Dehydration of vegetables by using indirect solar dryer

Year 2018, Volume: 1 Issue: 1, 22 - 28, 30.09.2018

Younas Khan , Jafar Khan Kasi , Ajab Khan Kasi

Abstract

The temperature controlled indirect solar dryer
is designed in Quetta by using simple available stuffs in the market to dry the
agricultural products for its longer shelf life. The dryer consists of drying
cabinet, solar cell, electrical fan and collector. Inside the cabinet there are
four trays at equally distance from each other, each tray receive uniformly
heated air from the collector to dry the agricultural product. During the
drying process temperature and relative humidity inside the cabinet is measured
with help of digital hygrometer. Tomatoes, mint leaves, eggplant and onion were
dried in newly low cost designed dryer. The drying time, color and quality of
these products are compared with open sun drying. The result shows that the
product dried in the newly dryer is good in quality and dry faster than open
sun drying method. The drying occurs in falling rate period. Uniformity of the
dryer in each tray was also checked by placing vegitable slices of same size
and weight in each tray, the drying time for each tray was same. By increasing
the size of vegitable slices increase the drying time, result also shows that
increasing in drying air temperature also increase the drying time.

Keywords

Low cost dryer, sawtooth wave absorber plate, Uniform heated air dryer, Tomatoes, Mint leaves, Eggplant, Onion

References

• [1] Sarsilmaz, C., Yildiz, C., & Pehlivan, D. (2000). Drying of apricots in a rotary column cylindrical dryer (RCCD) supported with solar energy. Renewable Energy, vol. 21, no. 2 p. 117-127.
• [2] Demiray, E., & Tulek, Y. (2012). Thin-layer drying of tomato (Lycopersicum esculentum Mill. cv. Rio Grande) slices in a convective hot air dryer. Heat and Mass Transfer, vol. 48, no. 5 p. 841-847.
• [3] Ashtiani, S. H. M., Salarikia, A., & Golzarian, M. R. (2017). Analyzing drying characteristics and modeling of thin layers of peppermint leaves under hot-air and infrared treatments. Information Processing in Agriculture, vol. 4, no. 2 p. 128-139
• [4] Al-Juamily, K. E., Khalifa, A. J. N., & Yassen, T. A. (2007). Testing of the performance of a fruit and vegetable solar drying system in Iraq. Desalination, vol. 209, no. 1-3 p. 163-170.
• [5] Bahloul, N., Boudhrioua, N., Kouhila, M., & Kechaou, N. (2009). Effect of convective solar drying on colour, total phenols and radical scavenging activity of olive leaves (Olea europaea L.). International journal of food science & technology, vol. 44, no. 12 p. 2561-2567.
• [6] Doymaz, I. (2006). Thin-layer drying behaviour of mint leaves. Journal of Food Engineering, vol. 74, no. 3 p. 370-375. [7] Tiris, C., Tiris, M., & Dincer, I. (1996). Experiments on a new small-scale solar dryer. Applied Thermal Engineering, vol. 16, no. 2 p. 183-187.
• [8] Azad, E. (2008). Design and experimental study of solar agricultural dryer for rural area. Livestock Research for Rural Development, vol. 20, no. 9 p. 2008
• [9] Amer, B. M. A., Hossain, M. A., & Gottschalk, K. (2010). Design and performance evaluation of a new hybrid solar dryer for banana. Energy conversion and management, vol. 51, no. 4 p. 813-820.
• [10] Musembi, M. N., Kiptoo, K. S., & Yuichi, N. (2016). Design and Analysis of Solar Dryer for Mid-Latitude Region. Energy Procedia, vol. 100, no. 1 p. 98-110.
• [11] Bala, B. K., Mondol, M. R. A., Biswas, B. K., Chowdury, B. D., & Janjai, S. (2003). Solar drying of pineapple using solar tunnel drier. Renewable Energy, vol. 28, no. 2 p. 183-190.
• [12] Chen, H. H., Hernandez, C. E., & Huang, T. C. (2005). A study of the drying effect on lemon slices using a closed-type solar dryer. Solar Energy, vol. 78, no. 1 p. 97-103.
• [13] Bena, B., & Fuller, R. J. (2002). Natural convection solar dryer with biomass back-up heater. Solar energy, vol. 72, no. 1 p. 75-83. [14] Diamante, L. M., & Munro, P. A. (1993). Mathematical modelling of the thin layer solar drying of sweet potato slices. Solar energy, vol. 51, no. 4 p. 271-276.
• [15] Demiray, E., & Tulek, Y. (2012). Thin-layer drying of tomato (Lycopersicum esculentum Mill. cv. Rio Grande) slices in a convective hot air dryer. Heat and Mass Transfer, vol. 48, no. 5 p. 841-847.
• [16] Celma, A. R., Cuadros, F., & López-Rodríguez, F. (2012). Convective drying characteristics of sludge from treatment plants in tomato processing industries. Food and Bioproducts Processing, vol. 90, no. 2 p. 224-234.
• [17] Movagharnejad, K., & Nikzad, M. (2007). Modeling of tomato drying using artificial neural network. Computers and electronics in agriculture, vol. 59, no. 1-2 p. 78-85.
• [18] Ringeisen, B., Barrett, D. M., & Stroeve, P. (2014). Concentrated solar drying of tomatoes. Energy for sustainable development, vol. 19, no. 1 p. 47-55.
• [19] Khazaei, J., Chegini, G. R., & Bakhshiani, M. (2008). A novel alternative method for modeling the effects of air temperature and slice thickness on quality and drying kinetics of tomato slices: superposition technique. Drying Technology, vol. 26, no. 6 p. 759-775.
• [20] Sadin, R., Chegini, G. R., & Sadin, H. (2014). The effect of temperature and slice thickness on drying kinetics tomato in the infrared dryer. Heat and Mass Transfer, vol. 50, no. 4 p. 501-507.
• [21] Rajkumar, P., Kulanthaisami, S., Raghavan, G. S. V., Gariépy, Y., & Orsat, V. (2007). Drying kinetics of tomato slices in vacuum assisted solar and open sun drying methods. Drying Technology, vol. 25, no. 7-8 p. 1349-1357.