2018 Volume 2018 Issue 143 Pages 143_8-143_19
We introduced the growth technique of fine bubbles by piezo nozzles vibration which had a micro size hole in plate or needle. The hole of piezo nozzles were fabricated by YAG laser etching and focused ion beam deposition. This nozzle dipped in the pure water and produced the gas pressure. In this experiment, we observed the bubble growth status from piezo nozzle when this nozzle was applied voltage to the vibration. The experiment results showed that there are two kind of bubble growth condition. In case of pressing the gasses which range from 10 kPa to 100 kPa, a few hundred micro size bubbles were growth from piezo nozzle continuously and applied the voltage to piezo nozzle, it was not show the any change for growth bubbles. In other case, low pressure which amount under the 5 kPa, it was not observed the bubbles. However, when we applied the voltage and frequency to this piezo nozzle, fine bubbles were appeared and had any relationships between fine bubbles size and any conditions. These results indicated that the fine bubbles growth condition was cased from piezo vibration mode which was flex vibration. For dissolving much oxygen concentration in water, we consider a method using ultrasound to finely disperse and dissolve a supplied gas. In addition, we investigated the use of a coaxial dielectric barrier discharge plasma actuator at a nozzle exit for jet of electrical-charged fine bubbles.