Acoustic pressure and temperature distribution in a novel continuous ultrasonic tank reactor: A simulation study

Abstract

This study addresses the design of continuous ultrasonic tank reactor (CUTR) and focusing on the study of acoustic pressure and temperature distribution inside the CUTR. The total volume of inner CUTR was design to be 235 mL; a cooling water layer was also developed to achieve a well temperature control during the ultrasonic processing. A three-dimension CUTR was firstly established in Comsol Multi-physics. After combining physical models (i.e. pressure acoustics frequency domain, fluid flow and heat transfer), the acoustic pressure and temperature distribution were presented. The highest acoustic pressure was able to reach to 414 atm when the averaged processing temperature was determined to be 75.0 °C; and the core temperature was able to raise to 79.6, 86.1, 103.2, 133.3, 166.6, 268.2, 364.1 °C depending on the residence time ranging from 15 to 120 min at 15 min interval with the assistance of high-intensity ultrasound (frequency: 20 kHZ, intensity: 11.90 W cm-2) at a temperature of 75.0 °C. Therefore, results of this study indicated two typical consequences of ultrasound processing: 1) an extremely high-pressure cycle leading to the strong agitation and turbulence, and 2) a momentary, albeit high temperature generated during ultrasonic processing. © Published under licence by IOP Publishing Ltd.