吸波材料辅助的初始非饱和物料微波冷冻干燥  

Wave-absorbing material assisted microwave freeze-dryingof initially unsaturated materials

作　　者：唐宇佳 王维[1] 张朔 姬艺佳 张大为[1] TANG Yu-jia;WANG Wei;ZHANG Shuo;JI Yi-jia;ZHANG Da-wei(School of Chemical Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学化工学院,辽宁大连116024

出　　处：《高校化学工程学报》2021年第3期430-439,共10页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金项目(21676042);辽宁省自然科学基金(201602167)。

摘　　要：为了强化冷冻干燥过程,制备咖啡溶液的初始饱和与非饱和2种冷冻样品,分别使用石英与碳化硅底盘进行常规和微波冷冻干燥实验,同时采用电阻法测定溶液的共晶温度。结果表明,在温度为25℃、压力为22 Pa时采用石英底盘,初始非饱和物料冷冻干燥时间比饱和物料缩短了14.9%,适当提高操作温度可以强化冷冻干燥过程。在25℃、22 Pa时施加功率为1 W的微波,饱和与非饱和物料干燥时间分别缩短了19.1%和12.5%;当温度提高至35℃时,非饱和物料可避免崩塌,微波冷冻干燥时间比非饱和与饱和物料常规冷冻干燥(0 W)分别缩短了20.6%和30.8%。在35℃、22 Pa、1 W下采用碳化硅底盘,非饱和物料微波冷冻干燥时间比非饱和与饱和物料常规冷冻干燥分别缩短了32.4%和42.5%。吸波材料辅助的初始非饱和物料微波冷冻干燥实现了过程传质传热的同时强化。The conventional and microwave freeze-drying experiments were carried out using initial saturated and unsaturated samples frozen from coffee solution on quartz and silicon carbide chassis respectively,and the eutectic temperature of coffee solution was determined by resistance method.The experiment results showed that the freeze-drying time of the initial unsaturated sample on quartz chassis was 14.9%shorter than that of the saturated one at radiation temperature 25℃and chamber pressure 22 Pa,and that increasing operating temperature could improve the freeze-drying process properly.The freeze-drying time of initial saturated and unsaturated samples under 25℃,22 Pa and 1 W microwave power input was reduced by 19.1%and 12.5%respectively.When temperature was increased to 35℃,the unsaturated sample was more stable to avoid collapse,and the microwave freeze-drying time of the unsaturated sample was 20.6%and 30.8%shorter than the conventional freeze-drying(0 W input)time of unsaturated and saturated samples respectively.Under 35℃,22 Pa and 1 W,the microwave freeze-drying time of the unsaturated sample on silicon carbide chassis was shortened by 32.4%and 42.5%compared with the conventional freeze-drying time of unsaturated and saturated samples respectively.This means that wave-absorbing materials assisted microwave freeze-drying of initial unsaturated materials has an enhanced effect on mass and heat transfer.

关 键 词：吸波材料 饱和度 冷冻干燥 微波加热 传质传热 

分 类 号：TQ028.5[化学工程] TQ026.6