党参根气体射流冲击干燥特性和干燥模型

摘要

研究了不同干燥风温(40、50、60、70、80℃)、喷嘴到物料托盘的间距(5、10、15 cm)和风速(8、11、14 m/s)三个因素对党参根气体射流冲击干燥特性的影响,结果表明对党参根气体射流冲击干燥速率(DR)和水分有效扩散系数(Deff)的影响强弱顺序依次是风温、喷嘴到物料托盘的间距和风速;党参根气体射流冲击干燥水分有效扩散系数在1.5904×10-10～3.0684 × 10-10 m2·s-1之间;干燥活化能为15.86 kJ·mol-1;Modified Page模型能反映党参根气体射流冲击干燥动力学过程,建立的水分比MR与时间t及干燥工艺参数的方程可有效预测党参根在气体射流冲击干燥过程中水分变化.%Drying characteristics of Codonopsis pilosula roots were investigated in an air-impingement jet dryer under different drying temperatures (40,50,60,70 and 80 ℃),distance from jet nozzle to material tray (DJNMT) (5,10 and15cm),and air velocities (8,11 and 14 m/s).Results indicated that the drying rate (DR) and moisture effective diffusion coefficient (Deff) were mainly influenced by the drying temperature of air,followed by DJNMT and air velocity.Deff was in the range of 1.5904 × 10-10 to 3.0684 × 10-10 m2· s-1 and the drying activation energy (Ea) was 15.86 kJ ·/mol-1.The Modified Page model can reflect the dynamics of Codonopsis pilosula roots air impingement drying.The equation of moisture ratio and time and drying process parameters can effectively predict the moisture change of Codonopsis pilosula roots air impingement drying.