Finite element modelling of the ultrasonic system used in ultrasonic gas filters

Abstract

The paper presents the general scheme of the ultrasonic filter proposed and the finite element modeling of this system. The method can be used in air purification system from the highly polluting processing technology of an industrial shop (paint shops, foundries, welding constructions, forging, etc.). The advantages of using ultrasounds in the pollutant air filtration and purification process and an ultrasonic filter designed are presented. Paper insists in the design of the main part of the ultrasonic system represented by ultrasonic transducer. In this case, the transducer that is used consist in two asymmetrical passive elements (reflector and radiant element). For the ultrasonic system design there are presented the principal theoretical elements and in the final the finite element analyze of the whole ultrasonic system. The FEA provides the optimal frequency used in system during its operation time. The considered theoretical elements: the mechanical resonance condition; the electromechanical resonance condition; the acoustic power emitted by the resonance; acoustic power emitted at low frequencies; the acoustic power frequency characteristic; the electrical impedance of the transducer; electro-acoustical, acoustical-mechanic and electromechanical efficiency; the sensitivity of the low frequency transducer; the transducer sensitivity frequency characteristic and the resonance sensitivity of the transducer.