Process unit for drying sawn timber rotating in the ultra high frequency field with a discrete arrangement of magnetrons
Keywords:
process unit, ultra high, frequency drying, magnetron, sawn timber, moisture, mathematical modelAbstract
Wood is a natural and environmentally friendly construction material widely used in various fields of industrial and civil engineering. Timber drying process has an effect on the consumer properties of the final product and is basic in wood processing technology. Ultra high frequency range is the most effective in drying sawn timber with the use of electromagnetic energy. A process unit comprising discretely arranged magnetrons and a mechanism for rotation of sawn timber along the axis in the chamber is presented in the study. Magnetrons discretely and uniformly arranged ensure better distribution of heat on the sawn timber during rotation and reduces drying time. The engineering solution reduces drying time by 38.75% and increases the volume of dried timber by 27.3%. Variable drying mode control improves efficiency of the process by 8-10% depending on the timber species and initial moisture. Experimental dependences characterizing operational modes of the process unit are obtained. A mathematical model of sawn timber drying in the chamber with discretely arranged magnetrons and a mechanism to ensure rotation of sawn timber along the axis is developed. The mathematical model is made in the object-visual modelling MatLab package (Simulink). The model adequacy is confirmed experimentally, discrepancy between the experimental data and the data obtained from the mathematical modelling is no more than 3%.
References
Aipov, R. S. & Tukhvatullin, M. I. (2011). UHF plant for drying lumber. Scientific and Production Journal Farm Mechanic, Мoscow: Sel’skiy mekhanizator Publ., 8, 8–9.
Aipov, R. S. & Tukhvatullin, M. I. (2012). Improving the Efficiency of Rotary Sawn wood Crashes by Discrete Sources of Microwave Magnetrons. Current issues of the energy sector of the agro-industrial complex: proceedings of the International Scientific and Practical Conference. Saratov, 7-9.
Arkhangel’skiy, Yu. S. (2011). Reference Book on the UHF Electrothermia. Saratov, OOO “Nauch. kn.”, 559.
Bartholme, M., Avramidis, G., Viöl, W. & Kharazipour, A. (2009). Microwave drying of wet processed wood fibre insulating boards. European Journal of Wood and Wood Products, 67(3), 357–360.
Boldyrev, P. V. (2010). Wood Drying: Practice Guide. 4 th edition. Sankt Peterburg, Profi Publ., 165.
Brodie, G. I. (2008). Innovative Wood Drying: Applying Microwave and Solar Technologies to Wood Drying. VDM Publishing.
Dashti, H., Tarmian, A., Faezipour, M., Hedjazi, S. & Shahverdi, M. (2012). Effect of pre-steaming on mass transfer properties of fir wood (Abies alba L.), A gymnosperm species with torus margo pit membrane. BioResources, 7(2), 1907–1918.
Dautov, O. Sh. (1993). Engineering-Functional Equation for Stationary Problems in Actuation of Magnetic-Dielectric Bodies, Thesis of a doctor of technical sciences. Kazan’, 240.
Didenko, A. N. (2003). UHF Energy: Theory and Practice. Russian Academy of Sciences, Department of Power Supply, Mechanical Engineering and Management Processes, Department of Electric Power Engineering Issues. Moscow, Nauka Publ., 444.
Donghua, J., Muhammad, T., Afzal, M. G. & Alemayehu, H. B. (2010). Modeling of moisture diffusion and heat transfer during softening in wood densification. International Journal of Engineering, 42(4), 191–200.
Gareev, F. Kh. (2010). Ultra high frequency plus vacuum: from the complex to the simple. Lesprom Publ., 102–104.
Gorokhovskiy, A. G., Shishkina, E. E., Starova, E. V. & Mikov, A. A. (2018). Analysis of wood drying processes in absolutely non-isothermal modes. IVUZ, 2, 88–96.
Harris, G. A., Torgovnikov, G., Vinden, P., Brodie, G. I. & Shaginov, A. (2008). Microwave pretreatment of backsawn messmate boards to improve drying quality: Part 1. Drying Technology, 26 (5), 579–584.
Karampatea, A. & Siakavara, K. (2018). Analysis and synthesis of double negative dielectric media rectenna systems for ambient microwave energy harvesting. International Journal of Antennas and Propagation.
Khamaletdinov, R. R., Gabitov, I. I., Mudarisov, S. G., Farkhutdinov, I. M. & Shirokov, D. Y. (2018). Improvement in engineering design of machines for biological crop treatment with microbial products, Journal of Engineering and Applied Sciences, 13, 6500–6504.
Li, X. J. (2009). Mechanism of Heat Transfer and Characteristics of Microwave Vacuum Drying in Wood. Environmental Science Press. Beijing, China.
Li, X. J., Zhang, B. G. & Li, W. J. (2008). Microwave-vacuum drying of wood: Model formulation and verification. Drying Technology, 26(11), 1382–1387.
Li, X., Luo, Y., Chen, H., He, X., Lv, J. & Wu, Y. (2013). Mathematical simulation of temperature profiles within microwave heated wood made for wood-based nanocomposites. Journal of Nanomaterials, 4.
Luo, Y., Li, X. & Zhang, J. (2014). Theoretical study of wood microwave pretreatment in rectangular cavity for fabricating wood-based nanocomposites. Journal of Nanomaterials, 102.
Lykov, A. V. (1968). Theory of Drying Process: textbook. Moscow, Energiya Publ., 471.
Masalimov, I. Kh., Faizrakhmanov, S. F., Gabitov, I. I., Martynov, V. M., Permyakov, V. N., Aipov, R. S., Yarullin, R. B., Davydova, A. A., Rakipov, I. R. & Ramazanov, A. S. (2018). Optimal operating modes reasoning of sunflower seeds microwave drying in a conveyor type unit. Journal of Engineering and Applied Sciences, 13, 6570–6575.
Mbou, E. T., Njeugna, A., Kemajou, E., Sikame, N. R. & Ndapeu, D. (2017). Modelling of the Water Absorption Kinetics and Determination of the Water Diffusion Coefficient in the Pith of Raffia vinifera of Bandjoun, Cameroon. Advances in Materials Science and Engineering.
Pimenov, Yu.V., Vol’man, V. I. & Muravtsov, A. D. (2000). Technical Electrodynamics: Textbook for University Students. Moscow, Radio i svyaz’ Publ., 536.
Sergovskiy, P. S. & Rasev, A. I. (1987). Hydrothermal Processing and Wood Canning. Moscow, Lesn. prom. Publ., 360.
Slimani, A., Bennani, S. D., El Alami, A. & Terhzaz, J. (2017). Ultra wideband planar microstrip array antennas for C-band aircraft weather radar applications. International Journal of Antennas and Propagation.
Tarmian, A., Remond, R., Dashti, H. & Perre, P. (2012). Moisture diffusion coefficient of reaction woods: compression wood of Picea bies L. and tension wood of Fagus sylvatica L. Wood Science Technology, 46(1/3), 405–417.
Tukhvatullin, M. I. (2018). Modelling Results of Lumber UHF Drying. Proceedings of the International Scientific and Practical Conference ‘Research in the Field of Natural Science, Engineering and Technology as a Factor of Scientific and Technological Progress’, Belgorod, 137–141.
Vongpradubchai, S. & Rattanadecho, P. (2009). The microwave processing of wood using a continuous microwave belt drier. Chemical Engineering and Processing, 48(5), 997–1003.
Zhou, Y. D., Fu, F., Li, X. J., Jiang, X. M. & Chen, Z. L. (2009). Effects of microwave treatment on residue growth stress and microstructure of Eucalyptus urophylla. Journal of Beijing Forestry University, 31(2), 2146–2150.
Downloads
Published
Issue
Section
License
Copyright (c) 2019 Bulgarian Journal of Agricultural Science
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
