Prototype ultrasonic desalination instrument and its performance test

A large-scale ultrasonic washing instrument was developed, and its performance was evaluated using an ultrasonic instrument and mechanical washing for desalination in sea sand. Preliminary experiments with a portable ultrasonic device confirmed that increasing the ultrasonic power intensity and application time increased effectiveness of salt washing in sea sand. On the basis of these findings, a large-scale washing instrument with a maximum output of 1500 W, an ultrasonic frequency of 28 kHz, and a 25 L capacity washing tank was developed. Parametric experiments via the developed system were performed to investigate the effects of the sea-sand-to-washing water ratio, ultrasonic intensity, and washing time on washing effectiveness. The greatest reduction in salinity was observed when both ultrasonic treatment and mixing of sea sand with water were applied. The optimal washing conditions were an ultrasonic intensity of 1200 W, a washing water-to-sea sand ratio of 2:1, and a minimum washing time of 3 min. The results confirm that the developed equipment is effective for removing salt from sea sand and that further optimization of the ultrasonic intensity and mixing techniques can increase the washing efficiency.