施放深度对气泡水体携带能力影响的实验研究

水中上升气泡对周围水体的携带能力受多方面因素的影响，由于测量手段缺乏等原因，其影响规律研究一直是两相流领域的难点。引入气泡上升携带水量的概念表征其水体携带能力的大小，进而利用专门设计的实验装置，采用双液分离测量法，调整喷嘴至27．5～52．5cm之间的不同施放深度，进行气泡上升携带水量的测量实验。结果表明：在注气量（20ml）和注气速度（3ml／s）等一定的条件下，随着气体施放深度的增加，气泡水体携带能力呈现缓慢增强并逐渐稳定的总趋势，但其间（施放深度约35．0～45．0cm）该能力会略有下降，并有极小值出现；且在绝大多数情况下，小口径喷嘴生成气泡的水体携带能力稍强。上述结论可为化工等领域工程应用中设计合理气体施放深度、确定最佳喷嘴口径等问题提供参考依据。

Experimental research for influence of injecting depth on water volume carried by bubbles

The rising bubble＇s capacity to carry water is influenced by many factors. For the lack of technologies to measure it, the investigation on influence laws of the capacity is a difficult point of gas-liquid two-phase flow research. In this paper, the concept of water carried by bubbles volume was introduced to characterize rising bubble＇s capacity to carry water surrounding bubbles, and the special experimental apparatus was made. The influence laws of different air injecting depth （27.5-52.5cm） on bubble＇s capacity to carry water were studied by this equipment with water and diesel fuel. The results show that air injecting depth will significantly affect bubble＇s capacity to carry water with the same air volume （20ml） and injection rate （3ml/s）. The capacity will increase correspondingly with air injecting depth increasing and tend to approach stable, though in some special depth （35.0-45.0cm） it will decrease to a minimum. And the bubbles which are from smaller nozzle will carry more water. The conclusion will help to find optimal air injecting depth or more rational nozzle diameter, and it will be valuable in other related fields.