循环压力下真空冷冻干燥青菜试验研究

Freeze Drying of Green Vegetables Under Cyclic Pressure

用大葱和胡萝卜作实验材料，在产品感官质量约束下，进行恒压与循环压力下真空冷冻干燥的模糊优化试验研究，得出导热和辐射两种加热方式下，除去单位水分所用干燥时间较短的工艺参数以及温度分布。对于真空冷冻干燥散放颗粒状物料，以辐射加热方式循环压力为最佳。

Under the control of organoleptic quality, the freeze drying test of green onion and carrot was conducted at constant pressure and cyclic pressure. By use of fuzzy optimization, the minimum time required to remove unit water of the samples and the temperature profile in the bed of the samples were found for both models of heat conduction and radiation. To freeze drying granular materials, like green onion and carrot, the optimal drying conditions are as follows: heat transfered to the samples is in the radiation model, and the pressure is cyclically changed from 10 to 1000 Pa.