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| Theoretical analysis of heat transfer of adsorption fluidization freeze-dryii^ at atmospheric pressure |
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FENG Hong-qing1,LI Wei-yi2
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(1. College of Transport & Storage and Cwii Engineering in China University of Petroleum，Dongying^ 257061，Shandong Province, China ;2.College of Mechanical Engineering, Tianjin University, Tixir^in 300072, China )
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| Abstract: |
| Freeze-drying at atmospheric pressure is a new way to reduce energy consumption. In this process the adsorbent m fluidized bed absorbs water steam and gives out Accounting for tlie characteristics of freeze-drying of granular malerial, a theoretical heat transfer model of atmospheric freeze-drying in spherical geometry was developed. The temperature distribution and movement distance of sublimation inteiface were calculated，then the speed of diying process can be deduced. Theoretical analysis was done on influence factors such as bed temperature，material size and adsorbent diameter. The temperature diBtribution in the freezing material was measured experimentally. The mathematical model was verified. The results show ikat the diying rate can be increased by improving bed temperature or using small material and adsorbent. |
| Key words: Stfreeze drying adsoiption fluidization Keat and mass transfer atmospheric pressure |
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