Improved solar drying performance by ultrasonic desiccant dehumidification in indirect forced convection solar drying of ginger with phase change material

摘要

One of the vital crops used in the recent times of pandemic COVID-19 for making medicines is ginger. It is essential to reduce the drying time compared to open sun drying while maintaining the quality of the dried ginger. The current work highlights about the novel arrangement in indirect forced convection solar drying of ginger by the combined application of liquid desiccant supplied as droplets using ultrasonic atomizer for dehumidification of air stream and paraffin wax as the thermal energy storage medium. The present study is a performance comparison of forced convection solar drying of ginger against open sun drying with and without dehumidification of air stream using liquid calcium chloride as desiccant at air flow rates of 0.153 kg/s and 0.077 kg/s. Using the dryer, fresh ginger having initial moisture content of greater than 80% is reduced to nearly 10% using liquid desiccant at the flow rate of 0.153 kg/s taking 13 h less compared to open sun drying while it is 9 h less without using desiccant. At a flow rate of 0.077 kg/s, moisture content is reduced to nearly 20% with saving of 11 and 6 h, respectively. Three drying models are also presented with the experimental data, amongst which the parabolic fit is found to be the best model for both with and without using desiccant. (C) 2021 Elsevier Ltd. All rights reserved.