250mm×1800mm板坯连铸结晶器浸入式水口优化的物理模拟

Physical Simulation on Optimization of Submerged entry Nozzle for 250 mm×1800 mm Slab Casting Mold

采用1:2水模型研究了水口结构(S1-侧孔倾角矩形,总面积6 868 mm^2,倾角-25°;S2-跑道型,总面积8 468 mm^2,倾角-15°;S3-椭圆形,总面积8 011 mm^2,倾角-15°),拉速0.85~1.05 m/min和浸入深度55~75mm对结晶器内液面波动、流场分布及保护渣覆盖情况的影响、结果表明,液面波动量随侧孔面积和倾角减小而增大,当侧孔面积减小5.4%时,波动量增加约为32.4%:波动量随拉速的增加、浸入深度的减小而增加;冲击深度随侧孔面积、侧孔倾角及拉速的增加而增加、现有水口S2下液面波动过小,不利于保护渣的熔化与均匀传热;现有水口S1下的冲击深度过大,小利于夹杂物的去除。优化水口S3下的液面波动及冲击深度均更加合理,保护渣更加活跃,有利于保护渣熔化和去除夹杂物、

With using geometric similarity 1 ： 2 water model, the effect of nozzle structure （ lateral holes type, hole di- mension and dip angle： S1- rectangle, 6 868 mm2 , -25° ; S2- racing way type, 8 468 mm^2 , - 15° ; S3- ellipse, 8 011 mm^2, - 15°） , casting speed （0. 85 ~ 1.05 m/min） and immersion depth （55 ~ 75 mm） on mold liquid level fluctuation, distribution of flow field and mold flux coverage condition has been studied. Results show that with decreasing dimension and dip angle of lateral holes, the liquid surface wave height increases, as dimension of lateral holes decreases by 5.4% , the wave height increases by about 32.4% ; with increasing casting speed and decreasing immersion depth the wave height increases ; and with increasing dimension and dip angle of lateral holes and casting speed the impact depth increases. With present nozzle S2 the fluctuation of liquid level is very small it is unfavorable for melting mold powder and uniformly heat - transferring and with present nozzle S1 the impact depth is too large, it is unavailable to remove inclusions in liquid, but with optimized nozzle S3 the fluctuation of liquid level and impact depth are more reasonable, the flux becomes more active, it is available to melt mold powder and remove inclusions in liquid. Material Index Mold for Casting Slab, Water Model, Structure of Submerged Nozzle, Fluctuation of Liquid Level, Flow Field, Mold Flux Layer