HF power source for acoustic cavitation reactor

We present a high efficiency inverter (>90%) which can drive an acoustic cavitation reactor with 1500 watt power between 10 and 100 kHz. This reactor is composed of numerous piezoelectric transducers and is particularly used to accelerate various industrial chemical reactions and destroy a variety of organic contaminants in water. The class-D amplifier or inverter is composed of type IRFP460 power MOSFETs in a full bridge configuration driven by IR2110 circuits in bootstrap mode. The specific nature of the problem comes from the fact that at frequencies slightly different from a resonant frequency f/sub m/, the load is mostly capacitive. The insertion of an appropriate low-pass filter in front of the load allowed an efficient solution to the problem due to the load being capacitive for harmonics. The realized system can provide nearly 2 kW to this type of piezoelectric load, with an efficiency larger than 95%.