Experimental and Comparison Studies on Drying Characteristics of Tomatoes in a Solar Tunnel Greenhouse Dryer Coupled with and without Biomass Backup Heater
S. Arun1, N. Yashwanth2, R. Adharsh3
1S. Arun, Mechanical Engineering, Dr. Mahalingam College of Engineering and Technology, Pollachi, India.
2N. Yashwanth, Mechanical Engineering, Easwari Engineering College, Chennai, India.
3R. Adharsh, Mechanical Engineering, Dr. Mahalingam College of Engineering and Technology, Pollachi, India.
Manuscript received on October 02, 2014. | Revised Manuscript Received on October 19, 2014. | Manuscript published on October 20, 2014. | PP: 6-13 | Volume-2, Issue-11, October 2014. | Retrieval Number: K05281021114/2014©BEIESP
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© The Authors. Published By: Blue Eyes Intelligence Engineering & 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 of Pollachi, Tamil Nadu (India) for carrying out the experimental and comparison studies of drying characteristics of tomatoes during the month of May, 2014. About 50kgs of fresh and good quality tomatoes were loaded into those two respective 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. The solar tunnel dryer coupled with the biomass heater dried the tomatoes which has an initial moisture content of 90% (w.b.) to a final moisture content of 9.5% (w.b.) over a time period of 24 hours whereas the solar tunnel greenhouse dryer without the biomass heater took 49 hours for reducing the moisture content of the tomatoes 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 steady increase in temperature inside the dryer by supplying sufficient heat during the night time (after 5PM) where there would be a drop in sunshine. Also the quality of the tomatoes obtained from the solar tunnel greenhouse dryer coupled with biomass heater was found to be superior to that of the tomatoes 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, moisture content, open sun drying, quality, solar tunnel greenhouse dryer, sunshine, temperature.