Moslem Namjoo

The main objective of this study was to assess the potency of ultrasonic waves to modify the moisture removal characteristics of cumin seeds and the dryer performance from the energy viewpoint in a conventional air drying system. In this regard, a thin layer of the seeds was dried, practicing different drying air temperatures (30, 35, and 40 ◦C) and ultrasound power levels (0–180 W) at a constant flow velocity of 0.6 m/s. Accelerated moisture removal rate, diminished drying duration, and reduced energy expenditure was among the benefits achieved during the drying process by increasing drying air temperature and ultrasound power level. The variation range of effective moisture diffusivity was 0.648 × 10-10 to 2.670 × 10-10 m2/s, revealing that sonication by power ultrasound increased diffusion transport within the samples. Further, specific energy consumption, energy efficiency, and thermal efficiency were obtained within the ranges of 203.68–450.70 MJ/kg, 0.689–1.524 %, and 1.728 to 3.617 %, respectively. Sonication by 180 W at the drying temperature of 40 ◦C caused the maximum energy (1.524 %) and thermal (3.617 %) efficiencies, indicating that ultrasound intervention in airflow results in a more energy-efficient dewatering process.