Analysis moisture diffusion characteristics of paddy drying parameters based Logarithmic model equation

Drying rate of paddy rice was mainly determined by the internal moisture diffusion rate. Based on the Logarithmic equation of hot air drying,the moisture diffusion dynamics model was established,and the effects of heated air temperature( 40,50,60,70 ℃) and air velocity( 0.3,0.4,0.5 m / s) on effective diffusion coefficient and activation energy of moisture diffusion were studied. With the increase of drying temperature and air velocity,the drying rate and corresponding moisture effective diffusion coefficient was increased within the range of 5.123 ×10^-12~ 2.141 × 10~(- 11)m²/ s. Meanwhile,the diffusion activation energy was increased from 32.94 k J / mol to36.30 k J / mol. Logarithmic model could fit the thin- layer drying of paddy rice with R2> 0.997 and RMSE < 2.810 ×10^-3. The effective moisture diffusion coefficient and diffusion activation energy models were reliable with differences less than 3.8 × 10^-13m²/ s and 2.53 k J / mol.