surface with the gas column.When tne tracer moves to the and moves to the bottom of the eccentric side,the tracer moves along the eccentric side wall to the vicinity of the small circulation flow near the upper 1/3 of the eccentric side,circulates to the vicinity of the gas column in the small circulation flow,moves along the gas column to the upper surface,cyclic motion and diffusion mixing in the water model.3)The mechanism of"butterfly effect"of tracer in water model is as follows:when the amount of KCl solution tracer is increased from 20 mL to100mL,the transport speed of KCl solution is faster and the mixing time is also faster in water model.However,when 150 mL KCl solution tracer is added,the mixing time increases,it is because the existence of"inactive region"at the bottom of eccentric side affects the mixing process of the tracer in water model.4)The water model of ladle bottom blowing?bottom diameter,top diameter and liquid level height are 0.538 m,0.585 m and 0.6 m respectively?can monitor the transport process of tracer in the water model without disturbing the flow field.The reasonable amount of tracer is 20 mL of saturated KCl solution,and the volume ratio of tracer to water is 0.134×10-3. |
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