Modeling of Silica Gel Dehydration Assisted by Power Ultrasonic

Regeneration of dehumidizers (a typical drying process) is the most important stage in the working cycle of desiccant system. Lowering the regeneration temperature is one of the most effective way to improve the energy efficiency of the system. Ultrasonic technology, as a non-heating method, may help improve mass transfer in materials and accomplish the drying process under a lower temperature. In the present work, the dehydration of silica gel assisted by power ultrasonic was experimentally studied under different drying air temperatures (i.e. 45 , 55 , 65 and 75 ). Three kinds of frequencies (i.e. 21 kHz, 26 kHz and 35 kHz) combined with three power levels (20W, 40W and 60W) of ultrasonic were employed to investigate the affects of acoustic frequency and intensity on the dehydration process. Moreover, the characteristics of ultrasonic drying were modeled, respectively, by different drying models, i.e. the Page, the Lewis, the Henderson & Pabis, the Logarithmic and the Weibull model. Meanwhile, the suitability of these models for the ultrasonic regeneration was evaluated by the following indexes: the root mean square error (RMSE) and the relative percent error (PE).