Size distributions of fine mist particles by changing in the ultrasonic frequency

摘要

The sound wave or elastic oscillation over audible 20 kHz range is defined as an ultrasonic wave. By selecting the effective frequency of the ultrasonic wave, it is possible to acquire the special effect of mist generation. This effect is called as “Ultrasonic atomization”, and a high frequency ultrasonic wave (2.4 MHz) is generally used for the atomization which does not require large amounts of energy in comparison with the heating process. And also, the ultrasonic atomization can provide relatively smaller particles than the spray nozzles, whose diameters of number concentrations are less than 100 nm. Therefore, the ultrasonic atomization is a very useful technique to produce fine liquid particles. This technique has been used for inhalation drug delivery, fuel combustion and analytical nebulizers.