Abstract
This chapter presents developments and potentials of solar drying technologies for drying fruits, vegetables, spices, medicinal plants, and fish. Experimental performances of different types of forced solar dryers such as solar tunnel dryer, improved version of solar tunnel dryer, roof-integrated solar dryer, and greenhouse-type solar dryers are addressed. Drying time in the solar dryers was significantly less than that required for natural sun drying and the products are quality products in terms of color and texture. Simulated performances of solar tunnel dryer, improved version of solar tunnel dryer, roof-integrated solar dryers, and greenhouse solar dryers are presented. The agreement between the simulated and experimental results is very good. A multilayer neural network approach was used to predict the performance of the solar tunnel dryer and the prediction of the performance of the dryer was found to be excellent after it was adequately trained.
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Abbreviations
- C p :
-
Specific heat, kJ/kg oK
- E :
-
Solar radiation, W/m2
- G a :
-
Mass flow rate of air, kg/m2s
- H :
-
Humidity ratio, kg/kg
- K :
-
Drying constant, min−1
- L g :
-
Latent heat of chili, kJ/kg
- M :
-
Moisture content, % or ratio (db) or (wb)
- M e :
-
Equilibrium moisture content, % or ratio (db) or (wb)
- M 0 :
-
Initial moisture content, % or ratio (db) or (wb)
- T :
-
Temperature, °C
- V :
-
Air velocity, m/s
- B :
-
Depth of collector/dryer, m
- h c :
-
Convective heat transfer coefficient, W/m2 oK
- h r :
-
Radiative heat transfer coefficient, W/m2 oK
- t :
-
Time, min
- z :
-
Thickness, m
- α:
-
Absorbance
- ρ:
-
Density, kg/m3
- ρ:
-
Reflectance
- τ:
-
Transmittance
- a:
-
Air
- am:
-
Ambient
- c:
-
Collector
- e:
-
Equilibrium moisture content
- g:
-
Chili
- l:
-
Liquid
- L:
-
Long wave
- p:
-
Absorber plate
- s:
-
Sky
- S:
-
Short wave
- w:
-
Water
- v:
-
Water vapor
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Bala, B.K., Janjai, S. (2012). Solar Drying Technology: Potentials and Developments. In: Uqaili, M., Harijan, K. (eds) Energy, Environment and Sustainable Development. Springer, Vienna. https://doi.org/10.1007/978-3-7091-0109-4_10
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DOI: https://doi.org/10.1007/978-3-7091-0109-4_10
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