Research On Aeration Mechanism Of Membrane Vibrated Fine Bubble Aerator

The traditional fine bubble aerator can’t achieve crushing breakthrough in improving the oxygenation efficiency, toward this objective, seeking the new aeration movement pattern and oxygenation pattern become a great breakthrough points. The researched membrane vibrated fine bubble aerator reduces the bubble size and increases water bodies turbulence level of the pool by changing the membrane movement to improve oxygenation efficiency and reduce sewage treatment energy in paper.Firstly, oxygen mass transfer model of membrane vibrated fine bubble aerator is proposed which is based on the classical mass transfer model, and analyze the influencing factors of aeration and mass transfer affecting aeration mass to identify the key parameters of affecting the oxygenation efficiency in this paper. Then, according to the theoretical study of bubble formation, the stress analysis of bubble generation process of membrane vibrated fine bubble aerator is established, and it is demonstrated feasible that the vibration of the membrane can be reduced bubble size, increase water bodies turbulence level of the pool. The self-exited oscillation fine bubble aerator, pulse fine bubble aerator and experimental apparatus are designed and produced. Finally, aeration performance evaluation and calculation methods are introduced, and the preparation of the corresponding MATLAB. The designed pulse fine bubble aerator is conducted experiments to observe the working conditions, and it is found that the designed pulse fine bubble aerator has a certain role in improving aeration effect through the experimental data analysis and it also verifies correctness of membrane vibrated fine bubble aeration theory, namely, the vibration of the membrane can decreases bubble size, increase fluid turbulence to further improve the oxygenation efficiency level of the existing fine bubble aerator.The statistical results show that the vibration of membrane can increase the degree of sewage turbulence of aeration tank, the diffusion coefficient of the liquid film and decreases the film thickness to promote continually updated of gas-liquid contact interface, to improve the gas-liquid contact time and bubbles retention rate, which increases the oxygen transfer rate; the vibration of membrane stretch and extrude to break away the orifice to form small bubbles. The smaller bubbles, the larger gas-liquid contact area is. The longer gas bubbles rising in the liquid, the higher the oxygen transfer efficiency is. This experiment also found that fine bubble membrane projection angle and material have a certain influence on its aeration effect.This study has a certain reference value for exploring the aeration mechanism under different movement pattern to provide a new approach of improving the oxygenation efficiency.