SOLAR DRYER PERFORMANCE STUDY OF SOME CROPS (MINT, OKRA AND GRAPES) I - ASSESSING THE DRYING RATES | ||||
| Misr Journal of Agricultural Engineering | ||||
| Article 12, Volume 32, Issue 1, January 2015, Page 205-222 PDF (1.04 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/mjae.2015.98705 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| Mona M. A. Hassan | ||||
| Associate Prof. of Agric. Eng., Fac. of Agric., Zagazig Univ., Egypt. | ||||
| Abstract | ||||
| Three crops were subjected to drying in the passive crop dryer. Crop samples were also open-sun dried as control treatment and the weight losses and temperature were taken. Mint leaves, okra and grapes were dried in the dryer and the same masses of samples were dried in the open–sun (control). The maximum stagnation temperature attained in the dryer is 66 oc and the corresponding values of solar radiation and ambient temperature were 832 W/m2 and 36 oc, respectively. The overall heat loss coefficient of the dryer varied between 28.34 and 21.56 W/m2 oc. All the drying process occurred in the falling rate period, starting from the initial moisture contents which are (83 wb or 488 db % for mint), (88.5 wb or 770 db % for okra) and (78 wb or 354 db for% grapes) to the final moisture content after drying were (1.18 and 19 db % for mint), (43 and 108 db % for okra) and (3.8 and 65.8 db % for grapes), for (solar dryer and natural drying) respectively. The assessment of the drying rate of the crops in the solar dryer and in open-sun gives an average of 7.68 g/h and 7.40 g/h for mint leaves, 7.08 g/h and 5.91 g/h for okra and 7.17 g/h and 5.92 g/h for grapes respectively. For mint, drying efficiencies during different days of drying for the dryer and natural drying were (60.92, 7.11 and 2.84%) and (55.51, 9.82 and 2.98%) on (first, second and third drying days), respectively and the averages were 23.62 and 22.77%. For okra drying efficiencies during different days of drying for the dryer and natural drying were (42.93, 17.01 and 2.62%) and (37.09, 15.36 and 4.49%)on (first, second and third drying days), respectively and the averages were 20.85 and 18.98%.For grapes, drying efficiencies during different days of drying for the dryer and natural drying were (34.27, 20.32 and 11.65%) and (40.31, 8.88 and 5.46%) on (first, second and third drying days), respectively and the average values were 22.05 and 18.21%. | ||||
| Keywords | ||||
| crop dryer; weight losses; dryer efficiency; moisture content | ||||
| References | ||||
|
Abdel-Galil, H.S. and El-Nakib A.A.(2008).Effect of Natural Convection Solar Drying on Quality of Peppermint. Misr J. Agric. Eng. 25(2): 513-534.
Akpinar, E. K. (2010). Drying of mint leaves in a solar dryer and under open sun: Modeling, performance analyses. Journal of Energy Conversion and Management, 51 pp. 2407-2418.
Al-Juamily, K.A.J; Khalifa, A.J.N. and Yassen, T.A. (2007). Testing of the performance of a fruit and vegetable solar drying system in Iraq. College of Engineering, Al-Nahrin University, Baghdad, Iraq. Desalination 209 (2007) 163–170.
Butter, J.L, and Goodrum, J.W. (1998). “Crop Drying Using Solar Energy”. CRC Handbook of Engineering in agriculture. Vol.111.CRC Press,Inc.
Doymaz, I.(2011). Drying of Green Bean and Okra Under Solar Energy. Chemical Industry & Chemical Engineering Quarterly 172 199−205.
Ezekoyi, B.A. and Enebe, O.M. (2006). “Development and performance Evaluation of Modified Integrated Passive Solar Grain Dryer”. Pacific Journal of Science and Technology 7(2):185-190.
Gallali, Y.M.; Abujnah, Y.S.; Bannani, F.K.(2000). Preservation of fruits and vegetables using solar dryer: a comparative study of natural and solar drying, III; chemical analysis and sensory evaluation data of the dried samples (grapes, figs, tomatoes and onions). Renewable Energy; 19:203–12.
Lahsasni, M. Kouhila, M. Mahrouz and J. T. Jaouhari (2004). Drying kinetics of prickly pear fruit (Opuntia ficus indica). Journal of Food Engineering Volume 61, Issue 2, February 2004, Pages 173-179.
Mohamed M. A. ; Gamea, G. R. ; and Keshek, M. H.(2010). Drying Characteristics of Okra by Different Solar Dryers. Misr J. Ag. Eng., 27(1): 294 – 312.
Pangavhane, D. R.; Sawhney, R. L. and Sarasvadia, P. N. (2002). Design and development and performance of testing of a new natural convection solar dryer, Energy, 27, 579-590.
Radwan, M.S. (2002). Utilization of solar energy for drying grapes under Egyptian climatic condition. Misr. J. Ag., (1: 100- 112).
Shewen, E. C., Hollands, K. G. T. and Remick, C. D. (1980)."Development of A Fixed Position, Fixed Configuration Air Heating Solar Collector, Solar Energy Project," Report No. Coll-9, National Research Council, Canada, Ottawa.
Togrul, I.T.; D. Pehlivan (2004). Modelling of thin layer drying kinetics of some fruits under open-air sun drying process. Faculty of Engineering, Department of Chemical Engineering, Frat University, Kimya Muh. Bolumu, 23279, Elazg, Turkey. Journal-of-Food-Engineering. 2004; 65(3): 413-425. | ||||
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