摘要
为探索节能型的冷冻干燥方式,进行了在常压下利用流化床中吸附剂吸附水分同时放出热量实现冷冻干燥的研究。以粒状物料为例,建立了球坐标下常压冷冻干燥的传热过程理论模型,计算了物料干燥过程中的温度和升华界面的移动距离,并对床温、物料尺寸和吸附剂粒径等影响因素进行了理论分析。实验测量了物料内的温度分布变化,验证了数学模型的可靠性。结果表明,通过适当提高床温、采用小尺寸物料和吸附剂,可以提高干燥速率。
Freeze-drying at atmospheric pressure is a new way to reduce energy consumption. In this process the adsorbent in fluidized bed absorbs water steam and gives out heat. Accounting for the characteristics of freeze-drying of granular material, a theoretical heat transfer model of atmospheric freeze-drying in spherical geometry was developed. The temperature distribu- tion and movement distance of sublimation interface were calculated, then the speed of drying process can be deduced. Theoretical analysis was done on influence factors such as bed temperature, material size and adsorbent diameter. The temperature distribution in the freezing material was measured experimentally. The mathematical model was verified. The results show that the drying rate can be increased by improving bed temperature or using small material and adsorbent.
出处
《中国石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2007年第4期102-105,111,共5页
Journal of China University of Petroleum(Edition of Natural Science)
关键词
冷冻干燥
吸附
流化
传热传质
常压
freeze drying
adsorption
fluidization
heat and mass transfer
atmospheric pressure
