Experimental Studies on Drying Characteristics of Coconuts in a Solar Tunnel Greenhouse Dryer Coupled with Biomass Backup Heater
S. Arun1, S. Shankar Balaji2, P. Selvan3

1S.Arun, Department of Mechanical Engineering, Dr. Mahalingam College of Engineering and Technology, Pollachi (Tamil Nadu), India.
2S.Shankar Balaji, Department of Automobile Engineering, Dr. Mahalingam College of Engineering and Technology, Pollachi (Tamil Nadu), India.
3P.Selvan, Department of Mechanical Engineering, SNS College of Engineering, Coimbatore (Tamil Nadu), India.
Manuscript received on 17 October 2014 | Revised Manuscript received on 24 October 2014 | Manuscript Published on 30 October 2014 | PP: 56-60 | Volume-4 Issue-5, October 2014 | Retrieval Number: E1832104514/14©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: A natural convection solar tunnel greenhouse dryer coupled with biomass backup heater was designed and developed for studying the drying characteristics of coconuts in Pollachi region of Tamil Nadu. Three trails of loading 5000 coconuts in the dryer were carried out during the month of January, 2014. The biomass backup heater was used after 5PM where there would be no sufficient solar radiation and was loaded with the remains of coconut such as coconut fronts, coconut husk and coconut shells which could be used as a fuel for biomass heater. The drying time and the product quality were the main deciding performance parameters of the dryer which are studied in comparison with the traditional drying method (open sun drying). It was found that the coconuts which has an initial moisture content of 53.84% (w.b.) were dried to final moisture content of 7.003% (w.b.) in the solar tunnel greenhouse dryer for a time period of 44 hours whereas the open sun drying method took 148 hours for the reduction of moisture content of the coconuts to the same level. Also, the superior quality coconuts can be produced from the solar tunnel greenhouse dryer since the dryer is free from contamination, dust & dirt, damage by birds and infections by bacteria and fungus.
Keywords: Biomass Backup Heater, Coconuts, Drying Time, Moisture Content, Open Sun Drying, Product Quality, Solar Radiation, Solar Tunnel Greenhouse Dryer.

Scope of the Article: Production Engineering