Experimental and Comparison Studies on Drying Characteristics of Grapes in a Solar Tunnel Greenhouse Dryer Coupled with and without Biomass Backup Heater
S. Arun1, N. Yashwanth2
1Omar E. Elnokity, Department of System & Computer, Alazhar University, Faculty of Engineering, Cairo, Egypt.
2Imbaby I. Mahmoud, Department of Engineering and Scientific Institute, Atomic Energy Authority of Egypt, Nuclear Research Center, Inshas, Egypt.
3Mohamed K. Refai, Department of System & Computer, Alazhar University, Faculty of Engineering, Cairo, Egypt.
4Hasan M. Farahat, Department of System & Computer, Alazhar University, Faculty of Engineering, Cairo, Egypt.
Manuscript received on October 15, 2014. | Revised Manuscript received on October 22, 2014. | Manuscript published on October 25, 2014. | PP:15-21 | Volume-2 Issue-12, October 2014. | Retrieval Number: L08291021214/2014©BEIESP
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© The Authors. Published By: 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 heater was designed and developed in Nallampalli region of Pollachi, Tamil Nadu (India) and also a natural convection solar tunnel greenhouse dryer without biomass heater was designed and developed in Negamam region o f Pollachi, Tamil Nadu (India) for carrying out the experimental and comparison studies of drying characteristics of grapes during the month of May, 2014. About 50kgs of fresh and good quality grapes were loaded into those dryers and it was repeated for three trails. The mass of fuel added to the biomass heater was about 7.5kg/hr. The biomass heater was ignited when there is a fall in sunshine (after 5PM) in order to maintain the temperature inside the dryer and the fuel used is the remains of the coconuts such as coconut fronts, coconut husk, coconut shell and firewood. The solar tunnel dryer coupled with the biomass heater dried the grapes which has an initial moisture content of 80% (w.b.) to a final moisture content of 10% (w.b.) over a time period of 30 hours whereas the solar tunnel greenhouse dryer without the biomass heater took 55hours for reducing the moisture content of the grapes to the same level. The reduced drying time in the solar tunnel greenhouse dryer coupled with the biomass heater than that of the dryer without the biomass heater is due to the effect of biomass heater that is responsible for the constant increase in temperature inside the dryer which is made possible by supplying sufficient heat during the night time (after 5PM) where there would be a drop in sunshine. Also, the quality of the grapes obtained from the solar tunnel greenhouse dryer coupled with biomass heater was found to be superior to that of the grapes obtained from the solar tunnel greenhouse dryer without the biomass heater which is due to the high temperature and low relative humidity prevailed all the time inside the dryer irrespective of fall in sunshine.
Keywords: Biomass heater, drying time, grapes, moisture content, open sun drying, product quality, solar tunnel greenhouse dryer, sunshine.