Author/Authors :
Golmohammadi، Morteza نويسنده School of Chemical Engineering, College of Engineering,University of Tehran,Tehran,Iran , , Foroughi-dahr، Mohammad نويسنده School of Chemical Engineering, College of Engineering,University of Tehran,Tehran,Iran , , Rajabi Hamaneh، Mehdi نويسنده School of Chemical Engineering, College of Engineering,University of Tehran,Tehran,Iran , , Shojamoradi، Ali Reza نويسنده School of Chemical Engineering, College of Engineering,University of Tehran,Tehran,Iran , , Hashemi، Jalaledin نويسنده Pulp and Paper Research Centre,Department of Chemical Engineering,McGill University,Montreal,CANADA ,
Abstract :
The intermittent drying characteristics of an Iranian popular paddy rice variety were experimentally investigated to determine the drying kinetics and obtain the effective moisture diffusivity. A labscale fluidized bed dryer was designed and constructed to enable obtaining the required results while controlling critical drying parameters. The effects of drying temperature and tempering period on drying kinetics and moisture diffusivity were studied. The results showed a significant effect on drying performance and effective moisture diffusivity by adding tempering stage. Drying rate improved sharply by implementing the tempering stage, increase of drying air temperature as well as the tempering duration.Several thin layer drying models were fitted separately to experimental data of each drying stages namely pretempering and posttempering and suitability of these models were examined using the statistical analysis. The Midilli and TowTerm model were found to be the most appropriate one for the first and second drying stages, respectively.
Keywords :
Intermittent drying , Effective moisture diffusivity , Drying model , Statistical analysis , Paddy rice , Tempering
