关键词: 机理模型, 渗透脱水, 质量传递, 超声空化

Abstract: Variations in water loss and dry matter gain with respect to solution concentration, temperature, ultrasonic power, material thickness and ultrasonic time were investigated. Meanwhile, the interphase mass transfer of ultrasonic cavitation bubbles was analyzed. As a result, a mathematical model that describes the interphase mass transfer of ultrasonic cavitation bubbles was obtained as follows: Km≈ DABπtmRδAfφ(BI－cf2), where A was empirical constant (10-8－10-15 m2), B and C relevant liquid constants with an approximate value of 1014 and 106, respectively, f sound frequency(s-1), DAB diffusion coefficient(m2/s), tm time (s), R radius(m), δboundary layer thickness (m), φratio of number of bubbles with a radius of R to total bubbles, and I ultrasonic intensity(W/cm2). The predicted values from the model were consistent with the experimental values, indicating that the model could accurately describe the interphase mass transfer of ultrasonic cavitation bubbles.

Key words: osmotic dehydration, mass transfer, ultrasoni cavitation, mechanism model