Theoretical and experimental study of a new freezing desalination system assisted by ultrasound

Compared with traditional seawater desalination methods, freezing desalination has gotten more attention for its advantages in reducing energy consumption and environmental protection. In this study, a new freezing desalination assisted by ultrasonic is proposed to improve desalination efficiency. A detailed freezing desalination model is established based on phase transition analysis and ultrasonic-assisted freezing theory. The experiment system is also developed to analyze the desalination process. The factors such as temperature, interface transformation and salinity in the process of droplet freezing under the action of ultrasound were analyzed and discussed. The result showed that the salinity of the droplet residual brine could decline to less than 2.4% when the initial salinity was 5% and droplet diameter was 2 mm after 1 min centrifugal treatment. After the treatment, the salinity of the existed ice-brine mixing was decreased below 0.2%. According to experiments and simulation analysis, the application of ultrasonic wave in freezing desalination can effectively increase the freezing speed of droplets and improve the efficiency of desalination. This study will contribute to the application of ultrasonic in the freezing desalination. • A new freezing desalination assisted by ultrasonic is proposed. • The heat and mass transfer properties of the droplets are studied in detail. • The relevant factors affecting freezing and desalination are analyzed in detail.