MANUFACTURE OF INDIRECT SOLAR DRYER FROM SOME LOCAL MATERIAL TO DRY APRICOTS | ||
| Misr Journal of Agricultural Engineering | ||
| Article 9, Volume 36, Issue 3, July 2019, Pages 897-928 PDF (886.89 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/mjae.2019.94795 | ||
| Authors | ||
| W. M. Hanafy; H. H. H. Tarabye | ||
| Lecturer of Agric. Eng. and Bio-system Dept., Fac. of Agric. and Natural Resources, Aswan Univ., Egypt. | ||
| Abstract | ||
| In the present work, a new special, prototype of an indirect solar–electrical dryer for agricultural products was set up and also tested at Faculty Of Agricultural & Natural Resources, AswanUniversity, Egypt.The main objective of the study was to transform some local materials unbeneficial to useful components and reuse it to fabricte an indirect solar–electrical dryer.Apricots were studied with different temperatures and velocities of drying airto study the influence of these parameters on the removal moisture content from the product and their effective moisture diffusivity to determine their suitable values.In order to estimate and select the suitable form of solar drying curves, fivedifferent mathematical models,were compared according to their coefficient of determination R2,MBE,RMSE,E% and chi square X2 to estimate experimental drying curves.The Page model in this condition proved to be the best for predicting drying behavior of apricots slice with (R2 = 0.9968, X2 = 0.000068).The effective moisture diffusivity (Deff) was obtained using Fick’s diffusion equation and its mean values ranged between 1.94×10-5 and 3.19×10-5 m2/s for all investigated conditions.Average activation energy increased with the decrease of IR radiation and increase of air flow velocity.Thermal behavior of dryer and the effect of high air mass flow on the collector and system drying efficiency were compared.These results showed that the percentage of collector efficiency ranged from (13.28 to 36.55),(15.82 to 48.28) and (37.83 to 64.49)% while the effectivness were ranged from (11.26 to 64.97), (18.69 to 68.58) and (22.11 to 56.80) in addition to that the percentage of dryer efficiency ranged from (22.42 to 60.43),(12.69 to 57.43) and (15.14 to 60.24) while the effectiveness were ranged from (20.37 to 58.69), and (24.82 to 70.96) for exhusted fan speed 1.5, 2.2 and 3 m/s respectively. The highest collector efficiency were acompanied with speed 3 m/swhileitacompanied with speed 2.2 for dryer. The calculated value of the moisture diffusivity varied from 1.94708 ×10-5 to 3.01943 ×10-5m2/s for apricot fruit. And the value of activation energy ranged from 34.35 to 71.12 kJ/mol at different velocities of air.Finally an economic evaluation was calculated using the criterion of payback period which is found very small 1.22 years compared to the life of the dryer 25 years. | ||
| Keywords | ||
| Solar drying; Drying models; Apricots; Effective diffusivity; activation energy; efficiency; effectivness | ||
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