Parametric Study of High-intensity Ultrasonics for Silica Gel Regeneration

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• 作者：Ye Yao ; Weijiang Zhang ; Shiqing Liu
• 刊名：Energy & Fuels
• 出版年：2009
• 出版时间：June 18, 2009
• 年：2009
• 卷：23
• 期：6
• 页码：3150-3158
• 全文大小：320K
• 年卷期：v.23,no.6(June 18, 2009)
• ISSN：1520-5029

文摘

The use of ultrasonic power in the regeneration of silica gel may be very promising because it helps to improve the regeneration efficiency at the lower regeneration temperature. This work is to study experimentally the effects of ultrasonic power and frequency on the regeneration of silica gel using the ultrasound at different regeneration temperatures (i.e., 45, 55, 65, and 75 °C). Three kinds of frequencies (i.e., 21, 26, and 35 kHz) combined with different power (i.e., 0, 20, 40, and 60 W) of ultrasound were employed to perform the experiments. The moisture change in the silica gel during the ultrasonic regeneration was modeled by the Page equation, and the effective moisture diffusivity was estimated through the diffusion equation that is based on the Fick’s second law. Three parameters, including the enhanced rate (ER) of regeneration, the conditioned regeneration time (CRT), and the energy-saving rate (ESR), are suggested to evaluate the effect of ultrasonic power and frequency on the regeneration. The results show that the regeneration rate constant (k) in the regeneration model, the ER of regeneration, and the effective moisture diffusivity in silica gel increase with the rising of the ultrasonic power and the lowering of frequency. The higher power and the lower frequency of ultrasound lead to the shorter CRT and the use of less energy for the regeneration. In addition, the effects of ultrasonic parameters (i.e., frequency and power) on the regeneration are more significant at the lower regeneration temperatures.