Experimental study on discharging current to reduce voltage stress during underwater shock wave generation

Abstract

In food processing using underwater shock waves, the intensity of shock waves is determined by a discharging current from an output capacitor. In past studies, to realize efficient food processing, the underwater shock wave has been generated by charging a high voltage to the output capacitor with high withstand voltage characteristics. For this reason, the conventional method suffers from high manufacturing costs. Furthermore, the conventional method is dangerous due to high voltage requirements such as 3.5 kV. In this work, a low-cost and safe non-heat treatment technology using underwater shock waves is presented for food processing. Unlike the conventional methods, the proposed method generates underwater shock waves by using multiple large output capacitors with low withstand voltage characteristics. Therefore, the proposed method can achieve safe and low-cost non-thermal food processing, because the output capacitors do not need to be charged at high voltage. In the proposed method, the output voltage is about one-fourth that of the conventional methods. The effectiveness and reliability of the proposed technique are confirmed by several experiments using a laboratory experimental system. The experiment revealed that the proposed technique can process a target food at 865 V output, where the rise time of the high voltage generator is 126 s and the output capacitor is 3300 μF.

Keywords

• High voltage discharging
• Low voltage stress
• High voltage multipliers
• Non-thermal processing
• Underwater shock waves