番木瓜片的微波真空干燥特性与动力学模型

摘要

The microwav e vacuum drying characteristics of papaya slices under different microwave parameters such as microwave power, relative pressure, slice thickness and loading capacity were studied and the mathematical model of microwave vacuum drying of papaya slices was established. The results showed that the microwave vacuum drying process of papaya slices could be characterized by three distinct drying rate stages:increasing rate stage, constant rate stage and falling rate stage. Most time during drying was for the constant rate stage. The whole process of papaya slices drying was affected by the microwave power, vacuum degree, thickness and loading capacity. The comparison of dry-basis moisture content and moisture ratio ( MR) of papaya slices between experimental and predicted date at the same condition was basically fitted, so the Page equation could be used to accurately describe the microwave vacuum drying process of papaya slices.%研究了番木瓜片在不同微波功率、 相对压力、 切片厚度和装载量等干燥参数条件下的微波真空干燥特性,并建立微波真空干燥数学模型.结果表明:番木瓜片微波真空干燥过程可分为加速、 恒速和降速过程;番木瓜片的干燥主要集中于恒速干燥阶段;番木瓜片的微波真空干燥过程同时受到微波功率、 相对压力、 切片厚度和装载量的影响;Page方程关于番木瓜片干基含水量和水分比的预测值与试验值均拟合较好,能较准确地反映番木瓜片微波真空干燥过程中的水分变化规律.