A novel particle separation technique using 20-kHz-order ultrasound irradiation in water

An innovative unit operation of particle separation/classification by irradiating low‐frequency ultrasound into water

“…As the existence of ACOBs depends on temperature and atmospheric pressure and because the purpose of the present study was to collect fundamental and reliable data that would contribute to the design of a practical system, we conducted the experiments in a temperature‐controlled room at 22 ± 1°C, 40 ± 3% humidity, and 1000 ± 10 hPa atmospheric pressure. The experimental setup for measuring the sound‐pressure profile in an acrylic vessel was as described . To measure the sound pressure three‐dimensionally, we used motorized stages (SGSP46–300, Sigma Koki, Tokyo).…”

“…The experimental setup for measuring the sound-pressure profile in an acrylic vessel was as described. 24 To measure the sound pressure three-dimensionally, we used motorized stages (SGSP46-300, Sigma Koki, Tokyo). A primary sine-wave signal from a function generator (SG-4105, Iwatsu, Tokyo) was amplified through an amplifier (2100L, E&I, Rochester, NY).…”

“…We proposed a novel technology to separate and classify particles with diameters from a few hundred micrometers to a few millimeters by their diameter, by controlling the amplitude/frequency of the ultrasound radiation. 24 We discovered another interesting phenomenon in which a motion-control stick near the SFPS enables us to manipulate the SFPS. A practical operating system for both of the phenomena described above (i.e., the appearance of the SFPS and its manipulation with a motion-control stick) might be simple, and the combination of these phenomena might be very promising for completing urgent tasks such as the absorption of radioactive materials (e.g., radioactive cesium compounds) using Prussian blue particles.…”

“…Our previous study revealed a part of this flocculation mechanism experimentally: a spherically flocculated particle swarm (SFPS) arose from the action of acoustic cavitation‐oriented bubbles (ACOBs). We proposed a novel technology to separate and classify particles with diameters from a few hundred micrometers to a few millimeters by their diameter, by controlling the amplitude/frequency of the ultrasound radiation …”