双余弦自吸气淹没喷嘴气泡粒径分布规律

Bubble size distribution in double cosine self-suction submerged nozzle

根据引射吸气方式设计了一种双余弦自吸气喷嘴,为解析该喷嘴在不同操作因素下的气泡粒径分布特征规律。选择甲基异丁基甲醇(MIBC)作为起泡剂,利用图像分析法测量了不同起泡剂浓度、入流压力、喷嘴距、不同深度下的气泡粒径分布,分析了不同入流压力下喷嘴的吸气能力。结果表明:随起泡剂浓度的增大,气泡Sauter直径逐渐减小,当浓度达到临界兼并浓度0. 112 mmol/L时,气泡粒径稳定于某个常数值,且入流压力越大,常数值越小,气泡粒径分布范围越窄,小气泡含量增大,如入流压力P=0. 14 MPa时,气泡Sauter直径为0. 32 mm,中间粒径气泡含量为40. 73%;气泡直径随入流压力的增大逐渐减小,随喷嘴距增大逐渐减小,随不同深度增加线性增大,且药剂浓度达到临界兼并浓度时,减小(增加)趋势均变缓慢;吸气量随入流压力增大线性增大,且喷嘴距越大吸气量越大。

A double cosine self-suction nozzle was designed based on the spraying inspiration.The influence of operating parameters on the bubble size distribution in a double cosine self-suction nozzle was analyzed using methyl isobutyl carbinol(MIBC)as the frother.Bubble Sauter mean diameter of nozzle was investigated at different concentrations of frother,inflow pressure,sampling height,nozzle distance,and the suction capacity of the nozzle was researched under different inflow pressures using the image analysis technique.The results show that with the increase of frother concentration,the Sauter mean diameter(d32)decreases until the critical coalescence concentration(CCC)was determined as 0.112 mmol/L above which the d32 is constant.With a higher inflow pressure,the constant is lower and the scope of bubble size distribution becomes narrow with the increases of the smaller bubble content.For example,the Sauter mean diameter was 0.32 mm and the content of bubble middle size distribution was 40.73%when the inflow pressure P is 0.14 MPa.The d 32 decreases with the increase of inflow pressure,nozzle distance and sampling height.The decrease(increase)tread changes slower when the frother concentration reaches the CCC.With the inflow pressure the inspiratory capacity increases linearly,and the inspiratory capacity is larger when the nozzle distance increases.