【作者】 徐振华；

【导师】 赵红卫；

【作者基本信息】 四川大学 ， 生物化工， 2006， 硕士

【摘要】 本文主要研究了用金属微孔管制造微气泡,这是一种比较新颖的气泡制造方法。它是通过金属管内外压差提供推动力,推动管内气体从管上的微孔流出,在表面张力、惯性力、浮力等力的作用下,在管外壁形成微气泡,管外高速流过的剪切流把气泡带走,形成气液混合水。并探讨了管内外压差、气液比等因素对形成气泡大小和数量的影响,最后对产生的气泡进行了气浮效果测试。本课题通过对气泡制造系统的释气量和气泡直径的测试,对该气泡制造系统进行了分析和评价。实验过程中采用了间歇式释气量测试方法,该测试方法能较直观、较准备的测定气泡制造系统的释气量,且装备简单、操作方便。同时,本课题除采用气泡稳定时间进行定性测定外,还采用了数码显微摄像技术对从气泡发生器流出的气液混合水进行摄像,准确测定水中微气泡的直径分布情况。实验结果表明:产生的微气泡的直径在20～70μm之间变化,数密度在1.3×103～8.2×103个/mm3之间;随着膜管内外压差的增大,产生的微气泡的直径逐渐变小,当膜管内外压差由0.045MPa增大到0.075MPa时,产生的微气泡的平均直径由53μm减小到40μm;随着气液比减小,产生的微气泡直径也逐渐变小,当气液比由1:2减小到1:4时,产生的微气泡平均直径由48.5μm减小到39.2μm;膜管内外压差增大时,气体利用率提高,水中产生的微气泡的数密度也逐渐增大,当膜管内外压差由0.045MPa增大到0.075MPa时,气体利用率由30.2%增加到82.2%,数密度由1.3×103个/mm3增加到8.2×103个/mm~3。并对该气泡制造系统制造的气泡进行了气浮效果测试,测试了不同气液比、不同气浮时间、不同絮凝剂用量、不同悬浮物浓度下悬浮物的去除率,实验结果表明水中悬浮物的去除率可达90%,取得了良好的气浮效果。对实验数据进行了分析,讨论了不同气液比,气浮时间、絮凝剂用量、悬浮物浓度对气浮效果的影更多还原

【Abstract】 This paper mainly discussed about the research on microbubbles generation by metal microporous tube,it is a new method of bubble formation.The air inside the tube is impelled to run off the tube by the impetus which is provided by the difference of pressure inside and outside the tube.The microbubbles formation based on an overall force balance of surface tension force , buoyancy force , inertia force and so on. The microbubbles are taken away by high speed liqulid cross-flow outside the tube, the mixture of water and microbubbles are formed.The factors affect the size and the number of microbubbles are also discussed ,such as the difference of pressure inside and outside the tube, air-water ratio.At last , the disposal efficiency of the microbubbles is presented.A analysis on the system of bubble formation was made after measured the amount of air precipitation and the bubble size in this paper. The measuring method of air precipitation is based on measuring the precipitated air volume with a batch system,which is more accurate and easier. On the other hand ,the bubble size is measured by micro-video system. The distribution of the microbubbles diameter can be determinde by picking up the images on the mixture of water and microbubbles. Experimental results show that the diameter of micro-bubble between 20 and 70μm,and the number density between1.3×103and 8.2×103/mm3.The bubble diameter is decreased when the difference of pressure inside and outside of the tube is increased,the mean bubble diameter decreased from 53μm to 40μm with increasing更多还原