Experimental Investigation on Dill Drying in a Solar-Assisted Heat Pump Dryer

Authors
R. Tabatabaekoloor
H. Jafarian
S. R. Moosavi Seyedi
Department of Biosystems Engineering, Sari Agricultural and Natural Resources University, Sari, Islamic Republic of Iran.
Abstract
In this study, a solar dryer assisted with heat pump was developed and thin layer drying of dill was carried out at air temperatures of 40, 50, and 60ºC and air velocities of 0.5, 1 and 1.5 ms-1. Also, the drying rates, Specific Moisture Extraction Rate (SMER), and energy consumption were evaluated. Dill samples were dried from initial moisture content of 90% to the final moisture content of 10% in 195-275 minutes without assisted heat pump, and with assisted heat pump in 80-140 minutes. By using heat pump, the drying rate increased with increase in temperature at a given air velocity, thus, reducing the drying time. Increase in the air velocity at a given temperature improved the drying rate. By increasing the air velocity from 0.5 to 1.5 m s-1, drying time decreased up to 42%. The specific moisture extraction rate values were found to vary between 0.078 and 0.18 Kg Kw-1 h-1. The minimum value of energy consumption was 3312 kJ at air temperature of 60ºC and air velocity of 1.5 m s-1. Also, the total energy consumption of dryer with heat pump was reduced by 19%, which reflects the higher energy efficiency.

Keywords

1. Aktas, M., Ceylan, I. and Yilmaz, S. 2009. Determination of Drying Characteristics of Apples in a Heat Pump and Solar Dryer. Desalin., 239: 266-275.
2. Biondi, P., Cicala, L. and Farina, G. 1988. Performance Analysis of Solar Air Heaters of Conventional Design. Solar Ener., 41: 101-107.
3. Chua, K. J., Mujumdar, A. S., Chou, S. K., Hawlader, M. N. A. and Ho, J. C. 2000. Convective Drying of Banana, Guava and Potato Pieces: Effect of Cyclical Variations of Air Temperature on Drying Kinetics and Color Change. Dry. Technol., 18: 907–36.
4. Duffie, J. A. and Beckman, W. A. 2013. Solar Engineering of Thermal Processes. John Wiley and Sons. New York, USA.
5. Ekechukwa, O. V. and Norton, B. 1999. Review of Solar Energy Drying Systems II: An Over View of Solar Drying Technology. Ener. Conv. Manage., 40: 615 -655.
6. Eltief, S. A., Ruslan, M. H. and Yatim, B. 2007. Drying Chamber Performance of V-groove Forced Convective Solar Dryer. Desalin., 209: 151–155.
7. Fatouh, M., Metwally, M. N., Hellal, A. B. and Shedld, M. H. 2006. Herbs Drying Using a Heat Pump Dryer. Ener. Conv. Manage., 47: 2629-2643.
8. Hawlader, M. N. A, Perera, C. O. and Tian, M. 2006. Properties of Modified Atmosphere Heat Pump Dried Foods. J. Food Eng., 74: 392–401.
9. Hawlader, M. N. A. and Jahangeer, K. A. 2006. Solar Heat Pump Drying and Water Heating in the Tropics. Solar Ener., 80: 492–499.
10. Hussain, M. A., Gottschalk, K. and Hassan, M. S. 2013. Mathematical Model for a Heat Pump Dryer for Aromatic Plant. Procedia Eng., 56: 510-520.
11. Kaya, A. and Aydin, O. 2009. An Experimental Study on Drying Kinetics of Some Herbal Leaves. Ener.Conv. Manage., 50: 118-124.
12. Krokida, M. K., Kiranoudis, C. T., Maroulis, Z. B. and Marino, K. 2000. Drying Related Properties of Apple. Dry. Technol., 18: 1251–1267.
13. Ling, K. F. 2002. The Fodd of Asia. Periplus Editions (HK), Singapore, 155 PP.
14. Madhyanon, T. and Soponronnarit, S. 2005. High Temperature Spouted Bed Paddy Drying with Varied Down Comer Air Flows and Moisture Contents: Effects on Drying Kinetics, Critical Moisture Content, and Milling Quality. Dry. Technol., 23: 473-495.
15. Mortezapour, H., Ghobadian, B., Khoshtaghaza, M. H. and Minaei, S. 2012. Performance Analysis of a Two-way Hybrid Pv/Thermal Solar Collector. J. Agr. Sci. Tech., 14: 767-780.
16. Mortezapour, H., Ghobadian, B., Khoshtaghaza, M. H. and Minaei, S. 2014. Drying Kinetics and Quality Characteristics of Saffron Dried with Heat Pump Assisted Hybrid Photovoltaic–Thermal Solar Dryer. J. Agr. Sci. Tech., 16: 33-45.
17. Pal, U., Khan, M. K. and Mohanty, S. 2008. Heat Pump Drying of Green Sweet Pepper. Dry. Technol., 26: 1584-1590.
18. Perera, C. O. and Rahman, M. S. 1997. Heat Pump Dehumidifier Drying of Food. Trend. Food Sci. Technol. 8: 75–79.
19. Prasertsan, S. and SaenSaby, P. 1998. Heat Pump Drying of Agricultural Materials. Dry. Technol., 16: 235–250.
20. Ramani, B. M., Gupta, A. and Kumar, R. 2010. Performance of a Double Pass Solar Air Collector. Solar Ener., 84: 1929-1937
21. Setayesh-Mehr, Z. and Ganjali, A. 2013. Effects of Drought Stress on Growth and Physiological Characteristics of Dill (Anethum graveolens L.). J. Hort. Sci., 27: 27-35.
22. Sevik, S., Aktas, M., Dogan, H. and Kocak, S. 2013. Mushroom Drying with Solar Assisted Heat Pump System. Ener. Conv. Manage., 72: 171-178.
23. Sharma, G. P., Verma R. C. and Pathare, P. 2005. Mathematical Modeling of Infrared Radiation Thin Layer Drying of Onion Slices. J. Food Eng., 71: 282-286.
24. Silva, A. S., De Almeida, A. C., Lima, E. E., Silva, F. L. H. and Gomes, J. P. 2008. Drying Kinetics of Coriander (Corianderum sativum) Leaf and Stem. Sci. Technol. Alimentaria, 6: 13-19.
25. Strommen, I., Eikevik, T. M., Alves-Filho, O., Syverud, K. and Jonassen, O. 2002. Low Temperature Drying with Heat Pumps New Generations of High Quality Dried Products. Proceeding in 13th International Drying Symposium (IDS2002), August 27-30, Beijing, China.
26. Teeboonma, U., Tiansuwan, J. and Soponronnarit, S. 2003. Optimization of Heat Pump Fruit Dryers. J. Food Eng., 59: 369–377.
27. Tulek, Y. 2011. Drying Kinetics of Oyster Mushroom (Pleurotus ostreatus) in a Convective Hot Air Dryer. J. Agr. Sci. Tech., 13: 655-664.
28. VijayaVenkataRaman, S., Iniyan, S. and Goic, R. 2012. A Review of Solar Drying Reviews. Renew. Sustain. Ener. Rev., 16: 2652-2670.
29. Zomorodian, A. Zare, D. and Ghasemkhani, H. 2007. Optimization and Evaluation of a Semi-Continuous Solar Dryer for Cereals (Rice, etc). Desalin., 209: 129-135.
Journal of Agricultural Science and Technology
Volume 19, Issue 4
July and August 2017
Pages 835-845