荔枝真空远红外辐射过热干燥的特性

Drying Characteristics of Vacuum and Selective Far-Infrared Radiation Superheat for Litchi chinensis Sonn.

应用Clausius-Clapeyron方程,导出真空腔体干燥介质过热度干燥过程变化式,观察工艺条件改变下的过热度干燥过程变化及过热度影响下的荔枝去水速率。结果表明:真远红外辐射过热干燥荔枝,荔枝与辐射源光谱匹配显著加快去水;干燥效率及品质强化存在适度真空干燥介质、辐射热流密度、质传递速率匹配;采用近距离、光谱匹配及适度真空度、加热/缓苏时间比,干燥介质过热度与干燥效率综合最大。

By applying the Clausius-Clapeyron equation, the formula for the drying medium superheat during Litchi chinensis Sonn. drying in a vacuum chamber was derived and the superheat during drying and the dehydrating rate of L. chinensis under different conditions of technology were observed. The results showed that using vacuum and selective far-infrared radiation（FIR） superheat drying for L. chinensis, the spectral matching between L. chinensis and radiation source remarkably accelerated the dehydrating rate;the drying efficiency and the quality strengthening existed in the matching of moderate vacuum drying medium,radiation heat flux and mass transfer rate; under the conditions of a short radiation distance, spectral matching,a moderate vacuum and rate of heating time and tempering time, the integration of drying medium superheat and drying efficiency was maximized.