Theoretical justification for increasing the efficiency of ultrasonic treatment for dehydration of long-term storage products

The article deals with the combined (ultrasonic+convective) dehydration of food products. Ultrasonic low-temperature drying allows you to speed up the process of obtaining food products with a small mass, high nutritional value and a small amount of waste. Preliminary experimental studies were carried out, which proved the acceleration of the combined drying process in comparison with convective drying due to the dispersion of moisture at a high initial moisture content. A theoretical model of ultrasonic dispersion based on the cavitation mechanism has been developed. The optimal dimensions of the material to be dried have been revealed, which correspond to the resonant dimensions of the wavelength of ultrasonic vibrations in air at which the maximum intensification of the process occurs. The cylindrical shape of the cavitation bubble arising in large capillaries of the material has been substantiated. The developed theoretical model is in good agreement with the experimental data and makes it possible to establish the modes and conditions of ultrasonic exposure to increase the drying efficiency.