元件排列方式对液液静态混合的影响

Influence of Element Arrangement on Liquid-Liquid Mixing in a Static Mixer

以静态混合器为研究对象,应用FLUENT软件对4种排列方式的混合器的液液两相混合浓度场进行数值模拟,计算得出混合不均匀系数ψ和压力降,并进行比较分析.结果表明:在Re=10 000~21 000范围内,经由10个混合元件混合,不均匀系数由低到高依次为异旋叉排型(模型二)、同旋叉排型(模型四)、同旋顺排型(模型三)和异旋顺排型(模型一),前两种不均匀系数达到0.05以下,混合效果良好.由此看来,对混合效果提升起到最大作用的是分流,其次是转置,其压降是空管的25~130倍;同样达到ψ≤0.05时,同旋叉排的压降仅为异旋叉排的1/3左右,可作为优先选择的排列方式.当混合元件长径比Ar在1.0~2.0变化时,ψ值达到0.05所需混合长度L约为混合管直径D的1~1.5倍,而混合压降却相差7倍左右.

With static mixers as the research object, FLUENT software was applicated to simulate con- centration field of two-phase liquid in four mixers with different arrangements for each other. The nonuniform coefficient and pressure drop were calculated, compared and analyzed. The results showed that in the range of Re = 10 000 -21 000, after 10 mixed components, the mixed nonuniform coefficient from low to high of each model were the different spin staggered type,the same spin staggered type,the same spin se- dation type and the different spin sedation type. The nonuniform coefficient of the first two models was less than 0.05, which indicated there was good mixing. From this view, flow division was essential to en- hancing the mixing effect,fluid reversing was secondary. Pressure drop is about 25 to130 times as that in empty tube and when ψ≤0.05, it in model 4 was only 1/3 that in model 2, which indicated model 4 was prior. Within the range of Ar = 1.0 - 2. 0, the mixing length differed 1 - 1.5 times of tube diameter, while pressure drop differed 7 times.