Abstract
This paper presents the design, construction and performance evaluation of mixed (SCMD) and indirect (SCID) -mode solar cabinet dryers for drying of maize grain with varieties of BH-540 and BH-660. The performances of the solar dryers were tested with three levels of sample loading, 21.74 kg/m2 (thick layer), 16.3 kg/m2 (medium layer), and 10.87 kg/m2 (thin layer). In both dryers, the air was heated in the solar collector and passed naturally through a grain bed. For SCMD, the drying cabinet absorbs solar energy directly through the transparent roof. The solar irradiance, temperature and relative humidity distribution for ambient and in different parts of the dryer, and moisture loss of the grain at each try have been recorded. The result revealed that, a temperature raise of 15 °C was found in both dryers with respect to the ambient air. The required drying time was varied depending on the amount of sample loaded. About 32 h was required in thin layer compared to 53 h in thick layers drying process to reduce the moisture content of the grain to its safe storage value of 13% (w,b). The drying rate, collector efficiency and overall system efficiency were varied from 0.41–0.56, kg/h, 44.4–57.2%, and 24.0–32%, for SCID and from 0.47–0.58, kg/h, 44.4–57.2%, and 24.6–33%, for SCMD respectively. Statistically, no significant difference has observed on drying rate and overall dryer efficiency between SCMD and SCID.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsReferences
Phadke, P.C., Walke, P.V., Kriplani, V.M.: A review on indirect solar dryers. ARPN J. Eng. Appl. Sci. (2015). ISSN 1819-6608
Hii, C.L., Jangam, S.V., Ong, S.P., Mujumdar, A.S. (eds.): Solar Drying: Fundamentals, Applications and Innovations. TPR Group Publication, Singapore (2012)
Singh, S., Kumar, S.: Comparative thermal performance study of indirect and mixed-mode solar dryers. Int. J. Sustain. Energy Dev. (IJSED) 1(1), 6–13 (2012)
Jain, D., Tiwari, G.: Thermal aspects of open sun drying of various crops. Energy 28(1), 37–54 (2003)
Yaldiz, O., Ertekin, C., Ibrahim Uzun, H.: Mathematical modeling of thin layer solar drying of sultana grapes. Energy 26(5), 457–465 (2001)
Boxall, R.A.: Grains post-harvest loss assessment in Ethiopia. Final report NRI Report No 2377. Natural Resources Institute, Chatham, UK, p. 44 (1998)
Postharvest Loss Challenges. Discussion Paper. Office of Agriculture, Biotechnology, and Textile Trade Affairs Bureau of Economic and Business Affairs. U.S. Department of State (2013)
United Nations, Food and Agricultural Organization. Global Food Losses and Food Waste- Extent, Causes and Prevention. Rome (2011)
Augustus Leon, M., Kumar, S., Bhattacharya, S.C.: A comprehensive procedure for performance evaluation of solar food dryers. Renew. Sustain. Energy Rev. 6, 367–393 (2002)
Ekechukwe, O.V., Norton, B.: Review of solar energy drying systems II: an overview of solar drying technology. Energy Convers. Manag. 40, 616–655 (1999)
Sodha, M.S., Chandra, R.: Solar drying systems and their testing procedures: a review. Energy Convers. Manag. 35(3), 219–267 (1994)
Diamante, L.M., Munro, P.A.: Mathematical modelling of the thin layer solar drying of sweet potato slices. Sol. Energy 51, 271–276 (1993)
Simate, I.: Optimization of mixed-mode and indirect-mode natural convection solar dryers. Renewable Energy 28(3), 435–453 (2003)
Tokar, G.M.: Food drying in Bangladesh. Agro-based industries and technology project (ATDP), IFDC, Dhaka 1213, December 1997
Nabnean, S., Janjai, S., Thepa, S., Sudaprasert, K., Songprakorp, R., Bala, B.K.: Experimental performance of a new design of solar dryer for drying osmotically dehydrated cherry tomatoes. Renewable Energy 94, 147–156 (2016)
Tonui, K.S., Mutai, E.B.K., Mutuli, D.A., Mbuge, O.O., Too, K.V.: Design and evaluation of solar grain dryer with a back-up heater. Res. J. Appl. Sci. Eng. Technol. 7(15), 3036–3043 (2014)
Forson, F.K., Nazha, M.A.A., Akuffo, F.O., Rajakaruna, H.: Design of mixed-mode natural convection solar crop dryers: application of principles and rule of thumb. Renewable Energy 32, 1–14 (2007)
Henderson, S.M.: Progress in developing the thin layer drying equation. Trans. ASAE 17, 1167–1172 (1974)
Acknowledgment
The authors are grateful for the financial and material support by USAID, Feed the Future Innovation Lab for the Reduction of Post Harvest Loss project (Grant No.: AID-OAA-L-14-00002) through a collaborative agreement of Kansas State University, Mekelle and Bahir Dar university.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2019 ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering
About this paper
Cite this paper
Molla, A., Alavi, S., Subramanyam, B., Workneh, S., Gabbiye, N. (2019). Performance Comparisons of Solar Mixed and Indirect Dryers for Maize Grain Drying. In: Zimale, F., Enku Nigussie, T., Fanta, S. (eds) Advances of Science and Technology. ICAST 2018. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, vol 274. Springer, Cham. https://doi.org/10.1007/978-3-030-15357-1_12
Download citation
DOI: https://doi.org/10.1007/978-3-030-15357-1_12
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-15356-4
Online ISBN: 978-3-030-15357-1
eBook Packages: Computer ScienceComputer Science (R0)