Intensification of apple drying due to ultrasound enhancement

The effect of high power airborne ultrasound and microwaves on convective drying effectiveness and quality of green pepper

“…These results correspond to those reported by Kowalski and Pawłowski [20], where the ''heating effect" and the ''vibration effect" in the case of apple drying amounted to about 17% and 80%, respectively.…”

“…For this purpose, the coupled ordinary differential equations by Kowalski and Pawłowski [39] and Kowalski and Pawłowski [20] were used. The proposed global mathematical model of drying kinetics allows the numerical calculation of drying curves and material temperature plots, which should be reflected in the experiments.…”

“…To describe the ''heating effect" (T), ''vibration effect" (v) and the ''synergistic effect" (s) quantitatively, the equation of drying rate enhancement (10), together with the equation of the evaporation [20], is reformulated as follows:…”

Ultrasound in wet materials subjected to drying: A modeling study

“…One can mention, for instance, the reduction in adherence between pore wall and the liquid, viscosity decrease due to energy dissipation, acoustic streaming, acoustic cavitation, in-pore turbulence, shrinkage of drying bodies, drying induced stresses, cracks phenomena, etc. The analytical assessment of such effects as ''heating effect'', ''vibration effect'', and ''synergistic effect'' will be presented in separate article [12] and proved that the estimated in this way effects contribute to drying efficiency. Hybrid dryer with the air-born ultrasound transducer of high power up to 200 W and frequency of 26 kHz will be used to carry out the experimental drying test and to validate the agreement between the predicted and experimental data.…”

“…Fig. 1 presents, as a forerunner, the kinetics of convective drying enhanced with airborne ultrasound, which was applied to drying a layer of 16 apple slices of dimensions 40 Â 20 Â 5 mm, realized on this new equipment [12].…”