International Scientific Journal

Authors of this Paper

External Links


This research concerns the convective intermittent drying of in-shell walnuts, as well as the comparison between intermittent and continuous regimes. The collected data from the continuous drying experiment served as the basis for the modeling of intermittent drying, where the kinetic semi-theoretical model was implemented. Mathematical model for the intermittent drying precedes the computer simulation and experimental procedure for a single layer. As the validity of the proposed model is confirmed, deep fixed bed drying simulation was included as well. Intermittent drying regimes with shorter tempering periods gave better results compared to the longer ones. Deep bed simulations showed that a fixed bed of walnuts should not be bigger than 15-20 cm.
PAPER REVISED: 2019-05-15
PAPER ACCEPTED: 2019-05-20
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2019, VOLUME 23, ISSUE Issue 6, PAGES [3687 - 3699]
  1. ***, Food and Agricultural Commodities Production, (Accessed on 10.07.2018.)
  2. Hassan-Beygi, S.R., et al., Drying characteristics of walnut (Juglans Regia L.) during convection drying, International Agrophysics 23 (2009), pp. 129-135
  3. Rumsey, T., Thompson, J., Ambient air drying of English walnuts, Transactions of ASAE 27 (1984), 3, pp. 942-945
  4. Mamani, I., Modeling of thermal properties of Persian walnut kernel as a function of moisture content and temperature using response surface methodology. Journal of Food Processing and Preservation 39 (2015), 6, pp. 2762-2772
  5. Altuntas, E., Erkol M., Physical properties of shelled and kernel walnuts as affected by the moisture content,Czech Journal of Food Science, 28 (2010), 6, pp. 547-556
  6. Khir,R.,et al., Size and moisture distribution characteristics of walnuts and their components. Food and Bioprocess Technology, 6 (2013), pp. 771-782
  7. Barbosa de Lima, A.G., et al., Drying of bioproducts: Quality and energy aspects, in: Drying and Energy Technologies (Eds.Barbosa de Lima AG, Delegado JMPQ), Springer International Publishing, Switzerland 2016, pp. 19-42
  8. Motevali, A., et al., Comparison of Energy Parameters in Various Dryers. Energy Conversion and Management, 87 (2014), pp. 711-725
  9. Pan, Z., et al., Improving processing and energy efficiencies of walnut drying, Sacramento, CA:Walnut Research Reports. California Walnut Board, 2009
  10. Hacıhafızoğlu, O., etal., Numerical investigation of intermittent drying of a corn for different drying conditions,Thermal Science,
  11. Kumar, C., et al., Intermittent drying of food products: A critical review. Journal of Food Engineering 121, (2014), pp. 48-57
  12. Qu,Q.,et al., Effects of three conventional drying methods on the lipid oxidation, fatty acids composition, and antioxidant activities of walnut (JuglansRegia L.), Drying Technology 34 (2016), 7, pp. 822-829
  13. Baini, R., Langrish, T.A.G., Choosing an appropriate drying model for intermittent and continuous drying of bananas. Journal of Food Engineering 79 (2007), 7, pp. 330-343
  14. Shei, H.J., Chen, Y.L., Computer simulation on intermittent drying of rough rice, Drying Technology 20 (2002), 3, pp. 615-636
  15. Srivastava, V.K., John, J., Deep bed grain drying modeling. Energy Conversion and Management 43 (2002), pp. 1689-1708
  16. Kowalski, S.J., Pawłowski, A., Energy Consumption and Quality Aspect by Intermittent Drying, Chemical Engineering and Processing 50 (2011), pp. 384-390
  17. ***, ASHRAE Handbook (2006): Refrigeration: SI edition, American Society of Heating, Refrigeration and Air-Conditioning Engineers, Atlanta, 2006
  18. ***, AOAC International (2000) Official Methods of Analysis of AOAC International, 17th ed. AOAC International, Gaithersburg, 2000
  19. Balbay, A., et al., Modeling of convective drying kinetics of pistachio kernels in a fixed bed drying system, Thermal Science 17 (2013), 3, pp. 839-846
  20. Akpinar, E., et al., Single layer drying behavior of potato slices in a convective cyclone dryer and mathematical modeling, Energy Conversion and Management 44 (2003), pp. 1689-1705
  21. Incropera, F.P., DeWitt, D.P. Fundamentals of heat and mass transfer, fourth ed., John Wiley and Sons, New Jersey, USA, 1996
  22. Seshadri, V., Silva Pereira, R.O., Comparison of Formulae for Determining Heat Transfer Coefficient of Packed Beds, Transactions ISIJ 26 (1986), pp. 604-610
  23. Alnak, D.E., Karabulut, K., Computational Analysis of Heat and Mass Transfer of Impinging Jet onto Different Foods during the Drying Process at Low Reynolds Numbers, Journal of Engineering Thermophysics 28 (2019), 2, pp. 255-268

© 2021 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence