Drying and Heat Transfer Behavior of Combined Low ... - JGSEE

The 2 nd Joint International Conference on “Sustainable Energy and Environment (SEE 2006)”E-037 (O) 21-23 November 2006, Bangkok, Thailand4. CONCLUSIONA drying system combining the radiative and convective heat transfer process, so called a combined low-pressure superheatedsteam and far-infrared radiation drying system (LPSSD-FIR), for drying food products was developed and studied to understand thedrying and heat transfer behavior. The results showed that with the use of far-infrared radiation, the temperature of both LPSSD-FIRand VACUUM-FIR samples during the later stage of drying were higher than the pre-determined medium temperatures. It was alsofound that LPSSD-FIR drying required more drying time than VACUUM-FIR drying at almost all drying conditions except at thetemperature of 90 o C; this indicated that the inversion temperature calculated from the overall drying rates should be somewherebetween 80 o and 90 o C. Although LPSSD-FIR drying required more energy consumption than VACUUM-FIR drying at almost alldrying conditions, the lowest specific energy consumption was obtained during LPSSD-FIR drying at 90 o C and 7 kPa. This conditionwas suggested, based on the energy utilization, as the optimum condition in this study.5. ACKNOWLEDGMENTSThe authors express their sincere appreciation to the Commission on Higher Education, the Thailand Research Fund (TRF), theNational Research Council of Thailand and the International Foundation for Science (IFS), Sweden for supporting the studyfinancially.6. REFERENCES[1] Abe, T. and Afzal, T.M. (1997) Thin-layer infrared radiation drying of rough rice, Journal of Agricultural Engineering Research,67, pp. 289-297.[2] Abe, T. and Afzal, T.M. (1998) Diffusion in potato during far infrared radiation drying, Journal of Food Engineering, 37, pp.353-365.[3] Afzal, T.M., Abe, and Hikida, Y. (1999) Energy and quality aspects during combined FIR-convection drying of barley, Journalof Food Engineering, 42, pp. 117-182.[4] AOAC (1984) Official methods of analysis (14th ed.), Washington DC: Association of Official Agricultural Chemists.[5] Barbieri, S., Elustondo, M.P. and Urbicain, M.J. (2004) Retention of aroma compounds in basil dried with low pressuresuperheated steam, Journal of Food Engineering, 65, pp. 109-115.[6] Devahastin, S., Suvarnakuta, P., Soponronnarit, S. and Mujumdar, A.S. (2004) A comparative study of low-pressure superheatedsteam and vacuum drying of a heat-sensitive material, Drying Technology, 22, pp 1845-1867.[7] Dostie, M., Seguin, J.N., Maure, D., Ton-That Q.A. and Chatingy, R. (1989) Preliminary measurements on the drying of thickporous materials by combinations of intermittent infrared and continuous convection heating, in: A. S. Mujumdar, M. A. Roques(eds.), Drying ’89, Hemisphere, New York.[8] Ginzburg, A.S. (1969) Application of infrared radiation in food processing, Chemical and Process Engineering Series, LeonardHill, London.[9] Leeratanarak, N., Devahastin, S. and Chiewchan, N. (2006) Drying kinetics and quality of potato chips undergoing differentdrying techniques, Journal of Food Engineering, 77, pp. 635-643.[10] Mills, A.F. (1999) Basic heat and mass transfer (2nd ed.), Prentice-Hall, New Jersey.[11] Mongpraneet, S., Abe, T. and Tsurusaki, T. (2002) Accelerated drying of welsh onion by far infrared radiation under vacuumconditions, Journal of Food Engineering, 55, pp. 147-156.[12] Mongpraneet, S., Abe, T. and Tsurusaki, T. (2002) Far infrared-vacuum and convection drying of welsh onion, Transactions ofthe ASAE, 45, pp. 1529-2535.[13] Mujumdar, A.S. (2000) Superheated steam drying–Technology for the future, in: S. Devahastin, (eds.), Mujumdar’s PracticalGuide to Industrial Drying, Brossard, Exergex, pp. 115-138.[14] Ratti, C. and Mujumdar, A.S. (1995) Infrared Drying, in: A.S. Mujumdar, (eds.), Handbook of industrial drying: Volume 1,Marcel Dekker, New York.[15] Sandu, C. (1986) Infrared radiative drying in food engineering: A Process Analysis, Biotechnology Progress, 2, pp. 109-119.[16] Sun, D.W. and Wang, L.J. (2006) Development of a mathematical model for vacuum cooling of cooked meats, Journal of FoodEngineering, 77, pp. 379-385.[17] Suvarnakuta, P., Devahastin, S., Soponronnarit, S. and Mujumdar, A.S. (2005) Drying kinetics and inversion temperature in alow-pressure superheated steam-drying system, Industrial & Engineering Chemistry Research, 44, pp. 934-1941.6