Investigation on applying ultrasonic to the regeneration of a new honeycomb desiccant.

Abstract: The ultrasound is applied to the regeneration of a new honeycomb desiccant material to decrease its regeneration temperature. Different inlet air conditions, i.e., 40, 45 and 50 °C in temperature, 0.008 and 0.012 kg/(kg dry air) in humidity ratio, combined with 0.5, 0.7 and 0.9 m/s in airflow rate, are designed for the experimental study. The initial moisture content of desiccant material sample used in this study is 0.35 kg water/(kg dry sample), and the acoustic frequency and power of ultrasound are 23 kHz and 30 W, respectively. Three indexes, ERR (Enhancement Ratios of Regeneration), ERARR (Enhancement Ratios of Average Regeneration Rate) and AEE (Average Electricity utilization Efficiency), are used to evaluate the enhancement effect and energy-saving characteristic of using ultrasonic. The experimental results show that the enhancement effect of ultrasound on the regeneration is greatly influenced by material structural parameters and regeneration conditions. It increases with the airflow rate (increasing from 0.5 m/s to 0.9 m/s), and decreases with the drying air humidity (increasing from 0.008 to 0.012 kg/(kg dry air)). The drying air temperature has little effects on the ERARR. The AEE decreases with the regeneration air temperature, humidity ratio and velocity. Besides, applying ultrasound to the regeneration of M-type material is more effective. Furthermore, the contributions of ‘heating effect’ and ‘micro-vibration effect’ induced by power ultrasonic are discussed and the results show the contributions of the micro-vibration effect dominate. Meanwhile, a model is developed to predict the regeneration rate of the new desiccant material assisted by ultrasound. [Copyright &y& Elsevier]