摘要
超声波辐照使W/O乳状液中水滴产生位移效应,水滴向波腹或波节运动、聚集,并发生碰撞及聚并。采用显微高速摄像系统结合图像处理技术对水滴的聚并行为进行了拍摄和分析。结果表明,超声波的机械振动削减W/O乳状液的油-水界面膜强度,促进水滴聚并。水滴在聚并前作类正弦振荡运动,在超声波声强4.89W/cm2、频率20kHz、油-水界面张力13.62mN/m的实验条件下,W/O乳状液中粒径200~400μm的水滴振荡剧烈,聚并效果最好。超声波声强、频率,W/O乳状液的水滴粒径、油相黏度、油-水界面张力显著影响W/O乳状液中水滴的振荡频率和聚并时间。随着超声波声强的增大,水滴聚并时间减小;随着超声波频率的增大,水滴聚并时间增大;随着水滴粒径、油相黏度的减小,水滴振荡频率增大,聚并时间减小;随着油-水界面张力的减小,水滴振荡频率先增大后减小,聚并时间先减小后增大。
Under ultrasonic irradiation, the displacement effect of water droplets in W/O emulsion occurred. The water droplets moved to the wave loop or wave node, then gathered and collided into one. The coalescence characteristics of water droplets in W/O emulsion under ultrasonic irradiation were analyzed by using microscopic high-speed camera system combined with image processing technology. The results indicated that ultrasonic mechanical vibration could reduce the oil-water interracial film strength, thus promoted the coalescence of droplets in W/O emulsion, and the water droplets took the similar sine oscillation movement before coalescence. Under ultrasonic intensity of 4.89 W/cm2 and ultrasonic frequency of 20 kHz, the water droplets with 200--400/lm diameters in the W/O emulsion with 13.62 mN/m interfacial tension took severe oscillation movement with the best coalescence effect. The oscillation frequency and coalescence time of water droplets were mainly affected by ultrasonic intensity, ultrasonic frequency, droplet size, oil viscosity and oil-water interracial tension. With the increase of ultrasonic intensity, the coalescence time of water droplets decreased. With the increase of ultrasonic frequency, the coalescence time of water droplets increased. With the decrease of droplet size and oil viscosity, the oscillation frequency of water droplets increased and the coalescence time decreased. With the decrease of oil-water interfacial tension, the oscillation frequency of water droplets increased to the maximum and then decreased, while the change of coalescence time was inverse.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2015年第3期803-811,共9页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家自然科学基金项目(51274233)
山东省自然科学基金项目(ZR2014EEM045)资助
关键词
超声波辐照
油中水滴
聚并
界面膜强度
ultrasonic irradiation
water droplet in oil
coalescence
interracial film strength
