KKU Engineering Journal (Mar 2014)
Thin-Layer Drying Models for Para Rubber Sheet
Abstract
The purpose of this project was to study para rubber sheet drying at temperature of 40°, 50°, 60° and 70°, air velocity of 0.5 and 1 meter/second. The obtained experimental results were used to calculate moisture ratio values. Then the results obtained from 10 different types of thin layer drying models were compared with the experimental results. The experimental results of moisture ratio values of para rubber sheets indicated that at the same rate of air flow velocity but with different temperature, the higher the temperature, the faster velocity rate of the moisture evaporation of para rubber sheet. Whereas, with same temperature but at the different velocity rates of air flow, the higher the velocity rate of air flow, the faster the moisture evaporation of para rubber sheet. The comparative results of the 10 different types of thin layer drying models revealed that 5 models could predict the moisture ratio of para rubber sheet drying with a satisfactory level in all experimental conditions. The said 5 models were Modified Henderson and Pabis, Verma et al., Midilli et al., Weibull Distribution; and Page respectively with R2 ranges of 0.984 to 0.9995, adjusted R2 range of 0.9817 to 0.9993, SSE range of 0.0004162 to 0.01981 and RMSE range of 0.006451 to 0.03209. The best model that could predict moisture ratio in all experimental conditions was Modified Henderson and Pabis with R2 range of 0.9956 to 0.9992, adjusted R2range of 0.9943 to 0.9989, SSE range of 0.0008541 to 0.005914 and RMSE range of 0.007811 to 0.01786.
