EXPERIMENTAL INVESTIGATION ON DRYING CHARACTERISTICS OF ANCHOVY FISHES USING SOLAR GREEN HOUSE DRYER
Fishery is the prime most economic activity in the coastal areas of India. Fish is an extremely perishable commodity requires sufficient cooling until it processing or any preservation method adapted. Sun drying is a traditional method of preserving fish. Though it does not requires any operating cost but it is susceptible to contamination, dust, damage by animals and rain. Hence, solar green house dryer was developed to dry the fish in a closed system where it's having high air temperature for drying, low relative humidity and lower final moisture content of the product with acceptable quality.
The present study was aimed to investigate the field performance of the developed solar greenhouse dryer in Nagapattinam (10L752 N, 79L 848 E) with an average solar irradiance of 5.8 kW/ m2. It consists of a parabolic roof structure covered by poly carbonate sheet as a solar collector on a black kaddappa stone floored with an area of 99 m2 (Fig. 1).
Ventilation of solar greenhouse dryer done with a help of nine 24v DC fans powered by 100 W solar photovoltaic module. The dryer had a loading capacity of 300 - 500 kg of fresh fishes. To investigate the drying performance, dryer was tested to dry three hundred kg of fresh anchovies during July - August 2018.
The maximum air temperature inside the solar greenhouse dryer was observed in the range of 45 - 55oC during peak sunny hours (Fig. 2). The results from the experiment shows that, it took only 8h of drying time to get desired moisture content of 6% w.b from 84% w.b., whereas 16 - 20 peak sunny hours are required for conventional sun drying under similar conditions.
Most importantly, the quality of the anchovies dried in the solar greenhouse dryer was too good since it was protected from sand, dust, insects and rain (Fig.3). The developed solar greenhouse dryer guides the fisher folks to fetch higher price for their dried products.
