Removal of Liquid in a Long Pore Opened at Both Ends Using High-Intensity Aerial Ultrasonic Waves

Abstract

We experimentally verified a method by which a liquid that has entered a long pore with open ends can be removed from the pore by using the acoustic radiation force produced by high-intensity aerial ultrasonic waves at a frequency of 20 kHz. The intensity of the ultrasonic waves was about 6 to 10 kPa. By using this method, it was confirmed that a liquid in pores of 1.5 to 5.0 mm diameter and 3 to 20 mm length could be instantaneously removed from the pores. This method, which did not use any air flow at a high pressure, has the significant advantage that it does not produce any strong air flow around the pore. We consider the intensity of the ultrasonic waves required to remove the liquid, the time required to remove the liquid, and the quantity of liquid removed, all of which were determined by varying the diameter and length of the pore.

High-intensity airborne sound generated by irradiation of nanosecond laser pulse to water-immersed optical absorber

“…[12][13][14] Ito et al reported the generation of strong aerial ultrasonic waves of 15 kPa as an estimated value in a point-converging source consisting of a deflection diaphragm connected to a BLT and a rotating parabolic reflector. 15) High-intensity airborne ultrasound is used for many applications such as surface cleaning, 16) atomization, 17,18) liquid removal, [19][20][21] gas removal, 22) non-contact excitation, 23) internal defect detection, 24,25) damage detection, 26,27) surface monitoring, 28) impregnation, 29) drying, 30) and agglomeration. 31) On the other hand, a different approach is the idea of using powerful laser ultrasound as an airborne ultrasonic source with high intensity and small size.…”

High-intensity aerial ultrasonic source with a stripe-mode vibrating plate for improving convergence capability

“…Several technologies that employ these phenomena have been developed. The irradiated high-intensity aerial ultrasonic waves can be used to instantaneously atomize and remove a liquid that has entered a narrow channel or void [11][12][13]. If this becomes practically possible, a cleaning liquid, for example, that leaks into a narrow gap or channel on a circuit board on which electronic devices are mounted or on a precision machine part can be expected to be removed with ease.…”

New technique for linearly converging ultrasonic waves radiated by a stripe-mode vibrating plate

“…[7][8][9][10][11] For the cleaning process in the manufacture of machinery and equipment, some cleaning methods have already been developed in which cleaning liquid that had entered into pores and narrow voids could be removed by the acoustic radiation force of aerial ultrasonic waves. [12][13][14][15] Also, some cleaning methods have been realized in which fine grains sticking to the surfaces of objects could be removed by irradiating them with aerial ultrasonic waves in a noncontact and instantaneous way. 16) Recently, we developed a new method of aerial ultrasonic inspection that uses high-intensity aerial ultrasonic waves.…”