Solar Drying: Fundamentals,Applications and Innovations - National ...

More documents

Recommendations

Info

Bala and Hossain - Solar Drying of Fishery Products movement of moisture to the surface is reduced and the drying rate becomes slower, approaching zero at equilibrium between the product and the surrounding drying conditions. Moisture content, % 100 90 80 70 60 50 40 30 20 10 0 Silver jew Ribbon Fish Bombay duck 0 5 10 15 20 25 30 35 Drying time, hr Figure 4.12. Comparison of moisture content change of three tropical marine fish during solar drying using solar tunnel drier Variation of solar radiation over the different period of day resulted in higher/lower insolation. Interestingly, during high insolation period, the increased air velocity driven by the solar-powered DC fans compensated the temperature inside the drier, and reversely during lower insolation period compensated by lower air velocity. The effect of variation of air temperature inside the drier was thereby minimized, resulting in the uniform drying of the fish products. Sengar et al. (2009) reported solar drying of prawns (Kolambi) in India. Salted prawns were found to be most liked for its color and texture than unsalted solar dried sample in sensory evaluation. Unsalted prawns sample dried in solar drier was overall accepted, while traditionally open sun dried sample was least liked for its color and texture. Local fisherman can recover solar drier cost within the period of 0.19 years by adopting solar drying technology 4.6. POTENTIALS AND LIMITATIONS The following are some observations made based on series of field trials: i. Studies have demonstrated the potentialities of solar tunnel drier for drying of fish and the drying air temperature must not exceed the maximum permissible drying air temperature. In case of a solar tunnel drier the drying air temperature can be achieved by simply adjusting collector length (in solar tunnel drier) or air flow rate by changing the number of fans in operation. ii. Solar driers with UV stabilized plastic cover require frequent replacement of the plastic cover. However, this problem can be overcome if solar drier with polycarbonate cover is used. iii. The photovoltaic system has the advantage that the temperature of the drying air is automatically controlled by the solar radiation. 106 Drying of Foods, Vegetables and Fruits
Bala and Hossain - Solar Drying of Fishery Products iv. In cloudy days the PV ventilated solar driers can be used for drying since it operates on diffuse solar radiation but the drying rate is significantly reduced. v. One major disadvantage of this drier is that it does not have any back up heating system. But in rainy days the PV ventilated solar drier can be used if it is integrated with either a biomass furnace or oil or gas burner. vi. The year round operation of the PV ventilated solar driers for production of different solar dried products would further reduce payback period and would justify the financial viability of the PV ventilated solar driers as attractive and reliable alternative to the sun drying in the tropics and subtropics. vii. Solar tunnel driers are now in operation in different regions of the tropics and subtropics. viii. Since the drier is PV operated it can be used in the areas where there is no electric grid connection. ix. The photovoltaic driven solar drier must be optimized for efficient operation. 4.7. CONCLUDING REMARKS The use of solar drier leads to considerable reduction of drying time in comparison to sun drying and the quality of the solar dried fishery product is comparable or better than sun dried products. Field level tests demonstrate that PV ventilated solar tunnel drier is appropriate for production of quality dried fish in the tropics and subtropics. The solar drier can be operated by a photovoltaic module independent of electrical grid. The photovoltaic driven solar driers must be optimized for efficient operation. Finally, solar driers are environmentally sound as compared to hot air driers that use fossil fuels. 4.8. REFERENCES Andriazafimahazo, L.F.G., Razafiarison1, I.A.J., Zeghmati, B., Ramamonjisoa, B.O.A., Rabary, F., Rakotomahevitra, A., 2010, Determination of the Drying Speed in Thin Layer of Shrimp, Revue des Energies Renouvelables, 13(2), pp. 295–309. Bala, B.K., 1997a, Drying and Storage of Cereal Grains, Agrotech Publishing Academy, India. Bala, B.K., 1997b, Experimental Investigation of the Performance of the Solar Tunnel Drier for Dying Fish, Final Research Report, Department of Farm Power and Machinery, Bangladesh Agricultural University, Mymensingh, Bangladesh. Bala, B.K., 1998, Solar Drying Systems: Simulation and Optimization, Agrotech Publishing Academy, India. Bala, B.K., 2000, Adaptive Research on Solar Drier for Drying Mango, Pineapple and Fish, Final Research Report, Department of Farm Power and Machinery, Bangladesh Agricultural University, Mymensingh. Bala, B.K., Hossain, M.D., Mondol, M.R.A., 1997, Photovoltaic Based Forced Convection Solar Tunnel Drier for Pineapple, Journal of Agricultural Engineering, 32(4), pp. 23-31. Drying of Foods, Vegetables and Fruits 107
Page 1:
Solar Drying:Fundamentals,Applicati
Page 5 and 6:
Solar Drying: Fundamentals, Applica
Page 7:
PREFACE Drying using solar radiatio
Page 11:
Index Chapter No Title / Authors Pa
Page 14 and 15:
Visavale - Principles, Classificati
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Table 1.4. Quality and other drying
Page 52 and 53:
It was seen that for all fish, hot
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Aware and Thorat - Solar Drying of
Page 66 and 67:
Aware and Thorat - Solar Drying of
Page 68 and 69: Aware and Thorat - Solar Drying of
Page 85 and 86: Jangam, Hii, C.L.; S.V. Law, and C.
Page 87 and 88: Hii and Law - Solar Drying of Major
Page 107 and 108: Bala, Jangam, B.K.; S.V. Hossain, a
Page 109 and 110: Bala and Hossain - Solar Drying of
Page 117: Bala and Hossain - Solar Drying of
Page 123 and 124: Hii, Jangam, C.L., Ong, S.V. and S.
Page 125 and 126: Hii and Ong - Quality Characteristi
Page 135: Fadhel, Jangam, M.I., S.V. Recent a
Page 138 and 139: Fadhel - Recent Advancements in Sol
Page 164 and 165: 12. Thangvaravut, H., Chiewchan, N.
Page 166 and 167: 39. Nimmol, C., Devahastin, S. (201
Page 168 and 169:
69. Mujumdar, A. S., & Law, C. L. (
Page 170 and 171:
98. Chung, L. L., Waje, S. S., Thor
Page 172 and 173:
129. Qing-guo, H., Min, Z., Mujumda
Page 176:
Solar Drying: Fundamentals, Applica
show all

Solar Drying: Fundamentals,Applications and Innovations - National ...

Create successful ePaper yourself

Delete template?

Save as template?