부산대학교 도서관

Power ultrasound that uses the local high-temperature and high-pressure environment generated by ultrasonic cavitation to accelerate or change the chemical reaction process has been widely used in the petrochemical industry. Unfortunately, huge heat is inevitably conducted by tool head and ultrasonic horn to the piezoelectric ceramics while the transducer is dealing with high-temperature liquid medium such as the pitch of 180°C. In order to prevent the heat influencing the piezoelectric ceramics, a novel high-temperature high power sandwich piezoelectric ultrasonic transducer is proposed. The frequency equations of the ultrasonic vibrator are deduced and the corresponding correctness is verified by the modal through the finite element method (FEM)and COMSOL software. In addition, the heat conduction in the transducer while dealing with high-temperature liquid is analyzed by FEM analysis to ensure the temperature of piezoelectric ceramics is below the Curie temperature. Finally, an experimental prototype is manufactured and a high-temperature liquid medium experiment has been implemented. It indicates that the ultrasonic transducer designed in this study is proved to be able to work stably in the 180°C oil bath.