Empirical Modeling of Air Dried Rubberwood Drying System
Rubberwood is a crucial commercial timber in Southern Thailand. All processes in a rubberwood production depend on the knowledge and expertise of the technicians, especially the drying process. This research aims to develop an empirical model for drying kinetics in rubberwood. During the experiment, the temperature of the hot air and the average air flow velocity were kept at 80-100 °C and 1.75 m/s, respectively. The moisture content in the samples was determined less than 12% in the achievement of drying basis. The drying kinetic was simulated using an empirical solver. The experimental results illustrated that the moisture content was reduced whereas the drying temperature and time were increased. The coefficient of the moisture ratio between the empirical and the experimental model was tested with three statistical parameters, R-square (R²), Root Mean Square Error (RMSE) and Chi-square (χ²) to predict the accuracy of the parameters. The experimental moisture ratio had a good fit with the empirical model. Additionally, the results indicated that the drying of rubberwood using the Henderson and Pabis model revealed the suitable level of agreement. The result presented an excellent estimation (R² = 0.9963) for the moisture movement compared to the other models. Therefore, the empirical results were valid and can be implemented in the future experiments.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3455581Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 219
 T. Theppaya and S. Prasertsan, “Parameters Influencing Drying Behavior of Rubber Wood (Hevea brazilliensis) as Determined from Desorption Experiment,” Dry. Technol., vol. 20, no. 2, pp. 507–525, 2002.
 R. Yamsaengsung and T. Sattho, “Superheated Steam Vacuum Drying of Rubberwood,” Dry. Technol., vol. 26, no. 6, pp. 798–805, May 2008.
 S. Ormarsson and D. Cown, “Moisture-related distortion of timber boards of radiata pine: Comparison with Norway spruce,” Wood Fiber Sci., vol. 37, no. 3, pp. 424–436, 2005.
 T. Ratanawilai, K. Boonseng, and S. Chuchom, “Drying Time Reduction of Rubberwood,” KKU Res. J., vol. 17, no. 4, pp. 505–514, 2012.
 N. Hashim, O. Daniel, and E. Rahaman, “A Preliminary Study: Kinetic Model of Drying Process of Pumpkins (Cucurbita moschata) in a Convective Hot Air Dryer,” Agric. Agric. Sci. Procedia, vol. 2, pp. 345–352, Jan. 2014.
 Y. Tanongkankit, K. Narkprasom, and N. Narkprasom, “Empirical Modeling on Hot Air Drying of Fresh and Pre-treated Pineapples,” MATEC Web Conf., vol. 62, p. 02007, 2016.
 N. Promtong, T. Ratanawilai, and C. Nuntadusit, “Effect of Combined Microwave Heating and Impinging Hot-Air on Rubberwood Drying,” Adv. Mater. Res., vol. 538–541, pp. 2413–2416, Jun. 2012.
 G. E. PAGE, “Factors Influencing the Maximum Rates of Air Drying Shelled Corn in Thin Layers,” Theses Diss. Available ProQuest, p. 1, Jan. 1949.
 S. M. Henderson, “Grain drying theory temperature effect of drying coefficient,” J Agri Eng Res, vol. 6, pp. 169–174, 1961.
 İ. T. Toğrul and D. Pehlivan, “Mathematical modelling of solar drying of apricots in thin layers,” J. Food Eng., vol. 55, no. 3, pp. 209–216, Dec. 2002.
 P. K. Chandra and R. P. Singh, “Applied numerical methods for food and agricultural engineers,” CRC Press, pp. 163–167, 1993.
 N. Kumar, B. C. Sarkar, and H. K. Sharma, “Mathematical modelling of thin layer hot air drying of carrot pomace,” J. Food Sci. Technol., vol. 49, no. 1, pp. 33–41, Feb. 2012.
 T. Ratanawilai, C. Nuntadusit, and N. Promtong, “Drying Characteristics of Rubberwood by Impinging Hot-Air and Microwave Heating,” Wood Res., vol. 60, no. 1, pp. 59–70, 2015.
 K. Puangsuwan, M. Chongcheawchamnan, and C. Tongura, “Effective Moisture Diffusivity, Activation Energy and Dielectric Model for Palm Fruit Using a Microwave Heating,” J. Microw. Power Electromagn. Energy, vol. 49, no. 2, pp. 100–111, Jan. 2015.